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Ethereum smart contracts are a special type of computer programs. Once deployed on the blockchain, they cannot be modified. This presents a significant challenge to the security of smart contracts. Previous research has proposed static and dynamic detection tools to identify vulnerabilities in smart contracts. These tools check contract vulnerabilities based on predefined rules, and the accuracy of detection strongly depends on the design of the rules. However, the constant emergence of new vulnerability types and strategies for vulnerability protection leads to numerous false positives and false negatives by tools. To address this problem, we analyze the characteristics of vulnerabilities in smart contracts and the corresponding protection strategies. We convert the contracts' bytecode into an intermediate representation to extract semantic information of the contracts. Based on this semantic information, we establish a set of detection rules based on semantic facts and implement a vulnerability detection tool SafeCheck using static program analysis methods. The tool is used to detect six common types of vulnerabilities in smart contracts. We have extensively evaluated SafeCheck on real Ethereum smart contracts and compared it to other tools. The experimental results show that SafeCheck performs better in smart contract vulnerability detection compared to other typical tools, with a high F‐measure (up to 83.1%) for its entire dataset. [ABSTRACT FROM AUTHOR]

• n-TiO 2 aggravated developmental toxicity of DBP in zebrafish larvae. • n-TiO 2 enhanced DBP-induced oxidative damage in zebrafish larvae. • Co-exposure of DBP and n-TiO 2 leads to severe nerve damage and massive apoptosis. • Co-exposure exacerbates amino acid metabolism disorder and disrupts lipid metabolism. Dibutyl phthalate (DBP) is a commonly used plasticizer that is frequently detected in water samples due to its widespread use. Titanium dioxide nanoparticles (n-TiO 2) have been found to enhance the harmful effects of organic contaminants by increasing their bioavailability in aquatic environments. However, the combined toxic effects of DBP and n-TiO 2 on aquatic organisms remain unclear. This study aimed to investigate the neurotoxicity of DBP and n-TiO 2 synergistic exposure during the early life stage of zebrafish. The results of the study revealed that co-exposure of DBP and n-TiO 2 led to an increase in deformities and a significant reduction in the active duration of zebrafish larvae. Furthermore, the co-exposure of DBP and n-TiO 2 resulted in elevated levels of oxidative stress and altered gene expression related to neurodevelopment and apoptosis. Notably, n-TiO 2 exacerbated the oxidative damage and apoptosis induced by DBP alone exposure. Additionally, co-exposure of the 1.0 mg/L DBP and n-TiO 2 significantly affected the expression of genes associated with neurodevelopment. Moreover, disturbances in amino acid metabolism and interference with lipid metabolism were observed as a result of DBP and n-TiO 2 co-exposure. In general, n-TiO 2 aggravated the neurotoxicity of DBP in the early life stage of zebrafish by increasing oxidative stress, apoptosis, and disrupting amino acid synthesis and lipid metabolism. Therefore, it is essential to consider the potential risks caused by DBP and nanomaterials co-existence in the aquatic environment. [Display omitted] [ABSTRACT FROM AUTHOR]

Due to the worldwide outbreak of COVID-19, many strategies and models have been put forward by researchers who intend to control the current situation with the given means. In particular, compartmental models are being used to model and analyze the COVID-19 dynamics of different considered populations as Susceptible, Exposed, Infected and Recovered compartments (SEIR). This study derives control-oriented compartmental models of the pandemic, together with constructive control laws based on the Lyapunov theory. The paper presents the derivation of new vaccination and quarantining strategies, found using compartmental models and design methods from the field of Lyapunov theory. The Lyapunov theory offers the possibility to track desired trajectories, guaranteeing the stability of the controlled system. Computer simulations aid to demonstrate the efficacy of the results. Stabilizing control laws are obtained and analyzed for multiple variants of the model. The stability, constructivity, and feasibility are proven for each Lyapunov-like function. Obtaining the proof of practical stability for the controlled system, several interesting system properties such as herd immunity are shown. On the basis of a generalized SEIR model and an extended variant with additional Protected and Quarantined compartments, control strategies are conceived by using two fundamental system inputs, vaccination and quarantine, whose influence on the system is a crucial part of the model. Simulation results prove that Lyapunov-based approaches yield effective control of the disease transmission. [ABSTRACT FROM AUTHOR]

