As COVID-19 is rapidly spreading around the world, some countries have launched or plan to implement contact-tracing apps to detect exposure risks. In China, the government relies on Health Code, ...developed by Alipay and WeChat, for identifying people potentially exposed to COVID-19. The color-based code can determine people’s exposure risks and freedom of movement based on factors like travel history, duration of time spent in risky areas, and relationships to potential carriers. This essay discusses the rise of Health Code from a platform perspective, arguing that digital platforms are key players conducting health surveillance and mediating state–citizen relations in China. More importantly, tracing apps might become a normal practice in many countries, suggesting that platforms will be substantially adopted for health surveillance.
Mesenchymal stem cells (MSCs) have been extensively investigated for the treatment of various diseases. The therapeutic potential of MSCs is attributed to complex cellular and molecular mechanisms of ...action including differentiation into multiple cell lineages and regulation of immune responses via immunomodulation. The plasticity of MSCs in immunomodulation allow these cells to exert different immune effects depending on different diseases. Understanding the biology of MSCs and their role in treatment is critical to determine their potential for various therapeutic applications and for the development of MSC-based regenerative medicine. This review summarizes the recent progress of particular mechanisms underlying the tissue regenerative properties and immunomodulatory effects of MSCs. We focused on discussing the functional roles of paracrine activities, direct cell–cell contact, mitochondrial transfer, and extracellular vesicles related to MSC-mediated effects on immune cell responses, cell survival, and regeneration. This will provide an overview of the current research on the rapid development of MSC-based therapies.
The separation of wear microparticles in lubricating oil is crucial for improving the accuracy and throughput of the subsequent detection. However, there are few kinds of research on the separation ...of high‐density metallic microparticles in high‐viscosity lubricating oil. In this paper, a passive method for separating the metallic microparticles in oil is proposed. Gravity sedimentation was adopted to realize three‐dimensional (3D) focusing of the particle by using an inclined capillary. The gravity‐based 3D focusing made the sheath flow no longer responsible for the particle focusing and effectively reduced the sheath flow. Then, the separation of different‐sized metallic microparticles was achieved in a horizontal channel with the aid of a sheath flow based on the different driving forces. The present method solved the problem of nonsynchronous separation of the particle in comparison to the traditional methods. This device has a simple structure with high separation efficiency, and it is easy to integrate with the detection channel. The influence of numerous parameters on the gravity‐based focusing and separation was systematically studied by the numerical simulation and the experiment. The design criteria were established, which is useful in designing and employing the device, expanding its application to other non‐neutral buoyancy particle separation cases, and opening up more prospects for microfluidic technology.
Xiyanping (XYP) is a Chinese herbal medicine used in the clinic to treat respiratory infection and pneumonia. Recent evidence identified XYP as a potential inhibitor of severe acute respiratory ...syndrome coronavirus 2, implying XYP as a possible treatment for the coronavirus disease 2019 (COVID‐19). Here, we conducted a prospective, multicenter, open‐label and randomized controlled trial to evaluate the safety and effectiveness of XYP injection in patients with mild to moderate COVID‐19. We consecutively recruited 130 COVID‐19 patients with mild to moderate symptoms from five study sites, and randomized them in 1:1 ratio to receive XYP injection in combination with standard therapy or receive standard supportive therapy alone. We found that XYP injection significantly reduced the time to cough relief, fever resolution and virus clearance. Less patients receiving XYP injection experienced disease progression to the severe stage during the treatment process. No severe adverse events were reported during the study. Taken together, XYP injection is safe and effective in improving the recovery of patients with mild to moderate COVID‐19. However, further studies are warranted to evaluate the efficacy of XYP in an expanded cohort comprising COVID‐19 patients at different disease stages.
