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Abstract The amino acid response (AAR) and unfolded protein response (UPR) pathways converge on eIF2α phosphorylation, which is catalyzed by Gcn2 and Perk, respectively, under different stresses. This close interconnection makes it difficult to specify different functions of AAR and UPR. Here, we generated a zebrafish model in which loss of threonyl-tRNA synthetase (Tars) induces angiogenesis dependent on Tars aminoacylation activity. Comparative transcriptome analysis of the tars-mutant and wild-type embryos with/without Gcn2- or Perk-inhibition reveals that only Gcn2-mediated AAR is activated in the tars-mutants, whereas Perk functions predominantly in normal development. Mechanistic analysis shows that, while a considerable amount of eIF2α is normally phosphorylated by Perk, the loss of Tars causes an accumulation of uncharged tRNAThr, which in turn activates Gcn2, leading to phosphorylation of an extra amount of eIF2α. The partial switchover of kinases for eIF2α largely overwhelms the functions of Perk in normal development. Interestingly, although inhibition of Gcn2 and Perk in this stress condition both can reduce the eIF2α phosphorylation levels, their functional consequences in the regulation of target genes and in the rescue of the angiogenic phenotypes are dramatically different. Indeed, genetic and pharmacological manipulations of these pathways validate that the Gcn2-mediated AAR, but not the Perk-mediated UPR, is required for tars-deficiency induced angiogenesis. Thus, the interconnected AAR and UPR pathways differentially regulate angiogenesis through selective functions and mutual competitions, reflecting the specificity and efficiency of multiple stress response pathways that evolve integrally to enable an organism to sense/respond precisely to various types of stresses.

Hypersplenism (HS) is a concomitant symptom of liver or blood disease. Not only does the treatment of HS face challenges, but the transcriptome of individual cells is also unknown. Here, the transcriptional profiles of 43,037 cells from four HS tissues and one control tissue were generated by the single-cell RNA sequencing and nine major cell types, including T-cells, B-cells, NK cells, hematopoietic stem cells, neutrophil cells, mast cells, endothelial cells, erythrocytes, and dendritic cells were identified. Strikingly, the main features were the lack of CCL5+ B-cells in HS and the presence of SESN1+ B cells in HS with hepatocellular carcinoma (HS-HCC). In cell-cell interaction analysis, CD74-COPA and CD94-HLA-E in HS were found to be up-regulated. We further explored HS-specifically enriched genes (such as FKBP5, ADAR, and RPS4Y1) and found that FKBP5 was highly expressed in HCC-HS, leading to immunosuppression. Taken together, this research provides new insights into the genetic characteristics of HS via comprehensive single-cell transcriptome analysis.

In this paper, we study the nonlinear matrix equation (NME) X+∑i=1mAi*X−1Ai=Q. We transform this equation into an equivalent zero-point equation, then we use Newton’s iteration method to solve the equivalent equation. Under some mild conditions, we obtain the domain of approximation solutions and prove that the sequence of approximation solutions generated by Newton’s iteration method converges to the unique solution of this equation. In addition, the error estimation of the approximation solution is given. Finally, the comparison of two well-known approaches with Newton’s iteration method by some numerical examples demonstrates the superiority of Newton’s iteration method in the convergence speed.

This paper involves related inverse eigenvalue problem and least-squares problem of skew-Hermitian {P,k + 1}-reflexive(antireflexive) matrices and their optimal approximation problems. The above problems are studied by converting them into two simpler cases: k = 1 and k = 2. Firstly, with some special properties of skew-Hermitian {P,k + 1}-reflexive(antireflexive) matrices, the necessary and sufficient conditions for the solvability and the general solution are presented, and the solution of corresponding optimal approximation problems also given, respectively. Then, we give the least-squares solution of AX=B satisfying the special condition by the singular value decomposition. Finally, we give an algorithm and an example to illustrate our results.

