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The Platinum (Pt)-based catalysts exhibit excellent catalytic performance for the hydrogen evolution reaction (HER) while suffering from poor stability due to the weak interaction between the carbon support and Pt. Herein, a molybdenum-doped titanium dioxide (Ti0.9Mo0.1O2) supported low-Pt electrocatalyst with stronger interaction between catalyst and support is applied to tune the electrocatalytic performance of Pt. The Ti0.9Mo0.1O2 support can not only tolerate the corrosion environment in the catalytic system, but also generate strong metal-support interaction (SMSI) between the oxide and catalyst. A facile solvothermal method is used to prepare Ti0.9Mo0.1O2 as support to anchor Pt nanoparticles. The 5% Pt supported on Ti0.9Mo0.1O2 catalyst exhibits 4.4-fold mass activity (MA) at an overpotential of 50 mV and higher stability than 20% Pt/C with only 1/4 Pt loading. The SMSI between the Ti0.9Mo0.1O2 and Pt prevents the Pt aggregation to achieve excellent stability, and hydrogen spillover effect in the interface between Pt and support benefits the hydrogen production process. This work presents a novel sight for the fabrication and design of oxide supported catalysts in various catalytic system by reasonably employing support effect.

Exploring cost-effective electrodes operating at a high current density above 400 mA cm−2 is still challenging for the industrial application of water splitting. Herein, the corrosion layers of iron foam are tailored towards preparing self-supporting electrodes for the oxygen evolution reaction (OER). Corrosion reactants (Ni2+, O2 and H2O) are adopted to regulate the structures and electrochemical performances of electrodes on account of the diverse iron corrosion behaviors. By further comparing the spontaneous iron corrosion in ZnCl2, CoCl2, NiCl2 and FeCl3 solutions, it is identified that the appropriate electrode potentials of Ni/Ni2+ and Co/Co2+ are favourable for achieving uniformly ordered corrosion layers owing to the simultaneously occurring oxygen corrosion and replacement reaction. The as-prepared electrode exhibits excellent OER performances of affording low overpotentials of 221 and 291 mV to reach 100 and 500 mA cm−2, respectively, as well as steadily operating at 500 mA cm−2 for 100 h. Integrating with a prominent hydrogen evolution reaction (HER) catalyst, an industrially required current density of 500 mA cm−2 has been obtained at 1.81 V. Importantly, a large-area electrode (8 × 8 cm2) has been successfully prepared. This work establishes potential possibilities for designing inexpensive and efficient electrocatalysts through regulated metal corrosion.

It is of paramount importance to explore high efficient and stable electrocatalysts toward anodic hydrogen oxidation reaction (HOR) in anion exchange membrane fuel cells. Herein, a new class of ter...

Nowadays, the overuse of antibiotics in cow breeding is a common issue worldwide. Real-time monitoring is critical for antibiotic control of dairy products. Herein, we report a rapid detection method for the duplex detection of two beta-lactam antibiotics (cephalexin and ampicillin) in milk powder using lateral flow (LF) combined with surface-enhanced Raman spectroscopy (SERS). The duplex detection was accomplished using a single test line loaded with two antigens targeting the two corresponding antibody-gold-Raman reporter conjugates. The obtained SERS spectra contributed by the Raman reporter labeled to the two antibodies were analyzed using both peak height method and multiple linear regression (MLR). A good regression fitting was achieved by these two methods (R2 = 0.99 and 0.98, respectively). The limit of detection (LOD) was 10−4 ng/mL for both peak height method and MRL. This study indicated that LF-SERS is a good candidate for real-time multiplex and quantitative analysis for antibiotics in dairy products.

