Identification and characterization of two Bacillus anthracis bacteriophages.

Anthrax is an acute infectious zoonotic disease caused by Bacillus anthracis, a bacterium that is considered a potential biological warfare agent. Bacillus bacteriophages shape the composition and evolution of bacterial communities in nature and therefore have important roles in the ecosystem community. B. anthracis phages are not only used in etiological diagnostics but also have promising prospects in clinical therapeutics or for disinfection in anthrax outbreaks. In this study, two temperate B. anthracis phages, vB_BanS_A16R1 (A16R1) and vB_BanS_A16R4 (A16R4), were isolated and showed siphovirus-like morphological characteristics. Genome sequencing showed that the genomes of phages A16R1 and A16R4 are 36,569 bp and 40,059 bp in length, respectively. A16R1 belongs to the genus Wbetavirus, while A16R4 belongs to the genus Hubeivirus and is the first phage of that genus found to lyse B. anthracis. Because these two phages can comparatively specifically lyse B. anthracis, they could be used as alternative diagnostic tools for identification of B. anthracis infections.

Transcription factor GmAlfin09 regulates endoplasmic reticulum stress in soybean via peroxidase GmPRDX6.

Soybean (Glycine max [L.] Merr.) is a valuable oil crop but is also highly susceptible to environmental stress. Thus, developing approaches to enhance soybean stress resistance is vital to soybean yield improvement. In previous studies, transcription factor Alfin has been shown to serve as an epigenetic regulator of plant growth and development. However, no studies on Alfin have yet been reported in soybean. In this study, the endoplasmic reticulum (ER) stress- and reactive oxygen species (ROS)-related GmAlfin09 was identified. Screening of genes co-expressed with GmAlfin09 unexpectedly led to the identification of soybean peroxidase 6 (GmPRDX6). Further analyses revealed that both GmAlfin09 and GmPRDX6 were responsive to ER stress, with GmPRDX6 localizing to the ER under stress. Promoter binding experiments confirmed the ability of GmAlfin09 to bind to the GmPRDX6 promoter directly. When GmAlfin09 and GmPRDX6 were overexpressed in soybean, enhanced ER stress resistance and decreased ROS levels were observed. Together, these findings suggest that GmAlfin09 promotes the upregulation of GmPRDX6, and GmPRDX6 subsequently localizes to the ER, reduces ROS levels, promotes ER homeostasis, and ensures the normal growth of soybean even under ER stress. This study highlights a vital target gene for future molecular breeding of stress-resistant soybean lines.

Extreme condition-tolerant stretchable flexible supercapacitor and triboelectric nanogenerator based on carrageenan-enhanced gel for energy storage, energy collection and self-powered sensing.

As flexible electronics devices for energy storage, mechanical energy collection and self-powered sensing, stretchable flexible supercapacitor and triboelectric nanogenerator (TENG) have attracted extensive attention. However, it is difficult to satisfy the requirements of high safety and resistance to extreme conditions. Dual roles of mechanical and electrical enhancement of inorganic salt are put forward, and a carrageenan (CG) enhanced poly (N-hydroxyethyl acrylamide)/CG/lithium chloride/glycerol (PCLG) conductive gel is prepared by designing hydrogen bonding self-crosslinking and chain entanglement. A high concentration and rapid deposition strategy is proposed to prepare a PCLG gel-based stretchable flexible all-in-one supercapacitor for energy storage, and a single electrode PCLG gel-based TENG is designed for mechanical energy collection, self-powered strain and tactile sensing. The supercapacitor has high capacitance, excellent cycling stability. The TENG possesses efficient energy harvesting with high and stable output voltage and power density, and sensitive and stable self-powered strain and tactile sensing without external power supply. Even under extreme conditions such as low temperatures, self-healing after damage, prolonged placement, deformation, post-deformation, multiple continuous work, pinprick and burning, the supercapacitor and TENG still have excellent properties. Therefore, we provide novel ideas to design flexible supercapacitor and TENG used under extreme conditions for future wearable electronics.

