SPL50 Regulates Cell Death and Resistance to Magnaporthe Oryzae in Rice.

BACKGROUND: The identification of spotted leaf 50 (spl50), a novel lesion mimic mutant (LMM) in rice, provides critical insights into the mechanisms underlying programmed cell death (PCD) and innate immunity in plants. RESULTS: Based on ethyl methane sulfonate (EMS)-induced mutagenesis, the spl50 mutant mimics hypersensitive responses in the absence of pathogen by displaying spontaneous necrotic lesions after the tillering phase. SPL50, an ARM repeat protein essential for controlling reactive oxygen species (ROS) metabolism and boosting resistance to blast disease, was identified by map-based cloning techniques. This work also demonstrates the detrimental effects of spl50 on photosynthetic efficiency and chloroplast development. The crucial significance of SPL50 in cellular signaling and stress response is shown by its localization to the cytoplasm and constitutive expression in various plant tissues. In light of growing concerns regarding global food security, this study highlights the pivotal role of SPL50 in regulating programmed cell death (PCD) and enhancing the immune response in plants, contributing to strategies for improving crop disease resistance. CONCLUSIONS: The novel identification of the SPL50 gene in rice, encoding an ARM repeat protein, reveals its pivotal role in regulating PCD and innate immune responses independently of pathogen attack.

Cancer Stemness Online: A Resource for Investigating Cancer Stemness and Associations with Immune Response.

Cancer progression involves the gradual loss of a differentiated phenotype and the acquisition of progenitor and stem-cell-like features, which are potential culprits of immunotherapy resistance. Although the state-of-art predictive computational methods have facilitated the prediction of cancer stemness, currently there is no efficient resource that can meet various usage requirements. Here, we present the Cancer Stemness Online, an integrated resource for efficiently scoring cancer stemness potential at the bulk and single-cell levels. The resource integrates 8 robust predictive algorithms as well as 27 signature gene sets associated with cancer stemness for predicting stemness scores. Downstream analyses were performed from five different aspects, including identifying the signature genes of cancer stemness, exploring the associations with cancer hallmarks, cellular states, the immune response, and communication with immune cells; investigating the contributions to patient survival; and performing a robustness analysis of cancer stemness among different methods. Moreover, the pre-calculated cancer stemness atlas for more than 40 cancer types can be accessed by users. Both the tables and diverse visualizations of the analytical results are available for download. Together, Cancer Stemness Online is a powerful resource for scoring cancer stemness and expanding the downstream functional interpretation, including immune response as well as cancer hallmarks. Cancer Stemness Online is freely accessible at http://bio-bigdata.hrbmu.edu.cn/CancerStemnessOnline.

Second-Harmonic-Generation Switching via Pressure-Suppressed Dynamical Disorder.

Second-harmonic-generation (SHG) switching is an emerging phenomenon with potential applications in bistable storage and optical switches while also serving as a sensitive probe for inversion-symmetry. Temperature-induced disorder-order phase transition has been proven to be a rational design strategy for achieving SHG bi-state switching; however, pressure-sensitive SHG switching via a disorder-order structural transition mechanism is rarely reported and lacks sensitivity and cyclicity as practical switching materials. Herein, we demonstrate the pressure-induced "dynamical disorder-order" phase transition as an effective strategy for triggering SHG and SHG switching in NH4Cl. The "dynamical disorder-order" phase transition of NH4Cl occurring at as low as 1 GPa is confirmed by comprehensive in situ high-pressure XRD, molecular vibrational spectra, and Brillouin scattering spectra. The pressure-induced SHG is responsive to a wide excitation wavelength region (800-1500 nm), and the "off-on" switching is reversible for up to 50 cycles, setting a record for pressure-driven switching materials. It is worth noting that when pressure is further increased to 14 GPa, NH4Cl exhibits another SHG "on-off" switching, which makes it the first triplet SHG "off-on-off" switching material. Molecular dynamics simulations reveal the key role of N-H···Cl hydrogen bonding in the pressure-induced "dynamic disorder-order" mechanism. Finally, we verified that chemical pressure and physical pressure can jointly regulate the SHG switching behavior of NH4X (X = Cl, Br). The pressure-driven "dynamic disorder-order" transition mechanism sheds light on the rational design of multistable SHG switching materials for photoswitches and information storage.

