Air pollution in transportation cabins has recently become a public concern. However, few studies assessed the exposure levels of suspected air pollutants including Volatile Organic Compounds (VOCs). ...This paper studied the exposure levels of in-carriage VOCs (benzene, toluene, ethylbenzene, xylene, styrene, formaldehyde, acetaldehyde, acetone and acrolein) in Shanghai, China and estimated the health risk in different conditions. The results indicated that VOCs concentrations in metro carriages varied from different train models, due to the difference in carriage size and ventilation system. The concentrations of aromatic VOCs in old metro carriage were 1–2 times higher than the new ones, as better paintings were used in new trains. Poor air circulation and ventilation in the underground track was likely to be the cause of higher VOCs levels (~10%) than the above-ground track. Lower aromatic compounds levels and higher carbonyls levels were observed in metro carriages at suburban areas than those at urban areas, likely due to less aromatic emission sources and more carbonyls emission sources in suburban areas. Acetone and acrolein were found to increase from 7.71 to 26.28μg/m3 with number of commuters increasing from 40 to 200 in the carriages. According to the acceptable level proposed by the World Health Organization (1×10−6–1×10−5), the life carcinogenic risk of commuters by subway (8.5×10−6-4.8×10−5) was little above the acceptable level in Shanghai. Further application of our findings is possible to act as a reference in facilitating regulations for metro systems in other cities around world, so that in-carriage air quality might be improved.
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•The VOCs concentration in different metro carriages under different route conditions were analyzed.•The VOCs exposure levels inside metro carriages in Shanghai, China were calculated.•The health risk of commuters' exposure to VOCs inside subway was estimated.
•Hierarchically-structured CuO@TiO2-Al2O3 was adopted as oxygen carrier in CLAS.•Appropriate operating parameters were attained for continuous oxygen production.•Continuous stream of O2/CO2 was ...produced in a paralleled fluidized bed reactor.•Different concentrations of O2/CO2 can be attained by varying inlet CO2/H2O ratio.
Chemical looping air separation (CLAS) provides a novel route for O2 production, which can be coupled with integrated gasification combined cycle (IGCC) or oxy-fuel combustion to address the O2 source issue. The development of regenerable and robust oxygen carrier, which should be able to release gaseous oxygen in O2-deficient atmosphere (usually CO2/H2O) and regenerate itself by oxidizing with O2 in air, is critical for the successful deployment of CLAS systems. In this work, a CuO@TiO2-Al2O3 oxygen carrier with hierarchical structure (i.e., CuO-rich, TiO2-stabilized and Al2O3-supported), which was prepared by the self-assembly template combustion synthesis (SATCS) method, was adopted for continuous oxygen production in a paralleled fluidized bed reactor. Before which, isothermal experiments in a thermogravimetric analyzer (TGA) were first conducted to analyze the effect of temperature on OC decoupling and regeneration characteristics. The influence of inlet gas flow rate on the oxygen decoupling rate of the oxygen carrier was then investigated in a batch fluidized bed reactor. Appropriate reaction temperature as well as inlet gas flow rate for continuous O2 production in the paralleled fluidized bed reactor was ultimately attained. During a consecutive operation of 10 h, continuous stream of O2/CO2 with relatively stable and high O2 concentration (19.7–27.6 vol, steam free basis) was obtained. The superior reactivity and stability of CuO@TiO2-Al2O3 achieved during the continuous operation in the paralleled fluidized bed reactor indicate that it could be a promising oxygen carrier candidate for the CLAS process.
•The difference of in-nozzle flow between the Bosch long-tube method and actual injection is clarified.•The fuel injection rate (FIR) as fuel input boundary condition for CFD simulation should not ...start from zero.•A very simple but effective model to revise the FIR profile is formulated.•The newly developed FIR profiles lead to better predictability for both the spray and flame penetrations.•The “Velocity Revised” profile is more preferable for predicting the initial spray and flame penetrations.
The start of injection (SOI) transition processes present challenges for diesel spray combustion simulations by computational fluid dynamics (CFD). In the previous studies, claims are usually placed on the experimental uncertainties or numerical methods such as grid size selection and sub-model comparison. Until now, few studies have been attempted to revise the fuel injection rate (FIR) profile used as the fuel input boundary condition for numerical models. It this paper, considering the difference of in-nozzle flow between the Bosch long-tube method and actual injection, the ''Velocity Revised'' and ''Mass Revised'' FIR profiles are formulated to keep the fuel injection velocity and fuel injection mass consistent with the actual injection, respectively. After a brief description of the experimental and numerical methods, the effectiveness of the newly developed two FIR profiles and the uncorrected and the Engine Combustion Network (ECN) FIR profiles used as boundary conditions for CFD simulation is validated against the experimental data under both the non-reacting and burning conditions. The simulations with the uncorrected FIR profile show remarkably lower spray and flame penetrations at the initial stage of injection, while the simulations with the newly developed two FIR profiles exhibit almost identical spray and flame penetrations with the experimental data. The accuracy of the ECN FIR profile simulation is between the above two cases. These results are believed to be valuable reference for researchers to evaluate whether the potential shortcoming in diesel spray combustion simulations is from the variation in boundary condition or the code itself.