Background: Dendritic cells (DCs) play an important role in host defense against pathogen infection. DC-specific intercellular adhesion molecule-3-grabbing nonintegrin (SIGN) is a group II C-type lectin receptor and specifically expressed on the surface of DCs. This study aimed to determine whether DC-SIGN affects intracellular signaling activation, Th1/Th2 imbalance and aspergillus immune evasion in aspergillus infection, and explore the application of DC-SIGN-modified DCs in immunotherapy. Methods: DCs were first obtained from the mononuclear cells of peripheral blood. The interferon (IFN)-γ and dexamethasone (Dex) were used to stimulate DCs. The expression of DC-SIGN, Th1 and Th2 cytokines, and the capacity of DCs in stimulating T cells proliferation and phagocytosis, and nuclear factor (NF)-κB activation were analyzed. In addition, adenovirus expression vector Ad-DC-SIGN was generated to transfect DCs. Mannan was used to block DC-SIGN signaling for confirming the involvement of DC-SIGN function in Aspergillus fumigatus (Af)-induced DCs maturation. The unpaired, two-tailed Student's t-test was used in the comparisons between two groups. Results: Exogenous IFN-γ could activate Af-induced DCs and promote the Th0 cells toward Th1 profile (interleukin [IL]-12 in IFN-γ/Af group: 50.96 ± 4.38 pg/ml; control/Af group: 29.70 ± 2.00 pg/ml, t = 10.815, P < 0.001). On the other hand, Dex inhibited the secretion of Th2 cytokines (IL-10 in Dex/Af group: 5.27 ± 0.85 pg/ml; control/Af group: 15.14 ± 1.40 pg/ml, t = 14.761, P < 0.001)), and successfully caused immunosuppression. After transfection with Ad-DC-SIGN, DCs have improved phagocytosis (phagocytosis rates in Ad-DC-SIGN group: 74.0% ± 3.4%; control group: 64.7% ± 6.8%, t = 3.104, P = 0.013). There was more Th1 cytokine secreted in the Af-induced DC-SIGN modified DCs (IL-12 in Ad-DC-SIGN/Af group: 471.98 ± 166.31 pg/ml; control/Af group: 33.35 ± 5.98 pg/ml, t = 6.456, P = 0.001), correlated to the enhanced NF-κB activation. Conclusion: Overexpressing DC-SIGN in DCs had a protective function on aspergillosis.

Objective: The aim of this study was to compare clinical outcomes of patients with femoral neck fractures treated with the dynamic hip system blade (DHS-BLADE) or cannulated compression screws. Methods: Eighty-six patients with femoral neck fractures were treated by closed reduction internal fixation with a DHS-BLADE (n = 42; 18 males and 24 females; mean age: 56.3 years (37–87)) or cannulated compression screws (n = 44; 20 males and 24 females; mean age: 53.8 years (26–83)) between March 2011 and August 2013. The groups were compared with Harris hip score, operation time, surgical blood loss, incision size, hospital stay, and related complications. Results: The average follow-up time was 27 months (range, 24–36 months). There was no significant difference for the operation time, incision size, hospital stay, and Harris hip score between the groups. Also, no statistically significant differences in the rates of nonunion (4.5% vs. 0) and avascular necrosis of the femoral head (9.1% vs. 7.1%) were observed. However, the screw group experienced significantly less surgical blood loss (32.4 ± 24.7 ml) than the blade group (87.2 ± 46.6 ml; P = 0.041). The incidence of femoral neck shortening above 10 mm in the screw group was significantly higher than that in the blade group (15.9% vs. 2.4%, P = 0.031). The blade group had a significantly lower incidence of screw migration than the screw group (4.8% vs. 22.7%, P = 0.016). Conclusion: The DHS-BLADE and cannulated compression screws might be equally effective in terms of postoperative fracture union. However, the DHS-BLADE has advantages over cannulated compression screws for preventing femoral neck shortening, screw migration, and cut-out. Level of evidence: Level III, Therapeutic study. Keywords: Femoral neck fracture, Cannulated screw, Dynamic hip system blade, Internal fixation

