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Genome duplication occurs while the template DNA is bound by numerous DNA-binding proteins. Each of these proteins act as potential roadblocks to the replication fork and can have deleterious effects on cells. In Escherichia coli, these roadblocks are displaced by the accessory helicase Rep, a DNA translocase and helicase that interacts with the replisome. The mechanistic details underlying the coordination with replication and roadblock removal by Rep remain poorly understood. Through real-time fluorescence imaging of the DNA produced by individual E. coli replisomes and the simultaneous visualization of fluorescently-labeled Rep, we show that Rep continually surveils elongating replisomes. We found that this association of Rep with the replisome is stochastic and occurs independently of whether the fork is stalled or not. Further, we visualize the efficient rescue of stalled replication forks by directly imaging individual Rep molecules as they remove a model protein roadblock, dCas9, from the template DNA. Using roadblocks of varying DNA-binding stabilities, we conclude that continuation of synthesis is the rate-limiting step of stalled replication rescue.

Elongation by RNA polymerase is dynamically modulated by accessory factors. The transcription-repair coupling factor (TRCF) recognizes paused/stalled RNAPs and either rescues transcription or initiates transcription termination. Precisely how TRCFs choose to execute either outcome remains unclear. With Escherichia coli as a model, we used single-molecule assays to study dynamic modulation of elongation by Mfd, the bacterial TRCF. We found that nucleotide-bound Mfd converts the elongation complex (EC) into a catalytically poised state, presenting the EC with an opportunity to restart transcription. After long-lived residence in this catalytically poised state, ATP hydrolysis by Mfd remodels the EC through an irreversible process leading to loss of the RNA transcript. Further, biophysical studies revealed that the motor domain of Mfd binds and partially melts DNA containing a template strand overhang. The results explain pathway choice determining the fate of the EC and provide a molecular mechanism for transcription modulation by TRCF.

Genome duplication occurs while the template DNA is bound by numerous DNA-binding proteins. Each of these proteins act as potential roadblocks to the replication fork and can have deleterious effects on cells. InEscherichia coli, these roadblocks are displaced by the accessory helicase Rep, a DNA translocase and helicase that interacts with the replisome. The mechanistic details underlying the coordination with replication and roadblock removal by Rep remain poorly understood. Through real-time fluorescence imaging of the DNA produced by individualE. colireplisomes and the simultaneous visualization of fluorescently-labeled Rep, we show that Rep continually surveils elongating replisomes. We found that this association of Rep with the replisome is stochastic and occurs independently of whether the fork is stalled or not. Further, we visualize the efficient rescue of stalled replication forks by directly imaging individual Rep molecules as they remove a model protein roadblock, dCas9, from the template DNA. Using roadblocks of varying DNA-binding stabilities, we conclude that replication restart is the rate-limiting step of stalled replication rescue.

The Humulus japonicus pollen is one of the most common allergenic pollens in China. However, little is unveiled regarding the allergenic components in Humulus japonicus pollen. Our study aimed to purify and identify the pathogenesis-related 1 (PR-1) protein from Humulus japonicus pollen, and to characterize the molecular and immunochemical properties of this novel allergen.The natural PR-1 protein (named as Hum j PR-1) was purified from Humulus japonicus pollen extracts with a combined strategy of chromatography, and identified by mass spectrometry. The coding sequence of Hum j PR-1 was confirmed by cDNA cloning. The recombinant Hum j PR-1 was expressed and purified from Escherichia coli. The allergenicity was assessed by immunoblot, enzyme-linked immunosorbent assay (ELISA), inhibition ELISA, and basophil activation test using Humulus japonicus allergic patients' whole blood. The physicochemical properties and 3-dimensional structure of it were comprehensively characterized by in silico methods.The allergenicity analysis revealed that 76.6 % (23/30) of the Humulus japonicus pollen allergic patients displayed specific IgE recognition of the natural Hum j PR-1. The cDNA sequence of Hum j PR-1 had a 516-bp open reading frame encoding 171 amino acids. Physicochemical analysis indicated that Hum j PR-1 was a stable and relatively thermostable protein. Hum j PR-1 shared a similar 3-dimensional folding pattern with other homologous allergens, which was a unique αβα sandwich structure containing 4 α-helices and 6 antiparallel β-sheets, encompassing 4 conserved CAP domain.The natural PR-1 was firstly purified and characterized as a major allergenic allergen in Humulus japonicus pollen. These findings would contribute to developing diagnostic and therapeutic strategies for Humulus japonicus pollinosis.

