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Fulltext Female chromosome X mosaicism is age-related and preferentially affects the inactivated X chromosome

Machiela MJ, Zhou W, Karlins E, Sampson JN, Freedman ND, Yang Q, et al.

Nat Commun, 2016 06 13;7:11843.
PMID: 27291797 DOI: 10.1038/ncomms11843

To investigate large structural clonal mosaicism of chromosome X, we analysed the SNP microarray intensity data of 38,303 women from cancer genome-wide association studies (20,878 cases and 17,425 controls) and detected 124 mosaic X events >2 Mb in 97 (0.25%) women. Here we show rates for X-chromosome mosaicism are four times higher than mean autosomal rates; X mosaic events more often include the entire chromosome and participants with X events more likely harbour autosomal mosaic events. X mosaicism frequency increases with age (0.11% in 50-year olds; 0.45% in 75-year olds), as reported for Y and autosomes. Methylation array analyses of 33 women with X mosaicism indicate events preferentially involve the inactive X chromosome. Our results provide further evidence that the sex chromosomes undergo mosaic events more frequently than autosomes, which could have implications for understanding the underlying mechanisms of mosaic events and their possible contribution to risk for chronic diseases.
Fulltext Rapid Targeted Next-Generation Sequencing Platform for Molecular Screening and Clinical Genotyping in Subjects with Hemoglobinopathies

Shang X, Peng Z, Ye Y, Asan, Zhang X, Chen Y, et al.

EBioMedicine, 2017 Sep;23:150-159.
PMID: 28865746 DOI: 10.1016/j.ebiom.2017.08.015

Hemoglobinopathies are among the most common autosomal-recessive disorders worldwide. A comprehensive next-generation sequencing (NGS) test would greatly facilitate screening and diagnosis of these disorders. An NGS panel targeting the coding regions of hemoglobin genes and four modifier genes was designed. We validated the assay by using 2522 subjects affected with hemoglobinopathies and applied it to carrier testing in a cohort of 10,111 couples who were also screened through traditional methods. In the clinical genotyping analysis of 1182 β-thalassemia subjects, we identified a group of additional variants that can be used for accurate diagnosis. In the molecular screening analysis of the 10,111 couples, we detected 4180 individuals in total who carried 4840 mutant alleles, and identified 186 couples at risk of having affected offspring. 12.1% of the pathogenic or likely pathogenic variants identified by our NGS assay, which were undetectable by traditional methods. Compared with the traditional methods, our assay identified an additional at-risk 35 couples. We describe a comprehensive NGS-based test that offers advantages over the traditional screening/molecular testing methods. To our knowledge, this is among the first large-scale population study to systematically evaluate the application of an NGS technique in carrier screening and molecular diagnosis of hemoglobinopathies.
Global wild rice germplasm resources conservation alliance: World Wild-Rice Wiring

Zheng X, Ratnasekera D, Fan J, Henry RJ, Song BK, Olsen KM, et al.

Mol Plant, 2024 Apr 01;17(4):516-518.
PMID: 38444157 DOI: 10.1016/j.molp.2024.03.001
Fulltext Mutant p53 cooperates with the SWI/SNF chromatin remodeling complex to regulate VEGFR2 in breast cancer cells

Pfister NT, Fomin V, Regunath K, Zhou JY, Zhou W, Silwal-Pandit L, et al.

Genes Dev., 2015 Jun 15;29(12):1298-315.
PMID: 26080815 DOI: 10.1101/gad.263202.115