Evaluating the psychometric properties of the simplified Chinese version of PROMIS-29 version 2.1 in patients with hematologic malignancies.

The Patient-Reported Outcomes Measurement Information System 29-item Profile version 2.1 (PROMIS-29 V2.1) is a widely utilized self-reported instrument for assessing health outcomes from the patients' perspectives. This study aimed to evaluate the psychometric properties of the PROMIS-29 V2.1 Chinese version among patients with hematological malignancy. Conducted as a cross-sectional, this research was approved by the Medical Ethical Committee of the Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College (registration number QTJC2022002-EC-1). We employed convenience sampling to enroll eligible patients with hematological malignancy from four tertiary hospitals in Tianjin, Shandong, Jiangsu, and Anhui province in China between June and August 2023. Participants were asked to complete a socio-demographic information questionnaire, the PROMIS-29 V2.1, and the Functional Assessment of Cancer Therapy-General (FACT-G). We assessed the reliability, ceiling and floor effects, structural, convergent discriminant and criterion validity of the PROMIS-29 V2.1. A total of 354 patients with a mean age of 46.93 years was included in the final analysis. The reliability of the PROMIS-29 V2.1 was affirmed, with Cronbach's α for the domains ranging from 0.787 to 0.968. Except sleep disturbance, the other six domains had ceiling effects, which were seen on physical function (26.0%), anxiety (37.0%), depression (40.4%), fatigue (18.4%), social roles (18.9%) and pain interference (43.2%), respectively. Criterion validity was supported by significant correlations between the PROMIS-29 V2.1 and FACT-G scores, as determined by the Spearman correlation test (P < 0.001). Confirmatory factor analysis (CFA) indicated a good model fit, with indices of χ2/df (2.602), IFI (0.960), and RMSEA (0.067). The Average Variance Extracted (AVE) values for the seven dimensions of PROMIS-29 V2.1, ranging from 0.500 to 0.910, demonstrated satisfactory convergent validity. Discriminant validity was confirmed by ideal √AVE values. The Chinese version of the PROMIS-29 V2.1 profile has been validated as an effective instrument for assessing symptoms and functions in patients with hematological malignancy, underscoring its reliability and applicability in this specific patient group.

In situ autophagy regulation in synergy with phototherapy for breast cancer treatment.

Autophagy is an important factor in reducing the efficacy of tumor phototherapy (including PTT and PDT). Accurate regulation of autophagy in tumor cells is a new strategy to improve the anti-tumor efficiency of PTT/PDT. This project intended to construct a tumor-activated autophagy regulator to efficiently block PTT/PDT-induced autophagy and realize synergistic sensitization to tumor phototherapy. To achieve this goal, we first synthesized TRANSFERRIN (Tf) biomimetic mineralized nano-tellurium (Tf-Te) as photosensitizer and then used disulfide bond reconstruction technology to induce Tf-Te self-assembly. The autophagy inhibitor hydroxychloroquine (HCQ) and iron ions carried by Tf were simultaneously loaded to prepare a tumor-responsive drug reservoir Tf-Te/HCQ. After entering breast cancer cells through the "self-guidance system", Tf-Te/HCQ can generate hyperpyrexia and ROS under NIR laser irradiation, to efficiently induce PTT/PDT effect. Meanwhile, the disulfide bond broke down in response to GSH, and the nanoparticles disintegrated to release Fe2+ and HCQ at fixed points. They simultaneously induce lysosomal alkalinization and increased osmotic pressure, effectively inhibit autophagy, and synergistically enhance the therapeutic effect of phototherapy. In vivo anti-tumor results have proved that the tumor inhibition rate of Tf-Te/HCQ can be as high as 88.6% on 4T1 tumor-bearing mice. This multifunctional drug delivery system might provide a new alternative for more precise and effective tumor phototherapy.

