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The chemical investigation of the EtOAc extract from the solid rice medium cultured with a sponge-associated fungus

The aim of this study was to investigate the extraction of antibacterial substances from Galla chinensis (ASGC) that act against the aquatic pathogen Vibrio harveyi, to identify the chemical composition and explore the mechanism of action. The optimal extraction process was as follows: anhydrous methanol, liquid/material ratio (mL/g) 26:1, extraction temperature 98 °C and extraction time 157 min. The diameter of the inhibition zones (21.31 ± 0.51 mm) under the optimal conditions agreed with the predicted value by experimental rechecking. The yield of ASGC was 39.39% ± 0.69%, and two compounds including gallic acid (GA) and penta-O-galloyl-β-d-glucose (5GG) were identified in ASGC. The minimal inhibitory concentration (MIC) values of ASGC and GA were 0.50 and 0.25 mg/mL, respectively. Meanwhile, 5GG and other chemical constituents did not exert antibacterial activities against V. harveyi (MICs > 1 mg/mL). Further investigation of the mechanisms of action of ASGC and GA against V. harveyi revealed their strong destructive effects on the growth of bacterial cells, the integrity and permeability of the cell membrane, and morphological alterations. The report provides a favorable prospect of GA as a potential control agent against V. harveyi in aquaculture.

The chemical investigation of the EtOAc extract from the solid rice medium cultured with a sponge-associated fungus Penicillium sp. SCSIO41033 led to the isolation of two quinolones including a new one, penicinolone (1), three xanthone derivatives (3–5), and four anthraquinones (6–9). Their structures were determined by comprehensive analysis of 1H and 13C NMR, COSY, HSQC, and HMBC spectroscopic, and HRESIMS mass spectrometric data. The bioactive assays revealed that compounds 1 and 2 showed no antimicrobial activities against five bacteria and eight fungi, and compounds 5, 8 and 9 exhibited inhibition against AChE with IC50 values of 45.9, 42.5 and 40.5 μg/mL. Molecular docking analysis was performed to explore the interactions between active molecules and AChE protein, which indicated that xanthone and anthraquinone derivatives had the potential for developing AChE inhibitors.

High-strength concrete can effectively reduce the cross-sectional size, increase space usage, and cut material costs. To analyze the mechanical properties of high-strength concrete vertical members, various confinement models have been proposed to define the ties-confined concrete stress–strain relationship. However, most existing models are divided into ascending and descending segments. These are continuous but not derivable at the peak point, which does not facilitate numerical calculations. Moreover, these models have a large number of parameters that are mostly obtained based on the fitting of experimental data, which may also lead to the limited applicability of the models. In this study, existing confinement models for high-strength concrete under axial compression are reviewed, and the differences between the models are discussed. Based on the results of normal triaxial experiments on high-strength concrete and the test data from other studies on ties-confined concrete columns, the effective confinement coefficient and empirical formula of ties strain at the peak stress of confined concrete are proposed. A confinement model is proposed based on the continuous derivable function, and it is validated based on the available experimental data. Results show that the proposed model can reflect the stress–strain relationship of the test specimens more simply while keeping the basic accuracy with other models.

In order to reduce the detention time of ships in the port, make full use of port resources and optimize port services. This paper analyzes the factors that affect the efficiency of the dispatching of ships entering and leaving the port, and studies the coordinated dispatching of multiple ship types and multiple berth types. Based on the proposed hypothesis, with the minimum total scheduling time and the minimum waiting time as the optimization goals, a coordinated scheduling model for berth allocation and channel was established. Based on the NSGA-II algorithm, a multi-objective optimization genetic algorithm suitable for solving the model of berth allocation and channel coordination scheduling is designed. By testing the intensive ship entry and exit data in a short period of time, the solution efficiency and stability of the algorithm in this paper are better than those of the NSGA-II algorithm, and it is more suitable for solving the optimization problem of berth allocation and channel coordination scheduling.

Two-stage ORC (Organic Rankine Cycle) is a very competitive configuration. However, most of the works have narrowed the studies within a single or just several fluids in spite of the great effect of working fluids on system performance. In this paper, 400 combinations of working fluids are investigated. The evaporation and condensation pressures of both the high and low temperature ORCs are optimized by PSO (Particle Swarm Optimization) with the objective function of maximum exergy efficiency. The results show that the effect of fluid1 on the system exergy efficiency is much greater than that of fluid2. Critical temperature is a key indicator for fluid1 selection and triple point temperature is a crucial indicator for fluid2 selection. The largest exergy destruction occurs in the condenser of cycle II. The proper solution to reduce this exergy destruction is raising the inlet temperature of LNG, rather than lowering the condensation temperature of cycle II.