Biomass gasification is recognized as one of the most promising solutions for renewable energy and environmental sustainability. However, tar formation in gasifier remains as one of the main hurdles ...that hinder commercialization. Nickel based catalyst is widely used in chemical industries and is proven as one of the most effective transition metal catalysts in biomass gasification for tar cracking and reforming. This paper presents a review of various commercial nickel catalysts that have been evaluated for tar elimination in biomass gasification. This review also looks at recent advancements in nickel based catalyst used in biomass gasification, including discussion on the effects of different support, promoter and particle size on the catalytic performance. Future direction of biomass gasification, including reactive flash volatilization and steam gasification, are also discussed in this review.
Abstract
Narrow-line Seyfert 1 galaxies (NLS1s), a subclass of active galactic nuclei (AGNs) in an early stage of the accretion process, are also found to host relativistic jets. However, currently ...known jetted NLS1s are rare. The majority of NLS1s are undetected at the radio band. The radio detection rate of NLS1s increases with the LOFAR Two-metre Sky Survey (LoTSS), which provides a good opportunity for finding more jetted NLS1s. The better sensitivity raises the question whether the radio emission of NLS1s with a low radio luminosity originates from the jet activity. In order to clarify the origin of the radio emission for NLS1s and search for more jetted NLS1s, we explore the mid-infrared properties of LoTSS-detected NLS1s by comparing them with known jetted AGNs and star-forming galaxies (SFGs), which are located above and on the well-studied radio/far-infrared correlation, respectively. The majority of NLS1s show mid-infrared (MIR) excess compared with SFGs. Their radio emission shows a significant correlation with the MIR emission. In the MIR color–color diagram, NLS1s overlap flat spectrum radio quasars, but they are well separated from SFGs and optically selected radio galaxies. The flux ratio of the radio and MIR emission of these NLS1s is also similar to that of a radio-quiet quasar with a weak jet. These results imply substantial contributions from the AGN activities for both the radio and MIR emission of NLS1s. A small fraction of NLS1s with relatively higher radio luminosities are located in a similar region as blazars in the radio-MIR diagram, which suggests that the radio emission of these NLS1s is dominated by the jet. We obtain a sample of jetted NLS1 candidates through their radio excess in the radio-MIR diagram.
Chemical looping methane partial oxidation provides an energy and cost effective route for methane utilization. However, there is considerable CO
co-production in current chemical looping systems, ...rendering a decreased productivity in value-added fuels or chemicals. In this work, we demonstrate that the co-production of CO
can be dramatically suppressed in methane partial oxidation reactions using iron oxide nanoparticles embedded in mesoporous silica matrix. We experimentally obtain near 100% CO selectivity in a cyclic redox system at 750-935 °C, which is a significantly lower temperature range than in conventional oxygen carrier systems. Density functional theory calculations elucidate the origins for such selectivity and show that low-coordinated lattice oxygen atoms on the surface of nanoparticles significantly promote Fe-O bond cleavage and CO formation. We envision that embedded nanostructured oxygen carriers have the potential to serve as a general materials platform for redox reactions with nanomaterials at high temperatures.
Aluminum is an ideal material for metallic fuel cells. In this research, different grain sizes of aluminum anodes are prepared by equal channel angular pressing (ECAP) at room temperature. ...Microstructure of the anodes is examined by electron backscatter diffraction (EBSD) in scanning electron microscope (SEM). Hydrogen corrosion rates of the Al anodes in 4 mol L−1 NaOH are determined by hydrogen collection method. The electrochemical properties of the aluminum anodes are investigated in the same electrolyte using electrochemical impedance spectroscopy (EIS) and polarization curves. Battery performance is also tested by constant current discharge at different current densities. Results confirm that the electrochemical properties of the aluminum anodes are related to grain size. Finer grain size anode restrains hydrogen evolution, improves electrochemical activity and increases anodic utilization rate. The proposed method is shown to effectively improve the performance of Al–air batteries.
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•Higher electrochemical performance of Al anode with finer grain size.•The capacity and energy density of 2308 mAh g−1 and 3525 mWh g−1 with finer grain size Al anode.•Improvement by 41.5% of capacity density and 55.5% of energy density as compared with the cast anode.
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