In-Sb Covalent Bonds over Sb2Se3/In2Se3 Heterojunction for Enhanced Photoelectrochemical Water Splitting.

Antimony selenide is a promising P-type photocatalyst, but it has a large number of deep energy level defects, leading to severe carrier recombination. The construction of a heterojunction is a common way to resolve this problem. However, the conventional heterojunction system inevitably introduces interface defects. Herein, we employ in situ synthesis to epitaxially grow In2Se3 nanosheets on Sb2Se3 nanorods and form In-Sb covalent interfacial bonds. This petal-shaped heterostructure reduced interface defects and enhanced the efficiency of carrier separation and transport. In this work, the photocurrent density in the proposed Sb2Se3/In2Se3 photocathode is 0.485 mA cm-2 at 0 VRHE, which is 30 times higher than that of pristine Sb2Se3 and it has prominent long-term stability for 24 h without obvious decay. The results reveal that the synergy of the bidirectional built-in electric field constructed between In2Se3 and Sb2Se3 and the solid In-Sb interfacial bonds together build a high-efficiency transport channel for the photogenerated carriers that display enhanced photoelectrochemical (PEC) water-splitting performance. This work provides efficient guidance for reducing interface defects via the in situ synthesis and construction of interfacial bonds.

Metaphire guillelmi exhibited predominant capacity of arsenic efflux.

Earthworm could regulate their body concentration of arsenic via storage or excretion, and the ability of As efflux among different earthworms is not consistent. Here, whole and semi As exposure patterns with 0-10-30-60-100 mg kg-1 exposure concentrations were set to characterize the As efflux in geophagous earthworm, Metaphire guillelmi. Cast As (As-C) and earthworms' antioxidative responses were monitored to explore the efflux mechanisms under 30 mg kg-1 As-spiked soil (As30), besides, As concentration in earthworm tissue after egestion and dissection depurations were compared. In the whole exposure pattern, As concentration in gut content (As-G, 19.2-120.3 mg kg-1) surpassed that in the tissue (As-T, 17.2-53.2 mg kg-1), and they both increased with exposure concentrations. With the prolong time, they firstly increased and kept stable between day 10-15, then As-G increased while As-T decreased between day 15-20. In the semi-exposure pattern, both As-G and As-T decreased when M. guillelmi was transferred to clean soil for 5 days. During the 42-day incubation in As30, the antioxidative responses including reactive oxygen species (ROS), glutathione (GSH) and glutathione-S-transferase (GST) were firstly increased and then decreased, and As-C (13.9-43.9 mg kg-1) kept higher than As-G (14.2-35.1 mg kg-1). Significantly positive correlations were found between As-T and GSH, As-C and GST. Moreover, tissue As after dissection (11.6-22.9 mg kg-1) was obviously lower than that after egestion (11.4-26.4 mg kg-1), but significantly related to ROS and GSH. Taken together, M. guillelmi exhibited excellent capacity of As efflux, and GSH explained tissue As accumulation while GST facilitated the As elimination via cast. Besides, dissection instead of egestion revealed the As efflux in M. guillelmi more accurately. These findings contributed to a better understanding of how geophagous earthworm M. guillelmi regulated tissue As accumulation for As stress tolerance, and recommended an optimal depuration mode to characterize As accumulation.

Formation and Application of Starch-Polyphenol Complexes: Influencing Factors and Rapid Screening Based on Chemometrics.

Understanding the nuanced interplay between plant polyphenols and starch could have significant implications. For example, it could lead to the development of tailor-made starches for specific applications, from bakinag and brewing to pharmaceuticals and bioplastics. In addition, this knowledge could contribute to the formulation of functional foods with lower glycemic indexes or improved nutrient delivery. Variations in the complexes can be attributed to differences in molecular weight, structure, and even the content of the polyphenols. In addition, the unique structural characteristics of starches, such as amylose/amylopectin ratio and crystalline density, also contribute to the observed effects. Processing conditions and methods will always alter the formation of complexes. As the type of starch/polyphenol can have a significant impact on the formation of the complex, the selection of suitable botanical sources of starch/polyphenols has become a focus. Spectroscopy coupled with chemometrics is a convenient and accurate method for rapidly identifying starches/polyphenols and screening for the desired botanical source. Understanding these relationships is crucial for optimizing starch-based systems in various applications, from food technology to pharmaceutical formulations.

