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• Supercritical power cycles may experience trans-critical procedures during start-up, shut down, or accident condition. • The thermal–hydraulic code has been upgraded for simulation of trans-critical transients. • A calibration model to IAFB heat transfer correlation at the near critical pressure condition has been developed. • The modified code gets well validated by trans-critical experiments. Though designed to be operated in supercritical conditions, supercritical power systems could experience trans-critical transients in which the pressure transfers between supercritical and subcritical condition during startup, shutdown, or accident condition. In the present work the thermal–hydraulic code ATHLET-SC was upgraded to predict the heat transfer behavior during trans-critical procedures. Prediction model of dispersed droplet flow film boiling (DFFB) heat transfer correlation, critical heat flux (CHF) correlation, and the correlation of minimum film boiling temperature T MFB has been upgraded. It is demonstrated by the validation work that the prediction error is large in the inverted annular film boiling (IAFB) regime. However, steady-state IAFB heat transfer experiment at high-pressure condition is unavailable. Hence, a calibration approach to IAFB heat transfer correlation is developed based on trans-critical transient experiment. As validated, the change of the wall temperature during the trans-critical transient gets well predicted by the corrected Bromley correlation. [ABSTRACT FROM AUTHOR]

• A new PDO heat transfer was established including 31603 data points. • Spearman's rank correlation coefficient method and group-wise statistic method are applied to develop the new PDO correaltion. • Different heat transfer modes among heated wall, vapor and droplet are considered. • The new PDO correlation gets well validated under different working conditions. The present study established a new experimental databank of stable post-dryout (PDO) heat transfer which contains 31,603 data points in total. It is demonstrated by the assessment work with the new databank that previous PDO heat transfer prediction methods could not provide high prediction accuracy to various working conditions. Therefore, this study aims to develop a universal correlation for stable PDO heat transfer. With effect of convective and radiation heat transfer considered, a new prediction model for stable PDO heat transfer is developed, which is a dimensionless one and independent to upstream information. By identifying significant dimensionless parameters with Spearman's rank correlation coefficient method and the group-wise statistic method, three dimensionless parameters (R e T P , Pr W , and x e) are selected to establish the new PDO correlation. Though developed from water experiments for vertical flow in uniformly heated round tubes, the new correlation shows good predictive capability when validated against water experiments with non-uniform heating and R134a experiments with uniform heating, which means the new correlation can be applied to various working conditions. However, if applied to cryogenic pipeline chill-down transient or nuclear power plant accident scenarios, validation with transient experiments needs to be completed in the future. [ABSTRACT FROM AUTHOR]

Polybrominated biphenyl ethers (PBDEs) are a group of persistent organic pollutants with endocrine-disrupting, neurotoxic, tumorigenic and DNA-damaging activities. They are hydroxylated by human liver microsomal CYP enzymes, however, their mutagenicity remains unknown. In this study, 2,2′,4,4′-tetrabromobiphenyl ether (BDE-47, relatively abundant in human tissues) was investigated for micronuclei induction and DNA damage in mammalian cells. The results indicated that BDE-47 up to 80 μM under a 6 h/18 h (exposure/recovery, covering 2 cell cycles) regime did not induce micronuclei in V79-Mz and V79-derived cell lines expressing human CYP1A1 or 1A2, while it was moderately positive in human CYP2B6-, 2E1-and 3A4-expressing cell lines (V79-hCYP2B6, V79-hCYP2E1-hSULT1A1 and V79-hCYP3A4-hOR, respectively). Following 24 h exposure, BDE-47 induced micronuclei in V79-hCYP2E1-hSULT1A1 and V79-hCYP3A4 cells at increased potencies. In the human hepatoma (HepG2) cells BDE-47 (48 h exposure) was inactive up to 40 μM, however, pretreatment of the cells with ethanol (0.2%, v:v, inducer of CYP2E1) or rifampicin (10 μM, inducer of CYP3A4) led to significant micronuclei formation by BDE-47; pretreatment with bisphenol AF (100 nM) also potentiated BDE-47-induced micronuclei formation (which was blocked by a CYP2E1 inhibitor trans -1,2-dichloroethylene or a CYP3A inhibitor (ketoconazole). Immunofluorescent staining of centromere protein B with the micronuclei formed by BDE-47 in HepG2 cells pretreated with ethanol or rifampicin demonstrated selective formation of centromere-containing micronuclei. The increased phosphorylation of both histones H2AX and H3 in HepG2 by BDE-47 also indicated an aneugenic potential. Therefore, this study suggests that BDE-47 is an aneugen activated by several human CYP enzymes. [Display omitted] • 2,2′,4,4′-Tetrabromobiphenyl ether (BDE-47) is aneugenic in mammalian cells. • The aneugenicity of BDE-47 depends on metabolic activation by human CYP enzymes. • Human CYP3A4 and 2E1 might be the major enzymes activating BDE-47. [ABSTRACT FROM AUTHOR]