Abstract Background Intramyocardial dissecting hematoma (IDH) is a rare mechanical complication following myocardial infarction (MI), and only a few isolated cases have been reported to date. IDH presents with diverse clinical manifestations, often resulting in missed or misdiagnosed cases due to limited physician understanding. The diagnosis and treatment of IDH is a major challenge. Case presentations We report a case of acute extensive anterior MI in a 73-year-old woman, who underwent percutaneous coronary intervention (PCI); the left ventricular intramyocardial dissecting hematoma (LVIDH) penetrated the right ventricular outflow tract (RVOT), resulting in thrombus formation and subsequent RVOT obstruction. Clinically insignificant IDH was detected by transthoracic echocardiography (TTE) at 3 days, 43 days, and 75 days post-PCI, with characteristic changes in the left ventricular wall ultrasound images. This unusual case highlights the important role of continuous transthoracic echocardiography in identifying this rare complication of LVIDH. After a detailed discussion with the patient, the choice between conservative or surgical management of IDH depends on factors such as the size of the hematomae, left ventricular systolic function, and the patient’s clinical and haemodynamic status. In this particular case, conservative management was chosen by the patient who declined surgery but unfortunately succumbed to cardiogenic shock. Conclusions This case describes a rare complication of acute myocardial infarction (AMI) and also focuses on the utility of TTE in the diagnosis of this rare complication. Whether LVIDH is treated conservatively or surgically requires careful evaluation to achieve the best prognosis for the patient.

Abstract Rapid advancements in electronic devices yield an urgent demand for high‐performance electronic packaging materials with high thermal conductivity, low thermal expansion, and great mechanical properties. However, it is a great challenge for current design philosophies to fulfill all the requirements simultaneously. Here, an effective strategy is proposed for significantly promoting the thermal conductivity and machinability of negative thermal expansion alloy (Zr,Nb)Fe2 through eutectic precipitation of copper networks. The eutectic dual‐phase alloy exhibits an isotropic chips‐matched thermal expansion coefficient and a thermal conductivity enhancement exceeding 200% compared with (Zr,Nb)Fe2, along with an ultimate compressive strength of 550 MPa. The addition of copper reorganizes the composition of (Zr,Nb)Fe2, which smooths the magnetic transition and shifts it toward higher temperature, resulting in linear low thermal expansion in a wide temperature range. The highly fine eutectic copper lamellae construct high thermal conductivity networks within (Zr,Nb)Fe2, serving as highways for heat transfer electrons and phonons. The in situ forming of eutectic copper lamellae also facilitates the mechanical properties by enhancing interfacial bonding and bearing additional stress after yielding of (Zr,Nb)Fe2. This work provides a novel strategy for promoting thermal conductivity and mechanical properties of negative thermal expansion alloys via eutectic precipitation of copper networks.

Both selenium (Se) and anthocyanins are crucial for maintaining human health. Preharvest Se treatments could promote anthocyanin biosynthesis and augment Se levels in vegetables, helping to combat Se deficiencies in dietary intake. However, it remains unknown whether preharvest Se treatment could balance growth and anthocyanin biosynthesis in plants and what the appropriate treatment concentration is. In this study, preharvest treatments with sodium selenite at varying concentrations (0, 5, 10, and 30 mg/kg) affect the growth and nutritional quality of purple leaf mustard (Brassica juncea) with abundant anthocyanins. Lower Se concentrations (≤10 mg/kg) of preharvest treatments enhanced photosynthesis, facilitated root system development, consequently elevated the biomass. Conversely, higher Se levels (≥30 mg/kg) reduced photosynthesis and biomass. The dosage-dependent effects of Se treatments were corroborated through seedlings cultivated in hydroponic conditions. Moreover, nearly all Se treatments elevated the contents of various nutrients in leaf mustard, particularly anthocyanin and organic se. These results suggest an overall enhancement in nutritional quality of leaf mustard plants. Furthermore, the application of 10 mg/kg Se significantly enhanced the activity of phenylalanine ammonia-lyase and upregulated the expression of 12 genes pivotal for anthocyanin biosynthesis, further demonstrating the fortified effects of Se enrichment on anthocyanins in leaf mustard. Low-level Se treatments resulted in heightened antioxidant activity (APX, CAT, and POD), mitigating reactive oxygen species induced by increasing Se content in tissues. The enhanced antioxidant activities may be beneficial for the normal growth of leaf mustard under Se stress conditions. In conclusion, our study demonstrated preharvest Se treatment at 10 mg/kg could balance the growth and anthocyanin biosynthesis in purple leaf mustard. This study offers valuable insights into anthocyanin fortification through Se enrichment methods in agricultural practices, ensuring that such fortification does not compromise leafy vegetable yield.