NG (Natural gas) distribution pressure varies in a wide range in different applications and has significant effect on system exergy efficiency. RC (Rankine cycle) and DEC (direct expansion cycle) can utilize the cold and pressure exergies of LNG (liquefied natural gas), respectively. In this paper, SRC (single-stage RC), PTRC (parallel two-stage RC) and CTRC (cascade two-stage RC) with and without DEC are optimized by Particle Swarm Optimization and compared to obtain the optimal configurations for different NG distribution pressures. Propane, propylene, ethane and ethylene are adopted as the working fluids. The results show that the addition of DEC could increase the exergy efficiency by lifting the evaporation temperature of LNG. CTRC + DEC with propane/ethylene and CTRC + DEC with propane/ethane as the working fluid achieve the largest exergy efficiencies of 23.89% and 18.25% at NG distribution pressures of 1 MPa and 2 MPa, respectively. PTRC + DEC with propane/ethane is the optimal system with maximum exergy efficiencies of 15.18%, 13.24%, 11.7% and 10.4% at NG distribution pressures of 3, 4, 5 and 6 MPa, respectively. PTRC + DEC with ethane as the working fluid in both cycles is a generally suitable system for all NG distribution pressures with high efficiency and only one type of working fluid.

This paper focuses on a novel strengthening method for stone beams. An experimental study on the flexural behavior of six full scale stone beams, including three beams unstrengthened and three beams strengthened with a combination of angle steels and PET (polyethylene terephthalate plastic) belts, was performed. The failure modes, flexural capacity, deformability, and influence of different types and dimensions of stones, along with the different specifications of angle steels on the flexural behavior, were analyzed. The experimental results indicated that: unstrengthened greenish white marble beams exhibited a typical brittle failure mode, and unstrengthened white marble beams with better deformation properties exhibited a non-fully brittle failure mode; each of the strengthened stone beams exhibited a non-fully brittle failure mode. Furthermore, the flexural capacity and deformation capacity of the strengthened stone beams were improved to some extent. After the ultimate load, strengthened stone beams still had a certain flexural capacity, namely the flexural capacity margin, because of the action of angle steels. A theoretical analysis of the flexural capacity of stone beams was conducted, and a simplified calculation formula of the ultimate flexural capacity and flexural capacity margin was proposed.

Response surface optimization was applied for the extraction of antibacterial substances from Rhubarb (ASR) against aquatic pathogenic Vibrio harveyi. Based on the experimental results of single factors, the optimal extraction conditions were determined by Box–Behnken design combined with response surface methodology with conditions: 100% ethanol as extraction solvent, liquid/material ratio of 29 mL/g and extraction temperature at 88 °C for 148 min. The factual value of inhibition zones can reach 21.31 ± 0.95 mm and is not different from the predicted value (21.74 mm), which showed that the response surface methodology applied to the extraction optimization of antibacterial substances from Rhubarb against V. harveyi is feasible. Moreover, the yield of ASR was 30.29 ± 2.27%. Five compounds, namely, aloe-emodin, rhein, emodin, chrysophanol and physcion, were identified in ASR by comparing the HPLC chromatogram of the reference mixtures and the sample. Contents of the five compounds were 0.68 ± 0.02, 0.24 ± 0.05, 0.78 ± 0.07, 6.68 ± 0.97 and 0.58 ± 0.15%, respectively. The minimal inhibitory concentration (MIC) values of ASR, aloe-emodin, rhein, emodin, chrysophanol and physcion were 0.625, 0.125, 0.015, > 1, > 1, and > 1 mg/mL, respectively, which indicated that aloe-emodin and rhein are the main antibacterial compounds of Rhubarb.

Natural gas is considered as a green fuel due to its low environmental impact. LNG contains a large amount of cold exergy and must be regasified before further utilization. ORC (Organic Rankine Cycle) has been proven to be a promising solution for both low grade heat utilization and LNG cold exergy recovery. Due to the great temperature difference between the heat source and LNG, the efficiency of one-stage ORC is relatively small. Hence, some researchers move forward to a two-stage Rankine cycle. Working fluid plays a quite important role in the cycle performance. Working fluid selection of a two-stage ORC is much more challenging than that of a single-stage ORC. In this paper, a two-stage ORC is studied. Heat source temperatures of 100,150 and 200°C are investigated. 20 substances are selected as potential candidates for both the high and low Rankine cycles. The evaporating, condensing and turbine inlet temperatures of both Rankine cycles are optimized by PSO (Particle Swarm Optimization). The results show that the best combination for heat source temperature of 100°C is R161/R218 with the maximum exergy efficiency of 35.27%. The best combination for 150°C is R161/RC318 with the maximum efficiency of 37.84% and ammonia/ammonia with the maximum efficiency of 39.15% for 200°C. Fluids with intermediate critical temperature, lower triple point temperature and lower normal boiling temperature are good candidates.

A high-performance liquid chromatographic method has been developed for the simultaneous analysis of the flavonols myricitrin (1), avicularin (2), and juglanin (3) in rat plasma and urine after oral administration of the total flavonoids from Polygonum aviculare. Samples were prepared by solid-phase extraction then separated on a C18 reversed-phase column by use of a mobile-phase gradient prepared from methanol and aqueous formic acid solution. The flow rate was 1 mL min−1. Detection was performed at 254 nm. The calibration range was 11–1,100 μg mL−1 for both 2 and 3 in plasma; in urine the calibration ranges for 1, 2, and 3 were 32–1,600, 11–1,100, and 22–1,100 μg mL−1, respectively. Intra-day and inter-day RSD were less than 4.33 and 3.62% for 2 and 3, respectively, in plasma, and no more than 4.03 and 2.22% for all the analytes in urine. The analytical sensitivity and selectivity of the assay enabled successful application to pharmacokinetic studies of flavonols 1–3 in rats.