Modulation of Charge Redistribution in Heterogeneous CoSe-Ni0.95Se Coupling with Ti3C2Tx MXene for Hydrazine-Assisted Water Splitting.

Integrating abundant dual sites of hydrazine oxidation reaction (HzOR) and hydrogen evolution reaction (HER) into one catalyst is extremely urgent toward energy-saving H2 production. Herein, CoSe-Ni0.95Se heterostructure coupling with Ti3C2Tx MXene (CoSe-Ni0.95Se/MXene) is fabricated on nickel foam (NF) to enhance the catalytic performance. The heterogeneous CoSe-Ni0.95Se and MXene coupling effect can change the coordination of Ni and Co, resulting in adjusted interfacial electronic field and enhanced electron transfer from Ni0.95Se to CoSe especially near MXene surface. Also, the appearance of MXene can anchor more active sites, thereby abundant nucleophilic CoSe and electrophilic Ni0.95Se are formed induced by the charge redistribution, which can tailor d-band center, moderate *H adsorption free energy (∆GH *) and facilitate adsorption/desorption for hydrazine intermediates, contributing to much enhanced HER and HzOR performance. For example, the low potentials of -160.8 and 116.1 mV at 400 mA cm-2 are seen for HER and HzOR with long-term stability of 7 days. When assembled as overall hydrazine splitting (OHzS), a small cell voltage of 0.35 V to drive 100 mA cm-2 is obtained. Such concept of integrating abundant nucleophilic and electrophilic dual sites and regulating their d-band centers can offer in-depth understandings to design efficient bifunctional HER and HzOR electrocatalysts.

Correction to "Multicomponent Approach for Stable Methylammonium-Free Tin-Lead Perovskite Solar Cells".

[This corrects the article DOI: 10.1021/acsenergylett.3c02426.].

Perioperative systemic and prophylactic intraperitoneal chemotherapy for type 4/large type 3 gastric cancer: DRAGON-10.

Large type 3 and type 4 gastric cancers (GC) have a significantly poor prognosis, primarily due to their high predisposition for peritoneal dissemination. The application of intraperitoneal chemotherapy has emerged as a viable therapeutic strategy for managing GC patients with peritoneal metastasis. This study is planned to enroll 37 resectable large type 3 or type 4 GC patients. These patients are scheduled to undergo a treatment comprising preoperative chemotherapy with paclitaxel, oxaliplatin and S-1, followed by D2 gastrectomy, and concluding with postoperative treatments that include prophylactic intraperitoneal chemotherapy. The study's primary objective is to evaluate the 3-year peritoneal recurrence rate. Secondary objectives are to assess the 3-year disease-free survival, 3-year overall survival and to monitor the adverse events.Clinical trial registration number: ChiCTR2400083253 (https://www.chictr.org.cn).

Gastric cancer (GC), specifically the large type 3 and type 4 kinds, is a serious health condition that often leads to a very poor chance of survival. This is mainly because these types of cancer easily spread to the lining of the abdomen, a process known as peritoneal dissemination. One way to tackle this issue is through a treatment known as intraperitoneal chemotherapy, which directly targets the abdominal lining to kill cancer cells. In our study, 37 resectable large type 3 and type 4 GC patients will receive a combination of chemotherapy drugs before undergoing surgery to remove the cancer. After surgery, they will receive additional treatment that combines chemotherapy into the abdomen with standard chemotherapy. The main goal of our study is to see if this treatment approach can reduce the chance of cancer returning to the abdominal lining within 3 years. We are also looking at how long patients remain free from cancer, their overall survival after 3 years, and any side effects they may experience from the treatment. This study aims to provide a clearer understanding of how effective this combined treatment is for patients with these aggressive types of GC, with the hope of improving their chances of survival and quality of life.

PTPRZ1 dephosphorylates and stabilizes RNF26 to reduce the efficacy of TKIs and PD-1 blockade in ccRCC.