Non-native species have invaded most parts of the world, and the invasion process is expected to continue and accelerate. Because many invading non-native species are likely to become permanent inhabitants, future consideration of species-area relationships (SARs) should account for non-native species, either separately or jointly with native species. If non-native species occupy unused niches and space in invaded areas and extinction rate of native species remains low (especially for plants), the resultant SARs (with both native and non-native species) will likely be stronger. We used published and newly compiled data (35 data sets worldwide) to examine how species invasions affect SARs across selected taxonomic groups and diverse ecosystems around the world. We first examined the SARs for native, non-native, and all species. We then investigated with linear regression analyses and paired or unpaired t tests how degree of invasion (proportion of non-native species) affected postinvasion SARs. Postinvasion SARs for all species (native plus non-native) became significantly stronger as degree of invasion increased (rEfectos Globales de las Especies No Nativas sobre las Relaciones Especie-Área Resumen Las especies no nativas han invadido la mayor parte del mundo y se espera que el proceso de invasión continúe y se acelere. Ya que muchas especies invasoras no nativas probablemente se conviertan en habitantes permanentes, la consideración a futuro de las relaciones especie-área (REA) debería considerar a las especies no nativas, ya sea por separado o en conjunto con las especies nativas. Si las especies no nativas ocupan nichos sin usar y el espacio en las áreas invadidas y la tasa de extinción de las especies nativas permanecen bajas (especialmente para las plantas), las REA resultantes (tanto con las especies nativas como las no nativas) probablemente sean más fuertes. Usamos datos publicados y recientemente compilados (35 conjuntos de datos mundiales) para examinar cómo las invasiones de especies afectan a las REA en grupos taxonómicos selectos y en diversos ecosistemas en todo el mundo. Primero examinamos las REA para todas las especies, así como para las nativas y las no nativas. Después investigamos con análisis de regresión lineal y pruebas t emparejadas o no emparejadas cómo afectó el grado de invasión (proporción de la especie no nativa) a las REA post-invasión. Las REA post-invasión para todas las especies (nativas más no nativas) se volvieron significativamente más fuertes conforme incrementó el grado de invasión (r非本地种入侵正发生在全球的大部分地区, 并且在有些地区入侵过程愈演愈烈。由于许多非本地种都有可能会成为永久定居者, 在解释新的物种-面积关系 (SARs) 时就应该单独考虑非本地种与本地种, 然后综合考虑所有物种 (本地种与非本地种的总和) 。如果非本地种占据了入侵地区的未被利用生态位与空间, 且本地种的灭绝速率保持较低, 那么由此形成的所有物种的物种-面积关系会更加紧密。我们利用已发表的以及自行整合的数据 (全球35个数据集), 在全球尺度上对不同类群在不同生态系统中物种入侵后的物种-面积关系的影响进行了检验。我们首先检验了本地种、非本地种及所有物种的物种-面积关系。其次, 我们利用线性回归分析、配对t检验、非配对t检验等方法研究了入侵度 (非本地种占所有物种的比例) 对物种入侵后的物种-面积关系的影响。分析结果表明, 随着入侵程度的增加, 所有物种的物种-面积关系显著增强 (r

Pd-based materials are promising electrocatalysts for the formic acid oxidation reaction (FAOR) but suffer from poor durability due to the poisoning of adsorbed carbon monoxide species (COads). In ...

Nickel-rich layered oxides have drawn sustainable attentions for lithium ion batteries owing to their higher theoretical capacities and lower cost. However, nickel-rich layered oxides also have exposed several defects for commercial application, such as uncontrollable ordered layered structure, which leads to higher energy barrier for Li+ diffusion. In addition, suffering from structural mutability, the bulk nickel-rich cathode materials likely trigger overall volumetric variation and intergranular cracks, thus obstructing the lithium ion diffusion path and shortening the service life of the whole device. Herein, we report well-ordered layered LiNi0.8Co0.1Mn0.1O2 submicron spheroidal particles via an optimized co-precipitation and investigated as LIBs cathodes for high-performance lithium storage. The as-fabricated LiNi0.8Co0.1Mn0.1O2 delivers high initial capacity of 228 mAh g–1, remarkable energy density of 866 Wh kg–1, rapid Li ion diffusion coefficient (10–9 cm2 s–1) and low voltage decay. The remarkable electrochemical performance should be ascribed to the well-ordered layered structure and uniform submicron spheroidal particles, which enhance the structural stability and ameliorate strain relaxation via reducing the parcel size and shortening Li-ion diffusion distance. This work anticipatorily provides an inspiration to better design particle morphology for structural stability and rate capability in electrochemistry energy storage devices.

Bimetallic Pd-based electrocatalysts usually show enhanced activity toward the formic acid oxidation reaction (FAOR), while the ensemble effects on FAOR are less investigated compared with the elec...

Direct formic acid fuel cells (DFAFCs) are considered as one of the promising energy conversion devices. In recent years, Pd-based nanomaterials have attracted widespread attention for the anodic f...

Passive seismic source imaging can extract geophysical information from underground noise and has been widely utilized in geophysical research. Compared with conventional active seismic exploration, it is low-cost and eco-friendly; however, the application of passive seismic data is limited by coherent noise in the virtual-shot gathers. An approach involving direct denoising in the virtual-shot gathers has not previously been discussed; therefore, we present an iterative denoising strategy for passive seismic data. The reflection-preserving characteristic of focal transformation is adopted in the virtual-shot gathers to eliminate the coherent noise, and L1-norm sparse inversion is utilized to obtain a more accurate solution during focal transformation. A key aspect of this strategy is clean focal operator building at high noise levels. We apply local similarity as the criterion for extracting the majority of reflection energy for the focal operator. Because of strong coherent noise, a clean focal operator cannot be obtained in one iteration. We therefore obtain both denoised passive seismic data and a clean focal operator by denoising using a cleaner focal operator and operator building using updated denoising results. The presented approach can overcome the limits of coherent noise in virtual-shot gathers, which is significant for subsequent data processing and wider application. Synthetic examples achieve excellent performance in coherent noise attenuation and reflection energy reconstruction, especially in far-offset sections.