Abstract Efficient communication is crucial in reducing injuries and fatalities in coal mine accidents, necessitating the study of simulation methods for mine communication. When transceiver antennas are positioned close to the same side of the tunnel, the simulation results from the Ray Tracing (RT) method exhibit significant errors. Additionally, the Finite-Difference Time-Domain (FDTD) method demands substantial computational resources. In response to these challenges, we propose a RT-FDTD method, guided by the law of conservation of energy. This approach involves dividing the mine tunnel into a cuboidal region, using the RT method to calculate the electric field strength on the cuboid’s surface, and then employing this as the excitation source for the FDTD method. Subsequently, the FDTD method is used to calculate the electric field strength within the cuboid. Experimental results demonstrate that the RT-FDTD method effectively mitigates the limitations of the RT and FDTD methods, enhancing both the efficiency and accuracy of simulations in underground mine.

Plastic greenhouses (PGs) are integral to modern agricultural practices, enhancing crop yields but also raising environmental concerns. Consequently, comprehending their widespread distribution is essential. Although deep learning has been extensively used for land use/cover classification and extraction with satellite data, the large number of labels limits its application due to the time-consuming and labor-intensive nature of manual labeling. This study introduces a novel approach coupling Prior Knowledge and Deep Learning methods for PG Mapping (PGMPK+DL) using Sentinel-1/2 data. We use an automatic labeling strategy guided by prior knowledge from Sentinel-2 optical data to construct PG labels in six small regions. Moreover, to overcome the cloud contamination issue of optical data, the potential of Sentinel-1 time-series SAR data for PG extraction is analyzed. Deep learning methods are further utilized to capture more abstract and generalized temporal and spatial features from time-series radar data to accommodate complex scenes for large-scale PG extraction. The U-Net model emerges as superior from rigorous comparisons among FCN, SegNet, U-Net, DeepLabV3 + and U-Net3 + deep learning models. Finally, the U-Net model harnessed prior knowledge-based PG labels and Sentinel-1 time-series SAR data to generate a precise map depicting PG distribution across Shandong province, China. Remarkably, it accurately identifies approximately 238,000 ha of PG areas. This PGMPK+DL approach presents a groundbreaking solution for label construction, enabling the achievement of large-scale PG extraction. Beyond enhancing PG extraction, it also holds broader implications for advancing deep learning applications within remote sensing.