MHC-I-presented non-canonical antigens expand the cancer immunotherapy targets in acute myeloid leukemia.

Identification of tumor neoantigens is indispensable for the development of cancer immunotherapies. However, we are still lacking knowledge about the potential neoantigens derived from sequences outside protein-coding regions. Here, we comprehensively characterized the immunopeptidome landscape by integrating multi-omics data in acute myeloid leukemia (AML). Both canonical and non-canonical MHC-associated peptides (MAPs) in AML were identified. We found that the quality and characteristics of ncMAPs are comparable or superior to cMAPs, suggesting ncMAPs are indispensable sources for tumor neoantigens. We further proposed a computational framework to prioritize the neoantigens by integrating additional transcriptome and immunopeptidome in normal tissues. Notably, 6 of prioritized 13 neoantigens were derived from ncMAPs. The expressions of corresponding source genes are highly related to infiltrations of immune cells. Finally, a risk model was developed, which exhibited good performance for clinical prognosis in AML. Our findings expand potential cancer immunotherapy targets and provide in-depth insights into AML treatment, laying a new foundation for precision therapies in AML.

Polyarteritis nodosa complicated by renal aneurysm and intestinal perforation: A case report.

RATIONALE: Polyarteritis nodosa (PAN) is a necrotizing vasculitis that affects small- and medium-sized arteries, presenting with diverse clinical manifestations. It can impact tissues and organs throughout the body and may be life-threatening in severe cases. Common causes of death include cardiac, renal, and gastrointestinal complications or aneurysm rupture. While separate reports of renal aneurysm and intestinal perforation exist, the coexistence of these conditions is rarely documented. This study reports a severe case of PAN complicated by both renal aneurysm and intestinal perforation, aiming to deepen the understanding of this disease, aid in clinical diagnosis and treatment, and improve patient prognosis. PATIENT CONCERNS: The patient presented to the hospital with dorsal foot pain and abdominal pain persisting for more than 4 months, along with pain and discomfort in both lower extremities for over 1 month. INTERVENTIONS: The patient was diagnosed with PAN, renal aneurysm, intestinal perforation, and grade 3 hypertension (high risk). OUTCOMES: After treatment, the patient showed normal temperature and blood pressure, relief from abdominal pain, and disappearance of myalgia and numbness in the lower limbs. Additionally, the renal aneurysm shrank significantly, the intestinal perforation healed, the ileostomy was reduced, and the patient's condition stabilized. LESSONS: The clinical symptoms of PAN mostly lack specificity, and should be distinguished from microscopic polyangiitis and simulated vasculitis. For patients with intestinal perforation similar to this case, tocilizumab treatment may be effective, but further research is needed to confirm it.

Characterization of the ddt1 Mutant in Rice and Its Impact on Plant Height Reduction and Water Use Efficiency.