Developing highly efficient non-Pt catalysts for fuel cells and metal-air batteries is highly desirable but still challenging due to the sluggish oxygen reduction reaction (ORR). Herein, a facile and efficient strategy is demonstrated to prepare N-doped carbon encapsulated ordered Pd-Fe intermetallic (O-Pd-Fe@NC/C) nanoparticles via a one-step thermal annealing method. The obtained O-Pd-Fe@NC/C nanoparticles show enhanced ORR activity, durability and anti-poisoning capacity in both acid and alkaline medium. When O-Pd-Fe@NC/C serving as cathode catalyst for Zn-air battery, it exhibits higher voltage platform and superior cycling performance with respect to the Zn-air battery based on the mixture of Pt/C and Ir/C catalysts. The enhanced electrocatalytic performance can be ascribed to the formation of face-centered tetragonal (fct) Pd-Fe nanoparticles, the protective action of the N-doped carbon layer and the interface confinement effect between them. The in situ formed N-doped carbon shell not only restrains the Pd-Fe ordered intermetallics from aggregating effectively during the thermal annealing process, but also provides a strong anchoring effect to avoid the detachment of Pd-Fe nanoparticles from the carbon support during the potential cycling. This facile carbon encapsulation strategy may also be extended to the preparation of a wide variety of N-doped carbon encapsulated intermetallic compounds for fuel cell application.

Neuromyelitis optica (NMO) is a severe neurological demyelinating autoimmune disease that affects the optic nerves and spinal cord. There is currently no effective cure or therapy. Aquaporin‑4 (AQP4) is a known target of the autoimmune antibody NMO‑IgG. Therefore, binding of NMO‑IgG to AQP4, and subsequent activation of antibody‑mediated and complement‑dependent cytotoxicity (CDC), are thought to underlie the pathogenesis of NMO. In the present study, a cell‑based high‑throughput screening approach was developed to identify molecular inhibitors of NMO‑IgG binding to AQP4. Using this approach, extracts from the herb Petroselinum crispum were shown to have inhibitory effects on NMO‑IgG binding to AQP4, and the natural compound geraldol was purified from the herb extracts. Analytical high performance liquid chromatography, electrospray ionization‑mass spectrometry and nuclear magnetic resonance analyses confirmed the identity of the isolated compound as geraldol, a flavonoid. Geraldol effectively blocked binding of NMO‑IgG to AQP4 in immunofluorescence assays and decreased CDC in NMO‑IgG/complement‑treated FRTL‑AQP4 cells and primary astrocytes. Geraldol exhibited low cytotoxicity, with no effect on proliferation or apoptosis of FRTL‑AQP4 cells and primary astrocytes. Permeability assays indicated that geraldol did not alter the water transport function of AQP4 in either cell system. The present study suggests the potential therapeutic value of geraldol for NMO drug development.

In transversely isotropic (TI) media, accurate and efficient pure P-wave extrapolation is the basis of seismic imaging and inversion algorithms. For pure P-wave equations in TI media, combining the finite-difference (FD) method with the pseudo-spectral (PS) method is an effective solution. However, if the mixed-domain pure P-wave equation contains multiple wavenumbers, using the hybrid approach will involve multiple Fourier transforms, which will result in high computational costs. Referring to the weak anisotropy approximation, we propose a new approximate P-wave phase velocity expression. We then use an optimization strategy to reduce the number of wavenumber terms in the corresponding dispersion relations and derive the mixed-domain pure P-wave equations in 2D and 3D tilted transversely isotropic (TTI) media. Through numerical experiments in 2D and 3D TTI models, we verify the feasibility and efficiency of the proposed mixed-domain P-wave equations.

Electrochemical water splitting (EWS) is a sustainable and promising technology for producing hydrogen as an ideal energy carrier to address environmental and energy issues. Developing highly-efficient electrocatalysts for hydrogen and oxygen evolution reactions (HER and OER) is critical for increasing the efficiency of water electrolysis. Recently, nanomaterials derived from Prussian blue (PB) and its analogs (PBA) have received increasing attention in EWS applications owing to their unique composition and structure properties. In this Minireview, the latest progress of PB/PBA-derived materials for EWS is presented. Firstly, the catalyst design principles and the advantages of preparing electrocatalysts with PB/PBA as precursors are briefly introduced. Then, strategies for enhancing the electrocatalytic performance (HER, OER or overall water splitting) were discussed in detail, and the recent development and applications of PB/PBA-derived catalysts for EWS were summarized. Finally, major challenges and possible future trends related to PB/PBA-derived functional materials are proposed.

An orange-pigmented, short-rod-shaped, aerobic and non-motile bacterial strain, designated TK008T, was isolated from the shallow-sea hydrothermal systems off Kueishantao Island in Taiwan, China, and it was studied by using a polyphasic taxonomic approach. Cells were Gram-stain-negative, and catalase- and oxidase-positive. Strain TK008T exhibited highest 16S rRNA gene sequence similarity of 97.1 % to Paracoccus pacificus F14T. The phylogenetic trees based on 16S rRNA gene sequences showed that strain TK008T was a member of the genus Paracoccus . Digital DNA–DNA hybridization values between strain TK008T and two closely related species ( Paracoccus zhejiangensis and Paracoccus tegillarcae ) were 20.6 and 20.9 %. The average nucleotide identity values of strain TK008T compared with P. zhejiangensis and P. tegillarcae were 75.2 and 74.6 % respectively. The major isoprenoid quinone was ubiquinone-10. The predominant fatty acids (>10 %) were summed feature 8 (C18 : 1ω6c and/or C18 : 1ω7c). The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, three unidentified phospholipids, two unidentified lipids and an unidentified glycolipid. The DNA G+C content of strain TK008T from genomic sequence data was 62.54 mol%. On the basis of polyphasic analysis, strain TK008T represents a novel species, for which the name Paracoccus aurantiacus sp. nov. is proposed. The type strain is TK008T (=CGMCC 1.13898T=JCM 33630T).