Largemouth bass virus (LMBV) infections has resulted in high mortality and economic losses to the global largemouth bass industry and has seriously restricted the healthy development of the bass aquaculture industry. There are currently no antiviral therapies available for the control of this disease. In this study, we developed three types of vaccine against LMBV; whole virus inactivated vaccine (I), a subunit vaccine composed of the major viral capsid protein MCP (S) as well as an MCP DNA vaccine(D), These were employed using differing immunization and booster strategies spaced 2 weeks apart as follows: II, SS, DD and DS. We found that all vaccine groups induced humoral and cellular immune responses and protected largemouth bass from a lethal LMBV challenge to varying degrees and DD produced the best overall effect. Specifically, the levels of specific IgM in serum in all immunized groups were elevated and significantly higher than those in the control group. Moreover, the expression of humoral immunity (CD4 and IgM) and cellular immunity (MHCI-α) as well as cytokines (IL-1β) was increased, and the activity of immunity-related enzymes ACP, AKP, LZM, and T-SOD in the serum was significantly enhanced. In addition, the relative percent survival of fish following an LMBV lethal challenge 4 weeks after the initial immunizations were high for each group: DD(89.5 %) , DS (63.2 %),SS(50 %) and II (44.7 %). These results indicated that the MCP DNA vaccine is the most suitable and promising vaccine candidate for the effective control of LMBV disease. • DNA, subunit and inactivated vaccines against LMBV induced differential humoral and cellular immune responses. • The DNA prime-protein boost immunization strategy didn't show the potential advantage over a solo vaccination. • DNA, subunit and inactivated vaccines against LMBV all resulted in significant increases in survival. • DNA vaccines are significantly better than others and show great application prospects. [ABSTRACT FROM AUTHOR]

[Display omitted] • A full-spectrum solar-driven trigeneration system is proposed. • An optimization model for maximizing environmental benefit is developed. • The performance of the system throughout the year is analyzed in a case. • The annual energy and exergy efficiencies reach 66.97% and 8.27%. • The system reduces carbon dioxide emission by 41.75 %. Solar-driven trigeneration systems do not consume any fossil fuels and can output cooling, heating, and electricity independently, which effectively reduces environmental pollution and improves solar energy utilization. However, the traditional solar-driven trigeneration system only utilizes part of the solar spectrum, resulting in significant heat losses. Therefore, a new full-spectrum solar-driven trigeneration system integrated with an organic Rankine cycle is proposed to improve solar energy utilization efficiency. Applied the Engineering Equation Solver, the thermodynamic models of the trigeneration system are established, and the effects of some key parameters on thermodynamic performance are discussed. Additionally, the thermal allocation ratio is optimized to maximize the environmental benefits of the system. The simulation results indicate that solar to electric efficiency, energy efficiency, and exergy efficiency are positively correlated with the cut-off wavelength of norbornadiene. When the thermal allocation ratio is 0.3, the system has the most significant environmental benefit. The annual solar to electric efficiency, annual energy and exergy efficiencies reach 3.80%, 66.97%, and 8.27%, respectively. Compared with the reference system, both the carbon dioxide emission and primary energy consumption are reduced by 41.75%, demonstrating that the proposed system effectively improves the utilization of solar energy. [ABSTRACT FROM AUTHOR]

