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To address the problems of slow convergence speed, easy to fall into local minima and low convergence accuracy presented by previous algorithms in DC distribution network fault location, this paper adopts the improved artificial bee colony slime mould algorithm (SMA) to improve and solve. On the basis of SMA, an adaptive adjustable feedback factor and an improved crossover operator are introduced to improve the convergence speed; artificial bee colony (ABC) algorithm is introduced to improve the search ability to jump out of local minima, and the artificial bee colony slime mould algorithm (ISMA) is formed. Firstly, based on the six-terminal DC distribution network topology, a mathematical model of bipolar short-circuit fault as well as single-pole grounded short-circuit fault is established based on a fault occurring between G-VSC and W-VSC as an example. Then the principle of the improved ISMA is introduced in detail, and a suitable fitness function is established as the measure of fault location in DC distribution network. Finally, experimental simulations are conducted to obtain fault points from the optimization search and compare them with the actual values to verify the accuracy of the algorithm. In addition, the efficiency and robustness of ISMA are further verified by comparing with other algorithms.

Abstract: In order to explore the influence of the relative positional relationship between the dynamic load and the long axis of the elliptical cavern on the characteristics of impact rockburst, a cuboid sample with an elliptical hole is prepared. With two positional relationships of disturbance direction parallel or perpendicular to the long axis of the elliptical cavern, the elliptical cavern impact rockburst experiments are carried out. With the aid of video recording device, the characteristics of the impact rockburst of the elliptical cavern are discussed in terms of damage process of rockburst ejection, ejection speed, failure mode and fragment size. The experimental results show that the rockburst processes of the two samples with different positional relationships are the same, and the rockburst pits are all V-shaped. The initial failure stress, rockburst stress, rockburst ejection velocity, rockburst pit size, fragment mass and proportion of coarse-grained fragments of the samples whose disturbance direction is perpendicular to the long axis of the ellipse are smaller than those of the samples whose disturbance direction is parallel to the long axis. The fragment characteristics of the samples whose disturbance direction is perpendicular to the long axis of the ellipse are mainly presented as thin stripes. The samples whose disturbance direction is parallel to the long axis of the ellipse can significantly improve the bearing capacity of the cavern structure. However, the rockburst phenomenon is more severe and its debris characteristics are mainly of thick plate.

ObjectiveThis study aimed to assess the fairness of medical resource allocation in the Yangtze River Economic Belt, based on the Healthy China strategy. It aimed to identify the issues with resource allocation fairness and provide optimization suggestions.MethodsTo assess the allocation fairness from a geographical population perspective, the study used the Health Resource Concentration and Entropy Weight TOPSIS methods. Additionally, the study analyzed the allocation fairness from an economic level angle, using the Concentration Curve and Concentration Index.ResultsThe study found that the downstream area had higher resource allocation fairness than the midstream and upstream areas. The middle reaches had more resources than the upper and lower reaches, based on population concentration. The Entropy Weight TOPSIS method found that Shanghai, Zhejiang, Chongqing, and Jiangsu had the highest comprehensive score index of agglomeration. Furthermore, from 2013 to 2019, the fairness of medical resource distribution gradually improved for different economic levels. Government health expenditure and medical beds were distributed more equitably, while general practitioners had the highest level of unfairness. However, except for medical and health institutions, traditional Chinese medicine institutions, and primary health institutions, other medical resources were mostly distributed to areas with better economic conditions.ConclusionThe study found that the fairness of medical resource allocation in the Yangtze River Economic Belt varied greatly based on geographical population distribution, with inadequate spatial accessibility and service accessibility. Although the fairness of distribution based on economic levels improved over time, medical resources were still concentrated in better economic areas. The study recommends improving regional coordinated development to enhance the fairness of medical resource allocation in the Yangtze River Economic Belt.