Rice (Oryza sativa L.), a fundamental global staple, nourishes over half of the world's population. The identification of the ddt1 mutant in rice through EMS mutagenesis of the indica cultivar Shuhui527 revealed a dwarf phenotype, characterized by reduced plant height, smaller grain size, and decreased grain weight. Detailed phenotypic analysis and map-based cloning pinpointed the mutation to a single-base transversion in the LOC_Os03g04680 gene, encoding a cytochrome P450 enzyme, which results in a premature termination of the protein. Functional complementation tests confirmed LOC_Os03g04680 as the DDT1 gene responsible for the observed phenotype. We further demonstrated that the ddt1 mutation leads to significant alterations in gibberellic acid (GA) metabolism and signal transduction, evidenced by the differential expression of key GA-related genes such as OsGA20OX2, OsGA20OX3, and SLR1. The mutant also displayed enhanced drought tolerance, as indicated by higher survival rates, reduced water loss, and rapid stomatal closure under drought conditions. This increased drought resistance was linked to the mutant's improved antioxidant capacity, with elevated activities of antioxidant enzymes and higher expression levels of related genes. Our findings suggest that DDT1 plays a crucial role in regulating both plant height and drought stress responses. The potential for using gene editing of DDT1 to mitigate the dwarf phenotype while retaining improved drought resistance offers promising avenues for rice improvement.

Research Progress on Mechanical Strength of Rice Stalks.

As one of the most important food crops in the world, rice yield is directly related to national food security. Lodging is one of the most important factors restricting rice production, and the cultivation of rice varieties with lodging resistance is of great significance in rice breeding. The lodging resistance of rice is directly related to the mechanical strength of the stalks. In this paper, we reviewed the cell wall structure, its components, and its genetic regulatory mechanism, which improved the regulatory network of rice stalk mechanical strength. Meanwhile, we analyzed the new progress in genetic breeding and put forward some scientific problems that need to be solved in this field in order to provide theoretical support for the improvement and application of rice breeding.

Characteristics and Controlling Factors of Methane Adsorption of the Longmaxi Shale in Northeastern Chongqing: Implications for Shale Gas Occurrence in Complex Structural Areas.

Accurately determining the adsorption capacity of Longmaxi shale in complex structural areas is crucial for evaluating the shale gas resources in northeastern Chongqing. However, studies on the pore characteristics and methane adsorption capacity of these Longmaxi shales are currently limited. In this paper, we collected core samples from the YDB-1 well in northeastern Chongqing and determined the pore structure and adsorption capacity of the Longmaxi shale using low-pressure gas adsorption and high-temperature, high-pressure methane adsorption experiments, respectively. The results indicate that the adsorption capacity of shale in complex structural areas is significantly positively correlated with the organic matter (OM) content, weakly positively correlated with the quartz content, and weakly negatively correlated with clay minerals. Meanwhile, gas-in-place content is simultaneously controlled by the pressure and temperature of the reservoir, and with increasing depth, the adsorbed gas rapidly increases to a maximum value (at 0.8 km) and then slowly decreases, whereas the free gas continuously increases. Compared with the shale in the stable structural areas, the Longmaxi shale in complex structural areas usually develops OM-hosted pores and intergranular pores of OM and minerals and contains more micropores due to tectonic compression, resulting in a relatively larger specific surface area and adsorption capacity. This is the reason shale in complex structural areas has high development potential. The final result can provide an important basis for the evaluation of the gas content and the optimization of dessert areas in the Lower Paleozoic shale gas in southern China.

Associations of Cadmium Exposure with Peripheral Blood Cell Subtype Counts and Indices in Cadmium-Poisoned Mice.

This research was designed to investigate the effects of cadmium on blood cell injury in cadmium-poisoned mice. Twenty mice were randomly divided into two groups: control group and model group. The control group was intraperitoneally injected with normal saline every day and the model group was intraperitoneally injected with 1.4 mg/kg cadmium solution every day. The experimental period was 28 days. The blood of the mice was collected for detection and hematological analysis. The results demonstrated that cadmium increased the number of white blood cells and the number of neutrophils in mice. Cadmium reduced the number of eosinophils, the number of basophils, the number of monocytes, the amount of lymphocytes, the number of red blood cells, the hemoglobin concentration, mean corpusular volume, mean corpusular hemoglobin, mean corpusular hemoglobin concentration, and the number of platelets in mice. In summary, cadmium caused some damage to white blood cells, red blood cells, and platelets in mice, but the direction of damage to different cells was inconsistent. The possible reason for this result is that cadmium damages the generation of blood cells, and the body takes corresponding defense measures.