BackgroundThe Chinese ethnic medicine Jie-Du-Huo-Xue Decoction (JDHXD) is used to alleviate neuroinflammation in cerebral ischemia (CI). Our previous studies have confirmed that JDHXD can inhibit microglial pyroptosis in CI. However, the pharmacological mechanism of JDHXD in alleviating neuroinflammation and pyroptosis needs to be further elucidated. New research points out that there is an interaction between autophagy and inflammasome NLRP3, and autophagy can help clear NLRP3. The NLRP3 is a key initiator of pyroptosis and autophagy. The effect of JDHXD promoting autophagy to clear NLRP3 to inhibit pyroptosis on cerebral ischemia-reperfusion inflammatory injury is currently unknown. We speculate that JDHXD can inhibit pyroptosis in CI by promoting autophagy to clear NLRP3.MethodsChemical characterization of JDHXD was performed using LC-MS. Model of middle cerebral artery occlusion/reperfusion (MCAO/R) was established in SD rats. Neurological deficits, neuron damage, and cerebral infarct volume were evaluated. Western Blot and immunofluorescence were used to detect neuronal pyroptosis and autophagy.Results30 possible substance metabolites in JDHXD medicated serum were analyzed by LC-MS (Composite Score > 0.98). Furthermore, JDHXD protects rat neurological function and cerebral infarct size after CI. JDHXD inhibited the expression of pyroptosis and autophagy after CI. Our western blot and immunofluorescence results showed that JDHXD treatment can reduce the expression of autophagy-related factors ULK1, beclin1, and LC3-Ⅱ. The expression of NLRP3 protein was lower in the JDHXD group than in the I/R group. Compared with the I/R group, the expressions of pyroptosis-related factors caspase-1 P 10, GSDMD-NT, IL-18, and IL-1β decreased in the JDHXD group. Furthermore, we observed an unexpected result: immunofluorescence demonstrated that Gasdermin D (GSDMD) was significantly absent in the infarct core, and highly expressed in the peri-infarct and contralateral cerebral hemispheres. This finding challenges the prevailing view that GSDMD is elevated in the ischemic cerebral hemisphere.ConclusionJDHXD inhibited pyroptosis and autophagy after MCAO/R. JDHXD suppressed pyroptosis and autophagy by inhibiting NLRP3, thereby alleviating CI. In addition, we present a different observation from previous studies that the expression of GSDMD in the infarct core was lower than that in the peri-infarct and contralateral non-ischemic hemispheres on day 3 of CI.

SF6degradation mechanism in non-thermal plasma (NTP) systems is not fully understood due to the formation of a complex physico-chemical reaction network, especially when reactive gases and packing materials are involved. In this work, we conduct a combined experimental and theoretical study to unravel the SF6 degradation path in a γ-Al2O3packed plasma in the presence of H2O or O2. Our experimental results show that both H2O and O2 have a synergetic effect with γ-A12O3 packing on promoting SF6 degradation, leading to higher stable gas yields than typical spark or corona discharges. HO or O2addition promotes SO2or SO2F2 selectivity, respectively. Density functional theory (DFT) calculations reveal that SO2 generation corresponding with the highest activation barrier is the most critical step toward SF6 degradation. Radicals like H and O generated from H2O or O2 discharge can significantly promote the degradation process via Eley-Rideal mechanism, affecting key reactions of stable product generation, advancing degradation efficiency. The results of this work could provide insights on further understanding SF6 degradation mechanism especially in packed-bed plasma systems.

Background/Objectives: As a hyperaccumulator of selenium (Se), Cardamine violifolia (Cv) and its peptide extract could ameliorate the negative effects of a high-fat diet (HFD). However, the effects of the coaccumulation of cadmium (Cd) in Se-enriched Cv (Cv2) and the potential confounding effect on the roles of enriched Se remain unknown. We aimed to investigate whether Cv2 could alleviate HFD-induced lipid disorder and liver damage. Methods: Three groups of 31-week-old female mice were fed for 41 weeks (n = 10–12) with a control Cv-supplemented diet (Cv1D, 0.15 mg Se/kg, 30 µg Cd/kg, and 10% fat calories), a control Cv-supplemented HFD (Cv1HFD, 45% fat calories), and a Cv2-supplemented HFD (Cv2HFD, 1.5 mg Se/kg, 0.29 mg Cd/kg, and 45% fat calories). Liver and serum were collected to determine the element concentrations, markers of liver injury and lipid disorder, and mRNA and/or protein expression of lipid metabolism factors, heavy metal detoxification factors, and selenoproteins. Results: Both Cv1HFD and Cv2HFD induced obesity, and Cv2HFD downregulated Selenoi and upregulated Dio3 compared with Cv1D. When comparing Cv2HFD against Cv1HFD, Cv2 increased the liver Se and Cd, the protein abundance of Selenoh, and the mRNA abundance of 10 selenoproteins; reduced the serum TG, TC, and AST; reduced the liver TG, lipid droplets, malondialdehyde, and mRNA abundance of Mtf1 and Mt2; and differentially regulated the mRNA levels of lipid metabolism factors. Conclusions: Cv2 alleviated HFD-induced lipid dysregulation and liver damage, which was probably associated with its unique Se speciation. However, further research is needed to explore the interaction of plant-coenriched Se and Cd and its effects on health.