A chain-shattering polymeric SO2 prodrug micelle system was fabricated for effective SO2 delivery and redox-triggered SO2 based gas therapy of osteosarcoma.

Intra-articular (IA) injection of drugs is an effective strategy in treating osteoarthritis disease. However, the rapid drug loss and high-frequency injections are the main issues. Hence, we verily efforts to design and develop a point of care-based new biofunctional hydrogel by nanoengineer and chemistry approach. In this study, a novel gallic acid-grafted gelatin injectable hydrogel loaded with liposomes-anchored teriparatide (GGA@Lipo@PTH: GLP) was developed with an enzyme-linking method to control PTH release, aimed to alleviate osteoarthritis progress and protect chondrocytes degradation. In vitro studies of the GLP hydrogel promoted ATDC5 proliferation and upregulation of key proteins expression in the PI3K/AKT signaling pathway. Further, in vivo IA injection results of GLP confirmed the controlled release of PTH, promotes the secretion of glycosaminoglycan and protects the cartilage from degradation in DMM mice. Therefore, our study explored that the developed novel GLP hydrogel could be an alternative potential biomaterial in the osteoarthritis treatment.

Background: Enhanced recovery after surgery (ERAS) has been successfully adopted for the improvement of medical quality and efficacy in many diseases but the effect among the ankle fracture patients is variable. We intended to explore the short-term outcomes of ERAS among ankle fracture patients.Methods: One hundred sixty ankle fracture participations (41.71 ± 14.51 years-old) grouped into two groups (non-ERAS Vs. ERAS) with an average of 24 months follow-up were included in the retrospective study. Multivariable linear regression analysis and generalized estimating equation (GEE) model were performed to assess the association of outcomes including American Orthopaedic Foot and Ankle Society (AOFAS), length of stay (LOS), and hospital cost.Results: Analysis revealed that the patients in the ERAS group could obtain higher AOFAS score with LOS or hospital cost reduction than that in the ERAS group (p＜0.05) at month 3 postoperatively (PO3M) and month 6 postoperatively (PO6M). However, outcomes were comparable at month 12 postoperatively (PO12M) and later.GEE analysis and group by time interaction of AOFAS revealed the ERAS protocol could help ankle fracture patients recover faster and better in the short-term.Conclusions: Ankle fracture patients could recover better with the application of the ERAS protocol, especially in the short-term periods, all patients would obtain comparable function PO12M later. The ERAS protocol might improve medical quality and efficacy by reducing LOS and hospital costs as well. The current study would provide a realistic evaluation and comparison of the ERAS protocol among the ankle fracture patients for the surgeons in the short-term.

Digital transformation is a crucial strategy for enterprises to achieve improvements in quality, efficiency, and dynamism. It represents the key direction for enterprise innovation and reform, and it is also of great significance for promoting high-quality economic development. While the previous research has shown that digital transformation can affect business efficiency, performance, and corporate governance, there is a lack of literature clearly linking digital transformation to internal control. To determine whether enterprise digital transformation impacts the constructions and implementation of internal control, we analyze data from Shanghai and Shenzhen A-share listed companies between 2012 and 2019. Our study found that the extent of digital transformation in enterprises has a positive impact on the establishment and effectiveness of internal control. Furthermore, we examine the role of market competition in the relationship between the digital transformation and internal control. We found that the impact of digital transformation on internal control is limited in enterprises with relatively mild market competition, while in more fiercely competitive markets, the positive impact of digital transformation on internal control is more pronounced.

Grassland ecosystems worldwide are facing habitat degraded due to human activities. Although it is commonly proposed that livestock can have negative repercussions for multiple ecosystem functions in degraded grasslands, this question has yet to receive explicit scientific attention. We used a 3-year field-manipulated grazing experiment, including livestock grazing by sheep across three grasslands with different levels of degradation to evaluate the role of large herbivore in regulating soil nematodes and ecosystem multifunctionality. Our findings reveal the context dependency of this role in grassland degradation. We show that livestock show higher levels of soil nematode biomass and ecosystem multifunctionality than lightly degraded grassland with enclosure, and facilitate soil nematode diversity and maintain ecosystem multifunctionality in moderately and severely degraded grasslands. We propose that moderate herbivore grazing should be considered as nature-based solutions to improve and maintain both soil nematodes and ecosystem multifunctionality in degraded grasslands. The information is fundamental for improving nature’s benefits to people and considering conservation efforts of grassland restoration.

