Protection Effect and Vacancy of the Ecological Protection Redline: A Case Study in Guangdong–Hong Kong–Macao Greater Bay Area, China

The Ecological Protection Redline (EPR) is an innovative measure implemented in China to maintain the structural stability and functional security of the ecosystem. By prohibiting large-scale urban and industrial construction activities, EPR is regarded as the “lifeline” to ensure national ecological security. It is of great practical significance to scientifically evaluate the protection effect of EPR and identify the protection vacancies. However, current research has focused only on the protection effects of the EPR on ecosystem services (ESs), and the protection effect of the EPR on ecological connectivity remains poorly understood. Based on an evaluation of ES importance, the circuit model, and hotspot analysis, this paper identified the ecological security pattern in Guangdong–Hong Kong–Macao Greater Bay Area (GBA), analyzed the role of EPR in maintaining ES and ecological connectivity, and identified protection gaps. The results were as follows: (1) The ecological sources were mainly distributed in mountainous areas of the GBA. The ecological sources and ecological corridors constitute a circular ecological shelter surrounding the urban agglomeration of the GBA. (2) The EPR effectively protected water conservation, soil conservation, and biodiversity maintenance services, but the protection efficiency of carbon sequestration service and ecological connectivity were low. In particularly, EPR failed to continuously protect regional large-scale ecological corridors and some important stepping stones. (3) The protection gaps of carbon sequestration service and ecological connectivity in the study area reached 1099.80 km2 and 2175.77 km2, respectively, mainly distributed in Qingyuan, Yunfu, and Huizhou. In future EPR adjustments, important areas for carbon sequestration service and ecological connectivity maintenance should be included. This study provides a comprehensive understanding of the protection effects of EPR on ecological structure and function, and it has produced significant insights into improvements of the EPR policy. In addition, this paper proposes that the scope of resistance surface should be extended, which would improve the rationality of the ecological corridor simulation.

Research on the Wing-Type Antiscour Device of Pier Based on Scour Test and Numerical Simulation

In order to reduce the local scour before the antiscour device of piers, this paper proposed an improvement on a “V-type” device. That was to say, wing plates were set on the surface of the “V-type” device to enhance the diversion and reduce the local scour. To explore the protection effect of the modified device, the inclination angles of the wing plates were set to three angles, and the scour characteristics around the device were studied through the flume scour test and numerical simulation test. The results showed that the wing plates can reduce the impact force of the diving flow which was at the front end of the protective device. Besides, they could also disturb the flow around both sides of the device and weaken its sediment carrying capacity. Thus, the local scour around the device was effectively reduced. Especially, when the wing plates were 30°, the performance of reducing the local scour was the best.

Comprehensive Evaluation Model of Bearing Transportation Protection Effect of Bogie Traction Motor under Data Imbalance

Under different transportation protection, the sample data of bogie traction motor bearings of urban rail vehicles are seriously unbalanced, and the fault diagnosis ability and generalization effect are poor, which makes it difficult to evaluate the protection effect of bearings effectively. In this paper, a multimeasure hybrid evaluation model based on compressed sensing is proposed to evaluate the effect of bearing transportation protection under data imbalance. Firstly, bearing vibration signals under different transport protection conditions were compressed and sampled, and the original high-Witt collection in time domain, frequency domain, and time-frequency domain was extracted. Then, a multimeasure mixed feature evaluation model of correlation, distance, and signal was constructed, and the optimal multimeasure combination strategy was optimized by using comprehensive sensitivity score evaluation index. Finally, an evaluation model of bearing protection effect based on unified feature index was constructed by using the best feature subset evaluated, and the unified indicator was quantified to characterize the protection effect of different protection states. The experimental results show that the model can effectively evaluate bearings under different transport protection.

Del Nido versus HTK cardioplegia for myocardial protection during adult complex valve surgery: a retrospective study

Background Histidine-tryptophan-ketoglutarate (HTK) and del Nido (DN) cardioplegia are intracellular-type and extracellular-type solution respectively, both can provide a long period of myocardial protection with single-dose infusion, but studies comparing the two are rare for adult cardiac surgery. This study aims to evaluate whether DN is suitable for cardioplegia in complex and high-risk valve surgery with long-term cardiac ischemia when compared with HTK. Methods The perioperative records of adult patients infused with DN/HTK as a cardioplegic solution who underwent complex valve surgery with an expected myocardial ischaemic duration longer than 90 min between Oct 2018 and Oct 2019 were analysed retrospectively. Results Of the 160 patients who received DN/HTK and underwent complex valve surgery, we propensity matched 73 pairs. Both groups achieved satisfactory cardiac arrest effects, and no significant difference was found in their cTnI and CK-MB levels within 12 to 72 h postoperatively. The DN group had a higher rate of return to spontaneous rhythm (0.88 v 0.52, P < 0.001), a lower frequency of postoperative severe arrythmias (12% v 26%, P = 0.036), a higher postoperative stroke volume (65 v 59 ml, P = 0.011) and a higher cardiac output (6.0 v 4.9 L/min, P = 0.007) as evaluated by echocardiography, fewer transfusions and shorter ICU stays (both P < 0.05). The two groups had similar inotrope usage and similar incidences of low cardiac output, morbidities and mortality. Subgroup analysis showed that when the aortic clamping time was greater than 120 min, the advantages of DN were weakened. Conclusions DN can be safely applied to complex valve surgery, and it has a similar myocardial protection effect as HTK. Further prospective studies are required to verify these retrospective findings. Trial registration retrospectively registered.