Effect of cadmium on histopathological injuries and ultra-structural changes of kidney of the turtle Mauremys reevesii.

This research investigated the effect of cadmium on the tissue and cell of kidney of the turtle Mauremys reevesii. Twenty turtles were injected with cadmium at 0, 7.5, 15, 30 mg/kg separately and five turtles were taken in each group at two weeks after exposure. Kidneys were immediately excised and macroscopic pathological changes were observed, then the kidneys were fixed in 4% paraformaldehyde for histopathological examination and fixed in 2.5% (v/v) glutaraldehyde for examination of ultra-structure. The tissues of kidney presented varying degrees of histopathological lesions in cadmium treated turtles by a dose-dependent manner under the light microscope. Under transmission electron microscope, renal tubules cells presented varying degrees of dose-dependent lesions. The results indicated that cadmium can cause cell damages to the kidney, in particular to the mitochondria. Mitochondria can be used as one biomarker in the monitoring of cadmium pollution and its quantitative risk assessments.

Prevalence and transmission of pretreatment drug resistance in people living with HIV-1 in Shanghai China, 2017-2021.

The implementation of pretreatment drug-resistance (PDR) surveillance among people living with HIV-1 (PLWH) is a top priority in countries using efavirenz (EFV)/nevirapine (NVP) for first-line ART. In this study, we assessed the prevalence of PDR among PLWH in Shanghai, China during 2017-2021, and to reveal PDR transmission between Shanghai and other regions of China. A total of 5050 PLWH not on ART during 2017-2021 were included. Partial HIV-1 pol sequences were amplified, sequenced, and analysed for drug-resistance mutations (DRMs). Besides, transmission network of PDR variants was inferred using HIV-TRACE. The overall prevalence of PDR was 4.8% (242/5050; 95% CI, 4.2-5.4). Prevalence of NNRTI-associated PDR was 3.9% (95% CI, 3.4-4.5), higher than those of NRTI-associated (0.8%; 95% CI, 0.5-1.1) and PI-associated PDR (0.9%; 95% CI, 0.6-1.2). High prevalence of PDR (especially high-level resistance) to EFV (132/5050, 2.6%) and NVP (137/5050, 2.7%) were found. CRF01_AE (46.0%) was the predominant HIV-1 genotype with any DRMs, followed by CRF55_01B (21.0%), and CRF07_BC (15.1%). Two NRTI-associated (S68G/N/R and T215A/N/S/Y), five NNRTI-associated (V179D/E/T/L, K103N/R/S/T, E138A/G/K, V106M/I/A and Y181C/I) and two PI-associated mutations (M46I/L/V and Q58E) were the most common observed DRMs in PDR patients in Shanghai. The vast majority of S68G occurred in CRF01_AE (45%). M46I/L/V and Q58E showed a relatively high prevalence in CRF01_AE (4.1%) and CRF07_BC (12.6%). Transmission network analyses demonstrated cross-regional transmission links of PDR variants between Shanghai and other regions of China, which was mainly driven by the potential low-level DRM V179D/E. These results provide crucial information for clinical decision making of first-line ART in PLWH with PDR.

Improving Proton-Conducting Stability by Regulating Pore Size of MOF Materials through Mixed Grinding.