Ferroptosis is a non-apoptotic form of cell death characterized by the iron-dependent lipid peroxidation and is implicated in several human pathologies, such as tissue ischemia, neurodegeneration, and cancer. Ferroptosis appears to be high cell-context dependent and the regulation of ferroptosis by physiological or pathological conditions are unclear. Here, we report that tumor-derived IDH1 mutation sensitizes cells to ferroptosis. Deletion of the mutant IDH1 allele in IDH1 heterozygous tumor cells or pharmacological inhibition of mutant IDH1 to produce the oncometabolite D-2-hydroxyglutarate (D-2-HG) confers resistance to erastin-induced ferroptosis. Conversely, ectopic expression of mutant IDH1 or treatment of cells with cell-permeable D-2-HG promotes the accumulation of lipid reactive oxygen species (ROS) and subsequently ferroptosis. Mechanistically, mutant IDH1 reduces the protein level of the glutathione peroxidase 4 (GPX4), a key enzyme in removing lipid ROS and ferroptosis, and promotes depletion of glutathione. Our results uncover a new role of mutant IDH1 and 2-HG in ferroptosis.

Abstract Background The aims of this study were to evaluate the levels of preretinal oxygen tension in patients with diabetes who did not have hypertension by using three-dimensional spoiled gradient-recalled (3D-SPGR) echo sequence imaging and to explore the correlation between diabetic retinopathy (DR) and changes in preretinal oxygen tension. Method This study involved 15 patients with type 2 diabetes without hypertension, who were divided into a diabetic retinopathy (DR) group (n = 10 eyes) and a diabetic non-retinopathy (NDR) group (n = 20 eyes), according to the results of a fundus photography test. Another healthy control group (n = 14 eyes) also participated in the study. The preretinal vitreous optic disc area, nasal side, and temporal side signal intensity of the eyes was assessed before and after oxygen inhalation with the use of 3D-SPGR echo magnetic resonance imaging (MRI). The signal acquisition time was 10, 20, 30, 40, and 50 min after oxygen inhalation. Results The results showed that, in the DR and NDR groups, the preretinal vitreous oxygen tension increased rapidly at 10 min after oxygen inhalation and peaked at 30–40 min, and the increased slope of the DR group was higher than that of the NDR group. The oxygen tension of the preretinal vitreous gradually increased after oxygen inhalation, and the difference between the DR and NDR groups and the control group was statistically significant (P

Titanium (Ti)/stainless steel weld joints with copper (Cu) transition layer thicknesses of 0.2, 0.4, and 0.6 mm were studied through combined experimental and finite element methods. Then, the formation mechanism and distribution of the Ti–Cu compounds (intermetallic compounds, IMCs) were analyzed. The results showed that the thicknesses of the Ti–Cu IMCs decreased with increasing thickness of the Cu layer, and the tensile strength and elongation increased when welding was conducted under a ring oscillation laser with a spot diameter of 0.3 mm, an oscillating diameter of 0.1 mm, a welding speed of 220 cm/min, and a laser power of 2000 W. In the 0.2 and 0.4 mm Cu layers, Ti–Fe IMCs appeared in the welds, and the thicknesses of the Cu–Ti IMC layers were 60 and 30 μm, respectively. When the 0.6 mm Cu transition layer was used, a pure Cu layer appeared in the weld, which effectively inhibited the formation of Ti–Fe IMCs. The thickness of the Cu–Ti IMC layer was reduced owing to the faster cooling rate at the Cu–Ti interface. Furthermore, the Cu4Ti phase was distributed in a thin area of 15 μm, which improved the mechanical properties of the welded joint and allowed the tensile strength to reach 330 MPa. Compared to the welding joints with Cu layer thickness less than or equal to laser irradiation width, the joints with Cu layer thickness larger than laser irradiation width have a significantly improved tensile strength.

Apocynum venetum L. is an important medicinal perennial rhizome plant with good ecological and economic value. Its leaves have many pharmacological effects such as anti-inflammatory, anti-depression, anti-anxiolytic, etc., while its fibers have the title of “king of wild fibers”. Furthermore, it was suitable for the restoration of degraded saline soil in arid areas. An increasing studies have been published in the past years. A scientometric analysis was used to analyze the publications of Apocynum venetum L. to clearly review the pharmacology, fiber application of Apocynum venetum L. and the potential value with its similar species (Apocynum pictum Schrenk) to the environment.