Hydrothermal vents are one of the important sources of major or trace elements in the ocean. The elemental fluxes, however, may be dynamic due to coastal processes and hydrothermal plumes, especially in shallow-water hydrothermal vents. We collected water samples by using the trace-metal clean technique inside and outside two shallow-water hydrothermal vents (white vent: low temperature, high pH; and yellow vent: high temperature, low pH) off Kueishantao Islet, Taiwan, China via SCUBA divers. We analyzed these samples for their hydro-chemical parameters and dissolved elements (Fe, Mn, Mg, V, Cu, and Mo) thereafter. Our results show that dissolved metals’ concentrations were significantly different between the two vents, with higher Mn and Fe in the White Vent than in the Yellow Vent, likely due to the decreased affinity of the dissolved metals for particles in the white vent. We estimated the plume fluxes of dissolved metals from the hydrothermal mouth by multiplying in situ hydrothermal discharge flowrates with metals’ concentrations inside the vents, which were: 1.09~7.02 × 104 kg Mg, 0.10~1.23 kg Fe, 0.08~28 kg Mn, 33.4~306 g V, 2.89~77.7 g Cu, and 54.3~664 g Mo, annually. The results further indicate that such plumes probably have impacted nearby seawater due to coastal currents and particle desorption during transport. Furthermore, the concentrations of biogenic elements could be further modified in seawater, and potentially impact nearby ecosystems on a larger scale. Our study provides information with which to further understand metal redeployment in submarine shallow nearby ecosystems.

While large herbivores are critically important components of terrestrial ecosystems and can have pronounced top-down effects on plants, our understanding of the underlying mechanisms driving these effects remains incomplete. Large herbivores can alter plant growth, reproduction, and abundance through direct effects (predominantly consumption) and through indirect effects via altered interactions with abiotic factors and other species. We know considerably less about these indirect effects than the direct effects. Here, we integrate medium- and small-scale field experiments to investigate how a large vertebrate herbivore, cattle (Bos taurus), affects the aboveground biomass of a dominant forb species, Artemisia scoparia, via diverse direct and indirect pathways in a temperate grassland in northeast China. Although cattle consumed this forb, its biomass increased significantly in response to grazing, due to multiple indirect positive effects that outweighed the direct negative effects of consumption. Cattle preferentially consumed the competing grass Leymus chinensis, and altered Artemisia microhabitats by reducing total plant cover and litter biomass and by increasing the abundance of co-occurring ant species (e.g., Formica spp. and Lasius spp.). This led to additional indirect positive effects on A. scoparia likely due to (1) increased light availability in understory layers and other limiting resources (e.g., soil nutrients and moisture) caused by removal of competitors and plant litter at the soil surface and (2) the changes in resource availability (e.g., soil nutrients and moisture) associated with ant colonies. Our results show that large herbivores can affect plant growth not only via direct consumption, but also via multiple indirect effects. Focusing on the causes and consequences of herbivore-induced indirect effects will not only help us to better understand the influence of these animals in ecological systems, but will also lead to more effective land management and conservation practices in the regions they inhabit.

The traditional mathematical model of shape memory alloy (SMA) is complicated and difficult to program in numerical analysis. The artificial neural network is a nonlinear modeling method which does not depend on the mathematical model and avoids the inevitable error in the traditional modeling method. In this paper, an optimized neural network prediction model of shape memory alloy and its application for structural vibration control are discussed. The superelastic properties of austenitic SMA wires were tested by experiments. The material property test data were taken as the training samples of the BP neural network, and a prediction model optimized by the genetic algorithm was established. By using the improved genetic algorithm, the position and quantity of the SMA wires were optimized in a three-storey spatial structure, and the dynamic response analysis of the optimal arrangement was carried out. The results show that, compared with the unoptimized neural network prediction model of SMA, the optimized prediction model is in better agreement with the test curve and has higher stability, it can well reflect the effect of loading rate on the superelastic properties of SMA, and is a high precision rate-dependent dynamic prediction model. Moreover, the BP network constitutive model is simple to use and convenient for dynamic simulation analysis of an SMA passive control structure. The controlled structure with optimized SMA wires can inhibit the structural seismic responses more effectively. However, it is not the case that the more SMA wires, the better the shock absorption effect. When SMA wires exceed a certain number, the vibration reduction effect gradually decreases. Therefore, the seismic effect can be reduced economically and effectively only when the number and location of SMA wires are properly configured. When four SMA wires are arranged, the acceptable shock absorption effect is obtained, and the sum of the structural storey drift can be reduced by 44.51%.