• The safety analysis of supercritical coolant cooled nuclear reactors requires a CHF model for the high-pressure region. • A high-pressure CHF experimental databank with wide range is established. • A new CHF correlation for the high-pressure region is developed. Supercritical coolant cooled reactors may experience the high subcritical pressure region during pressurization or depressurization transients, where the occurrence of the boiling crisis phenomena cannot be avoided. Therefore, a prediction model of CHF for the high-pressure region is required for the design of the supercritical system, but it is still missing. The CHF databank with reduced pressure above 0.7 was compiled from literatures or experiments carried out in IATF, including three different fluids (water, R12, and CO 2). With the knowledge of the two-phase phenomena, we rearranged the sublayer dryout model for DNB and proposed a new mechanism for dryout. By introducing dimensionless theory, a new CHF prediction correlation with a simple structure but relatively high accuracy was proposed for water and shows a good adaptation to water and non-aqueous fluids. As illustrated, the new model can be implemented to safety analysis of supercritical systems. [ABSTRACT FROM AUTHOR]

• Parameters in a common accident are predicted by data- and model-driven approaches. • Data-driven gated recurrent unit network is used for autoregressive prediction. • Model-driven RELAP5 simulation code is used to predict unmeasured parameters. • The methods and predicted results are compared on six aspects. • The comparison results show the characteristics of the two approaches. Nuclear energy plays a crucial role in mitigating climate change as a near carbon-free and clean energy source. Predicting operating parameters is key to the digitalization and intellectualization of nuclear power plants, improving energy efficiency and reducing costs. Parameter prediction methods mainly consist of model-driven and data-driven approaches, and a comparative study is necessary to select the appropriate prediction method or combine them. In this paper, the gated recurrent unit network and the thermal–hydraulic program RELAP5 are chosen as representative data-driven and model-driven approaches to be used for predicting parameters for a specific operating condition to assess the characteristics and capabilities of each. The chosen experiment is a steam generator tube rupture accident which is important to pressurized water reactors. In this paper the modelling process and the prediction results for both approaches are given. The correlation coefficient for dome pressure, dome temperature, and primary outlet temperature of both approaches is greater than 0.993, except that the correlation coefficient of downcomer temperature is 0.83865 using RELAP5 and 0.99392 using gated recurrent unit network. Then the two approaches are compared from six perspectives of practical application, including accuracy (gated recurrent unit network and RELAP5 received scores of 8 and 6, respectively.), data requirements (7 and 5, respectively), model building algorithm (7 and 5, respectively), prediction speed (10 and 6, respectively), expertise requirements (6 and 6, respectively), and interpretability (5 and 9, respectively). It shows that model-driven and data-driven approaches both require specialist knowledge and appropriate data for modelling process. The data-driven gated recurrent unit network exhibits better accuracy and higher speed. The model-driven RELAP5 has better interpretability compared to the black-box gated recurrent unit network. It is suggested that hybrid approaches of model-driven and data-driven approaches could better deal with the prediction problems. [ABSTRACT FROM AUTHOR]

Computational Fluid Dynamics-Discrete Element Method (CFD-DEM) is employed to describe the co-gasification of biomass and coal in bubbling fluidized bed coupled with chemical reaction kinetic model. Six sets of simulations are set up to study the effect of blend ratio on the amount of gasification products compared with experiments. The calorific value of syngas, carbon conversion efficiency, hydrogen conversion efficiency and cold gas efficiency are calculated. Compared with the separate gasification, the hydrogen efficiency and cold gas efficiency in the co-gasification are enhanced. When biomass accounts for 75%, the contents of CO gas and CO 2 gas are the lowest, while the contents of H 2 gas and CH 4 gas are the highest. The high calorific value, carbon conversion efficiency and hydrogen conversion efficiency reach the maximum under this blend ratio. The cold gas efficiency is not obviously affected by the blend ratio, and reaches the maximum when the biomass content is 50%. • CFD-DEM for co-gasification of biomass and coal in bubbling fluidized bed is built. • When biomass accounts for 75%, the contents of H 2 gas and CH 4 gas are the highest. • The carbon conversion efficiency reach the maximum when biomass accounts for 75%. • The hydrogen conversion efficiency reach the maximum when biomass accounts for 75%. • The cold gas efficiency is not obviously affected by the increase of biomass amounts. [ABSTRACT FROM AUTHOR]