Accompanied with restriction of legacy per- and polyfluoroalkyl substances (PFASs), numbers of emerging PFASs are widely detected in the environment. However, information on environmental occurrences and behaviors of emerging PFASs were scarce in agricultural soils. In this study, the spatial distributions, sources, substitution trends and ecological risk assessment of 31 legacy and emerging PFASs were investigated in 69 agricultural soils from Fuxin, North China. The 26 out of 31 PFASs were detected with concentrations of 57.36 - 1271.06 pg/g dry weight. Perfluorooctanoic acid (PFOA) and hexafluoropropylene oxide dimer acid (HFPO-DA) were predominant in legacy and emerging PFASs, respectively. Based on principal component and dual carbon-nitrogen stable isotope analysis, atmosphere, fluorochemical activities and river irrigation were main sources of PFASs. Substitution trends indicated HFPO-DA and short chain perfluoroalkyl carboxylic acids (C 4 - C 7) as main alternatives of PFOA, and 6:2 fluorotelomer sulfonic acid (6:2 FTSA) and sodium p -perfluorous nonenoxybenzene sulfonate (OBS) as major substitutes to perfluorooctanesulfonic acid (PFOS). The calculated risk quotient values (< 0.006) only indicated potential low ecological risk of 7 target PFASs in agricultural soils. The results of this study broadened out the information of PFAS contamination in agricultural soils, which were significant for PFAS supervision in China. [Display omitted] • 31 legacy and emerging PFASs were analyzed in 69 agricultural soils from North China. • Region-specific distributions were disclosed for legacy and emerging PFASs. • PFOA and HFPO-DA were dominant congeners of legacy and emerging PFASs, respectively. • Atmosphere, fluorochemical activities and river irrigation were the main sources of PFASs. • HFPO-DA and 6:2 FTSA were main alternatives of PFOA and PFOS, respectively. [ABSTRACT FROM AUTHOR]

Demand-side management (DSM) can transfer the dynamic fluctuations of load to match the renewable energy sources and realize the interaction of source-load. In most existing combined cooling heating and power (CCHP) system scheduling, user-side and system-side resources are independently optimized to achieve optimum economic performances without efficiently combining resources. In this paper, the devices with adjusted loads on the system-side and the user-side are integrated to construct generalized energy storage (GES) model, including traditional flexible resources, batteries, electric vehicles, cooling and heating load response, and electro-to-thermal conversion devices. Then, the GES model is integrated into the system for optimization including economy, load fluctuation, energy efficiency, and exergy efficiency. A case study demonstrates the application of the proposed method. The scheduling results of four DSM cases under different objectives are comprehensively obtained and compared. The optimized schemes are assessed in multi-dimension decision-making method and the effects of objective weights on decision results are analyzed. The simulation results illustrate that the load variation is decreased by 54% to obtain a smooth electrical load, resulting in the stable operation of equipment and improving the security and stability of the CCHP system. The exergy efficiency, energy efficiency, and economy performances through the DSM optimization are improved by up to 8.7%, 2.5%, and 2.4%, respectively. The system optimized with the objective of load fluctuation achieves the highest score in the TOPSIS decision-making scenarios and has the best comprehensive performance. [Display omitted] • A multi-dimension day-ahead scheduling optimization model is proposed. • The transformation model between rigid and flexible electric load is built. • The multi-dimensional performance indicators are applied to demand response. • The load variance index has the most prominent performance improvement, 54%. • The exergy efficiency, energy efficiency and cost boosted by 8.7%, 2.5% and 2.4%, respectively. [ABSTRACT FROM AUTHOR]