Clear cell renal cell carcinoma (ccRCC), the most common subtype of renal cell carcinoma, often exhibits resistance to tyrosine kinase inhibitors (TKIs) when used as monotherapy. However, the integration of PD-1 blockade with TKIs has significantly improved patient survival, making it a leading therapeutic strategy for ccRCC. Despite these advancements, the efficacy of this combined therapy remains suboptimal, necessitating a deeper understanding of the underlying regulatory mechanisms. Through comprehensive analyses, including mass spectrometry, RNA sequencing, lipidomic profiling, immunohistochemical staining, and ex vivo experiments, we explored the interaction between PTPRZ1 and RNF26 and its impact on ccRCC cell behavior. Our results revealed a unique interaction where PTPRZ1 stabilized RNF26 protein expression by dephosphorylating it at the Y432 site. The modulation of RNF26 levels by PTPRZ1 was found to be mediated through the proteasome pathway. Additionally, PTPRZ1, via its interaction with RNF26, activated the TNF/NF-κB signaling pathway, thereby promoting cell proliferation, angiogenesis, and lipid metabolism in ccRCC cells. Importantly, inhibiting PTPRZ1 enhanced the sensitivity of ccRCC to TKIs and PD-1 blockade, an effect that was attenuated when RNF26 was simultaneously knocked down. These findings highlight the critical role of the PTPRZ1-RNF26 axis in ccRCC and suggest that combining PTPRZ1 inhibitors with current TKIs and PD-1 blockade therapies could significantly improve treatment outcomes for ccRCC patients.

Predicting suicidal behavior in individuals with depression over 50 years of age: Evidence from the UK biobank.

Objective: To construct applicable models suitable for predicting the risk of suicidal behavior among individuals with depression, particularly on the progression from no history of suicidal behavior to suicide attempts, as well as from suicidal ideation to suicide attempts. Methods: Based on a prospective cohort from the UK Biobank, a total of 55,139 individuals aged 50 and above with depression were enrolled in the study, among whom 29,528 exhibited suicidal behavior. Specifically, they were divided into control (25,611), suicidal ideation (24,361), and suicide attempt (5167) groups. Least absolute shrinkage and selection operator (LASSO) regression was used to identify a subset of important features for distinguishing suicidal ideation and suicide attempts. We used the Gradient Boosting Decision Tree (GBDT) algorithm with stratified 10-fold cross-validation and grid-search to construct the prediction models for suicidal ideation or suicide attempts. To address the dataset imbalance in classifying suicide attempts, we used random under-sampling. The SHapley Additive exPlanations (SHAP) were used to estimate the important variables in the GBDT model. Results: Significant differences in sociodemographic, economic, lifestyle, and psychological factors were observed across the three groups. Each classifier optimally utilized 8-11 features. Overall, the algorithms predicting suicide attempts demonstrated slightly higher performance than those predicting suicidal ideation. The GBDT classifier achieved the highest accuracy, with AUROC scores of 0.914 for suicide attempts and 0.803 for suicidal ideation. Distinctive predictive factors were identified for each group: while depression's inherent characteristics crucially distinguished the suicidal ideation group from controls, some key predictors, including the age of depression onset and childhood trauma events, were identified for suicide attempts. Conclusions: We established applicable machine learning-based models for predicting suicidal behavior, particularly suicide attempts, in individuals with depression, and clarified the differences in predictors between suicidal ideation and suicide attempts.

Effect of Exogenous Melatonin on Performance and Mastitis in Dairy Cows.

Mastitis is an important factor affecting the health of cows that leads to elevated somatic cell counts in milk, which can seriously affect milk quality and result in huge economic losses for the livestock industry. Therefore, the aim of this trial was to investigate the effect of melatonin on performance and mastitis in dairy cows. Forty-eight Holstein cows with a similar body weight (470 ± 10 kg), parity (2.75 ± 1.23), number of lactation days (143 ± 43 days), BCS (3.0-3.5), milk yield (36.80 ± 4.18 kg), and somatic cell count (300,000-500,000 cells/mL) were selected and randomly divided into four groups: control (CON group), trial Ⅰ (T80 group), trial Ⅱ (T120 group), and trial Ⅲ (T160 group). Twelve cows in trial groups I, II, and III were pre-dispensed 80, 120, and 160 mg of melatonin in edible glutinous rice capsules along with the basal ration, respectively, while the control group was fed an empty glutinous rice capsule along with the ration. The trial period was 37 days, which included a 7-day adaptive phase followed by a 30-day experimental period. At the end of the trial period, feeding was ended and the cows were observed for 7 days. Milk samples were collected on days 0, 7, 14, 21, 28, and 37 to determine the somatic cell number and milk composition. Blood samples were collected on days 0, 15, 30, and 37 of the trial to determine the serum biochemical indicators, antioxidant and immune indicators, and the amount of melatonin in the blood. The results showed that the somatic cell counts of lactating cows in the CON group were lower than those in the T120 group on days 14 (p < 0.05) and 28 (p < 0.01) at 1 week after melatonin cessation. The milk protein percentage and milk fat percentage of cows in the T120 group were higher than those in the CON group (p < 0.01). The total protein and globulin content in the T120 group were higher than those in the CON group (p < 0.01). In terms of antioxidant capacity and immunity, the cows 1 week after melatonin cessation showed higher superoxide dismutase activity and interleukin-10 contents (p < 0.01) compared with the CON group and lower malondialdehyde and tumor necrosis factor-alpha contents (p < 0.01) compared with the T120 group. The melatonin content in the T120 group was increased relative to that in the other groups. In conclusion, exogenous melatonin can increase the content of milk components, reduce the somatic cell count, and improve the antioxidant capacity and immune responses to a certain extent. Under the experimental conditions, 120 mg/day melatonin is recommended for mid- to late-lactation cows.