An effective strategy to improve the proton conductivity of metal-organic frameworks (MOFs) is to regulate the pore size of composite materials. In this work, composite materials of MOF-808@MOG-808-X (X is the mass ratios of MOF-808 to MOG-808) was successfully prepared by grinding and blending. MOF-808@MOG-808-1:2 was optimal for its suitable pore structure, which facilitates the practical construction of hydrogen bonding networks, promotes rapid and stable proton conduction, and enables the proton conductivity, achieving a 1 + 1 > 2 effect. At 353 K and 93% relative humidity (RH), the maximum proton conductivity of MOF-808@MOG-808-1:2 reaches 1.08 × 10-1 S·cm-1. Next, MOF-808@MOG-808-1:2 was blended with chitosan (CS) to obtain composite proton exchange membranes (PEMs), namely, CS@MOF-808@MOG-808-1:2-Y (Y = 5%, 10%, or 15%) with the maximum proton conductivity reaching 1.19 × 10-2 S·cm-1 at 353 K and 93% RH for CS@MOF-808@MOG-808-1:2-10% with additional stability. The conductive mechanisms of the composite materials were revealed by activation energy calculation. This investigation not only proposes a simple grinding-blending method for the development of MOF-doped composite materials for proton conductivity but also provides a producting material basis for future applications of MOFs in proton exchange membrane fuel cells (PEMFCs).

Design, synthesis, and anti-oomycete activity of 3-acyloxymaltol/ethyl maltol derivatives.

Twenty 3-acyloxymaltol/ethyl maltol derivatives (7a-j and 8a-j) were synthesized and evaluated in vitro for their anti-oomycete activity against Phytophthora capsici, respectively. Among all of twenty derivatives, more than half of the compounds 7f, 7h, 8a-h and 8j had anti-oomycete activity higher than the positive control zoxamide (EC50 = 22.23 mg/L), and the EC50 values of 18.66, 20.32, 12.80, 16.18, 10.59, 14.98, 16.80, 10.36, 15.32, 12.64, and 13.59 mg/L, respectively. Especially, compounds 8c and 8f exhibited the best anti-oomycete activity against P. capsici with EC50 values of 10.59 and 10.36 mg/L, respectively. Overall, hydroxyl group of maltol/ethyl maltol is important active modification site.

Transparent Cellulose/Multi-Walled Carbon Nanotube Hybrids with Improved Ultraviolet-Shielding Properties Prepared from Cotton Textile Waste.

Plastics offer many advantages and are widely used in various fields. Nevertheless, most plastics derived from petroleum are slow to degrade due to their stable polymer structure, posing serious threats to organisms and ecosystems. Thus, developing environmentally friendly and biodegradable plastics is imperative. In this study, biodegradable cellulose/multi-walled carbon nanotube (MCNT) hybrid gels and films with improved ultraviolet-shielding properties were successfully prepared using cotton textile waste as a resource. It was proven that MCNTs can be dispersed evenly in cellulose without any chemical or physical pretreatment. It was found that the contents of MCNTs had obvious effects on the structures and properties of hybrid films. Particularly, the averaged transmittance of cellulose/MCNT composite films in the range of 320-400 nm (T320-400) and 290-320 nm (T290-320) can be as low as 19.91% and 16.09%, when the content of MCNTs was 4.0%, much lower than those of pure cellulose films (T320-400: 84.12% and T290-320: 80.03%). Meanwhile, the water contact angles of the cellulose/MCNT films were increased by increasing the content of MCNTs. Most importantly, the mechanical performance of cellulose/MCNT films could be controlled by the additives of glycerol and MCNTs. The tensile strength of the cellulose/MCNT films was able to reach as high as 20.58 MPa, while the elongation at break was about 31.35%. To summarize, transparent cellulose/MCNT composites with enhanced ultraviolet-shielding properties can be manufactured successfully from low-cost cotton textile waste, which is beneficial not only in terms of environmental protection, but also the utilization of natural resources.

New insights into black carbon light absorption enhancement: A comprehensive analysis of two differential behaviors.