Penthiopyrad was extensively applied in agricultural production, however, the toxicities information of the penthiopyrad enantiomers on early life stages of aquatic organism were limited. This study investigated the enantioselective toxicity of penthiopyrad on the early life stage of zebrafish by acute toxicity, sublethal toxic effects and the mRNA relative expression levels of genes related to succinate dehydrogenase, cardiac development, and lipid metabolism. The results showed that the 96-h-LC 50 of penthiopyrad racemate and enantiomers to zebrafish embryos were Rac-: 2.784 mg/L; R-(−)-: 3.528 mg/L; S-(+)-: 1.882 mg/L. Penthiopyrad exposure induced autonomous movement abnormalities, slowed heart rate and delayed hatching in zebrafish embryos, and caused developmental toxic effects such as pericardial edema and yolk sac edema. The mRNA relative expression levels results showed that penthiopyrad exposure induced significant enantioselectivity effect for the expression of the Sdha , Pr1 and Nkx2.5 with a 1.94–4.98-fold difference between different enantiomers, and significantly affected succinate dehydrogenase (energy metabolism), lipid metabolism and cardiac development-related genes expression. In general, S-(+)-penthiopyrad induced higher toxic effects in zebrafish embryos, and mitochondrial dysfunction may be an important cause of abnormal development. This study contributed to improve the comprehensive risk assessment and enantiomeric research system of penthiopyrad to early life stage of zebrafish. [Display omitted] • Penthiopyrad had enantioselectivity developmental toxicity on zebrafish embryos. • Penthiopyrad had enantioselectivity toxicity on zebrafish embryos at mRNA level. • S-(+)-penthiopyrad induced higher embryotoxicity in zebrafish. • Mitochondrial function barrier could be the potential toxic mechanism. [ABSTRACT FROM AUTHOR]

The effects of different multi-walled carbon nanotubes on the enantioselective bioaccumulation and toxicity of the chiral pesticide bifenthrin to zebrafish were investigated in this work. The results showed that MWCNTs and MWCNTs-COOH did not affect the preferential bioaccumulation of 1R -cis-BF in zebrafish following exposure to cis -BF enantiomers for 28 days, but which increased cis -BF accumulation amount by 1.03–1.48 times. Further research demonstrated that the genes related to immunity, endocrine activity and neurotoxicity showed enantioselective expression in different zebrafish tissues, and sex-specific differences were observed. The levels of c-fos, th, syn2a, 17β-hsd and cc-chem were expressed as 1.09–2.84 times higher in females and males treated with 1R -cis-BF than in the 1S -cis-BF-treated groups. However, in the presence of MWCNTs or MWCNTs-COOH, c-fos, th, syn2a, 17β-hsd and cc-chem levels were expressed as 1.53–14.92 times higher in females and males treated with 1S -cis-BF than in 1R -cis-BF-treated groups, which indicated that enantioselective expression was altered. The effects of different types of MWCNTs on the enantioselective bioaccumulation and toxicity of BF in zebrafish have little difference. In summary, the presence of MWCNTs or MWCNTs-COOH increased the impact of BF on zebrafish. Therefore, the risks posed by coexisting nanomaterials and chiral pesticides in aquatic environments should be considered. [Display omitted] • 1 R-cis-bifenthrin preferential bioaccumulation in zebrafish. • MWCNTs/MWCNTs-COOH increased the bioaccumulation amount of bifenthrin in zebrafish. • The toxic effects of bifenthrin on female and male zebrafish were different. • MWCNTs/MWCNTs-COOH changed bifenthrin enantioselective gene expression in zebrafish. • The presence of MWCNTs or MWCNTs-COOH increased the impact of BF on zebrafish. [ABSTRACT FROM AUTHOR]

[Display omitted] • The toxicological effects of mefentrifluconazole were firstly studied in zebrafish. • Mefentrifluconazole caused the enantioselective changes in liver metabonomics. • Mefentrifluconazole induced the enantioselective expression of related genes. • Rac -mfz and (+)-mfz caused more serious toxicological effects than (-)-mfz. • Sex differences were observed in zebrafish liver toxicity. Mefentrifluconazole, a new type of chiral triazole fungicide, is widely applied to control a variety of fungal diseases in crops. However, the toxicological effects of mefentrifluconazole on aquatic organisms are unknown, especially at the enantiomer level. In the present study, zebrafish were selected as a typical model for mefentrifluconazole enantiomer exposure. Metabolomic and transcription analyses were performed with 0.01 and 0.10 mg/L mefentrifluconazole and its enantiomers (i.e., rac -mfz/(-)-mfz/(+)-mfz) at 28 days. The 1H nuclear magnetic resonance (NMR)-based metabolomics analysis showed that 9, 10 and 4 metabolites were changed significantly in the rac -mfz, (+)-mfz and (-)-mfz treatment groups compared with the control group, respectively. The differential metabolites were related to energy metabolism, lipid metabolism and amino acid metabolism. The qRT–PCR analysis revealed that the expression of lipid metabolism-, apoptosis- and CYP-related genes in the livers of female zebrafish in rac -mfz and (+)-mfz was 1.61–108.92 times and 2.37–551.34 times higher than that in (-)-mfz, respectively. The results above indicate that exposure to mefentrifluconazole induced enantioselective liver toxicity in zebrafish. Our study underlined the importance of distinguishing different enantiomers, which will contribute to environmental protection. [ABSTRACT FROM AUTHOR]