Supercapacitively Liquid-Solid Dual-State Optoelectronics.

Photo-transduction of solid-state optoelectronics occurs in semiconductors or their interfaces. Considering the confined active area and interfacial capacitance of solid-state materials, solid-state optoelectronics faces inherent limitations in photo-transduction, especially for bionic vision, and the performance is lower than that of living systems. For example, a photoreceptor generates pA-level photocurrent when absorbing a single photon. Here, a liquid-solid dual-state phototransistor is demonstrated, in which photo-transduction and modulation take place at the microporous interface between semiconductors and water, mimicking principles of the photoreceptor. When operating in the water, an orderly stacked photo-harvesting covalent organic framework layer generates supercapacitively photogating modulation of the channel conductivity via a dual-state interface, achieving responsivity of 4.6 × 1010 A W-1 and detectivity of 1.62 × 1016 Jones at room temperature, several orders of magnitude higher than other photodetectors. Such bio-inspired dual-state optoelectronics enables high-contrast scotopic neuromorphic imaging with responsivity greater than photoreceptors, holding promise for constructing optoelectronic systems with performance beyond conventional solid-state optoelectronics.

Two-Dimensional (2D) Conductive Metal-Organic Framework Thin Films: The Preparation and Applications in Electrochemistry.

Two-dimensional conductive MOF thin films have attracted attention due to their rich pore structure and unique electrical properties, and their applications in many fields, including batteries, sensing, supercapacitors, electrocatalysis, etc. This paper discusses several preparation methods for 2D conductive MOF thin films. And the applications of 2D conductive MOF thin films are summarized. In addition, the current challenges in the preparation of 2D conductive MOF thin films and the great potential in practical applications are discussed.

Functional characterization of prenyltransferases involved in de novo synthesis of isoprenoids in the leaf beetle Monolepta hieroglyphica.

Prenyltransferases play a pivotal role in the isoprenoid biosynthesis and transfer in insects. In the current study, two classes of prenyltransferases (MhieFPPS1 and MhieFPPS2, MhiePFT-ß and MhiePF/GGT-α) were identified in the leaf beetle, Monolepta hieroglyphica. Phylogenetic analysis revealed that MhieFPPS1, MhieFPPS2, MhiePFT-ß and MhiePF/GGT-α were clustered in one clade with homologous in insects. Moreover, MhieFPPS2 lacked one aspartate-rich motif SARM. Molecular docking and kinetic analysis indicated that the (E)-GPP displayed higher affinity with MhieFPPS1 compared to DMAPP within the binding pocket containing metal binding sites (MG). The other class of prenyltransferases (MhiePFT-ß and MhiePF/GGT-α) lack the aspartate-rich motif. Docking results indicated that binding site of MhiePFT-ß involved divalent metal ions (Zn) and bound farnesyl or geranylgeranyl. In vitro, only recombiant MhieFPPS1 could catalyze the formation of (E)-farnesol against different combination of substrates, including IPP/DMAPP and IPP/(E)-GPP, highlighting the importance of SARM for enzyme activities. Kinetic analysis further indicated that MhiePFT-ß operated via Zn2+-dependent substrate binding, while MhiePF/GGT-α stabilized the ß-subunit during catalytic reaction. These findings contribute to a valuable insight in to understanding of the mechanisms involved in the biosynthesis and delivery of isoprenoid products in beetles.

SENP1 prevents high fat diet-induced non-alcoholic fatty liver diseases by regulating mitochondrial dynamics.