• Vortex-related data using continuous observations at Kelameili Station in the Gurbantunggut Desert. • The correlation analysis of NEE, GPP, Reco and various environmental factors was carried out. • Assess the carbon sequestration capacity of China's second largest desert and largest fixed semi-fixed desert (Gurbantunggut Desert). • The comparison of carbon source/sink functions in different terrestrial ecosystems provides a reference. • a new direction for finding "carbon failures". Although previous studies have illustrated the variation of CO 2 fluxes in different terrestrial ecosystems, more needs to be reported on desert ecosystems. This study, based on the eddy covariance (EC) measurements data over the Gurbantunggut Desert, analyzed the controlling factors and variations of net ecosystem exchange (NEE), gross primary production (GPP), and ecosystem respiration (Reco) during the growing season (April-September2021) in Gurbantunggut Desert. The results were as follows: 1) Carbon fluxes in the Gurbantunggut Desert had prominent daily and seasonal variations during the growing season. On the daily scale, it showed a net uptake during the day and a net release at night, and the monthly average daily change curve of NEE was "U" shaped; on the seasonal scale, carbon uptake was observed in all months, with a peak of −37.76 gC m−2 month−1 in May. 2)The cumulative amounts of NEE, GPP, and Reco in the Gurbantunggut Desert were −193.74, 235.43, and 41.69 g C m−2, respectively, throughout the growing season, showing carbon sinks. 3) Correlation analysis with environmental factors revealed that NEE, GPP, and Reco of desert ecosystems were highly significantly correlated with photosynthetically active radiation (PAR) at different time scales (p < 0.01). Second, at the half-hourly scale, all environmental factors showed vital significance, with a high correlation with air temperature (Tair) and soil temperature (Tsoil); at the monthly scale, they were significantly correlated with Precipitation (p < 0.05). 4) Photosynthetically active radiation is the dominant factor affecting the daily net ecosystem carbon exchange rate. The two are consistent with the rectangle hyperbola model where the daily net ecosystem carbon exchange rate decreases with increasing photosynthetically active radiation. The results indicate that carbon fluxes in the growing season of the Gurbantunggut Desert ecosystem are more sensitive to the response of photosynthetically active radiation. The results have significant reference value for further understanding and research in predicting the source-sink function and influence mechanism of desert ecosystems. [ABSTRACT FROM AUTHOR]

The retinoic acid receptor-related orphan receptor γt (RORγt) is an important nuclear receptor that regulates the differentiation of Th17 cells and production of interleukin 17(IL-17). RORγt agonists increase basal activity of RORγt and could provide a potential approach to cancer immunotherapy. Herein, hit compound 1 was identified as a weak RORγt agonist during in-house library screening. Changes in LHS core of 1 led to the identification of tetrahydroquinoline compound 6 as a partial RORγt agonist (max. act. = 39.3%). Detailed structure-activity relationship on substituent of the LHS core, amide linker and RHS arylsulfonyl moiety was explored and a novel series of tetrahydroquinolines and benzomorpholines was discovered as potent RORγt agonists. Tetrahydroquinoline compound 8g (EC 50 = 8.9 ± 0.4 nM, max. act. = 104.5%) and benzomorpholine compound 9g (EC 50 = 7.5 ± 0.6 nM, max. act. = 105.8%) were representative compounds with high RORγt agonistic activity in dual FRET assay, and they showed good activity in cell-based Gal4 reporter gene assay and Th17 cell differentiation assay (104.5% activation at 300 nM of 8g ; 59.4% activation at 300 nM of 9g). The binding modes of 8g and 9g as well as the two RORγt inverse agonists accidentally discovered were also discussed. Image 1 • A series of tetrahydroquinolines and benzomorpholines was discovered as novel RORγt agonists. • The structure-activity relationships of the left-hand-side moiety, linker and right-hand-side moiety were explored. • The representative lead compounds 8g and 9g showed greatly increased RORγt agonistic activity in dual FRET assay. • 8g and 9g also performed good RORγt agonistic effect in Gal4 reporter gene assay and Th17 cell differentiation assay. • The binding modes of 8g and 9g in RORγt ligand binding domain were discussed by docking studies. [ABSTRACT FROM AUTHOR]

