Dingoes are wild canids living in Australia, originating from domestic dogs. They have lived isolated from both the wild and the domestic ancestor, making them a unique model for studying ...feralization. Here, we sequence the genomes of 10 dingoes and 2 New Guinea Singing Dogs. Phylogenetic and demographic analyses show that dingoes originate from dogs in southern East Asia, which migrated via Island Southeast Asia to reach Australia around 8300 years ago, and subsequently diverged into a genetically distinct population. Selection analysis identifies 50 positively selected genes enriched in digestion and metabolism, indicating a diet change during feralization of dingoes. Thirteen of these genes have shifted allele frequencies compared to dogs but not compared to wolves. Functional assays show that an A-to-G mutation in ARHGEF7 decreases the endogenous expression, suggesting behavioral adaptations related to the transitions in environment. Our results indicate that the feralization of the dingo induced positive selection on genomic regions correlated to neurodevelopment, metabolism and reproduction, in adaptation to a wild environment.
Recent fruitful studies on rechargeable zinc-air battery have led to emergence of various bifunctional oxygen electrocatalysts, especially metal-based materials. However, their electrocatalytic ...configuration and evolution pathway during battery operation are rarely spotlighted. Herein, to depict the underlying behaviors, a concept named dynamic electrocatalyst is proposed. By selecting a bimetal nitride as representation, a current-driven "shell-bulk" configuration is visualized via time-resolved X-ray and electron spectroscopy analyses. A dynamic picture sketching the generation and maturation of nanoscale oxyhydroxide shell is presented, and periodic valence swings of performance-dominant element are observed. Upon maturation, zinc-air battery experiences a near two-fold enlargement in power density to 234 mW cm
, a gradual narrowing of voltage gap to 0.85 V at 30 mA cm
, followed by stable cycling for hundreds of hours. The revealed configuration can serve as the basis to construct future blueprints for metal-based electrocatalysts, and push zinc-air battery toward practical application.
Electrochemical conversion of N2 to NH3 offers a clean and energy‐saving solution for artificial NH3 production, but requires cost‐effective, steady and highly efficient catalysts to promote N2 ...reduction reaction (NRR). Herein, CuO employed as a new non‐noble‐metal NRR catalyst was investigated both experimentally and theoretically. When supporting the CuO nanoparticles on reduced graphene oxide (RGO), it was demonstrated that the resulting CuO/RGO nanocomposite could effectively and robustly catalyze NRR under ambient conditions. At −0.75 V versus reversible hydrogen electrode, the CuO/RGO exhibited a high NH3 yield of 1.8×10−10 mol s−1 cm−2 and Faradaic efficiency of 3.9 %, along with the excellent selectivity and high stability. Density functional theory (DFT) calculations revealed that the “Suf‐end” was the most effective mode for N2 adsorption on catalytic Cu atoms. In NRR process, the alternating associative route was the preferable pathway with *N2→*NNH being the rate‐determining step.
Sub or Suf? Suf CuO/RGO nanocomposite exhibited a high NH3 yield of 1.8×10−10 mol s−1 cm−2 and Faradaic efficiency of 3.9 % at −0.75 V versus reversible hydrogen electrode. Theoretical calculations revealed that the “Suf‐end” was the most effective mode for N2 adsorption on CuO and the *N2→*NNH is the rate‐determining step.
Space for nature Baillie, Jonathan; Zhang, Ya-Ping
Science,
2018-Sep-14, 2018-09-14, 20180914, Letnik:
361, Številka:
6407
Journal Article
Recenzirano
Odprti dostop
How much of the planet should we leave for other forms of life? This is a question humanity must now grapple with. The global human population is 7.6 billion and anticipated to increase to around 10 ...billion by the middle of the century. Consumption is also projected to increase, with demands for food and water more than doubling by 2050. Simply put, there is finite space and energy on the planet, and we must decide how much of it we're willing to share. This question requires deep consideration as it will determine the fate of millions of species and the health and well-being of future generations.
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•An electrochemical sensor for SARS-CoV-2 was constructed based on a smartphone.•The signal amplification of the sensor was based on supersandwich-type recognition strategy.•The ...detectable ratios of the sensor were higher than those obtained by RT-qPCR.•The sensor has the lowest limit of detection among the published approaches to date.•The sensor showed high specificity and selectivity.