Mitochondrial dynamics plays a crucial role in the occurrence and development of non-alcoholic fatty liver diseases (NAFLD). SENP1, a SUMO-specific protease, catalyzes protein de-SUMOylation and involves in various physiological and pathological processes. However, the exact role of SENP1 in NAFLD remains unclear. Therefore, we investigated the regulatory role of SENP1 in mitochondrial dynamics during the progression of NAFLD. In the study, the NAFLD in vivo model induced by high fat diet (HFD) and in vitro model induced by free fatty acids (FFA) were established to investigate the role and underlying mechanism of SENP1 through detecting mitochondrial morphology and dynamics. Our results showed that the down-regulation of SENP1 expression and the mitochondrial dynamics dysregulation occurred in the NAFLD, evidenced as mitochondrial fragmentation, up-regulation of p-Drp1 ser616 and down-regulation of MFN2, OPA1. However, over-expression of SENP1 significantly alleviated the NAFLD, rectified the mitochondrial dynamics disorder, reduced Cyt-c release and ROS levels induced by FFA or HFD; moreover, the over-expression of SENP1 also reduced the SUMOylation levels of Drp1 and prevented the Drp1 translocation to mitochondria. Our findings suggest that the possible mechanisms of SENP1 were through rectifying the mitochondrial dynamics disorder, reducing Cyt-c release and ROS-mediated oxidative stress. The findings would provide a novel target for the prevention and treatment of NALFD.

Barrier Membrane with Janus Function and Structure for Guided Bone Regeneration.

Guided bone regeneration (GBR) technology has been demonstrated to be an effective method for reconstructing bone defects. A membrane is used to cover the bone defect to stop soft tissue from growing into it. The biosurface design of the barrier membrane is key to the technology. In this work, an asymmetric functional gradient Janus membrane was designed to address the bidirectional environment of the bone and soft tissue during bone reconstruction. The Janus membrane was simply and efficiently prepared by the multilayer self-assembly technique, and it was divided into the polycaprolactone isolation layer (PCL layer, GBR-A) and the nanohydroxyapatite/polycaprolactone/polyethylene glycol osteogenic layer (HAn/PCL/PEG layer, GBR-B). The morphology, composition, roughness, hydrophilicity, biocompatibility, cell attachment, and osteogenic mineralization ability of the double surfaces of the Janus membrane were systematically evaluated. The GBR-A layer was smooth, dense, and hydrophobic, which could inhibit cell adhesion and resist soft tissue invasion. The GBR-B layer was rough, porous, hydrophilic, and bioactive, promoting cell adhesion, proliferation, matrix mineralization, and expression of alkaline phosphatase and RUNX2. In vitro and in vivo results showed that the membrane could bind tightly to bone, maintain long-term space stability, and significantly promote new bone formation. Moreover, the membrane could fix the bone filling material in the defect for a better healing effect. This work presents a straightforward and viable methodology for the fabrication of GBR membranes with Janus-based bioactive surfaces. This work may provide insights for the design of biomaterial surfaces and treatment of bone defects.

3D chitosan scaffolds loaded with ZnO nanoparticles for bone tissue engineering.

Bone defect has always been a difficult problem in clinical work. According to the current research results, tissue engineered scaffolds with a single function, structure, and composition are not sufficient to repair complex bone defects. In this work, a three-dimensional (3D) chitosan degradable composite scaffold loaded with zinc oxide (ZnO) was constructed, and the effect of ZnO content on scaffold performance and osteogenesis was explored. The 3D composite scaffold was prepared by freeze-drying technology. The microstructure, porosity, degradation performance, release performance, swelling performance, cytotoxicity, cell adhesion and osteogenic ability of ZnO nanoparticles and chitosan (ZnONPs/CS) composite scaffolds were measured. The results show that an appropriate amount of ZnO may be helpful to regulate the stability and degradation characteristics of the scaffold to a certain extent. Moreover, the composite scaffold could release ZnO into the simulated body fluid environment. The appropriate amount of ZnO helps to promote the proliferation, adhesion, and osteogenic differentiation of MC3T3-E1 cells. At a ZnO content of 3 wt%, both in vitro and vivo results showed relatively optimal biocompatibility and bioactivity of the scaffolds. This work could at least provide some positive insights for the selection of ZnO dosage, construction of chitosan-based 3D scaffolds, tissue engineering applications, and clinical treatment.

Dual-Wave ZnO Film Ultrasonic Transducers for Temperature and Stress Measurements.