Mutant p53 impacts the expression of numerous genes at the level of transcription to mediate oncogenesis. We identified vascular endothelial growth factor receptor 2 (VEGFR2), the primary functional VEGF receptor that mediates endothelial cell vascularization, as a mutant p53 transcriptional target in multiple breast cancer cell lines. Up-regulation of VEGFR2 mediates the role of mutant p53 in increasing cellular growth in two-dimensional (2D) and three-dimensional (3D) culture conditions. Mutant p53 binds near the VEGFR2 promoter transcriptional start site and plays a role in maintaining an open conformation at that location. Relatedly, mutant p53 interacts with the SWI/SNF complex, which is required for remodeling the VEGFR2 promoter. By both querying individual genes regulated by mutant p53 and performing RNA sequencing, the results indicate that >40% of all mutant p53-regulated gene expression is mediated by SWI/SNF. We surmise that mutant p53 impacts transcription of VEGFR2 as well as myriad other genes by promoter remodeling through interaction with and likely regulation of the SWI/SNF chromatin remodeling complex. Therefore, not only might mutant p53-expressing tumors be susceptible to anti VEGF therapies, impacting SWI/SNF tumor suppressor function in mutant p53 tumors may also have therapeutic potential.
Fulltext Thermoregulation and golden hour practices in extremely preterm infants: an international survey

Jani P, Mishra U, Buchmayer J, Walker K, Gözen D, Maheshwari R, et al.

Pediatr Res, 2023 May;93(6):1701-1709.
PMID: 36075989 DOI: 10.1038/s41390-022-02297-0

BACKGROUND: Are thermoregulation and golden hour practices in extremely preterm (EP) infants comparable across the world? This study aims to describe these practices for EP infants based on the neonatal intensive care unit's (NICUs) geographic region, country's income status and the lowest gestational age (GA) of infants resuscitated.
METHODS: The Director of each NICU was requested to complete the e-questionnaire between February 2019 and August 2021.
RESULTS: We received 848 responses, from all geographic regions and resource settings. Variations in most thermoregulation and golden hour practices were observed. Using a polyethylene plastic wrap, commencing humidity within 60 min of admission, and having local protocols were the most consistent practices (>75%). The odds for the following practices differed in NICUs resuscitating infants from 22 to 23 weeks GA compared to those resuscitating from 24 to 25 weeks: respiratory support during resuscitation and transport, use of polyethylene plastic wrap and servo-control mode, commencing ambient humidity >80% and presence of local protocols.
CONCLUSION: Evidence-based practices on thermoregulation and golden hour stabilisation differed based on the unit's region, country's income status and the lowest GA of infants resuscitated. Future efforts should address reducing variation in practice and aligning practices with international guidelines.
IMPACT: A wide variation in thermoregulation and golden hour practices exists depending on the income status, geographic region and lowest gestation age of infants resuscitated. Using a polyethylene plastic wrap, commencing humidity within 60 min of admission and having local protocols were the most consistent practices. This study provides a comprehensive description of thermoregulation and golden hour practices to allow a global comparison in the delivery of best evidence-based practice. The findings of this survey highlight a need for reducing variation in practice and aligning practices with international guidelines for a comparable health care delivery.
Fulltext National nutrition surveillance programmes in 18 countries in South-East Asia and Western Pacific Regions: a systematic scoping review

Peters R, Li B, Swinburn B, Allender S, He Z, Lim SY, et al.

Bull World Health Organ, 2023 Nov 01;101(11):690-706F.
PMID: 37961057 DOI: 10.2471/BLT.23.289973

OBJECTIVE: To identify and analyse ongoing nutrition-related surveillance programmes led and/or funded by national authorities in countries in South-East Asian and Western Pacific Regions.
METHODS: We systematically searched for publications in PubMed® and Scopus, manually searched the grey literature and consulted with national health and nutrition officials, with no restrictions on publication type or language. We included low- and middle-income countries in the World Health Organization South-East Asia Region, and the Association of Southeast Asian Nations and China. We analysed the included programmes by adapting the United States Centers for Disease Control and Prevention's public health surveillance evaluation framework.
FINDINGS: We identified 82 surveillance programmes in 18 countries that repeatedly collect, analyse and disseminate data on nutrition and/or related indicators. Seventeen countries implemented a national periodic survey that exclusively collects nutrition-outcome indicators, often alongside internationally linked survey programmes. Coverage of different subpopulations and monitoring frequency vary substantially across countries. We found limited integration of food environment and wider food system indicators in these programmes, and no programmes specifically monitor nutrition-sensitive data across the food system. There is also limited nutrition-related surveillance of people living in urban deprived areas. Most surveillance programmes are digitized, use measures to ensure high data quality and report evidence of flexibility; however, many are inconsistently implemented and rely on external agencies' financial support.
CONCLUSION: Efforts to improve the time efficiency, scope and stability of national nutrition surveillance, and integration with other sectoral data, should be encouraged and supported to allow systemic monitoring and evaluation of malnutrition interventions in these countries.
Fulltext Phase III, randomised, double-blind, multicentre study to evaluate the efficacy and safety of vonoprazan compared with lansoprazole in Asian patients with erosive oesophagitis

Xiao Y, Zhang S, Dai N, Fei G, Goh KL, Chun HJ, et al.