The recent pandemic outbreak of COVID-19 caused by a novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), poses a threat to public health globally. Thus, developing a rapid, accurate, and easy-to-implement diagnostic system for SARS-CoV-2 is crucial for controlling infection sources and monitoring illness progression. Here, we reported an ultrasensitive electrochemical detection technology using calixarene functionalized graphene oxide for targeting RNA of SARS-CoV-2. Based on a supersandwich-type recognition strategy, the technology was confirmed to practicably detect the RNA of SARS-CoV-2 without nucleic acid amplification and reverse-transcription by using a portable electrochemical smartphone. The biosensor showed high specificity and selectivity during in silico analysis and actual testing. A total of 88 RNA extracts from 25 SARS-CoV-2-confirmed patients and eight recovery patients were detected using the biosensor. The detectable ratios (85.5 % and 46.2 %) were higher than those obtained using RT-qPCR (56.5 % and 7.7 %). The limit of detection (LOD) of the clinical specimen was 200 copies/mL, which is the lowest LOD among the published RNA measurement of SARS-CoV-2 to date. Additionally, only two copies (10 μL) of SARS-CoV-2 were required for per assay. Therefore, we developed an ultrasensitive, accurate, and convenient assay for SARS-CoV-2 detection, providing a potential method for point-of-care testing.
The highly oxidative operating conditions of rechargeable zinc–air batteries causes significant carbon‐support corrosion of bifunctional oxygen electrocatalysts. Here, a new strategy for the catalyst ...support design focusing on oxygen vacancy (OV)‐rich, low‐bandgap semiconductor is proposed. The OVs promote the electrical conductivity of the oxide support, and at the same time offer a strong metal–support interaction (SMSI), which enables the catalysts to have small metal size, high catalytic activity, and high stability. The strategy is demonstrated by successfully synthesizing ultrafine Co‐metal‐decorated 3D ordered macroporous titanium oxynitride (3DOM‐Co@TiOxNy). The 3DOM‐Co@TiOxNy catalyst exhibits comparable activities for oxygen reduction and evolution reactions, but much higher cycling stability than noble metals in alkaline conditions. The zinc–air battery using this catalyst delivers an excellent stability with less than 1% energy efficiency loss over 900 charge–discharge cycles at 20 mA cm−2. The high stability is attributed to the strong SMSI between Co and 3DOM‐TiOxNy which is verified by density functional theory calculations. This work sheds light on using OV‐rich semiconductors as a promising support to design efficient and durable nonprecious electrocatalysts.
An oxygen vacancy (OV)‐rich semiconductor is introduced to design an efficient and durable nonprecious bifunctional oxygen electrocatalyst in alkaline conditions. The OVs promote the electrical conductivity of the oxide support, and at the same time offer a strong metal–support interaction, which gives small metal size, high catalytic activity, and stability. This is demonstrated by synthesizing ultrafine Co‐metal‐decorated 3D ordered macroporous titanium oxynitride.
Ge‐based hybrid perovskite materials have demonstrated great potential for second harmonic generation (SHG) due to the geometry and lone‐pair induced non‐centrosymmetric structures. Here, we report a ...new family of hybrid 3D Ge‐based bromide perovskites AGeBr3, A=CH3NH3 (MA), CH(NH2)2 (FA), Cs and FAGe0.5Sn0.5Br3, crystallizing in polar space groups. These compounds exhibit tunable SHG responses, where MAGeBr3 shows the strongest SHG intensity (5×potassium dihydrogen phosphate, KDP). Structural and theoretical analysis indicate the high SHG efficiency is attributed to the displacement of Ge2+ along 111 direction and the relatively strong interactions between lone pair electrons of Ge2+ and polar MA cations along the c‐axis. This work provides new structural insights for designing and fine‐tuning the SHG properties in hybrid metal halide materials.
A new family of non‐centrosymmetric hybrid Ge‐based bromide perovskites are reported, showing second harmonic generation (SHG) responses. The largest SHG signal from CH3NH3GeBr3 is likely due to the perferable alignment of the polar cation with the lone pair electrons of Ge2+ along the 111 direction.