Coal direct liquefied diesel (DDCL) is a new alternative fuel with high cleanliness and quality. Its hydrocarbon composition and physicochemical properties are quite different from those of ...petrochemical diesel. In order to study the difference in evaporative burning characteristics between DDCL and diesel during the sequential burning of multiple droplets, three fuel droplets are suspended on fibers in order by a micro-injector. The first droplet was ignited by an electrode igniter, and then the sequential burning process of three droplets was captured by a high-speed camera. An automatic processing program is written based on Matlab software to calculate the equivalent diameter of each fuel droplet. The result shows that the burning process of the DDCL droplet can be divided into three stages: initial thermal expansion, steady burning, and late micro-explosion burning. DDCL is much easier to form the burning mixture and has better flammability than diesel. The droplet spacing and fuel type have significant effects on ignition delay. The square of the normalized diameter of droplets decreases linearly with time during the steady burning period, which follows the D2 law. The reduction rates of normalized squared diameter for DDCL droplets are higher than that for diesel. The pyrolysis of macromolecular components at high temperature produces many small molecules and low boiling point components, which induce the micro-explosions in the late burning stage. The micro-explosion intensity of DDCL droplets is obviously lower than that of diesel.
Pilot-diesel-ignition ammonia combustion engines have attracted widespread attentions from the maritime sector, but there are still bottleneck problems such as high unburned NH
and N
O emissions as ...well as low thermal efficiency that need to be solved before further applications. In this study, a concept termed as in-cylinder reforming gas recirculation is initiated to simultaneously improve the thermal efficiency and reduce the unburned NH
, NO
, N
O and greenhouse gas emissions of pilot-diesel-ignition ammonia combustion engine. For this concept, one cylinder of the multi-cylinder engine operates rich of stoichiometric and the excess ammonia in the cylinder is partially decomposed into hydrogen, then the exhaust of this dedicated reforming cylinder is recirculated into the other cylinders and therefore the advantages of hydrogen-enriched combustion and exhaust gas recirculation can be combined. The results show that at 3% diesel energetic ratio and 1000 rpm, the engine can increase the indicated thermal efficiency by 15.8% and reduce the unburned NH
by 89.3%, N
O by 91.2% compared to the base/traditional ammonia engine without the proposed method. At the same time, it is able to reduce carbon footprint by 97.0% and greenhouse gases by 94.0% compared to the traditional pure diesel mode.
Renifolin F is a prenylated chalcone isolated from Shuteria involucrata, a traditional minority ethnic medicine used to treat the respiratory diseases and asthma. Based on the effects of the original ...medicine plant, we established an in vivo mouse model of allergic asthma using ovalbumin (OVA) as an inducer to evaluate the therapeutic effects of Renifolin F. In the research, mice were sensitized and challenged with OVA to establish an allergic asthma model to evaluate the effects of Renifolin F on allergic asthma. The airway hyper-reactivity (AHR) to methacholine, cytokine levels, ILC2s quantity and mircoRNA-155 expression were assessed. We discovered that Renifolin F attenuated AHR and airway inflammation in the OVA-induced asthmatic mouse model by inhibiting the regulation of ILC2s in the lung, thereby, reducing the upstream inflammatory cytokines IL-25, IL-33 and TSLP; the downstream inflammatory cytokines IL-4, IL-5, IL-9 and IL-13 of ILC2s; and the co-stimulatory factors IL-2 and IL-7; as well as the expression of microRNA-155 in the lung. The findings suggest a therapeutic potential of Renifolin F on OVA-induced airway inflammation.
Colon cancer is a highly malignant cancer with poor prognosis.