Gut, 2020 02;69(2):224-230.
PMID: 31409606 DOI: 10.1136/gutjnl-2019-318365

OBJECTIVE: To establish the non-inferior efficacy of vonoprazan versus lansoprazole in the treatment of Asian patients with erosive oesophagitis (EO).
DESIGN: In this phase III, double-blind, multicentre study, patients with endoscopically confirmed EO were randomised 1:1 to receive vonoprazan 20 mg or lansoprazole 30 mg, once daily for up to 8 weeks. The primary endpoint was EO healing rate at 8 weeks. The secondary endpoints were EO healing rates at 2 and 4 weeks. Safety endpoints included treatment-emergent adverse events (TEAEs).
RESULTS: In the vonoprazan (n=238) and lansoprazole (n=230) arms, 8-week EO healing rates were 92.4% and 91.3%, respectively (difference 1.1% (95% CI -3.822% to 6.087%)). The respective 2-week EO healing rates were 75.0% and 67.8% (difference 7.2% (95% CI -1.054% to 15.371%)), and the respective 4-week EO healing rates were 85.3% and 83.5% (difference 1.8% (95% CI -4.763% to 8.395%)). In patients with baseline Los Angeles classification grade C/D, 2-week, 4-week and 8-week EO healing rates were higher with vonoprazan versus lansoprazole (2 weeks: 62.2% vs 51.5%, difference 10.6% (95% CI -5.708% to 27.002%); 4 weeks: 73.3% vs 67.2%, difference 6.2% (95% CI -8.884 to 21.223); and 8 weeks: 84.0% vs 80.6%, difference 3.4% (95% CI -9.187% to 15.993%)). Overall, EO healing rates appeared higher with vonoprazan versus lansoprazole. TEAE rates were 38.1% and 36.6% in the vonoprazan and lansoprazole group, respectively.
CONCLUSION: Our findings demonstrate the non-inferior efficacy of vonoprazan versus lansoprazole in terms of EO healing rate at 8 weeks in this population. Safety outcomes were similar in the two treatment arms.
TRIAL REGISTRATION NUMBER: NCT02388724.
Fulltext Characterization of a novel orthoreovirus isolated from fruit bat, China

Hu T, Qiu W, He B, Zhang Y, Yu J, Liang X, et al.

BMC Microbiol, 2014;14:293.
PMID: 25433675 DOI: 10.1186/s12866-014-0293-4

In recent years novel human respiratory disease agents have been described for Southeast Asia and Australia. The causative pathogens were classified as pteropine orthoreoviruses with a strong phylogenetic relationship to orthoreoviruses of bat origin.
Fulltext Identification of a novel Getah virus by Virus-Discovery-cDNA random amplified polymorphic DNA (RAPD)

Hu T, Zheng Y, Zhang Y, Li G, Qiu W, Yu J, et al.

BMC Microbiol, 2012;12:305.
PMID: 23268691 DOI: 10.1186/1471-2180-12-305

The identification of new virus strains is important for the study of infectious disease, but current (or existing) molecular biology methods are limited since the target sequence must be known to design genome-specific PCR primers. Thus, we developed a new method for the discovery of unknown viruses based on the cDNA--random amplified polymorphic DNA (cDNA-RAPD) technique. Getah virus, belonging to the family Togaviridae in the genus Alphavirus, is a mosquito-borne enveloped RNA virus that was identified using the Virus-Discovery-cDNA RAPD (VIDISCR) method.
Fulltext Molecular landscape of immune pressure and escape in aplastic anemia

Pagliuca S, Gurnari C, Hercus C, Hergalant S, Nadarajah N, Wahida A, et al.