The integrated energy system (IES) can effectively utilize the distributed renewable energies, but its performance improvement requires advanced design and optimization methods. This study proposes a new IES based on biomass gasification integrated with an internal combustion engine, photovoltaic and solar collectors, an absorption chiller/heater, a heat pump and a thermal storage unit to utilize renewable energies effectively. Based on the thermodynamic models of components considering off-design conditions, a multi-objective optimization model of biomass IES is established to improve the comprehensive performances of energy, economy, and environment. A decision method is proposed to select the optimal configuration considering the Euclidean distance between the Pareto solution and the ideal solution. The results demonstrate that in the specific case, the capacity of the internal combustion engine with biomass gasification is preferred to be low, and 71.4% of Pareto solutions is less than 200 kW during the set range from 20 to 1,000 kW. The larger capacity of solar photovoltaic panels achieves more benefits than solar heat collectors. Moreover, the optimal IES determined by the minimum Euclidean distance has primary energy utilization efficiency of 43.4% and exergy efficiency of 18.0%, which saves primary energy of 7.1%, the annual total cost of 7.2%, and reduces carbon dioxide emission by 41.5%. • An integrated energy system combining biomass energy and solar energy is designed. • The thermodynamic models of components take into account the off-design conditions. • A multi-objective optimization model of the system is built. • The annual total cost and CO 2 emissions are reduced by 7.2% and 41.5%, respectively. • The performance of the system in multiple time scales is analyzed. [ABSTRACT FROM AUTHOR]

• Integrate wind, solar and geothermal energy into the hybrid CCHP system. • Build a stochastic hierarchy scenario-generation method to depict uncertainty. • Propose a multi-objective stochastic multi-scenarios optimal design method. • Integrate the interaction between the system and the grid into the optimization. • Incorporate the environmental performance into multi-objective optimization. Combined cooling, heating and power (CCHP) system integrated with multiple renewable energies can improve the environmental performance while increasing the dependency on the national grid due to the multiple uncertainties. This paper proposes a multi-objective stochastic multi-scenario optimization method for the optimal capacity of a CCHP system integrated wind, solar and geothermal energy considering its energy supply independence, environmental impact, economic performance and energy efficiency. The spatiotemporal multiple uncertainties in wind velocity, solar irradiation and multiple loads are characterized by the stochastic multi-scenarios generated by the stochastic hierarchy scenario-generation method. The hybrid system's flexibility is evaluated by both the grid integration level and net interaction level. The environmental performance is assessed by both the carbon emission reduction rate and renewable energy penetration. The economic and energy performances are characterized by the annual cost-saving rate and primary energy-saving rate, respectively. The multi-objective stochastic optimal design method is formulated and solved using non-dominated sorting genetic algorithm II. The case study results show that there are slight deviations of objectives between the stochastic multi-scenario and traditional optimizations, while the former can save 58.69% computation time. Moreover, the installed capacity increase of the electrical energy storage to 870kWh can reduce the system's dependency on the national grid and the net interaction level to 3.74% while deteriorating the economic performance and dropping the annual cost-saving rate to −217.37%. Inversely, the installed capacity increase of renewable energy generators can enhance economic and environmental performances while worsening the net interaction level. [ABSTRACT FROM AUTHOR]