Grassland degradation is a retrogressive succession of grassland vegetation, which leads to the loss of biodiversity and the degradation of ecosystem functions. Soil microbiomes play critical roles in the functioning and services of grassland ecosystems, yet little is known about how their diversity, structure and co-occurrence network characteristics respond to grassland degradation. Here, we used lllumina Miseq technique to evaluate soil bacterial and fungal communities in a meadow steppe with different degrees of degradation in Northeastern China. Our results showed that Actinobacteria, Proteobacteria, and Chloroflexi and Acidobacteria were the dominant bacterial phyla, while Ascomycota, Basidiomycota, and Zygomycota were the predominant fungal phyla. The relative abundance of taxa assigned to Actinobacteria, Gemmatimonadetes, Firmicutes, and Deinococcus-Thermus increased with increasing degradation degrees, whereas those affiliated with Acidobacteria and Nitrospirae showed a decreasing pattern. Compared to bacteria, the relative abundance of most fungal phyla decreased gradually along the degradation gradient. Bacterial Shannon diversity index possessed a similar hump pattern, while fungal diversity decreased with increasing degree of grassland degradation. Bacterial and fungal communities have different responses to grassland degradation, indicating that fungi are more sensitive to grassland degradation than bacteria. Both bacterial and fungal community structures were significantly different among the three sites. Changes in soil bacterial and fungal community structures were best explained by soil salinity and pH. Plant diversity and nitrogen concentration in aboveground plant tissues were also important factors for regulating fungal communities. Co-occurrence network analysis revealed that microbial taxa increased positive interactions and average degree to strengthen the adaptability of microorganisms to grassland degradation. These findings could enhance our understanding of the formation and maintenance of microbial community diversity in degraded grasslands and the development of a new indicator for grassland ecosystem management.

Melatonin, a ubiquitous molecule found in almost all organisms, is considered an important regulator in plant growth. However, little is known about the interactive effect of melatonin and arbuscular mycorrhizal (AM) fungi on plant resistance against soil salinity and alkalinity. To fill in such a gap in knowledge, we conducted three experiments to explore (1) whether exogenous melatonin and an AM fungus had interactive effects on plant response to saline-alkaline stress, (2) whether the influence of melatonin on mycorrhizal plant stress tolerance was attributable to effect on the AM fungus, and (3) whether the effect of melatonin application was due to changes in soil salinity and alkalinity. We found interactive effects between melatonin and the AM fungus on alleviating ROS burst, decreasing malondialdehyde content and protecting Leymus chinensis photosynthetic activity through activation of antioxidant enzyme and gene expression (superoxide dismutase, catalase, ascorbate peroxidase, and glutathione reductase) in plant shoots and roots. Our results showed that exogenous melatonin promoted spore germination and hyphal length of the AM fungus under Petri-dish conditions. However, exogenous melatonin application did not exhibit significant effects on soil salinity and alkalinity. This study provides an insight into the beneficial effects of exogenous melatonin on saline-alkaline stress tolerance in mycorrhizal L. chinensis through regulating antioxidant systems, protecting photosynthetic activity, and promoting associated AM fungal growth without changing soil salinity and alkalinity. It also reveals potential applications of exogenous melatonin and AM fungi for the restoration of saline-alkaline degraded grassland.

Understanding the influences of environmental variation and anthropogenic disturbance on soil respiration (RS) is critical for accurate prediction of ecosystem C uptake and release. However, surprisingly, little is known about how soil respiration and its components respond to grazing in the context of global climate change (i.e., precipitation or nitrogen deposition increase). We conducted a field manipulative grazing experiment with water and nitrogen addition treatments in a meadow grassland on the Songnen Plain, China, and assessed the combined influences of grazing and global change factors on RS, autotrophic respiration (RA), and heterotrophic respiration (RH). Compared with the control plots, RS, RA and RH all exhibited positive responses to water or nitrogen addition in the wet year, while a similar effect occurred only for RH in the dry year. The responses of RS to precipitation regimes were dominated by both frequency and amount. However, grazing significantly inhibited both soil respiration and its components in all subplots. Further analysis demonstrated that the plant root/shoot ratio, belowground biomass and microbial biomass played dominant roles in shaping these C exchange processes. These findings suggest that changes in precipitation regimes, nitrogen deposition, and land utilization may significantly alter soil respiration and its component processes by affecting local carbon users (roots and soil microorganism) and carbon substrate supply in meadow steppe grasslands. The future soil carbon sequestration in the studied meadow steppe will be benefited more by the moderate grazing disturbance.

Lithium metal is a potential candidate for next-generation anode materials. However, the practical application of a lithium metal anode has been hindered by uncontrolled dendrite formation. Herein, a cost-effective single lithium ion conducting polymer electrolyte membrane based on a highly porous lithium sulfonated polyether ether ketone electrospun nanofiber membrane (es-LiSPCE) is designed to serve as both a separator and a lithium ion conductor. Impregnation of the ethylene carbonate (EC)/dimethyl carbonate (DMC) (v/v = 1 : 1) solvent mixture and 1 M LiFP6 in EC/PC (v/v = 1 : 1) yields gel pure es-LiSPCE and es-LiSPCE/1 M LiFP6 in an EC/PC (v/v = 1 : 1) membrane, respectively, which display high ionic conductivity, low interfacial compatibility and a high lithium ion transference number. Combined scanning electron microscopy (SEM) images and the long-term stripping/plating cycling test of lithium foil confirm that such a membrane is greatly favorable for inhibiting the formation of a concentration gradient and thus suppressing lithium dendrite growth. In addition, the fully aromatic polyether ether ketone backbone enables high thermal dimensional stability and high polarity and high polarity enables fast electrolyte wetting of the es-LiSPCE membrane. Notably, Li/LiFePO4 cells fabricated using es-LiSPCE membranes demonstrate promising rate capacity at 6C, and excellent electrochemical stability for 1500 cycles even at 6C. Therefore, it is believed that such an electrolyte can serve as an alternative to conventional polyolefin-based separators for high energy density lithium metal batteries.