Leukemia, 2023 Jan;37(1):202-211.
PMID: 36253429 DOI: 10.1038/s41375-022-01723-w

Idiopathic aplastic anemia (IAA) pathophysiology is dominated by autoreactivity of human leukocyte antigen (HLA)-restricted T-cells against antigens presented by hematopoietic stem and progenitor cells (HSPCs). Expansion of PIGA and HLA class I mutant HSPCs have been linked to immune evasion from T-cell mediated pressures. We hypothesized that in analogy with antitumor immunity, the pathophysiological cascade of immune escape in IAA is initiated by immunoediting pressures and culminates with mechanisms of clonal evolution characterized by hits in immune recognition and response genes. To that end, we studied the genetic and transcriptomic make-up of the antigen presentation complexes in a large cohort of patients with IAA and paroxysmal nocturnal hemoglobinuria (PNH) by using single-cell RNA, high throughput DNA sequencing and single nucleotide polymorphism (SNP)-array platforms. At disease onset, HSPCs displayed activation of selected HLA class I and II-restricted mechanisms, without extensive inhibition of immune checkpoint apparatus. Using a newly implemented bioinformatic framework we found that not only class I but also class II genes were often impaired by acquisition of genetic aberrations. We also demonstrated the presence of novel somatic alterations in immune genes possibly contributing to the evasion from the autoimmune T-cells. In contrast, these hits were absent in myeloid neoplasia. These aberrations were not mutually exclusive with PNH and did not correlate with the accumulation of myeloid-driver hits. Our findings shed light on the mechanisms of immune activation and escape in IAA and define alternative modes of clonal hematopoiesis.
Mechanistic insights into the lignin dissolution behavior in amino acid based deep eutectic solvents

Zhang Y, Ren H, Li B, Udin SM, Maarof H, Zhou W, et al.

Int J Biol Macromol, 2023 Jul 01;242(Pt 2):124829.
PMID: 37210053 DOI: 10.1016/j.ijbiomac.2023.124829

Deep eutectic solvents (DESs) composed by amino acids (L-arginine, L-proline, L-alanine) as the hydrogen bond acceptors (HBAs) and carboxylic acids (formic acid, acetic acid, lactic acid, levulinic acid) as hydrogen bond donors (HBDs) were prepared and used for the dissolution of dealkaline lignin (DAL). The mechanism of lignin dissolution in DESs was explored at molecular level by combining the analysis of Kamlet-Taft (K-T) solvatochromic parameters, FTIR spectrum and density functional theory (DFT) calculations of DESs. Firstly, it was found that the formation of new hydrogen bonds between lignin and DESs mainly drove the dissolution of lignin, which were accompanied by the erosion of hydrogen bond networks in both lignin and DESs. The nature of hydrogen bond network within DESs was fundamentally determined by the type and number of functional groups in both HBA and HBD, which affected its ability to form hydrogen bond with lignin. One hydroxyl group and carboxyl group in HBDs provided active protons, which facilitated proton-catalyzed cleavage of β-O-4, thus enhancing the dissolution of DESs. The superfluous functional group resulted in more extensive and stronger hydrogen bond network in the DESs, thus decreasing the lignin dissolving ability. Moreover, it was found that lignin solubility had a closed positive correlation with the subtraction value of α and β (net hydrogen donating ability) of DESs. Among all the investigated DESs, L-alanine/formic acid (1:3) with the strong hydrogen-bond donating ability (acidity), weak hydrogen-bond accepting ability (basicity) and small steric-hindrance effect showed the best lignin dissolving ability (23.99 wt%, 60 °C). On top of that, the value of α and β of L-proline/carboxylic acids DESs showed some positive correlation with the global electrostatic potential (ESP) maxima and minima of the corresponding DESs respectively, indicating the analysis of ESP quantitative distributions of DESs could be an effective tool for DESs screening and design for lignin dissolution as well as other applications.
Fulltext Optimizing strength of directly recycled aluminum chip-based parts through a hybrid RSM-GA-ANN approach in sustainable hot forging

Altharan YM, Shamsudin S, Lajis MA, Al-Alimi S, Yusuf NK, Alduais NAM, et al.