Corrosion Protection of Nano-Silica Powder Coatingon Artificial Seawater

Sea water resources are extensive and can be used to extinguish fires, but their corrosiveness is a major problem. Using the method of electrochemical workstation, the electrochemical corrosion behavior of aluminum sheet in artificial sea water solution and silica-coated artificial seawater was studied; by analyzing the surface morphology, polarization curve and electrochemical impedance spectroscopy, the electrochemical corrosion behavior of aluminum sheets under different immersion times and different immersion media is obtained. The conclusion is that the coating of nanosilica powder has a certain corrosion protection effect on artificial seawater.

Antioxidant and Anti-inflammatory Effects of Fermented Eggplant Fruit Extracts with Leuconostoc mesenteroides KD20

We isolated Leuconostoc mesenteroides KD20, which has its application as a cosmetic material, while searching for useful microbes in Gangwon-do’s traditional fermented foods. Eggplant fruit extract (EG) was fermented with lactic acid bacteria L. mesenteroides. HPLC analysis results for the component analysis of EG and the fermented eggplant fruit extract (FEG) showed bio-conversion of quercetin 3-O-β-D-glucoside and rutin. To investigate skin protection effects of EG and FEG against skin damage by ultraviolet ray, we measured antioxidation and inhibitory effect of inflammation-related cytokines in keratinocytes irradiated with ultraviolet B (UVB). Biosynthesis of IL- 1α, which is increased with UVB in keratinocytes, was inhibited by 24.7% and 28.3% at 100 μg/ml of EG and FEG, respectively. Biosynthesis of PGE2 in keratinocytes was inhibited by 45.7% and 52.3% at 100 μg/ml of EG and FEG, respectively, indicating a greater effect of FEG. Therefore, EG and FEG can be used as an excellent material for cosmetics with skin protection effect against ultraviolet irradiation in keratinocytes.

Analysis of the Influence of Upper Protective Layer Mining on the Effect of Pressure Relief and Protection of Coal and Rock Masses between the Lower Overburden Layers

Protective seam mining is an effective gas pressure relief method in deep mining. Effective theoretical calculation methods in the current studies on the prediction of pressure relief protection effect of interbed coal and rock masses and their distribution laws are lacking. Thus, the evaluation and research with respect to pressure relief effect in protective seam mining relatively lag behind. This situation restricts the engineering feasibility evaluation and decision making in the protective seam mining. Therefore, the influence of upper protective seam mining on the pressure relief protection effect of coal and rock mass between underlying beds was investigated in this study. On the basis of an analysis of concrete engineering projects, a mechanical model was constructed for the pressure relief protection effect of upper protective seam mining on the coal and rock mass between underlying beds. The distribution equation of pressure relief expansion ratio in the underlying protected seam was also derived. The influence laws of main influencing factors on the pressure relief protection effect of the protected seam were revealed as well. In the end, the pressure relief effect was analyzed and verified for the protected seam before and after mining through numerical simulation and similarity simulation test. The pressure relief effect of upper protective seam mining on the coal and rock mass between underlying beds and the distribution characteristics were deeply explored in this study, which could provide a theoretical reference for the decision making in the gas extraction engineering design and pre-evaluation of extraction effect. Results show that the effective pressure relief zone (expansion rate>0.3%) of the protected seam beneath the goaf is located within the range of approximately 40 m from the coal wall to the rear part. It also presents an approximate “Λ-shaped distribution characteristic,” that is, it experiences migration and evolution with the advancement in the working face. Moreover, the peak pressure relief lags behind the coal wall on the working face by nearly 10–20 m. In the numerical simulation, the expansion ratio in the goaf also presents an approximate “Λ-shaped distribution.” Its effective pressure relief zone is the 50 m range from the coal wall to the rear part of the goaf, and the peak value lags behind the coal wall by around 15 m. The theoretical results and numerical simulation results are basically consistent with the physical experiment results. The expansion rates are 1.25%, 1.268%, and 1.32%, respectively. The elastic modulus E of coal seam and interbed spacing H are the main influencing factors of the swelling deformation and are negatively correlated with the expansion ratio. In the actual mining process, E and H of the protected layer can be measured to infer the expansion deformation of the protected layer.