Gene promoter hypermethylation is a vital step in tumorigenesis. This paper set out to explore the use of polymerase chain reaction - surface-enhanced Raman spectroscopy (PCR-SERS) for the detection of gene methylation levels, with a focus on cancer diagnosis. Methods: PCR with methylation independent primers were used on DNA samples to amplify target genes regardless of their methylation states. SERS was used on the obtained PCR products to generate spectra that contained peak changes belonging to CG and AT base pairs. Multiple linear regression (MLR) was then used to deconvolute the SERS spectra so that the CG/AT ratios of the sample could be obtained. These MLR results were used to calculate methylation levels of the target genes. For protocol verification, three sets of seven reference DNA solutions with known methylation levels (0%, 1%, 5%, 25%, 50%, 75%, and 100%) were analysed. Clinically, blood plasma samples were taken from 48 non-small-cell lung cancer (NSCLC) patients and 51 healthy controls. The methylation levels of the genes p16, MGMT, and RASSF1 were determined for each patient using this method. Results: Verification experiment on the mixtures with known methylation levels resulted in an error of less than 6% from the actual levels. When applied to our clinical samples, the frequency of methylation in at least one of the three target genes among the NSCLC patients was 87.5%, but this percentage decreased to 11.8% for the control group. The methylation levels of p16 were found to be significantly higher in NSCLC patients with more pack-years smoked (p=0.04), later cancer stages (p=0.03), and cancer types of squamous cell and large cell versus adenocarcinoma (p=0.03). Prediction accuracy of 88% was achieved from classification and regression trees (CART) based on methylation levels and states, respectively. Conclusion: This research showed that the PCR-SERS protocol could quantitatively measure the methylation levels of genes in plasma. The methylation levels of the genes p16, MGMT, and RASSF1 were higher in NSCLC patients than in controls.

Electrocatalytic water splitting to produce clean and sustainable hydrogen energy is regarded as a promising strategy to address the growing energy and environmental problems. Thus, the search for low-cost and efficient electrocatalysts plays a vital role in water electrolysis. In recent years, metal alkoxides, which are a series of organic–inorganic hybrid compounds, have attracted tremendous attention in energy research owing to their appealing features of high porosity, large surface area, adjustable composition and regulated hierarchical structures. However, the development of metal alkoxides towards electrocatalysis has not been established systematically. Herein, we review and discuss the recent advances on metal alkoxides and their derivatives (including hydroxides, oxides, phosphides, sulfides, and selenides) for electrocatalytic water splitting. The fundamental principles of how to regulate their composition, phases and hierarchical structures to enhance their performance are highlighted, also including their correlative structure–activity relationship. Finally, the issues and future challenges with the use of metal alkoxide-based nanomaterials for electrocatalytic applications are proposed. This review aims to present a comprehensive understanding of metal alkoxide-based electrocatalysts and some suggestions for the future development of high-performance electrocatalysts for water splitting applications.

The sluggish methanol oxidation reaction (MOR) remains the biggest challenge for direct methanol fuel cells. To advance our understanding of the MOR mechanism, we have employed dual thin-layer diff...

The search for active, stable, and cost-effective electrocatalysts for hydrogen evolution reaction (HER) is desirable, but it remains a great challenge in the overall water splitting. Here, we report the synthesis of nickel boron nanoparticles supported on Vulcan carbon (Ni-B) via a simple, yet scalable, two-step chemical reduction–annealing strategy. The results of the electrochemical measurements suggest that the overpotentials of Ni-B-400 are 114 and 215 mV (in 1 mol L−1 KOH) at current densities of 10 and 40 mA cm−2, respectively, indicating an exceedingly good electrocatalytic activity in the HER. More importantly, Ni-B maintains a current density of 7.6 mA cm−2 at an overpotential of 0.15 V for 20 h in the durability test. The excellent HER activity of Ni-B-400 is derived from the small particle size and the expanded lattice of Ni, which can optimize the hydrogen absorption energy and enhance the electrocatalytic properties.