PLoS One, 2024;19(3):e0300504.
PMID: 38484005 DOI: 10.1371/journal.pone.0300504

Direct recycling of aluminum waste is crucial in sustainable manufacturing to mitigate environmental impact and conserve resources. This work was carried out to study the application of hot press forging (HPF) in recycling AA6061 aluminum chip waste, aiming to optimize operating factors using Response Surface Methodology (RSM), Artificial Neural Network (ANN) and Genetic algorithm (GA) strategy to maximize the strength of recycled parts. The experimental runs were designed using Full factorial and RSM via Minitab 21 software. RSM-ANN models were employed to examine the effect of factors and their interactions on response and to predict output, while GA-RSM and GA-ANN were used for optimization. The chips of different morphology were cold compressed into billet form and then hot forged. The effect of varying forging temperature (Tp, 450-550°C), holding time (HT, 60-120 minutes), and chip surface area to volume ratio (AS:V, 15.4-52.6 mm2/mm3) on ultimate tensile strength (UTS) was examined. Maximum UTS (237.4 MPa) was achieved at 550°C, 120 minutes and 15.4 mm2/mm3 of chip's AS: V. The Tp had the largest contributing effect ratio on the UTS, followed by HT and AS:V according to ANOVA analysis. The proposed optimization process suggested 550°C, 60 minutes, and 15.4 mm2 as the optimal condition yielding the maximum UTS. The developed models' evaluation results showed that ANN (with MSE = 1.48%) outperformed RSM model. Overall, the study promotes sustainable production by demonstrating the potential of integrating RSM and ML to optimize complex manufacturing processes and improve product quality.
Characterisation of calamansi (Citrus microcarpa). Part I: volatiles, aromatic profiles and phenolic acids in the peel

Cheong MW, Chong ZS, Liu SQ, Zhou W, Curran P, Bin Yu

Food Chem, 2012 Sep 15;134(2):686-95.
PMID: 23107679 DOI: 10.1016/j.foodchem.2012.02.162

Volatile compounds in the peel of calamansi (Citrus microcarpa) from Malaysia, the Philippines and Vietnam were extracted with dichloromethane and hexane, and then analysed by gas chromatography-mass spectroscopy/flame ionisation detector. Seventy-nine compounds representing >98% of the volatiles were identified. Across the three geographical sources, a relatively small proportion of potent oxygenated compounds was significantly different, exemplified by the highest amount of methyl N-methylanthranilate in Malaysian calamansi peel. Principal component analysis and canonical discriminant analysis were applied to interpret the complex volatile compounds in the calamansi peel extracts, and to verify the discrimination among the different origins. In addition, four common hydroxycinnamic acids (caffeic, p-coumaric, ferulic and sinapic acids) were determined in the methanolic extracts of calamansi peel using ultra-fast liquid chromatography coupled to photodiode array detector. The Philippines calamansi peel contained the highest amount of total phenolic acids. In addition, p-Coumaric acid was the dominant free phenolic acids, whereas ferulic acid was the main bound phenolic acid.
Characterisation of calamansi (Citrus microcarpa). Part II: volatiles, physicochemical properties and non-volatiles in the juice

Cheong MW, Zhu D, Sng J, Liu SQ, Zhou W, Curran P, et al.

Food Chem, 2012 Sep 15;134(2):696-703.
PMID: 23107680 DOI: 10.1016/j.foodchem.2012.02.139

Calamansi juices from three countries (Malaysia, the Philippines and Vietnam) were characterised through measuring volatiles, physicochemical properties and non-volatiles (sugars, organic acids and phenolic acids). The volatile components of manually squeezed calamansi juices were extracted using dichloromethane and headspace solid-phase microextraction, and then analysed using gas chromatography-mass spectrometry/flame ionisation detector, respectively. A total of 60 volatile compounds were identified. The results indicated that the Vietnam calamansi juice contained the highest amount of volatiles. Two principal components obtained from principal component analysis (PCA) represented 89.65% of the cumulative total variations of the volatiles. Among the non-volatile components, these three calamansi juices could be, to some extent, differentiated according to fructose and glucose concentrations. Hence, this study of calamansi juices could lead to a better understanding of calamansi fruits.
Fulltext To use or not to use: an update on licit and illicit ketamine use

Li JH, Vicknasingam B, Cheung YW, Zhou W, Nurhidayat AW, Jarlais DC, et al.