ZnO film ultrasonic transducers for temperature and stress measurements with dual-mode wave excitation (longitudinal and shear) were deposited using the reactive RF magnetron sputtering technique on Si and stainless steel substrates and construction steel bolts. It was found that the position in the substrate plane had a significant effect on the structure and ultrasonic performance of the transducers. The transducers deposited at the center of the deposition zone demonstrated a straight columnar structure with a c-axis parallel to the substrate normal and the generation of longitudinal waves. The transducers deposited at the edge of the deposition zone demonstrated inclined columnar structures and the generation of dominant shear or longitudinal shear waves. Transducers deposited on the bolts with dual-wave excitation were used to study the effects of high temperatures in the range from 25 to 525 °C and tensile stress in the range from 0 to 268 MPa on ultrasonic response. Dependencies between changes in the relative time of flight and temperature or axial stress were obtained. The dependencies can be described by second-order functions of temperature and stress. An analysis of the contributions of thermal expansion, strain, and the speed of sound to changes in the time of flight was performed. At high temperatures, a decrease in the signal amplitude was observed due to the decreasing resistivity of the transducer. The ZnO ultrasonic transducers can be used up to temperatures of ~500 °C.

Alginate-based hydrogels mediated biomedical applications: A review.

With the development in the field of biomaterials, research on alternative biocompatible materials has been initiated, and alginate in polysaccharides has become one of the research hotspots due to its advantages of biocompatibility, biodegradability and low cost. In recent years, with the further understanding of microscopic molecular structure and properties of alginate, various physicochemical methods of cross-linking strategies, as well as organic and inorganic materials, have led to the development of different properties of alginate hydrogels for greatly expanded applications. In view of the potential application prospects of alginate-based hydrogels, this paper reviews the properties and preparation of alginate-based hydrogels and their major achievements in delivery carrier, dressings, tissue engineering and other applications are also summarized. In addition, the combination of alginate-based hydrogel and new technology such as 3D printing are also involved, which will contribute to further research and exploration.

Central nervous system disturbances by thiamethoxam in Japanese quail (Coturnix japonica): In vivo, ex vivo, and in silico study.

The neurotoxic effects of neonicotinoids (NEOs) have been widely reported in relation to the poisoning of wild birds, yet the underlying molecular mechanism has remained elusive. This study employed Japanese quails (Coturnix japonica) and primary quail embryonic neurons as in vivo and ex vivo models, respectively, to investigate the neurotoxic effects and mechanism of thiamethoxam (TMX), a representative neonicotinoid insecticide, at environmentally relevant concentrations. Following a 28-day exposure to TMX, metabolomic analysis of quail brain revealed TMX-induced changes in glutamatergic, GABA-ergic, and dopaminergic function. Subsequent ex vivo and in silico experimentation revealed that the activation of nicotinic acetylcholine receptors and calcium signaling, induced by clothianidin (CLO), the primary metabolite of TMX, served as upstream events for the alterations in neurotransmitter synthesis, metabolism, release, and uptake. Our findings propose that the disruption of the central nervous system, caused by environmentally significant concentrations of NEOs, may account for the avian poisoning events induced by NEOs.

Cytotoxic effects of NIR responsive chitosan-polymersome layer coated melatonin-upconversion nanoparticles on HGC27 and AGS gastric cancer cells: Role of the ROS/PI3K/Akt/mTOR signaling pathway.

In this study, a formulation of NaGdF4:Tm/Er@NaGdF4 (core@shell) UCNPs loaded with melatonin drug was synthesized. The novel melatonin-loaded UCNPs were then encapsulated within NIR-responsive biopolymeric chitosan (CS) based polymersome and investigated against gastric cancer (HGC27 & AGS) cells. The photolysis of the ONB moiety and disruption of the disulfide linkage in the polymersome induced by NIR light facilitated by the NaGdF4:Tm/Er@NaGdF4 UCNPs and GSH results in an increased release of melatonin drug. The DLS and zeta potential measurements exhibit a reduced particle size (21.9 ± 3.56 nm) and a low zeta potential (17.91 mV). Furthermore, drug release profiles demonstrated superior melatonin drug release (79.78 %) at pH 5.0 for CS-polymersome-coated melatonin-UCNPs resembling the Hixson-Crowell model. Remarkably, CS-polymersome-coated melatonin-UCNPs exhibit excellent anti-proliferative properties for HGC27 (IC50 = 0.096 µM) and AGS (IC50 = 0.16 µM) cancer cells. The flow cytometry data demonstrate a significant elevation in ROS levels which promoted cell death in both HGC-27 and AGS cells. The observed cell mortality in HGC-27 and AGS cells is primarily caused by the destruction of the nucleus, mtDNA, rupture of disulfide (R-S-S-R) bonds, and nuclear DNA. Contrarily, L929 and HUVECs cells incubated with CS-polymersome coated melatonin-UCNPs (100 µg/mL) reveal a notable cell viability of 88.7 % and 93 % indicating superior biocompatibility. The western blotting analysis revealed the induction of autophagy by CS-polymersome-coated melatonin-UCNPs which subsequently led to apoptosis by regulating the ROS/PI3K/Akt/mTOR molecular signaling pathway.