High uncertainty in optical properties of black carbon (BC) involving heterogeneous chemistry has recently attracted increasing attention in the field of atmospheric climatology. To fill the gap in BC optical knowledge so as to estimate more accurate climate effects and serve the response to global warming, it is beneficial to conduct site-level studies on BC light absorption enhancement (Eabs) characteristics. Real-time surface gas and particulate pollutant observations during the summer and winter over Wuhan were utilized for the analysis of Eabs simulated by minimum R squared (MRS), considering two distinct atmospheric conditions (2015 and 2017). In general, differences in aerosol emissions led to Eabs differential behaviors. The summer average of Eabs (1.92 ± 0.55) in 2015 was higher than the winter average (1.27 ± 0.42), while the average (1.11 ± 0.20) in 2017 summer was lower than that (1.67 ± 0.69) in winter. Eabs and RBC (representing the mass ratio of non-refractory constituents to elemental carbon) constraints suggest that Eabs increased with the increase in RBC under the ambient condition enriched by secondary inorganic aerosol (SIA), with a maximum growth rate of 70.6% in 2015 summer. However, Eabs demonstrated a negative trend against RBC in 2017 winter due to the more complicated mixing state. The result arose from the opposite impact of hygroscopic SIA and absorbing OC/irregular distributed coatings on amplifying the light absorbency of BC. Furthermore, sensitivity analysis revealed a robust positive correlation (R > 0.9) between aerosol chemical compositions (including sulfate, nitrate, ammonium and secondary organic carbon), which could be significantly perturbed by only a small fraction of absorbing materials or restructuring BC through gaps filling. The above findings not only deepen the understanding of BC, but also provide useful information for the scientific decision-making in government to mitigate particulate pollution and obtain more precise BC radiative forcing.

Chicken gasdermins mediate pyroptosis after the cleavage by caspases.

Gasdermin (GSDM) proteins are executioners of pyroptosis in many species. Gasdermin proteins can be cleaved at their linker region between the amino domain (NT) and carboxyl domain (CT) by enzymes. The released GSDM-NTs bind cell membrane and form pores, thereby leading to the release of cellular components and lytic cell death. GSDM-mediated pyroptosis is considered to play important role in immune responses. However, little is known about the GSDM proteins and GSDM-mediated pyroptosis in birds. In the current study, genes encoding chicken gasdermin A (chGSDMA) and chGSDME were cloned. The cleavage of chGSDMA and chGSDME by chicken caspase-1 (chCASP1), chCASP3 and chCASP7 and the cleavage sites were determined. The chGSDMA-NT obtained form chCASP1-mediated cleavage and chGSDME-NT obtained from chCASP3/chCASP7-mediated cleavage could bind and damage cell membrane and lead to cell death of HEK293 cells. chGSDMA-NT also strongly localized to and formed puncta in nucleus. Besides, both chGSDMA-NT and chGSDME-NT showed growth inhibition and bactericidal activity to bacteria. In chickens challenged with Pasteurella multocida and Salmonella typhimurium, the expression of chGSDMA and chGSDME was upregulated and the activation of chCASP3 and the cleavage of chGSDME were observed. The work provides essential information for expanding our knowledge on pyroptosis in birds.

Brain radiotherapy and anlotinib control primary cardiac angiosarcoma with metastases: A case report.

RATIONALE: Primary cardiac angiosarcoma (PCA) is a rare and fatal disease with a poor prognosis. Whether the survival of PCA patients can be prolonged with additional treatment following complete surgical excision is controversial. PATIENT CONCERNS: In this case study, a 52-year-old male complained of chest tightness and pain for 7 days before admission into the hospital. Subsequently, he revisited the hospital because of dizziness and headache. DIAGNOSES: Initially, the patient was diagnosed with PCA in the right atrium by thoracic computed tomography (CT). Palliative resection identified brain, lung, and liver metastases. INTERVENTION: The patient accepted multimodal combination therapy, including first-line chemotherapy and then second-line anlotinib concurrent with brain radiotherapy and immunotherapy. OUTCOME: Although anlotinib combined with brain radiotherapy controlled the growth of intracranial lesions, progression-free survival (PFS) was only 5 months, and the overall survival (OS) was only 12 months. LESSON: The treatment for metastatic PCA needs an in-depth exploration.