Subst Abuse Rehabil, 2011;2:11-20.
PMID: 24474851 DOI: 10.2147/SAR.S15458

Ketamine, a derivative of phencyclidine that was developed in the 1960s, is an anesthetic and analgesic with hallucinogenic effects. In this paper, the pharmacological and toxicological effects of ketamine are briefly reviewed. Ketamine possesses a wide safety margin but such a therapeutic benefit is somewhat offset by its emergence phenomenon (mind-body dissociation and delirium) and hallucinogenic effects. The increasing abuse of ketamine, initially predominantly in recreational scenes to experience a "k-hole" and other hallucinatory effects but more recently also as a drug abused during the workday or at home, has further pushed governments to confine its usage in many countries. Recently, urinary tract dysfunction has been associated with long-term ketamine use. In some long-term ketamine users, such damage can be irreversible and could result in renal failure and dialysis. Although ketamine has not yet been scheduled in the United Nations Conventions, previous studies using different assessment parameters to score the overall harms of drugs indicated that ketamine may cause more harm than some of the United Nations scheduled drugs. Some countries in Southeast and East Asia have reported an escalating situation of ketamine abuse. Dependence, lower urinary tract dysfunction, and sexual impulse or violence were the most notable among the ketamine-associated symptoms in these countries. These results implied that the danger of ketamine may have been underestimated previously. Therefore, the severity levels of the ketamine-associated problems should be scrutinized more carefully and objectively. To prevent ketamine from being improperly used and evolving into an epidemic, a thorough survey on the prevalence and characteristics of illicit ketamine use is imperative so that suitable policy and measures can be taken. On the other hand, recent findings that ketamine could be useful for treating major depressive disorder has given this old drug a new impetus. If ketamine is indeed a remedy for treating depression, more research on the risks and benefits of its clinical use will be indispensable.
A highly sensitive perovskite oxide sensor for detection of p-phenylenediamine in hair dyes

He J, Sunarso J, Miao J, Sun H, Dai J, Zhang C, et al.

J Hazard Mater, 2019 05 05;369:699-706.
PMID: 30831522 DOI: 10.1016/j.jhazmat.2019.02.070

Effective regulation of p-phenylenediamine (PPD), a widely used precursor of hair dye that is harmful to human health in large concentration, relies upon an accurate yet simple detection of PPD. In this context, amperometric electrode sensor based on perovskite oxide becomes attractive given its portability, low cost, high sensitivity, and rapid processing time. This work reports the systematic characterization of a series of Sr-doped PrCoO3-δ perovskite oxides with composition of Pr1-xSrxCoO3-δ(x = 0, 0.2, 0.4, 0.6, 0.8, and 1) for PPD detection in an alkaline solution. PSC82 deposited onto glassy carbon electrode (PSC82/GCE) generates the highest redox currents which correlates with the highest hydrogen peroxide intermediates (HO2-) yield and the σ*-orbital (eg) filling of Co that is closest to unity for PSC82. PSC82/GCE provides the highest sensitivities of 655 and 308 μA mM-1 cm-2 in PPD concentration range of 0.5-2,900 and 2,900-10,400 μM, respectively, with a limit of detection of 0.17 μM. PSC82/GCE additionally demonstrates high selectivity to PPD and long term stability during 50 consecutive cyclic voltammetry scans and over 1-month storage period. The potential applicability of PSC82/GCE was also demonstrated by confirming the presence of very low concentration of PPD of below 0.5% in real hair dyes.
A Direct n-Butane Solid Oxide Fuel Cell Using Ba(Zr0.1Ce0.7Y0.1Yb0.1)0.9Ni0.05Ru0.05O3-δ Perovskite as the Reforming Layer

Wang D, Wong SI, Sunarso J, Xu M, Wang W, Ran R, et al.