In Escherichia coli, the DnaB helicase forms the basis for the assembly of the DNA replication complex. The stability of DnaB at the replication fork is likely important for successful replication initiation and progression. Single-molecule experiments have significantly changed the classical model of highly stable replication machines by showing that components exchange with free molecules from the environment. However, due to technical limitations, accurate assessments of DnaB stability in the context of replication are lacking. Using in vitro fluorescence single-molecule imaging, we visualise DnaB loaded on forked DNA templates. That these helicases are highly stable at replication forks, indicated by their observed dwell time of ∼30 min. Addition of the remaining replication factors results in a single DnaB helicase integrated as part of an active replisome. In contrast to the dynamic behaviour of other replisome components, DnaB is maintained within the replisome for the entirety of the replication process. Interestingly, we observe a transient interaction of additional helicases with the replication fork. This interaction is dependent on the τ subunit of the clamp-loader complex. Collectively, our single-molecule observations solidify the role of the DnaB helicase as the stable anchor of the replisome, but also reveal its capacity for dynamic interactions., Graphical Abstract Graphical AbstractSingle-molecule observation of the DnaB helicase in E. coli DNA replication shows a single, stably-integrated helicase supports replication, with additional helicases able to interact via available τ subunits.

AI techniques are pervading the medical field and facilitating the related educational applications, such as computer aided medical diagnosis, online surgery platforms and medical learning environments. Nowadays daily medical images and data come into being the big medical data need be processed as fast as possible. AI enables human to improve the accuracy and efficiency of diagnosis greatly relying on the techniques of radiological images analysis. In this paper one 7-layer deep Convolutional Neural Network (CNN) is designed to classify renal lesion in kidney Computed Tomography (CT) images. The CNN is trained on a middle-size dataset with 614 kidney CT images collected from real clinical data. Experiments show the mean and standard deviation of the overall accuracy of the binary classification reaches 90.36 ±1.02%. It has greatly better performance about 25% than the traditional Probability Neural Network (PNN) method with predefined features. The optimal structure of this CNN proves our method is rather promising to help doctors make medical diagnosis.

At present, the continuous accumulation of the flue gas desulfurization (FGD) gypsum in steel plants leads to the serious environmental issues and resource waste. To achieve green and sustainable development for the steel industry, it is significant to improve the usage of by-product gypsum. Employing the sintering FGD gypsum, ferric oxide, and graphite carbon as raw materials, the effects of the carbon content, reaction time, and molar ratio of CaO to Fe2O3 on the desulfurization rate of gypsum were studied based on the orthogonal experiment. The results show that the order of the three influencing factors on the desulfurization rate of FGD gypsum is: molar ratio of CaO to Fe2O3 > reaction time > carbon content. Under the optimal conditions of 20 wt.% carbon content, 4 h reaction time, and 1:1 molar ratio of CaO to Fe2O3, the desulfurization rate of desulfurization gypsum is 95.79%, and 97.57 wt.% of calcium ferrite appears in the solid product, which can be used as sintering additive to increase the economic benefits of enterprises and realize the green ecological development mode of internal generation and internal digestion of solid waste in iron and steel enterprises.

The pollen from Platanus acerifolia (P. acerifolia) is one of the main causes of allergic disorders. To date, only 4 allergens have been identified from this pollen. But previous studies showed that there still exist under-recognized allergens in it. The aim of this study was to comprehensively investigate the newly identified enolase (Pla a 6) as a novel allergen in the P. acerifolia pollen.The natural (n) Pla a 6 was purified by combined chromatographic strategies. According to the identified internal peptides, the cDNA sequence encoding this allergen was matched from the mRNA-sequencing results of P. acerifolia pollen, which was further amplified and cloned. The recombinant (r) Pla a 6 was expressed and purified from E. coli. The allergenicity of this novel allergen was characterized by enzyme linked immunosorbent assay (ELISA), Western blot, inhibition ELISA, and basophil activation test (BAT).A novel allergen from P. acerifolia pollen, named as Pla a 6 was thoroughly studied, which contained an open reading frame of 1338 bp encoding 445 amino acids. The IgE-binding activity of nPla a 6 was initially proved by Western-blot, and a similar IgE-binding pattern to rPla a 6 was also exhibited. Moreover, the positivity for specific IgE against rPla a 6 was tested as 45.95% (17/37) by ELISA, and IgE binding to pollen extract could be inhibited up to 45.77% by 10 µg/ml of rPla a 6. The protein was also confirmed to activate patients' basophils.In this study, a novel allergen belonging to enolase family was comprehensively investigated and characterized through its natural and recombinant forms in P. acerifolia pollen. The study will contribute to the development of novel molecular-based diagnostic and therapeutic approaches for P. acerifolia pollen allergy.