Due to disparities in area among various land cover types, class imbalance has always existed in crop mapping research, posing uncertainties in extracting minority classes which occupy a smaller area. In this paper, taking tea plantations mapping in Hangzhou city as an example, we created a series of training datasets with different imbalance-ratios (IRs), compared the accuracy between the extraction models using these datasets, and analyzed the impact of class imbalance on various machine learning algorithms (Artificial Neural Network, Decision Tree, Random Forest and XGBoost), aiming to provide a feasible approach to improve the mapping accuracy of minority classes. The leave-one-out cross validation results showed that in most cases, with the increase of the IR, the model’s F2-score first increased and then decreased, and the increase of F2-scores ranged from 0.2% to 29.2%, suggesting that moderately increasing the number of other samples in the training dataset can improve the tea plantations extraction accuracy. Consistent result can also be obtained by using the whole city’s samples for modeling and random sampling validation. XGBoost performed best among the four algorithms, which yielded the optimal tea plantations map with a PA of 97%, UA of 93% and F2-score of 96% when the IR of the training dataset was 6. The UA was 19% higher than that of the model using a balanced dataset (IR=1) and was 11% higher than that of the model using pseudo-balanced datasets created by the oversampling method. The conclusions of this study offer insights for the identification of minority classes, contributing to achieving higher accuracy in remote sensing crop mapping.

3D tracking of single‐port continuum surgical tools is an essential step toward their closed‐loop control in robot‐assisted‐laparoscopy, since single‐port tools possess multiple degrees‐of‐freedom (DoFs) without distal joint sensors and hence have lower motion precision compared to rigid straight‐stemmed tools used in multi‐port robotic laparoscopy. This work proposes a novel markerless 3D tracking framework for continuum surgical tools using a proposed surgical tool partial pose estimation network (STPPE‐Net) based on U‐Net and ResNet. The STPPE‐Net estimates the segmentation and a 5‐DoF pose of the tool end‐effector. This network is entirely trained by a synthetic data generator based on domain randomization (DR) and requires zero manual annotation. The 5‐DoF pose estimation from the STPPE‐Net is combined with the surgical tool axial rotation from the robot control system. Then, the entire pose is further refined via a region‐based optimization that maximizes the overlap between the tool end‐effector segmentation from the STPPE‐Net and its projection onto the image plane of the endoscopic camera. The segmentation accuracy and 6‐DoF pose estimation precision of the proposed framework are validated on the images captured from an endoscopic single‐port system. The experimental results show the effectiveness and robustness of the proposed tracking framework for continuum surgical tools.

In this study, okara was fermented with probiotic strains Lactobacillus gasseri LAC 343 and Limosilactobacillus fermentum PCC, respectively. Significant increases in cell count (by 2.22 log CFU/mL for LAC and 0.82 log CFU/mL for PCC) and significant decreases in pH (by 1.31 for LAC and 1.03 for PCC) were found in fermented okara slurry. In addition, strain LAC tended to produce amino acids, while strain PCC depleted most amino acids. An untargeted metabolomic-based approach using liquid chromatography coupled with quadrupole time-of-flight mass spectrometry was used to further understand the compositional changes and potential health benefits by identifying bioactive metabolites in fermented okara slurry. We successfully identified various beneficial bioactive compounds including γ-aminobutyric acid, indolelactic acid, d-phenyllactic acid, and p-hydroxyphenyllactic acid which had differences in fold-changes in okara slurry fermented with different strains. Our study indicated the feasibility of using probiotics to ferment okara for novel functional food development.