(Fisch.) Bunge (Huang Qi in Chinese, HQ), a well-known Chinese herbal medicine and a popular food additive, possesses various biological ...functions and has been frequently used for clinical treatment of colon cancer. However, the underlying mechanism is not fully understood. Isoflavonoids, including formononetin (FMNT) and calycosin (CS), are the main bioactive ingredients isolated from HQ. Thus, this study aimed to explore the inhibitory effects and mechanism of HQ, FMNT and CS against colon cancer by using network pharmacology coupled with experimental validation and molecular docking. The network pharmacology analysis revealed that FMNT and CS exerted their anticarcinogenic actions against colon cancer by regulating multiple signaling molecules and pathways, including MAPK and PI3K-Akt signaling pathways. The experimental validation data showed that HQ, FMNT and CS significantly suppressed the viability and proliferation, and promoted the apoptosis in colon cancer Caco2 and HT-29 cells. HQ, FMNT and CS also markedly inhibited the migration of Caco2 and HT-29 cells, accompanied by a marked increase in E-cadherin expression, and a notable decrease in N-cadherin and Vimentin expression. In addition, HQ, FMNT and CS strikingly decreased the expression of ERK1/2 phosphorylation (p-ERK1/2) without marked change in total ERK1/2 expression. They also slightly downregulated the p-Akt expression without significant alteration in total Akt expression. Pearson correlation analysis showed a significant positive correlation between the inactivation of ERK1/2 signaling pathway and the HQ, FMNT and CS-induced suppression of colon cancer. The molecular docking results indicated that FMNT and CS had a strong binding affinity for the key molecules of ERK1/2 signaling pathway. Conclusively, HQ, FMNT and CS exerted good therapeutic effects against colon cancer by mainly inhibiting the ERK1/2 signaling pathway, suggesting that HQ, FMNT and CS could be useful supplements that may enhance chemotherapeutic outcomes and benefit colon cancer patients.
In this paper, the thermal management of missile-borne components in a flight state is studied. Avoiding excessive component temperatures under the high-temperature circumstances brought by ...aerodynamic heat is a requirement to guarantee the equipment’s safe and reliable operation. In this work, we designed four finned shell constructions for a phase change module using the phase change temperature control method and then studied their effects on the module’s ability to dissipate heat using an experimental approach. Three sizes of 30 mm, 40 mm, and 50 mm heating pads were used to replicate heat sources with various heat flux densities and heat dissipation regions, with reference to the heating characteristics of various chips. The results demonstrated that the square-shaped fin had the best heat dissipation effect after operating for 10 min under the power of 10 W and 20 W, while the strip-shaped fins exhibited the highest performance under the power of 30 W. The square-shaped fins had the best heat dissipation effect when reducing working time to 5 min. This paper proposes the optimal fin scheme under different power densities, as well as an enhanced heat dissipation idea for the melting process of the phase change materials based on the test results.
Ferroptosis, which has attracted much attention, is a new form of regulated cell death that is closely associated with the progression of various diseases. Ferroptosis is dependent upon intracellular ...iron and reactive oxygen species and is morphologically, biochemically, and genetically distinct from other nonapoptotic forms of cell death. Cumulative evidence shows that ferroptosis plays a pivotal role in the development and progression of tumorigenesis. Ferroptosis induction has become a potential effective strategy in cancer prevention and treatment in the clinic. Thus, it is worth identifying the active chemical compounds that induce ferroptosis for cancer suppression. Chinese herbal medicines (CHMs), which contain a host of bioactive phytochemicals that could target many signaling pathways, have been increasingly used worldwide due to their effects against various diseases. Compelling evidence has demonstrated that many phytochemicals from CHMs exert potent anticarcinogenic effects and have been widely used for the clinical prevention and treatment of a variety of cancers. Furthermore, growing evidence suggests that phytochemicals could exhibit potent inhibitory effects against different cancers by inducing ferroptosis through the regulation of a large number of ferroptosis-related signaling pathways and targets. Herein, we summarized the current understanding of phytochemicals from CHMs in ferroptosis-mediated cancer prevention and treatment and the molecular mechanisms. We also concluded with potential applications of emerging ferroptosis-related strategies against cancer. This study may expand our current knowledge about the mechanisms of phytochemicals from CHMs as anticancer agents, which could be used clinically to enhance the effect of future ferroptosis-inducing CHM therapies against cancers.
Worldwide, cancer is a growing epidemic that results in large social and economic burdens. Despite advances in current diagnosis and treatment, most of the prognosis in cancer patients remains poor. ...It is urgent to find alternative therapies with effective cancer prevention and treatment. Chinese herbal medicines (CHMs) have been increasingly used worldwide for cancer prevention and treatment due to their privileged properties. CHMs are useful in the suppression of various types of cancers through different mechanisms of action. Non-coding RNAs (ncRNAs), including microRNAs, long non-coding RNAs and circular RNAs, are closely involved in the cancer progression and development. Regulation of ncRNAs in tumor cells may be a useful pharmacological strategy for the cancer prevention and treatment. Substantial evidence exists that various phytochemicals from CHMs exert potent anticarcinogenic effects by regulating ncRNAs-related targets and signaling pathways. Herein, the purpose of this paper is to conclude the current understanding of phytochemicals from CHMs in ncRNAs-mediated cancer suppression and the molecular mechanisms. This review will help to provide beneficial clues related to the clinical use of CHMs in the cancer prevention and treatment and further promote new drug discovery against cancer.
•NcRNAs are closely involved in the cancer progression and development.•Chinese herbal medicines have been widely used for cancer prevention and treatment.•NcRNAs mediate phytochemicals-induced cancer prevention and treatment.
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