A nomogram model of spectral CT quantitative parameters and clinical characteristics predicting lymphovascular invasion of gastric cancer.

Objective: The study established a nomogram based on quantitative parameters of spectral computed tomography (CT) and clinical characteristics, aiming to evaluate its predictive value for preoperative lymphovascular invasion (LVI) in gastric cancer (GC). Methods: From December 2019 to December 2021, 171 patients with pathologically confirmed GC were retrospectively collected with corresponding clinical data and spectral CT quantitative data. Patients were divided into LVI-positive and LVI-negative groups based on their pathological results. The univariate and multivariate logistic regression analyses were used to identify the risk factors and construct a nomogram. The calibration curve and receiver operating characteristic (ROC) curve were adopted to evaluate the predictive accuracy of nomogram. Results: Four clinical characteristics or spectral CT quantitative parameters, including Borrmann classification (P = 0.039), CA724 (P = 0.007), tumor thickness (P = 0.031), and iodine concentration in the venous phase (VIC) (P = 0.004) were identified as independent factors for LVI in GC patients. The nomogram was established based on the four factors, which had a potent predictive accuracy in the training, internal validation and external validation cohorts, with the area under the ROC curve (AUC) of 0.864 (95% CI, 0.798-0.930), 0.964 (95% CI, 0.903-1.000) and 0.877 (95% CI, 0.759-0.996), respectively. Conclusion: This study constructed a comprehensive nomogram consisting spectral CT quantitative parameters and clinical characteristics of GC, which exhibited a robust efficiency in predicting LVI in GC patients.

STING Agonist cGAMP Attenuates Sleep Deprivation-Induced Neuroinflammation and Cognitive Deficits via TREM2 Up-Regulation.

Sleep deprivation (SD) has been associated with several adverse effects, including cognitive deficit. Emerging evidence suggests microglia-associated neuroinflammation is a potential trigger of cognitive deficit after SD. Stimulator of interferon genes (STING) constitutes an important factor in host immune response to pathogenic organisms and is found in multiple cells, including microglia. STING is involved in neuroinflammation during neuronal degeneration, although how STING signaling affects SD-induced neuroinflammation remains unexplored. In the present study, the chronic sleep restriction (CSR) model was applied to examine the effects of STING signaling on cognition. The results revealed that cGAMP, a high-affinity and selective STING agonist, significantly improved cognitive deficit, alleviated neural injury, and relieved neuroinflammation in CSR mice by activating the STING-TBK1-IRF3 pathway. Moreover, triggering receptor expressed on myeloid cells 2 (TREM2) was upregulated in CSR mice treated with cGAMP, and this effect was abolished by STING knockout. TREM2 upregulation induced by cGAMP regulated the microglia from pro-inflammatory state to anti-inflammatory state, thereby relieving neuroinflammation in CSR mice. These findings indicate cGAMP-induced STING signaling activation alleviates SD-associated neuroinflammation and cognitive deficit by upregulating TREM2, providing a novel approach for the treatment of SD-related nerve injury.

Differentially Expressed Genes Identification of Kohlrabi Seedlings (Brassica oleracea var. caulorapa L.) under Polyethylene Glycol Osmotic Stress and AP2/ERF Transcription Factor Family Analysis.