Objective: To explore the role and molecular mechanism of cancer-associated fibroblasts (CAFs) in the tumor microenvironment of gastric cancer (GC). Methods: The expression of CAFs in GC patients was first assessed for abundance, and survival analysis was performed. Subsequently, The Cancer Genome Atlas (TCGA) data were used for differential analysis, survival analysis, and EPIC analysis, while single-cell data (GSE183904) were downloaded for differential analysis of CAFs. Clinical data pooling, univariate and multivariate Cox analysis, and immunofluorescence were carried out on clinical GC tissue samples to explore RCN3 expression within patient CAFs. Western blot and quantitative polymerase chain reaction (qPCR) were used to detect the expression of RCN3. The relationship between RCN3, PCSK6, and STAT1 was explored by chromatin immunoprecipitation (CHIP) experiments, and the effects of the genes on macrophage polarization were detected by detecting biomarkers of biological M1/M2. Results: CAFs in GC were found to be significantly higher compared to the normal group. Revealing the results of TCGA differential analysis, it was observed that GC exhibited a substantial upregulation in the expression levels of RCN3. The clinical statistics indicate a positive correlation between an elevated level of RCN3 expression and the T-stage classification of tumor size. In addition, RCN3 was found to have a significant impact on the overall survival of patients with gastric cancer, acting as an independent prognostic indicator. Analysis of single-cell data showed high expression of PCSK6 in macrophages, and immunofluorescence staining of samples from GC patients showed increased expression of PCSK6 on the cell membranes of macrophages in GC tissues. The subsequent cellular experiments confirmed RCN3 protein can regulate the expression of PCSK6, and PCSK6 regulates macrophage polarization through STAT1. Conclusions: CAFs regulate macrophage polarization through the RCN3/PCSK6/STAT1 pathway in GC.

In recent years, the increasing frequency of extreme weather events has exacerbated the severity of geological disasters. Therefore, it is important to understand the mechanisms of geological disasters under extreme rainfall conditions. From June to October 2021, Baoji City, Shanxi Province, China, experienced some extreme and continuous heavy rainfalls, which triggered more than 30 geological disasters. Those geo-disasters threatened the lives of 831 people and the safety of 195 houses. The field investigations found that most of these geological disasters were devastating collapses that occurred in the loess layer, primarily due to the cave dwelling construction. The shear strength, montmorillonite content, disintegration degree, and plasticity index of two typical loesses, namely the Sanmen Formation stiff clay and the Hipparion red clay, were analyzed, and their water sensitivities were evaluated. The failure mechanisms of the landslides, ground fissures, and collapses were analyzed and most of them were controlled by the cave dwelling construction and the strong water sensitivity of the loess. This study provides data for understanding shallow geological disasters induced by extreme rainfall in the loess area, which are more threatening than large geological disasters. We proposed an intensity–duration (I–D) rainfall threshold as I = 90 D−0.92, which relates the rainfall intensity (I) to the rainfall event duration (D). The empirical threshold provides some useful information for the early warning of collapses or landslides in similar geological settings in the loess area.

The movement process of debris flow in the complex roads system is important for risk evaluation and emergency rescue. This paper presents an in-depth study of the diversion effect of debris flow in cross channels, a common branching structure in both natural and engineered environments, especially in the field of urban debris flow prevention. A mathematical model is established based on the conservation of mass, momentum, and energy, and a solid–liquid two-phase motion equation for debris flow is derived from two-phase flow theory. A numerical solution method, combining the finite difference method and finite volume method, is employed to discretize and solve the equation. The model’s validity and effectiveness are confirmed through a numerical simulation of a typical engineering case and comparison with existing experimental data or theoretical results. This study reveals that debris flow at cross channels exhibits a diversion phenomenon, with some debris flow continuing downstream along the main channel and some diverting into the branch channel. The diversion rate, defined as the ratio of outlet flow to inlet flow of the branch channel, indicates the magnitude of this effect. This research shows that the solid–liquid ratio, inflow, width ratio, height ratio, and angle of the cross channel significantly impact the diversion effect. A series of numerical simulations are conducted by altering these parameters as well as the physical properties of debris flow and boundary conditions. These simulations analyze changes in flow rate, velocity, pressure, and other parameters of debris flow at cross channels, providing insights into the factors and mechanisms influencing the diversion effect. This research offers a robust instrument for comprehending and forecasting the dynamics of urban debris flows. It contributes significantly to mitigating the effects of debris flows on city infrastructure and enhancing the safety of city dwellers.