1-Methylpyrene (1-MP) is a ubiquitous environmental pollutant and rodent carcinogen. Its mutagenic activity depends on sequential activation by various CYP and sulfotransferase (SULT) enzymes. Previously we have observed induction of micronuclei and mitotic arrest by 1-MP in a Chinese hamster (V79)-derived cell line expressing both human CYP1A2 and SULT1A1 (V79-hCYP1A2-hSULT1A1), however, the mode of chromosome damage and the involvement of mitotic tubulin structures have not been clarified. In this study, we used immunofluorescent staining of centromere protein B (CENP-B) with the formed micronuclei, and that of β- and γ-tubulin reflecting the structures of mitotic spindle and centrioles, respectively, in V79-hCYP1A2-hSULT1A1 cells. The results indicated that 1-MP induced micronuclei in V79-hCYP1A2-hSULT1A1 cells from 0.125 to 2 μM under a 24 h/0 h (exposure/recovery) regime, while in the parental V79-Mz cells micronuclei were induced by 1-MP only at concentrations ≥ 8 μM; in both cases, the micronuclei induced by 1-MP were predominantly CENP-B positive. Following 54 h of exposure, 1-MP induced mitotic spindle non-congression and centrosome amplification (multipolar mitosis) in V79-hCYP1A2-hSULT1A1 cells, and anaphase/telophase retardation, at concentrations ≥ 0.125 μM with concentration-dependence; while in V79-Mz cells it was inactive up to 8 μM. This study suggests that in mammalian cells proficient in activating enzymes 1-MP may induce chromosome loss and mitotic disturbance, probably by interfering with the mitotic spindle and centrioles. 1-Methylpyrene is potently aneugenic in metabolism-proficient mammalian cells. 1-Methylpyrene may disrupt mitotic apparatus by interfering with tubulin. 1-Methylpyrene may retard mitotic progression. [ABSTRACT FROM AUTHOR]

GSK805 (1) is a potent RORγt inverse agonist, but a drawback of 1 is its low solubility, leading to a limited absorption in high doses. We have explored detailed structure-activity relationship on the amide linker, biaryl and arylsulfonyl moieties of 1 trying to improve solubility while maintaining RORγt activity. As a result, a novel series of carboxyl-containing biaryl urea derivatives was discovered as potent RORγt inverse agonists with improved drug-like properties. Compound 3i showed potent RORγt inhibitory activity and subtype selectivity with an IC 50 of 63.8 nM in RORγ FRET assay and 85 nM in cell-based RORγ-GAL4 promotor reporter assay. Reasonable inhibitory activity of 3i was also achieved in mouse Th17 cell differentiation assay (76% inhibition at 0.3 μM). Moreover, 3i had greatly improved aqueous solubility at pH 7.4 compared to 1 , exhibited decent mouse PK profile and demonstrated some in vivo efficacy in an imiquimod-induced psoriasis mice model. Image 1 • A series of carboxyl-containing biaryl ureas was discovered as novel RORγt inverse agonists. • 3i exhibited greatly improved aqueous solubility compared to the lead compound 1 (GSK805). • 3i showed potent RORγt inhibitory activity in FRET assay and in Th17-cell based assay. • 3i demonstrated good in vivo PK profile in mice and in vivo efficacy in IMQ-induced psoriasis mice model. [ABSTRACT FROM AUTHOR]

Polychlorinated biphenyls (PCBs) are persistent organic pollutants with human carcinogenicity. Many lower chlorinated and non-dioxin-like PCBs have been observed to be mutagenic following activation by human CYP2E1, while activation of dioxin-like (DL-) PCBs by this enzyme has never been evidenced. In this study, each DL-PCB was analyzed by molecular docking to human CYP2E1 protein for predicting a substrate interaction. All compounds demonstrated high affinities with the active site of human CYP2E1, binding energy being −8.7 ∼ −9.7 kcal/mol. However, most compounds demonstrated ligand-heme distances as ≥ 6.8 Å, while the values for 2,3,3′,4,4′- (PCB 105) and 2,3′,4,4′,5-pentachlorobiphenyl (PCB 118) were 5.3 and 5.4 Å, respectively (valid for electron transfer). Experimentally, both PCB 105 and 118 induced micronuclei in a V79-derived cell line engineered for expression of human CYP2E1 at low micromolar concentrations, while inactive or weakly positive in V79-Mz control cells; these effects were blocked or reduced by 1-aminobenzotriazole, a suicide CYP inhibitor. However, DL-PCBs 77, 81 and 126 were all negative in both cell lines. In a human hepatoma (C3A) cell line, PCB 105 and 118 induced micronuclei marginally, while with ethanol pretreatment (to stabilize CYP2E1) both compounds induced micronuclei efficiently, and co-exposure to trans -1,2-dichloroethylene (a selective CYP2E1 inhibitor) led to clearly negative results with both compounds. Finally, both PCB 105 and 118 induced PIG-A gene mutations in C3A cells, which was blocked by trans -1,2-dichloroethylene. In summary, in silico and experimental results consistently suggest that DL- PCBs 105 and 118 may be activated by human CYP2E1 for mutagenic activities. [ABSTRACT FROM AUTHOR]