In order to save the consumption of natural high quality aggregate and improve the utilization rate of nano-composite materials, the investigation on the compressive strength and water permeability ...of nano-composite modified reclaimed aggregate concrete materials was proposed. In this experiment, reclaimed nano-ceramic aggregate was used to replace natural aggregate, and the effects of reclaimed aggregate substitution rate, water-cement ratio and target porosity on the compressive strength and permeability coefficient of reclaimed ceramic aggregate pervious concrete were studied. The reclaimed ceramic aggregate was pretreated with modifier. The results show that with the increase of substitution rate, the compressive strength decreases and the permeability coefficient has little difference. With the increase of water-cement ratio, the compressive strength increases first and then decreases, and the water permeability coefficient has little difference, but the value is lower when the water-cement ratio is greater than 0.4. As the target pore increases, the compressive strength decreases and the permeability coefficient increases. The optimal test scheme is as follows: the replacement rate is 40 %, the water-cement ratio is 0.35, and the porosity is 15 %. In this case, the performance of the specimen is better.
With the increase of replacement rate, the performance index of recycled aggregate decreases, the compressive strength of pervious concrete decreases continuously, and the permeability coefficient has little difference. With the continuous increase of water-cement ratio, the compressive strength increases first and then decreases, which can meet the construction requirements.
With the rapid development of network, network technology has been applied to all aspects of real life and has been widely used in power system. There are many network resources in power system, ...which can strengthen the safe operation of power system and protect system data. However, in real life, there are still some problems in power system security, which have a great impact on power enterprises and people’s lives. In the long-term research and practice, genetic algorithm has shown positive significance in promoting the optimization design of computer interaction network in power system. Based on this, this paper analyzes the application of genetic algorithm in the optimization design of computer interaction network in power system, expounds the basic characteristics of genetic algorithm, and then constructs the optimization model of computer interaction in power system.
This study considers the strategic relations between emission tax and environmental corporate social responsibility (ECSR) in a Cournot–Bertrand comparison and analyzes two different timings of the ...games between a tax-then-ECSR (T game) and an ECSR-then-tax (E game). We show that the T game always yields higher emission tax than the E game irrespective of competition modes, but lower ECSR under Cournot competition and higher ECSR when the marginal damage is high under Bertrand competition. We also show that compared with Bertrand competition, Cournot competition yields lower (higher) ECSR in the T (E) game but lower emission tax in the E game and higher emission tax when the product substitutability is low in the T game. We finally show that firms endogenously choose Cournot competition with the commitment of the E game irrespective of marginal damage and product substitutability.
•We examine the strategic relations between emission tax and environmental corporate social responsibility (ECSR).•We compare two different timings between a tax-then-ECSR (T game) and an ECSR-then-tax (E game).•The T game always yields higher emission tax than the E game irrespective of competition modes.•Cournot competition yields lower (higher) ECSR in the T (E) game than Bertrand competition.•Firms endogenously choose Cournot competition with the commitment of the E game.
Plant-derived extracellular vesicles (PDEVs) have great potential for clinical applications. Ultracentrifugation, considered the gold standard method for the preparation of PDEVs, is efficacious but ...time-consuming and highly instrument-dependent. Thus, a rapid and handy method is needed to facilitate the basic researches and clinical applications of PDEVs.
In this study, we combined electrophoretic technique with 300 kDa cut-off dialysis bag (named ELD) for the isolation of PDEVs, which was time-saving and needed no special equipment. Using ELD, lemon derived extracellular vesicles (LDEVs) could be isolated from lemon juice. Nanoparticle tracking analysis and transmission electron microscopy confirmed that the method separated intact vesicles with a similar size and number to the standard method-ultracentrifugation. LDEVs caused the gastric cancer cell cycle S-phase arrest and induced cell apoptosis. The anticancer activities of LDEVs on gastric cancer cells were mediated by the generation of reactive oxygen species. In addition, LDEVs were safe and could be remained in gastrointestinal organs.
ELD was an efficient method for the isolation of LDEVs, and could be carried out in any routine biological laboratory as no special equipment needed. LDEVs exerted anticancer activities on gastric cancer, indicating the great potentials for clinical application as edible chemotherapeutics delivery vehicle.
Vaccines are urgently needed to control the ongoing pandemic COVID-19 and previously emerging MERS/SARS caused by coronavirus (CoV) infections. The CoV spike receptor-binding domain (RBD) is an ...attractive vaccine target but is undermined by limited immunogenicity. We describe a dimeric form of MERS-CoV RBD that overcomes this limitation. The RBD-dimer significantly increased neutralizing antibody (NAb) titers compared to conventional monomeric form and protected mice against MERS-CoV infection. Crystal structure showed RBD-dimer fully exposed dual receptor-binding motifs, the major target for NAbs. Structure-guided design further yielded a stable version of RBD-dimer as a tandem repeat single-chain (RBD-sc-dimer) which retained the vaccine potency. We generalized this strategy to design vaccines against COVID-19 and SARS, achieving 10- to 100-fold enhancement of NAb titers. RBD-sc-dimers in pilot scale production yielded high yields, supporting their scalability for further clinical development. The framework of immunogen design can be universally applied to other beta-CoV vaccines to counter emerging threats.