INTRODUCTION The efficacy of vitamin D for migraine remains controversial. We conduct a systematic review and meta-analysis to explore the influence of vitamin D versus placebo on treatment in migraine patients. METHODS We search PubMed, EMbase, Web of Science, EBSCO, and Cochrane library databases through April 2020 for randomized controlled trials assessing the effect of vitamin D versus placebo on treatment efficacy in migraine patients. This meta-analysis is performed using the random-effect model. RESULTS Five randomized controlled trials are included in the meta-analysis. Overall, compared with control group in migraine patients, vitamin D treatment is associated with substantially reduced number of headache days (standard mean difference [SMD], -0.53; 95% confidence interval [CI], -0.83 to -0.23; P = 0.0006), frequency of headache attacks (SMD, -1.09; 95% CI, -1.86 to -0.32; P = 0.006), headache severity (SMD, -0.55; 95% CI, -0.91 to -0.19; P = 0.0003), and Migraine Disability Assessment score (SMD, -0.76; 95% CI, -1.11 to -0.40; P < 0.0001). CONCLUSIONS Vitamin D treatment is effective to alleviate migraine.

Deficits in the clearance of amyloid β-protein (Aβ) play a pivotal role in the pathogenesis of sporadic Alzheimer’s disease (AD). The roles of blood monocytes in the development of AD remain unclear. In this study, we sought to investigate the alterations in the Aβ phagocytosis function of peripheral monocytes during ageing and in AD patients. A total of 104 cognitively normal participants aged 22–89 years, 24 AD patients, 25 age- and sex-matched cognitively normal (CN) subjects, 15 Parkinson’s disease patients (PD), and 15 age- and sex-matched CN subjects were recruited. The Aβ uptake by blood monocytes was measured and its alteration during ageing and in AD patients were investigated. Aβ1-42 uptake by monocytes decreased during ageing and further decreased in AD but not in PD patients. Aβ1-42 uptake by monocytes was associated with Aβ1-42 levels in the blood. Among the Aβ uptake-related receptors and enzymes, the expression of Toll-like receptor 2 (TLR2) was reduced in monocytes from AD patients. Our findings suggest that monocytes regulate the blood levels of Aβ and might be involved in the development of AD. The recovery of the Aβ uptake function by blood monocytes represents a potential therapeutic strategy for AD.

Based on our previous work, a series of indazolyl-substituted piperidin-4-yl-aminopyrimidines, which were firstly used as anti-HIV agents, were evaluated for their anticancer potency in five cancer cell lines. Notably, they exhibited excellent activities with IC50 values ranging from 2.29 to 22.89 μM in H1975 cells, among which 6c–e displayed lower cytotoxicity to normal lung cells than gefitinib. Furthermore, the typical compound 6e, which was fourfold more potent than gefitinib in H1975 cell line, was tested for its ability to inhibit H1975 cell migration. The results revealed that 6e showed superior anti-migration activity to gefitinib. In order to investigate the cytotoxicity of 6e in H1975 cells, AO/EB staining experiment was carried out and the results indicated 6e could induce cell apoptosis in a concentration-dependent manner. It is worth noting that comparing with first-generation EGFR inhibitors this series of compounds showed better anti-mutation activity, even if they lack acrylamide moiety which is regarded as necessary for anti-mutation potency in second or third-generation inhibitors. These findings indicate that it might be a new concept to explore noncovalent and high-affinity inhibitors with excellent anti-mutation potency.