Developing facile methods to construct hierarchical-structured transition metal phosphides is beneficial for achieving high-efficiency hydrogen evolution catalysts. Herein, a self-template strategy of hydrothermal treatment of solid Ni-Co glycerate nanospheres followed by phosphorization is delivered to synthesize hierarchical NiCoP hollow nanoflowers with ultrathin nanosheet assembly. The microstructure of NiCoP can be availably tailored by adjusting the hydrothermal treatment temperature through affecting the hydrolysis process of Ni-Co glycerate nanospheres and the occurred Kirkendall effect. Benefitting from the promoted exposure of active sites and affluent mass diffusion routes, the HER performance of the NiCoP hollow nanoflowers has been obviously enhanced in contrast with the solid NiCoP nanospheres. The fabricated NiCoP hollow nanoflowers yield the current density of 10 mA cm−2 at small overpotentials of 95 and 127 mV in 0.5 mol L−1 H2SO4 and 1.0 mol L−1 KOH solution, respectively. Moreover, the two-electrode alkaline cell assembled with the NiCoP and Ir/C catalysts exhibits sustainable stability for overall water splitting. The work provides a simple but efficient method to regulate the microstructure of transition metal phosphides, which is helpful for achieving high-performance hydrogen evolution catalysts based on solid-state metal alkoxides.

Designing efficient nonprecious catalysts with pH-universal hydrogen evolution reaction (HER) performance is of importance for boosting water splitting. Herein, a self-template strategy based on Ni-Co-glycerates is developed to prepare bimetallic Ni-Co-P microflowers with ultrathin nanosheet arrays. The highly porous core-shell structure gives rise to affluent mass transfer channels and availably prevents the aggregation of nanosheets, while the ultrathin nanosheets are favorable for producing abundant active sites. Besides, the produced CoP/NiCoP heterostructure in the bimetallic Ni-Co-P catalyst has excellent HER performance in a wide pH range. The as-prepared catalyst shows low potentials of 90, 157, and 121 mV to deliver a current density of 10 mA cm-2 in 0.5 M H2SO4, 0.5 M PBS, and 1 M KOH solution, respectively. Meanwhile, negligible overpotential decay is achieved in the polarization curves after a long-term stability determination. This work supplies a promising strategy for developing pH-universal HER electrocatalysts based on solid-state metal alkoxides.

Interactions between distantly related herbivores exert powerful influences on ecosystems, but most studies to date have only considered unidirectional effects. Few have simultaneously examined the mutual effects that vertebrate herbivores and insect herbivores have on one another. We conducted a set of manipulative experiments to evaluate the potential competition and facilitation between two pairs of distantly related herbivore taxa: an insect caterpillar (Gynaephora alpherakii) and two large vertebrate herbivores, yak (Bos grunniens) and Tibetan sheep (Ovis aries tibetica). We found that these large herbivores consistently increased the density of caterpillars likely by improving the habitat for caterpillars. The caterpillars, in turn, decreased yak but increased Tibetan sheep foraging time and intake bites by differently changing available food resources of the two large herbivores. Diet preferences of herbivores modified the habitat and food resources, thereby causing a diet‐mediated competition between yak and caterpillars, and facilitation between sheep and caterpillars. The vertebrate herbivores non‐feeding upon Lamiophlomis rotata and Gentiana straminea, the caterpillars preferred habitat, increased densities of the two plant species, thus favouring the caterpillars. In turn, the caterpillar preference for Kobresia pygmaea significantly reduced food resources for yak, while promoting food resources (multiple forbs) for sheep. Synthesis. Our study indicates that two different mechanisms (the changes in habitat and food availability) induced by herbivore foraging jointly determine competitive and facilitative interactions between distantly related herbivore species. We also suggest that examining the bi‐directional effects between herbivores offers a better understanding of competition and facilitation in terrestrial animal communities.

The development of fertile patches within an infertile matrix is a common phenomenon in drylands. Shrub-centered expansion of fertile islands is generally attributed to processes of sediment erosion and deposition, but there have been fewer studies of how litter might contribute to the development of fertile islands in semiarid shrub grassland. We quantified the capture of two tumble plant species (Cleistogenes squarrosa, Salsola collina; also known as tumble weeds) by shrubs across ten sites across 38,000 km2 of a semiarid grassland encroached by Caragana microphylla. Tumble plants are plants that blow across the grassland propelled by strong winds. Both tumble plant species were found over extensive areas of semiarid grassland, and their distribution coincides with the distribution of Caragana microphylla. Biomass production of both tumble plants averaged 12.2 g m−2 (range: 1.0 to 25.0 g m−2) and litter accumulation (amount accruing from wind-blown plants) of both tumble plants was significantly greater beneath shrubs (94.5 ± 28.9 g m−2 mean ± SE) than in the interspaces (3.3 ± 1.4 g m−2). Most of the material collecting under Caragana microphylla comprised tumble plants. Increases in the area of Caragana microphylla patches did not correspond to greater tumble plant capture. However, the supply of tumble plants was the strongest predictor of capture within shrub hummocks, suggesting that tumble plant capture is source limited rather than sink limited. Our structural equation model indicates that increases in grass cover and height were indirectly and negatively associated with tumble plant capture by reducing the tumble plant supply. Contrary to prediction, shrub height and shrub patch area had no overall effect on the tumble plant capture. Overall, we maintain that the capture of tumble plants by shrubs is an important self-maintaining mechanism of shrub-encroached grasslands. Tumble plant abundance is predicted to increase with increasing surface human disturbance and aridity. Therefore, the “shrub-litter island” effect is likely to be an important mechanism for maintaining and promoting the encroachment of shrubs into semiarid grasslands.