Study on Temperature Distribution and Smoke Spreading Behavior of Different Fire Source Locations in the UnderwaterW-Shaped Island-Crossing Tunnel

Called island-crossing tunnels,some specific underwater tunneling projects face constraints imposed by geological and water conditions,necessitating their passage through artificial or natural islands.The longitudinal of the tunnel follows aW-shaped distribution.The congestion situation does not allowfor immediate longitudinal smoke exhaust at the early stage of the fire,and the natural spread of smoke is complicated.An exhaustive investigation was carried out to analyze the smoke behaviors during a fire incident,employing the fire dynamics software FDS,considering five slopes and four fire locations.The simulation results reveal that the layer of high-temperature smoke becomes thicker as one gets closer to the fire source.The thermal pressure difference significantly impacts the temperature distribution within the tunnel and the distance of smoke spread.The value of the thermal pressure difference is significantly affected by changes in slope.It reaches a maximum of 157 Pa at a 5%slope,while it is only 41 Pa at a 1%slope when the fire occurs at the V-point.Fire hazards vary across locations within the W-shaped tunnel,necessitating separate consideration of the V-point and inverted V-point fire characteristics.The mass flow rate in small and large slope tunnels shows different decay rates due to variations in the main forces acting on the movement.Hence,two equations have been developed to predict the smoke mass flow rate,indicating a nonlinear relationship with the tunnel slope and the distance fromthe fire source.The tunnel slope inversely affects the smoke mass flowrate at the same location.The results can be utilized as a reference for conducting evacuation operations and aiding rescues during aW-shaped tunnel fire.

Study on the Influence of Setting Parameters of Tunnel Centralized Smoke Extraction System on Fire Smoke Flow and Temperature Decay

The centralized smoke exhaust system of shield tunnel is an important determinant for tunnel fire safety,and the use of different design parameters of the tunnel smoke exhaust system will affect the smoke exhaust effect in the tunnel,and the influence of different design parameters on the smoke exhaust effect and temperature attenuation of the tunnel can help engineers in designing a more effective centralized smoke exhaust system for the tunnel.In this paper,the Fire Dynamic Simulator(FDS)is utilized to examine smoke exhaust vent settings for a centralized exhaust system in shield tunnel with both flat and sloped conditions,including slopes of+4.5%and−4.5%,under a 30MWfire power with a 150m^(3)/s smoke exhaust rate.The results suggest that maintaining a vent spacing of 60m and a vent size of 4.0 m×1.5 m is a reasonable configuration for centralized smoke exhaust systems in both flat and slope shield tunnels.This choice helpsminimize construction costs and prevent excessive smoke accumulation.It also promotes favorable conditions for maintaining temperature distribution at 2-m height,visibility,smoke spread distance,and temperature below the ceiling,all below the threshold values,while ensuring high smoke extraction efficiency.However,in the slope section,the chimney effect can disrupt exhaust efficiency,visibility,ceiling temperature,and temperature distribution at a height of 2 m.Employing different opening methods,such as having 2 vents up and 4 vents down in a+4.5%slope and 4 vents up and 2 vents down in a−4.5%slope,can help mitigate these effects.Furthermore,the temperature decay formula for shield tunnels follows a bi-exponential decay pattern,and different design parameters of centralized smoke exhaust systems have minimal effects on temperature decay in shield tunnels.

Pyramiding of multiple genes generates rapeseed introgression lines with clubroot and herbicide resistance, high oleic acid content, and early maturity

Clubroot and herbicide resistance,high oleic acid(OA)content,and early maturity are targets of rapeseed(Brassica napus L.)breeding.The objective of this study was to develop new male-fertility restorer lines by pyramiding favorable genes to improve these traits simultaneously.Seven elite alleles for the four traits were introduced into the restorer line 621R by speed breeding with marker-assisted and phenotypic selection.Six introgression lines(ILs)were developed with four-to seven-gene combinations and crossed with two elite parents to develop hybrids.All ILs and their corresponding hybrids displayed high resistance to both clubroot pathotype 4 and sulfonylurea herbicides.Three ILs and their hybrids showed large increases in OA contents and four showed earlier maturity.These new ILs may be useful in rapeseed hybrid breeding for the target traits.

Syntheses of phenyl benzoate compounds and their bioactivity investigation

Eight phenyl benzoate compounds were synthesized in one step, and then their antioxidant, anti-tyrosinase, and anti-pancreatic lipase activities were evaluated in the present study. The total yields ranged from 31% to 85%. Compound 4 c exhibited a stronger antioxidant activity compared with Trolox, with half maximal inhibitory concentrations(IC50) of approximately 13.06 μM, and the antioxidant mechanism was further studied using computational chemistry. Compounds 1 c–5 c exhibited minimal anti-tyrosinase activity. Compounds 4 c, 5 d, 6 c and 6 d exhibited weak anti-pancreatic lipase activity, with an inhibition rate of 33.52%, 15.76%, 18.37% and 20.77%, respectively. These results demonstrated that all compounds had reference significance, especially compound 4 c.