IMPORTANCE: Determining the long-term impact of COVID-19 on cognition is important to inform immediate steps in COVID-19 research and health policy. OBJECTIVE: To investigate the 1-year trajectory of cognitive changes in older COVID-19 survivors. DESIGN, SETTING, AND PARTICIPANTS: This cohort study recruited 3233 COVID-19 survivors 60 years and older who were discharged from 3 COVID-19–designated hospitals in Wuhan, China, from February 10 to April 10, 2020. Their uninfected spouses (N = 466) were recruited as a control population. Participants with preinfection cognitive impairment, a concomitant neurological disorder, or a family history of dementia were excluded, as well as those with severe cardiac, hepatic, or kidney disease or any kind of tumor. Follow-up monitoring cognitive functioning and decline took place at 6 and 12 months. A total of 1438 COVID-19 survivors and 438 control individuals were included in the final follow-up. COVID-19 was categorized as severe or nonsevere following the American Thoracic Society guidelines. MAIN OUTCOMES AND MEASURES: The main outcome was change in cognition 1 year after patient discharge. Cognitive changes during the first and second 6-month follow-up periods were assessed using the Informant Questionnaire on Cognitive Decline in the Elderly and the Telephone Interview of Cognitive Status-40, respectively. Based on the cognitive changes observed during the 2 periods, cognitive trajectories were classified into 4 categories: stable cognition, early-onset cognitive decline, late-onset cognitive decline, and progressive cognitive decline. Multinomial and conditional logistical regression models were used to identify factors associated with risk of cognitive decline. RESULTS: Among the 3233 COVID-19 survivors and 1317 uninfected spouses screened, 1438 participants who were treated for COVID-19 (691 male [48.05%] and 747 female [51.95%]; median [IQR] age, 69 [66-74] years) and 438 uninfected control individuals (222 male [50.68%] and 216 female [49.32%]; median [IQR] age, 67 [66-74] years) completed the 12-month follow-up. The incidence of cognitive impairment in survivors 12 months after discharge was 12.45%. Individuals with severe cases had lower Telephone Interview of Cognitive Status-40 scores than those with nonsevere cases and control individuals at 12 months (median [IQR]: severe, 22.50 [16.00-28.00]; nonsevere, 30.00 [26.00-33.00]; control, 31.00 [26.00-33.00]). Severe COVID-19 was associated with a higher risk of early-onset cognitive decline (odds ratio [OR], 4.87; 95% CI, 3.30-7.20), late-onset cognitive decline (OR, 7.58; 95% CI, 3.58-16.03), and progressive cognitive decline (OR, 19.00; 95% CI, 9.14-39.51), while nonsevere COVID-19 was associated with a higher risk of early-onset cognitive decline (OR, 1.71; 95% CI, 1.30-2.27) when adjusting for age, sex, education level, body mass index, and comorbidities. CONCLUSIONS AND RELEVANCE: In this cohort study, COVID-19 survival was associated with an increase in risk of longitudinal cognitive decline, highlighting the importance of immediate measures to deal with this challenge.

Cerebrospinal fluid (CSF) biomarkers are essential for the accurate diagnosis of Alzheimer’s disease (AD), yet their measurement levels vary widely across centers and regions, leaving no uniform cutoff values to date. Diagnostic cutoff values of CSF biomarkers for AD are lacking for the Chinese population. As a member of the Alzheimer’s Association Quality Control program for CSF biomarkers, we aimed to establish diagnostic models based on CSF biomarkers and risk factors for AD in a Chinese cohort. A total of 64 AD dementia patients and 105 age- and sex-matched cognitively normal (CN) controls from the Chongqing Ageing & Dementia Study cohort were included. CSF Aβ42, P-tau181, and T-tau levels were measured by ELISA. Combined biomarker models and integrative models with demographic characteristics were established by logistic regression. The cutoff values to distinguish AD from CN were 933 pg/mL for Aβ42, 48.7 pg/mL for P-tau181 and 313 pg/mL for T-tau. The AN model, including Aβ42 and T-tau, had a higher diagnostic accuracy of 89.9%. Integrating age and APOE ε4 status to AN model (the ANA’E model) increased the diagnostic accuracy to 90.5% and improved the model performance. This study established cutoff values of CSF biomarkers and optimal combined models for AD diagnosis in a Chinese cohort.

Long non-coding (lnc) RNAs play crucial functions in human cancer. However, until recently, the involvement of the lncRNA GAS6-AS1 in breast cancer (BCa) malignancy has not been studied exhaustively. The roles and underlying mode of action of GAS6-AS1 action in BCa progression were examined through functional experiments. A decline in GAS6-AS1 level led to a significant decrease in BCa cell proliferation, and the ability for colony formation. Here, GAS6-AS1 competed as endogenous RNA by sequestering microRNA-215-5p (miR-215-5p) causing an enhanced expression of SRY-box transcription factor 9 (SOX9). The effects of silencing GAS6-AS1 on BCa malignant phenotypes could be ameliorated by inhibiting miR-215-5p or restoring SOX9. Thus, GAS6-AS1 acted as a lncRNA that drives tumor in BCa, and enabled progression of BCa through miR-215-5p /SOX9 axis regulation. These outcomes show that the GAS6-AS1/miR-215-5p/SOX9 axis is a potentially effective target for cancer treatment and management.