There is a need to find better strategies to promote wound healing, especially of chronic wounds, which remain a challenge. We found that synovium mesenchymal stem cells (SMSCs) have the ability to ...strongly promote cell proliferation of fibroblasts; however, they are ineffective at promoting angiogenesis. Using gene overexpression technology, we overexpressed microRNA‐126‐3p (miR‐126‐3p) and transferred the angiogenic ability of endothelial progenitor cells to SMSCs, promoting angiogenesis. We tested a therapeutic strategy involving controlled‐release exosomes derived from miR‐126‐3p‐overexpressing SMSCs combined with chitosan. Our in vitro results showed that exosomes derived from miR‐126‐3p‐overexpressing SMSCs (SMSC‐126‐Exos) stimulated the proliferation of human dermal fibroblasts and human dermal microvascular endothelial cells (HMEC‐1) in a dose‐dependent manner. Furthermore, SMSC‐126‐Exos also promoted migration and tube formation of HMEC‐1. Testing this system in a diabetic rat model, we found that this approach resulted in accelerated re‐epithelialization, activated angiogenesis, and promotion of collagen maturity in vivo. These data provide the first evidence of the potential of SMSC‐126‐Exos in treating cutaneous wounds and indicate that modifying the cells—for example, by gene overexpression—and using the exosomes derived from these modified cells provides a potential drug delivery system and could have infinite possibilities for future therapy. Stem Cells Translational Medicine 2017;6:736–747
Electrochemical CO2 reduction to CO is a potential sustainable strategy for alleviating CO2 emission and producing valuable fuels. In the quest to resolve its current problems of low‐energy ...efficiency and insufficient durability, a dual‐scale design strategy is proposed by implanting a non‐noble active Sn–ZnO heterointerface inside the nanopores of high‐surface‐area carbon nanospheres (Sn–ZnO@HC). The metal d‐bandwidth tuning of Sn and ZnO alters the extent of substrate–molecule orbital mixing, facilitating the breaking of the *COOH intermediate and the yield of CO. Furthermore, the confinement effect of tailored nanopores results in a beneficial pH distribution in the local environment around the Sn–ZnO nanoparticles and protects them against leaching and aggregating. Through integrating electronic and nanopore‐scale control, Sn–ZnO@HC achieves a quite low potential of −0.53 V vs reversible hydrogen electrode (RHE) with 91% Faradaic efficiency for CO and an ultralong stability of 240 h. This work provides proof of concept for the multiscale design of electrocatalysts.
To increase the energy efficiency while maintaining long durability of catalysts for CO2 electroreduction to CO, a dual‐scale delicate design of a non‐noble Sn–ZnO active interface inserted into nanopores of high‐surface‐area carbon nanospheres, through d‐bandwidth tuning of Sn and ZnO at the electronic scale, and local environment regulation from the nanoconfinement effect of tailored nanopores, is reported.
The cell‐to‐cell transfer of α‐synuclein (α‐Syn) greatly contributes to Parkinson's disease (PD) pathogenesis and underlies the spread of α‐Syn pathology. During this process, extracellular α‐Syn can ...activate microglia and neuroinflammation, which plays an important role in PD. However, the effect of extracellular α‐Syn on microglia autophagy is poorly understood. In the present study, we reported that extracellular α‐Syn inhibited the autophagy initiation, as indicated by LC3‐II reduction and p62 protein elevation in BV2 and cultured primary microglia. The in vitro findings were verified in microglia‐enriched population isolated from α‐Syn‐overexpressing mice induced by adeno‐associated virus (AAV2/9)‐encoded wildtype human α‐Syn injection into the substantia nigra (SN). Mechanistically, α‐Syn led to microglial autophagic impairment through activating toll‐like receptor 4 (Tlr4) and its downstream p38 and Akt‐mTOR signaling because Tlr4 knockout and inhibition of p38, Akt as well as mTOR prevented α‐Syn‐induced autophagy inhibition. Moreover, inhibition of Akt reversed the mTOR activation but failed to affect p38 phosphorylation triggered by α‐Syn. Functionally, the in vivo evidence showed that lysozyme 2 Cre (Lyz2cre)‐mediated depletion of autophagy‐related gene 5 (Atg5) in microglia aggravated the neuroinflammation and dopaminergic neuron losses in the SN and exacerbated the locomotor deficit in α‐Syn‐overexpressing mice. Taken together, the results suggest that extracellular α‐Syn, via Tlr4‐dependent p38 and Akt‐mTOR signaling cascades, disrupts microglial autophagy activity which synergistically contributes to neuroinflammation and PD development.
Autophagy‐dependent and independent machinery synergistically contribute to hα‐Syn‐caused neuroinflammation in PD. The basal autophagy activity restricts microglia inflammation. Extracellular hα‐Syn interacts with and activates Tlr4, resulting in inflammatory responses, as well as autophagy suppression in microglia via Tlr4‐dependent p38 and Akt/mTOR signaling cascades. This impairs the inhibitory effect of autophagy on inflammation, and thus aggravating hα‐Syn‐induced inflammatory responses.
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