What drives college students to use AI for L2 learning? Modeling the roles of self-efficacy, anxiety, and attitude based on an extended technology acceptance model.

Prior research highlights the critical role of AI in enhancing second language (L2) learning. However, the factors that practically affect L2 learners to engage with AI resources are still underexplored. Given the widespread availability of digital devices among college students, they are particularly poised to benefit from AI-assisted L2 learning. As such, this study, grounded in an extended Technology Acceptance Model (TAM), investigates the predictors of college L2 learners' actual use of AI tools, focusing on AI self-efficacy, AI-related anxiety, and their overall attitude toward AI. Data was gathered from 429 L2 learners at Chinese universities via an online questionnaire, utilizing four established scales. Through structural equation modeling (SEM) via AMOS 24, the results indicate that AI self-efficacy could negatively affect AI anxiety, and positively influence both learners' attitude toward AI and their actual use of AI tools. Besides, AI anxiety negatively predicted the actual use of AI. Moreover, AI self-efficacy was a positive predictor of AI use through reducing AI anxiety, enhancing attitude toward AI, or a combination of both. This study also discusses the theoretical and pedagogical implications and suggests directions for future research.

Rational Fabrication of Nickel Vanadium Sulfide Encapsulated on Graphene as an Advanced Electrode for High-Performance Supercapacitors.

Supercapacitors (SCs) are widely recognized as competitive power sources for energy storage. The hierarchical structure of nickel vanadium sulfide nanoparticles encapsulated on graphene nanosheets (NVS/G) was fabricated using a cost-effective and scalable solvothermal process. The reaction contents of the composites were explored and optimized. TEM images displayed the nickel vanadium sulfide nanoparticles (NVS NPs) with 20-30 nm average size anchored to graphene nanosheets. The interconnection of graphene nanosheets encapsulating NVS nanoparticles effectively reduces the ion diffusion path between the electrode and electrolyte, thereby enhancing electrochemical performance. The NVS/G composite demonstrated improved electrochemical performance, achieving a maximum of 1437 F g-1 specific capacitance at 1 A g-1, remarkable rate capability retaining of 1050 F g-1 at 20 A g-1, and exceptional cycle stability with 91.2% capacitance retention following 10,000 cycles. The NVS/G composite was employed as a cathode, and reduced graphene oxide (rGO) was used as an anode material to assemble a device. Importantly, asymmetric SCs using NVS/G//rGO achieved 74.7 W h kg-1 energy density at 0.8 kW kg-1 power density, along with outstanding stability with 88.2% capacitance retention following 10,000 cycles. These superior properties of the NVS/G electrode highlight its significant potential in energy storage applications.

Microstructure and Mechanical Properties of the Powder Metallurgy Nb-16Si-24Ti-2Al-2Cr Alloy.

The Nb-16Si-24Ti-2Al-2Cr alloy was prepared by plasma rotating electrode process (PREP) technology and the hot-pressing (HP) method, and the effects of sintering temperature on the microstructure, mechanical properties and fracture behavior were investigated. The HP alloys sintered at temperatures below 1400 °C are composed of Nbss (Nb solid solution), Nb3Si and Nb5Si3 phases. When the sintering temperature reaches 1450 °C, the Nb3Si phase is completely decomposed into Nbss and Nb5Si3 phases. Meanwhile, the microstructure coarsens significantly. Compared with the cast alloy, the HP alloy shows better mechanical properties. The fracture toughness of the alloy sintered at 1400 °C reaches 20.2 MPa·m1/2, which exceeds the application threshold. The main reason for the highest fracture toughness is attributed to the decomposition of large-sized brittle Nb3Si phase and the formation of a fine microstructure, which greatly increases the number of phase interfaces and improves the chance of crack deflection. In addition, the reduction in the size and content of silicides also reduces their plastic constraints on the ductile Nbss phase.