The Platanus acerifolia (P. acerifolia) pollen is one of the most common causes of allergic respiratory symptoms in China. However, the allergenic components in P. acerifolia are not fully studied yet. The study aimed to determine the molecular and immunochemical characterization of the profilin from P. acerifolia pollen.The coding sequence of profilin was amplified, cloned, and then expressed in Escherichia coli BL21 cells and purified by nickel affinity chromatography. Protein refolding was followed by structural characterization and homology 3D model building. The allergenicity and cross-reactivity were assessed by ELISA, immunoblotting, or basophil activation test (BAT) using the sera of P. acerifolia allergic patients.The cDNA sequence of profilin was cloned with a 396 bp open reading frame coding for 131 amino acids. The molecular weight of the profilin was approximately 14 kDa, and the predicted structure consisted of 3 α-helixes and 7 β-sheets. Physicochemical analysis indicated the profilin was a stable, relatively thermostable, and relatively conserved protein. The allergenicity determined by ELISA, western blot, and BAT suggested 76.9% (30/39) of the P. acerifolia pollen allergic patients displayed specific IgE recognition of the profilin. The profilin shared 80% sequence identity with Pop n 2, the profilin from Populus nigra, and observed a significant cross-reactivity with Pop n 2 in IgE-inhibition assay.Profilin, as one of the major component allergens in P. acerifolia pollen, was identified and characterized at molecular and immunochemical levels in this study. These findings would contribute to developing diagnostic and therapeutic strategies for P. acerifolia pollen allergic patients.

Giant ragweed (Ambrosia trifida) pollen is closely associated with respiratory allergy in late summer and autumn, and the prevalence of giant ragweed pollen allergy progressively increases. Compared with short ragweed (Ambrosia artemisiifolia), allergenic components from giant ragweed pollen are poorly investigated. To promote component-resolved diagnosis and treatment for giant ragweed pollen allergy, it becomes necessary to identify and characterize unknown allergens from giant ragweed pollen. In the present study, we identified and characterized a new cysteine-protease (CP) allergen from giant ragweed pollen, named as Amb t CP. The cloned Amb t CP gene encoded 387 amino acids. Recombinant Amb t CP (rAmb t CP) and natural Amb t CP (nAmb t CP) were purified by high-affinity Ni

Cockroaches are an important source of indoor allergens. Environmental exposure to cockroach allergens is closely associated with the development of immunoglobulin E (IgE)-mediated allergic diseases. However, the allergenic components in the American cockroaches are not fully studied yet. In order to develop novel diagnostic and therapeutic strategies for cockroach allergy, it is necessary to comprehensively investigate this undescribed allergen in the American cockroach.The full-length cDNA of the potential allergen was isolated from the cDNA library of the American cockroach by PCR cloning. Both the recombinant and natural protein molecules were purified and characterized. The allergenicity was further analyzed by enzyme linked immunosorbent assay, immunoblot, and basophil activation test using sera from cockroach allergic patients.A novel allergen belonging to glyceraldehyde 3-phosphate dehydrogenase (GAPDH) was firstly identified in the American cockroach and named as Per a 13. The cDNA of this allergen is 1255 base pairs in length and contains an open reading frame of 999 base pairs, encoding 332 amino acids. The purified Per a 13 was fully characterized and assessed to react with IgEs from 49.3 % of cockroach allergic patients, and patients with allergic rhinitis were more sensitized to it. Moreover, the allergenicity was further confirmed by immunoblot and basophil activation test.We firstly identified GAPDH (Per a 13) in the American cockroach, which is a novel type of inhalant allergen derived from animal species. These findings could be useful in developing novel diagnostic and therapeutic strategies for cockroach allergy.