Osmotic stress is a condition in which plants do not get enough water due to changes in environmental factors. Plant response to osmotic stress is a complex process involving the interaction of different stress-sensitive mechanisms. Differentially expressed genes and response mechanisms of kohlrabi have not been reported under osmotic stress. A total of 196,642 unigenes and 33,040 differentially expressed unigenes were identified in kohlrabi seedlings under polyethylene glycol osmotic stress. AP2/ERF, NAC and eight other transcription factor family members with a high degree of interaction with CAT and SOD antioxidant enzyme activity were identified. Subsequently, 151 AP2/ERF genes were identified and analyzed. Twelve conserved motifs were searched and all AP2/ERF genes were clustered into four groups. A total of 149 AP2/ERF genes were randomly distributed on the chromosome, and relative expression level analysis showed that BocAP2/ERF genes of kohlrabi have obvious specificity in different tissues. This study lays a foundation for explaining the osmotic stress resistance mechanism of kohlrabi and provides a theoretical basis for the functional analysis of BocAP2/ERF transcription factor family members.

Endogenous IAA affected fluoranthene accumulation by regulating H+-ATPase and SOD activity in ryegrass.

This study explores the role of endogenous indole-3-acetic acid (IAA) in modulating plant responses to pollution stress and its effect on pollutant accumulation, with a focus on fluoranthene (Flu) in ryegrass. To elucidate the mechanism, we employed an IAA promoter (α-aminobutyric acid [α-AB]) and an IAA inhibitor (naphthylphthalamic acid [NPA]) to regulate IAA levels and analyze Flu uptake characteristics. The experimental setup included a Flu treatment group (ryegrass with Flu addition) and a control group (ryegrass without Flu). Our findings demonstrate that Flu treatment enhanced IAA content and plant growth in ryegrass compared to the control. The Flu+AB treatment further enhanced these effects, while the Flu+NPA treatment exhibited a contrasting trend. Moreover, Flu+AB treatment led to increased Flu accumulation, in contrast to the inhibitory effect observed with Flu+NPA treatment. Flu treatment also enhanced the activities of key antioxidant enzymes (SOD, POD, CAT) and increased soluble sugar and protein levels, indicative of enzymatic and nonenzymatic defense responses, respectively. The Flu+AB treatment amplified these responses, whereas the Flu+NPA treatment attenuated them. Significantly, Flu treatment raised H+-ATPase activity compared to the control, an effect further elevated by Flu+AB treatment and diminished by Flu+NPA treatment. A random forest analysis suggested that Flu accumulation dependency varied under different treatments: it relied more on H+-ATPase activity under Flu+AB treatment and more on SOD activity under Flu+NPA treatment. Additionally, Flu+AB treatment boosted the transpiration rate in ryegrass, thereby increasing the Flu translocation factor, a trend reversed by Flu+NPA treatment. This research highlights crucial factors influencing Flu accumulation in ryegrass, offering potential new avenues for controlling the gathering of contaminants within plant systems.

Gastric Type Endocervical Adenocarcinoma With Concurrent High-Grade Squamous Intraepithelial Lesion: A Clinicopathologic Study of Three Patients.

OBJECTIVE: We investigate gastric-type endocervical adenocarcinoma (ECA), a prominent HPV-independent adenocarcinoma, and its coexistence with high-grade squamous intraepithelial lesion (HSIL) through the examination of three such tumors. METHODS: In this study, we conducted an in-depth review of three patients with gastric-type ECA, each associated with high-risk HPV infection as detected on Pap smears. We detailed the clinical and pathological features of each patient and utilized RNAscope for high-risk HPV testing to ascertain HPV status in both gastric-type ECA and HSIL components. Immunohistochemistry with p16, p53, and other biomarkers was also applied. RESULTS: The gastric-type ECA component, characterized by well-differentiated glands with abundant, clear to eosinophilic cytoplasm, distinct cellular borders, and pale nuclei with conspicuous nucleoli, tested negative for both p16 and high-risk HPV, unlike the concurrent HSIL components which were positive. Additionally, two tumors showed aberrant p53 protein expression in the gastric-type ECA areas, and elevated carbohydrate antigen19-9 levels were noted in two patients. Treatment consisted of total abdominal hysterectomy and bilateral salpingo-oophorectomy, supplemented by chemotherapy and/or radiation, with disease-free intervals of 24, 12, and 40 months post-treatment, respectively. CONCLUSION: This study highlights the critical need for meticulous diagnostic protocols that combine morphological examination, immunohistochemistry, and HPV RNA in situ hybridization. The rarity of gastric-type ECA coexisting with HPV infection underscores the necessity for continuous research and vigilant monitoring in the field of gynecological oncology.