Ruddlesden–Popper phase oxides, such as Ca3Ti2O7, have been established as hybrid improper ferroelectrics. However, investigations into Ca3Ti2O7 have primarily concentrated on their structural and ferroelectric properties. In this study, we prepared epitaxial Ca3Ti2O7 thin films via magnetron sputtering. Conducting atomic force microscopy was employed to characterize local current variations under an applied bias voltage. Electron paramagnetic resonance measurements of the Ca3Ti2O7/La0.67Sr0.33MnO3 film were conducted to assess its defect characteristics. Interestingly, the Ca3Ti2O7/La0.67Sr0.33MnO3 stacks exhibited remarkable macroscopic resistance switching, with a resistance on/off ratio reaching 100, alongside robust retention (∼2500 s) and endurance (∼2000 cycles) features. Additionally, density functional theory calculations suggest that the resistance switching is attributable to the interface barrier of the Ca3Ti2O7/La0.67Sr0.33MnO3 interface and the efficacy of space charge limitation. This work proposes an avenue for the utilization of Ruddlesden–Popper phase Ca3Ti2O7 in various applications. [ABSTRACT FROM AUTHOR]

Maintaining intracellular redox balance is essential for the survival, antibody secretion, and mucosal immune homeostasis of immunoglobulin A (IgA) antibody‐secreting cells (ASCs). However, the relationship between mitochondrial metabolic enzymes and the redox balance in ASCs has yet to be comprehensively studied. Our study unveils the pivotal role of mitochondrial enzyme PCK2 in regulating ASCs' redox balance and intestinal homeostasis. We discover that PCK2 loss, whether globally or in B cells, exacerbates dextran sodium sulphate (DSS)‐induced colitis due to increased IgA ASC cell death and diminished antibody production. Mechanistically, the absence of PCK2 diverts glutamine into the TCA cycle, leading to heightened TCA flux and excessive mitochondrial reactive oxygen species (mtROS) production. In addition, PCK2 loss reduces glutamine availability for glutathione (GSH) synthesis, resulting in a decrease of total glutathione level. The elevated mtROS and reduced GSH expose ASCs to overwhelming oxidative stress, culminating in cell apoptosis. Crucially, we found that the mitochondria‐targeted antioxidant Mitoquinone (Mito‐Q) can mitigate the detrimental effects of PCK2 deficiency in IgA ASCs, thereby alleviating colitis in mice. Our findings highlight PCK2 as a key player in IgA ASC survival and provide a potential new target for colitis treatment. [ABSTRACT FROM AUTHOR]

As a green, environmentally friendly, and cost-effective grouting material, geopolymer requires consideration of grouting performance indicators such as strength and fluidity in order to achieve good injectability. For this reason, indoor ratio optimization experiments were conducted using liquid-solid ratio, water glass content, and water glass modulus as experimental factors. A multivariate second-order response surface regression model was constructed for compressive strength, flowability, and final setting time, and the influences of single factor and its interaction on various grouting performance indicators were obtained through variance analysis. The degree of influence of experimental factors on grouting performance indicators is as follows: liquid-solid ratio, water glass content, and water glass modulus. The interaction between liquid-solid ratio and water glass content has a significant impact on compressive strength, while the interaction between the other two factors has no significant impact on grouting performance indicators. Using the analytic hierarchy process and expert assignment method to obtain the relative weights of various grouting performance indicators, a multi- objective satisfaction function was constructed to optimize the ratio of slag-fly ash geopolymer grouting materials. Based on this, SEM testing was conducted on the slurry stone body with the best comprehensive ratio of grouting performance indicators. The results show that a small number of spherical unreacted fly ash particles can still be observed in the system, the slag particles and cement particles are basically fully reacted, and the oligomeric gel-like reaction products are rearranged and extended by deposition, and cross-lap with each other to form a dense and complete spatial network-like structure. [ABSTRACT FROM AUTHOR]