Among metal–organic frameworks (MOFs), the interpenetrated MOFs commonly affect the gas adsorption properties. Herein, a cyano-containing 2-connected ligand, 4-(6-(4-cyanophenyl)-[2,3′-bipyridin]-4-yl)benzoic acid (HL1), was used to construct two novel MOFs ([Co(L1)2] and [Zn(L1)2]), and as a result, two two-fold interpenetrated MOFs were expectantly obtained. Both interpenetrated MOFs possess quasi-hexagonal channels and reveal good CO2 gas adsorption capacities at 273 K, attributable to the nitrile groups in the frameworks of MOFs. In contrast to CO2, both interpenetrated MOFs only have very low N2 gas adsorption capacities at 77 K, suggesting potential application in gas separation. More interestingly, when simple modification of the ligand functional group (from the cyano group to the carboxyl group), a new non-interpenetrated MOF ([Co2(L2)2(H2O)]) with rugby-like channels is constructed by using 3-connected 4,4′-([2,3′-bipyridine]-4,6-diyl) dibenzoic acid (H2L2), which is ascribed to the change in ligand functionality (from the cyano group to the carboxyl group). Significantly, this non-interpenetrated MOF reveals much high N2 gas adsorption capacity at 77 K, and moderate CO2 gas adsorption capacity at 273 K owing to the absence of the nitrile groups in the MOF. Furthermore, the magnetic properties of two Co-based MOFs and photoluminescence of three MOFs have also been investigated. The present work provides a promising approach to design and construct interpenetrated/non-interpenetrated MOFs by changing ligand functionality and to tune gas adsorption properties.

With the rapid development of social and economic level, the improvement of science and technology has brought great changes to all walks of life. In the automobile manufacturing industry, the new energy vehicle is a key development project, which has a good prospect. It is precisely because of this background that the corresponding maintenance work of new energy vehicles also needs to be upgraded to a certain extent. This paper first expounds the value of electronic diagnosis technology in the maintenance of new energy vehicles, then analyses the matters needing attention in the application of electronic diagnosis technology in the maintenance of new energy vehicles, and finally, from a reasonable and legitimate point of view, puts forward some suggestions for the application of electronic diagnosis technology in the maintenance of new energy vehicles.

Rapid technological advancements and increasing demand for the efficient utilisation of global resources have promoted the design and development of sustainable anode materials to achieve batteries with high specific capacities and excellent rate capability for energy-storage devices. Herein, a high-performance MnO nitrogen-doped carbon anode material for lithium-ion battery based on coffee residues, potassium permanganate, and urea is presented. MnO and N are uniformly embedded inside the carbon material, connected by N–Mn bonds. The introduction of N not only hinders the aggregation of Mn nanoparticles generated during lithiation, but also enhances the electrochemical activity of carbon and improves the electrical conductivity for better reaction kinetics. These benefitting factors promote the high reversible specific capacity of 768 mA h g−1 at the current density of 0.3 A g−1, as well as superior cyclic and stability performance. The demonstrated high-performance and low-cost anode material also provides a sustainable route for the high-value-added utilisation of waste biomass.

This study assessed the clinic outcomes of erbium: yttrium/aluminum/garnet (Er:YAG) laser and diode laser use in second phase of implant surgery. Fifty implants scheduled for stage II implant surgery were randomly assigned to 4 groups. In the first group (G1), Lite-touch Er:YAG laser was selected, and a vacuum-formed template was used for each site to indicate surgical entrance. For the second group (G2), Lite-touch Er:YAG laser was used and the surgery was performed in a free-hand way. The third group (G3) adopted free-hand surgery while diode laser was used. In the last group (G4), LightWalker Er:YAG laser was applied by free hand. The surgeon was allowed to look at cross-sectional images and 3D reconstruction in the computer to obtain implant position in G2, G3, and G4. The time of operation, healing time, and accuracy of operation were assessed. G1 and G4 took the shortest time in surgery than that of the other two groups (P 0.05). The healing time of Lite-touch Er:YAG laser with or without surgical guide was the shortest when compared with the other two groups (P

We demonstrate the preparation and electrochemical behavior of Pt/IrO2Nb2O5–rGO composite for oxygen reduction reaction, in which IrO2Nb2O5–rGO is firstly synthesized by one-pot hydrothermal process, and Pt is then supported on it through microwave-assisted polyol process. It is found that Nano-scaled Pt/IrO2Nb2O5 hybrid particles (ca. 6.3 nm) are well dispersed throughout the rGO sheets. Doping Ir into Nb2O5 and incorporation of rGO helps improve the catalytic performance. The kinetic current density of Pt/IrO2Nb2O5–rGO is 8.4 times higher than Pt/Nb2O5 catalyst. The special Pt/IrO2Nb2O5–rGO structure with interactions helps enhance the stability of Pt NPs. An improved Pt/IrO2Nb2O5–rGO electrocatalyst is synthesized, and it shows that doping Ir into Nb2O5 and incorporation of rGO helps improve the catalytic performance.