Evaluation of serum CA125, HE4 and CA724 and the risk of ovarian malignancy algorithm score in the diagnosis of high-grade serous ovarian cancer.

AIM: To develop a new algorithm for the detection of high-grade serous ovarian cancer (HGSOC). METHODS: Patients diagnosed with HGSOC, borderline ovarian tumours (BOTs) or benign ovarian masses (BOMs) were enrolled between February 2019 and December 2020. Patients with BOTs or BOMs were grouped as non-HGSOC. The cases were divided randomly into a training cohort (two-thirds of cases) and a validation cohort (one-third of cases). Logistic regression was used to find risk factors for HGSOC and to create a new algorithm in the training cohort. Receiver operating characteristic curves were used to compare the diagnostic value of tumour biomarkers. Sensitivity and specificity of tumour markers and the new algorithm were calculated in the training cohort and validation cohort. RESULTS: This study found significant differences in age; BRCA1/2 mutation status; CA125, CA724 and HE4 levels; and Risk of Ovarian Malignancy Algorithm score between the two groups.Logistic regression analysis showed that CA125 and BRCA1/2 were risk factors for HGSOC. A new algorithm combining CA125 and BRCA1/2 increased the specificity of CA125 for diagnosis of HGSOC. The new algorithm had sensitivity of 81.08% and specificity of 93.10% in the training cohort. CONCLUSION: The new algorithm using CA125 and BRCA1/2 helped to distinguish between patients with HGSOC and patients with non-HGSOC.

Enzyme-Triggered Polyelectrolyte Complex for Responsive Delivery of α-Helical Polypeptides to Optimize Antibacterial Therapy.

Responsive nanomaterials hold significant promise in the treatment of bacterial infections by recognizing internal or external stimuli to achieve stimuli-responsive behavior. In this study, we present an enzyme-responsive polyelectrolyte complex micelles (PTPMN) with α-helical cationic polypeptide as a coacervate-core for the treatment of Escherichia coli (E. coli) infection. The complex was constructed through electrostatic interaction between cationic poly(glutamic acid) derivatives and phosphorylation-modified poly(ethylene glycol)-b-poly(tyrosine) (PEG-b-PPTyr) by directly dissolving them in aqueous solution. The cationic polypeptide adopted α-helical structure and demonstrated excellent broad-spectrum antibacterial activity against both Gram-negative and Gram-positive bacteria, with a minimum inhibitory concentration (MIC) as low as 12.5 µg mL-1 against E. coli. By complexing with anionic PEG-b-PPTyr, the obtained complex formed ß-sheet structures and exhibited good biocompatibility and low hemolysis. When incubated in a bacterial environment, the complex cleaved its phosphate groups triggered by phosphatases secreted by bacteria, exposing the highly α-helical conformation and restoring its effective bactericidal ability. In vivo experiments confirmed accelerated healing in E. coli-infected wounds.

Mitofilin in cardiovascular diseases: Insights into the pathogenesis and potential pharmacological interventions.