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•A dimeric form of MERS-CoV RBD is highly immunogenic and protective in mice•RBD-dimer structure guides further design of a homogeneous dimer by tandem repeat•The strategy is generalizable to design beta-CoV vaccines against COVID-19 and SARS•CoV RBD-dimer immunogens can be produced at high yields in pilot scale production
Gao et al. present the structure-guided design of a coronavirus immunogen comprised of two protein subunits each containing the virus spike receptor binding domain fused together via a disulfide link or tandem repeat. The immunogen elicits strong immunogenicity in mice and protects them against viral challenge. The vaccine design strategy can be universally applied to SARS, MERS, COVID-19, and other CoV vaccines to counter emerging threats.
Against the background of digital development, this study’s research object is the platform-based highway transportation supply chain. It also analyzes two modes of supply chain financial credit ...financing, namely, upstream, and downstream enterprises of the platform, and network freight platform as the main financing body. Notably, the financial provider sets up a transaction credit based on the principle of business truth, and closed-loop transactions, determine the upper limit of the credit line based on the principle of financing self-compensation, build the expected profit maximization model, and establish the optimal credit line. Combined with the Highway Freight Index and Logistics Prosperity Index, the dynamic early warning value is established for the financing mode, where the platform as the main financing body. Through numerical analysis, the credit line and expected profit increase with the transaction credit, expected freight volume, and credit interest rate under the two modes, and the increase deriving from the credit interest rate is more significant. Finally, this paper describes the two-dimensional credit matrix of the financing subject via transaction credit and credit interest rate, which provides an intuitive credit reference for financial institutions to conduct the credit financing of the platform-based highway transportation supply chain.
Mycoplasma pneumoniae (M. pneumoniae) is an important pathogen of community-acquired pneumonia (CAP) in children. The coinfection rate of M. pneumoniae pneumonia (MPP) can reach 52% in some areas, ...but the effects of coinfection with different pathogens have not been clearly recognized. Compared with single M. pneumoniae infection, MPP coinfected with HAdV in children was relatively more serious.
Uric acid (UA) is the final product of purine metabolism in the human body, and impaired purine metabolism can increase the uric acid in serum, finally resulting in hyperuricemia (HUA). Current ...evidences suggest that urates might have antioxidant properties under certain circumstances, but most evidences suggest that urates promote inflammation. Hyperuricemia leads to the formation of urate crystals, which might be recognized as a red flag by the immune system. Such a response stimulates macrophage activation, leads to the activation of NOD-like receptor protein 3 (NLRP3) inflammasome vesicles, and ultimately the production and liberation of interleukin-1b (IL-1b) and interleukin-18 (IL-18), which can mediate inflammation, apoptosis and necroinflammation and cause an inflammatory cascade response. The kidney is one of the most commonly affected organs in HUA, which promotes the development of chronic kidney disease (CKD) by damaging endothelial cells, activating the renin-angiotensin system (RAS), and promoting inflammatory responses. Pharmacological interventions and lifestyle modifications are the primary means for controlling gout and lowering UA. The febuxostat is safe for CKD patients in the UA lowering therapy. Although dialysis can reduce UA levels, the application of drug is also necessary for dialysis patients. This article reviews the synthesis and metabolism of UA, etiology of HUA, the relationship between HUA and kidney disease, the treatment of gout and gouty nephropathy (GN).
A sensitive platform for the simultaneous electrochemical determination of Cd(II) and Pb(II) in aqueous solution has been developed based on the gold nanoparticle-graphene-cysteine composite ...(Au-GN-Cys) modified bismuth film glassy carbon electrode (GCE) using square wave anodic stripping voltammetry (SWASV). The synergistic effect of cysteine as well as the enlarged, activated surface and good electrical conductivity of gold nanoparticles and graphene contributed to the deposition of Cd(II) and Pb(II) on the electrode surface. Under the optimum conditions, a linear relationship existed between the currents and the concentrations of Cd(II) and Pb(II) in the range between 0.50μgL−1 to 40μgL−1 with the detection limits of 0.10μgL−1 for Cd(II) and 0.05μgL−1 for Pb(II), respectively, based on a signal-to-noise ratio equal to 3 (S/N=3). The interference experiments show that some metal cations had little influence on the SWASV signals of Cd(II) and Pb(II). In addition, the developed electrode displayed a good repeatability and reproducibility. These studies imply that the Au-GN-Cys composites might be an alternative candidate for practical applications in electrochemical detection of metal ions.
•Culture medium from OGD preconditioned astrocytes ameliorates OGD-induced neuron injury.•Exosomes derived from preconditioned astrocytes can be internalized into neurons.•OGD preconditioning ...promotes the production of exosomal miR-92b-3p from astrocytes.•MiR-92b-3p mimic as same as exosomes from preconditioned astrocytes exerts protective effects on neurons after OGD.
Ischemic preconditioning (IPC) exerts protective effects against ischemic cerebral injury. In the present study, an in vitro model of cerebral ischemia (oxygen and glucose deprivation, OGD) was established to investigate the neuroprotective mechanism of IPC. We found that conditioned medium (C.M.) from astrocytes rather than neurons nor microglia cell line BV2 exerted neuroprotection. Moreover, exosomes derived from OGD preconditioned astrocytes can be taken up by neurons and attenuated OGD-induced neuron death and apoptosis. High-throughput microRNA (miRNA) sequencing revealed that miR-92b-3p levels in exosomes released from preconditioned astrocytes were increased. Overexpression of miR-92b-3p in neurons with miR-92b-3p mimic achieved the same protective effects as C.M. from astrocytes. Thus, we propose that the mechanism of IPC may associate with astrocytes, and that exosome-mediated miR-92b-3p shuttle from preconditioned astrocytes to neurons participate in these process.
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