Proposals for gas-detection improvement of the FeMPc monolayer towards ethylene and formaldehyde by using bimetallic synergy.

Development and fabrication of a novel gas sensor with superb performance are crucial for enabling real-time monitoring of ethylene (C2H4) and formaldehyde (H2CO) emissions from industrial manufacture. Herein, first-principles calculations and AIMD simulations were carried out to investigate the effect of the Fe-M dimer on the adsorption of C2H4 and H2CO on metal dimer phthalocyanine (FeMPc, M = Ti-Zn) monolayers, and the electronic structures and sensing properties of the above adsorption systems were systematically discussed. The results show that the FeMPc (M = Ti, V, Cr, Mn) monolayers interact with C2H4 and H2CO by chemisorption except for the FeMnPc/H2CO system, while the other adsorption systems are all characterized by physisorption. Interestingly, the adsorption strength of C2H4 and H2CO can be effectively regulated by the bimetallic synergy of the Fe-M dimer. Moreover, the FeCrPc and FeMnPc monolayers exhibit excellent sensitivity towards C2H4 and H2CO, and have short recovery time (4.69 ms-2.31 s) for these gases at room temperature due to the effective surface diffusion at 300 K. Consequently, the FeCrPc and FeMnPc materials can be utilized as high-performance, reusable gas sensors for detecting C2H4 and H2CO, and have promising applications in monitoring the release of ethylene and formaldehyde from industrial processes.

Chemical Cross-Linking Cellulose Aerogel-Based Triboelectric Nanogenerators for Energy Harvesting and Sensing Human Activities.

Zinc oxide (ZnO) is a widely employed material for enhancing the performance of cellulose-based triboelectric nanogenerators (C-TENGs). Our study provides a novel chemical interpretation for the improved output efficiency of ZnO in C-TENGs. C-TENGs exhibit excellent flexibility and integration, achieving a maximum open-circuit voltage (Voc) of 210 V. The peak power density is 54.4 µW/cm2 with a load resistance of 107 Ω, enabling the direct powering of 191 light-emitting diodes with the generated electrical output. Moreover, when deployed as self-powered sensors, C-TENGs exhibit prolonged operational viability and responsiveness, adeptly discerning bending and motion induced by human interaction. The device's sensitivity, flexibility, and stability position it as a promising candidate for a diverse array of energy-harvesting applications and advanced healthcare endeavors. Specifically, envisaging sensitized wearable sensors for human activities underscores the multifaceted potential of C-TENGs in enhancing both energy-harvesting technologies and healthcare practices.

Secure multi-path routing for Internet of Things based on trust evaluation.

In the realm of the Internet of Things (IoT), ensuring the security of communication links and evaluating the safety of nodes within these links remains a significant challenge. The continuous threat of anomalous links, harboring malicious switch nodes, poses risks to data transmission between edge nodes and between edge nodes and cloud data centers. To address this critical issue, we propose a novel trust evaluation based secure multi-path routing (TESM) approach for IoT. Leveraging the software-defined networking (SDN) architecture in the data transmission process between edge nodes, TESM incorporates a controller comprising a security verification module, a multi-path routing module, and an anomaly handling module. The security verification module ensures the ongoing security validation of data packets, deriving trust scores for nodes. Subsequently, the multi-path routing module employs multi-objective reinforcement learning to dynamically generate secure multiple paths based on node trust scores. The anomaly handling module is tasked with handling malicious switch nodes and anomalous paths. Our proposed solution is validated through simulation using the Ryu controller and P4 switches in an SDN environment constructed with Mininet. The results affirm that TESM excels in achieving secure data forwarding, malicious node localization, and the secure selection and updating of transmission paths. Notably, TESM introduces a minimal 12.4% additional forwarding delay and a 5.46% throughput loss compared to traditional networks, establishing itself as a lightweight yet robust IoT security defense solution.