The impact of mitochondrial dysfunction on the pathogenesis of cardiovascular disease is increasing. However, the precise underlying mechanism remains unclear. Mitochondria produce cellular energy through oxidative phosphorylation while regulating calcium homeostasis, cellular respiration, and the production of biosynthetic chemicals. Nevertheless, problems related to cardiac energy metabolism, defective mitochondrial proteins, mitophagy, and structural changes in mitochondrial membranes can cause cardiovascular diseases via mitochondrial dysfunction. Mitofilin is a critical inner mitochondrial membrane protein that maintains cristae structure and facilitates protein transport while linking the inner mitochondrial membrane, outer mitochondrial membrane, and mitochondrial DNA transcription. Researchers believe that mitofilin may be a therapeutic target for treating cardiovascular diseases, particularly cardiac mitochondrial dysfunctions. In this review, we highlight current findings regarding the role of mitofilin in the pathogenesis of cardiovascular diseases and potential therapeutic compounds targeting mitofilin.

Highly efficient anion exchange membrane water electrolyzers via chromium-doped amorphous electrocatalysts.

In-depth comprehension and modulation of the electronic structure of the active metal sites is crucial to enhance their intrinsic activity of electrocatalytic oxygen evolution reaction (OER) toward anion exchange membrane water electrolyzers (AEMWEs). Here, we elaborate a series of amorphous metal oxide catalysts (FeCrOx, CoCrOx and NiCrOx) with high performance AEMWEs by high-valent chromium dopant. We discover that the positive effect of the transition from low to high valence of the Co site on the adsorption energy of the intermediate and the lower oxidation barrier is the key factor for its increased activity by synchrotron radiation in-situ techniques. Particularly, the CoCrOx anode catalyst achieves the high current density of 1.5 A cm-2 at 2.1 V and maintains for over 120 h with attenuation less than 4.9 mV h-1 in AEMWE testing. Such exceptional performance demonstrates a promising prospect for industrial application and providing general guidelines for the design of high-efficiency AEMWEs systems.

Self-Assembly Intermetallic PtCu3 Core with High-Index Faceted Pt Shell for High-Efficiency Oxygen Reduction.

Rational design of well-defined active sites is crucial for promoting sluggish oxygen reduction reactions. Herein, leveraging the surfactant-oriented and solvent-ligand effects, we develop a facile self-assembly strategy to construct a core-shell catalyst comprising a high-index Pt shell encapsulating a PtCu3 intermetallic core with efficient oxygen-reduction performance. Without undergoing a high-temperature route, the ordered PtCu3 is directly fabricated through the accelerated reduction of Cu2+, followed by the deposition of the remaining Pt precursor onto its surface, forming high-index steps oriented by the steric hindrance of surfactant. This approach results in a high half-wave potential of 0.911 V versus reversible hydrogen electrode, with negligible deactivation even after 15000-cycle operation. Operando spectroscopies identify that this core-shell catalyst facilitates the conversion of oxygen-involving intermediates and ensures antidissolution ability. Theoretical investigations rationalize that this improvement is attributed to reinforced electronic interactions around high-index Pt, stabilizing the binding strength of rate-determining OHads species.

Uncovering Structural Evolution during the Dealloying Process in Pt-Based Oxygen-Reduction Catalyst.

The comprehensive understanding toward the dealloying process is crucial for designing alloy catalysts employed in the oxygen reduction reaction (ORR). However, the specific leaching procedure and subsequent reconstruction of the dealloyed catalyst still remain unclear. Herein, we employ in situ X-ray absorption fine structure spectroscopy to monitor the dealloying process of a two-dimensional PtTe ordered alloy, known for its enhanced ORR activity. Our findings reveal the unsynchronous evolutions of Pt and Te sites, wherein the Pt component undergoes a structural transformation prior to the complete leaching of Te, leading to the formation of a defect-rich Pt catalyst. This dealloyed catalyst exhibits a significant enhancement in ORR activity, featuring a half-wave potential of 0.90 V versus the reversible hydrogen electrode and a mass activity of 0.62 A mgPt-1, outperforming the performance of commercial Pt/C counterpart. This in-depth understanding of the dealloying mechanism enriches our knowledge for the development of high-performance Pt-based alloy catalysts.