Sarcopenic obesity in liver disease: Handling both sides of the penny

Skeletal muscle and fat tissue show distinct pathophysiological roles and pivotal functions.The culmination of muscle wasting and fat accumulation represents an opposite terminal of each state.Specifically,this situation has been designated as sarcopenic obesity.However,sarcopenic obesity still lacks a unanimous definition,diagnostic criteria,and generalized modalities for assessment in the context of versatile liver diseases.Moreover,the underpinning mechanisms by which a combination of abnormal skeletal muscle and fat tissue leads to the progression of liver disease and impairs health‐related consequences are still elusive.Additionally,the interplay between skeletal muscle and fat,and the driving factors that shift different body compositions are not well understood.Therefore,in this review,we discuss skeletal muscle and fat components,with the purpose of conceptualization,as well as interpret their roles in liver diseases.We focus on the definitions,diagnostic criteria,and currently available measurements for sarcopenic obesity in the literature.We comprehensively discuss recent data and evidence regarding the potential role of sarcopenic obesity in the development and progression of numerous liver diseases and associated conditions,including nonalcoholic fatty liver disease,chronic viral hepatitis,cirrhosis,and liver transplantation.Furthermore,explicit information related to the pathogenesis of sarcopenic obesity from basic research is also provided in this narrative review.Finally,we discuss,from the clinical perspective of view,how to manage sarcopenic obesity using nutritional,physical,and pharmacological methods.

Synthesis of prenylated and geranylated xanthones and their bioactivities

Nine prenylated and geranylated xanthones were synthesized in two steps with total yields ranging from 11%to 36%.All of the compounds were first reported.Then,the antitumor,anti-tyrosinase,anti-pancreatic lipase,antifungal and antibacterial activities of all or part of compounds 1–9 were evaluated.Compound 9 exhibited clear antitumor activity,and its cytotoxicity against MCF-7 and MDA-MB-231 cells was stronger compared with cisplatin.Compounds 1–4 and 6–7 also exhibited certain activity other than the antitumor activity described above.These results demonstrated that compounds 1–4,6–7 and 9 were very promising leads for further structural modification.

Foliar application of strigolactones improves the desiccation tolerance,grain yield and water use efficiency in dryland wheat through modulation of non-hydraulic root signals and antioxidant defense

Non-hydraulic root signals(nHRS)are affirmed as a unique positive response to soil drying,and play a crucial role in regulating water use efficiency and yield formation in dryland wheat production.Strigolactones(SLs)can enhance plant drought adaptability.However,the question of whether strigolactones enhance grain yield and water use efficiency by regulating nHRS and antioxidant defense systems in dryland wheat remains unanswered.In this study,pot experiments were conducted to investigate the effects of strigolactones on nHRS,antioxidant defense system,and grain yield and water use efficiency in dryland wheat.The results showed that external application of SLs increased drought-induced abscisic acid(ABA)accumulation and activated an earlier trigger of nHRS at 73.4% field capacity(FC),compared to 68.5%FC in the control group(CK).This phenomenon was mechanically associated with the physiological mediation of SLs.The application of SLs significantly enhanced the activities of leaf antioxidant enzymes,reduced ROS production,and mitigated oxidative damage to lipid membrane.Additionally,root biomass,root length density,and root to shoot ratio were increased under strigolactone treatment.Furthermore,exogenous application of SLs significantly increased grain yield by 34.9%under moderate drought stress.Water use efficiency was also increased by 21.5% and 33.3% under moderate and severe drought conditions respectively,compared to the control group(CK).The results suggested that the application of strigolactones triggered earlier drought-sensing mechanism and improved the antioxidant defense ability,thus enhancing grain yield and water use efficiency in dryland wheat production.

Dissecting the Contributing Role of Divergent Adipose Tissue to Multidimensional Frailty in Cirrhosis

Background and Aims:Emerging evidence has demonstrated that abnormal body composition may potentiate the development of frailty,whereas little work focuses on the role of divergent adipose tissue.Therefore,we aimed to determine the potential contribution of adipose tissue distribution to multidimensional frailty in decompensated cirrhosis.Methods:We conducted a retrospective cohort study.Divergent adipose tissues were assessed by computed tomography-derived subcutaneous adipose tissue index(SATI),visceral adipose tissue index(VATI)and total adipose tissue index(TATI),respectively.Frailty was identified by our validated self-reported Frailty Index.Multiple binary logistic models incorporating different covariates were established to assess the relationship between adipose tissue distribution and frailty.Results:The study cohort comprised 245 cirrhotic patients with 45.3%being male.The median Frailty Index,body mass index(BMI)and model for end-stage liver disease(MELD)score were 0.11,24.3 kg/m2 and 8.9 points,respectively.In both men and women,patients who were frail exhibited lower levels of SATI in comparison with nonfrail patients.SATI inversely correlated with Frailty Index in the entire cohort(rs=−0.1361,p=0.0332).Furthermore,SATI or TATI was independently associated with frail phenotype in several multiple logistic regression models adjusting for age,BMI,presence of ascites,sodium,Child-Pugh class or MELD score in isolation.Conclusions:In the context of decompensated cirrhosis,low SATI and concomitant TATI were associated with higher risk of being frail.These findings highlight the importance to further apply tissue-specific tools of body composition in place of crude metric like BMI.