ACS Appl Mater Interfaces, 2021 May 05;13(17):20105-20113.
PMID: 33886260 DOI: 10.1021/acsami.1c02502

Hydrocarbon-fueled solid oxide fuel cells (SOFCs) that can operate in the intermediate temperature range of 500-700 °C represent an attractive SOFC device for combined heat and power applications in the industrial market. One of the ways to realize such a device relies upon exploiting an in situ steam reforming process in the anode catalyzed by an anti-carbon coking catalyst. Here, we report a new Ni and Ru bimetal-doped perovskite catalyst, Ba(Zr0.1Ce0.7Y0.1Yb0.1)0.9Ni0.05Ru0.05O3-δ (BZCYYbNRu), with enhanced catalytic hydrogen production activity on n-butane (C4H10), which can resist carbon coking over extended operation durations. Ru in the perovskite lattice inhibits Ni precipitation from perovskite, and the high water adsorption capacity of proton conducting perovskite improves the coking resistance of BZCYYbNRu. When BZCYYbNRu is used as a steam reforming catalyst layer on a Ni-YSZ-supported anode, the single fuel cell not only achieves a higher power density of 1113 mW cm-2 at 700 °C under a 10 mL min-1 C4H10 continuous feed stream at a steam to carbon (H2O/C) ratio of 0.5 but also shows a much better operational stability for 100 h at 600 °C compared with those reported in the literature.
Molybdenum and Niobium Codoped B-Site-Ordered Double Perovskite Catalyst for Efficient Oxygen Evolution Reaction

Sun H, Chen G, Sunarso J, Dai J, Zhou W, Shao Z

ACS Appl Mater Interfaces, 2018 May 23;10(20):16939-16942.
PMID: 29741862 DOI: 10.1021/acsami.8b03702

An abundant, highly active, and durable oxygen evolution reaction (OER) electrocatalyst is an enabling component for a more sustainable energy future. We report, herein, a molybdenum and niobium codoped B-site-ordered double perovskite oxide with a compositional formula of Ba2CoMo0.5Nb0.5O6-δ (BCMN) as an active and robust catalyst for OER in an alkaline electrolyte. BCMN displayed a low overpotential of 445 mA at a current density of 10 mA cm-2disk. BCMN also showed long-term stability in an alkaline medium. This work hints toward the possibility of combining a codoping approach with double perovskite structure formation to achieve significant enhancement in the OER performance.
Systematic Study of Oxygen Evolution Activity and Stability on La1- xSr xFeO3-δ Perovskite Electrocatalysts in Alkaline Media

She S, Yu J, Tang W, Zhu Y, Chen Y, Sunarso J, et al.

ACS Appl Mater Interfaces, 2018 Apr 11;10(14):11715-11721.
PMID: 29546981 DOI: 10.1021/acsami.8b00682

Perovskite oxide is an attractive low-cost alternative catalyst for oxygen evolution reaction (OER) relative to the precious metal oxide-based electrocatalysts (IrO2 and RuO2). In this work, a series of Sr-doped La-based perovskite oxide catalysts with compositions of La1- xSr xFeO3-δ ( x = 0, 0.2, 0.5, 0.8, and 1) are synthesized and characterized. The OER-specific activities in alkaline solution increase in the order of LaFeO3-δ (LF), La0.8Sr0.2FeO3-δ (LSF-0.2), La0.5Sr0.5FeO3-δ (LSF-0.5), SrFeO3-δ (SF), and La0.2Sr0.8FeO3-δ (LSF-0.8). We establish a direct correlation between the enhancement in the specific activity and the amount of surface oxygen vacancies as well as the surface Fe oxidation states. The improved specific activity for LSF-0.8 is clearly linked to the optimum amount of surface oxygen vacancies and surface Fe oxidation states. We also find that the OER performance stability is a function of the crystal structure and the deviation in the surface La and/or Sr composition(s) from their bulk stoichiometric compositions. The cubic structure and lower deviation, as is the case for LSF-0.8, led to a higher OER performance stability. These surface performance relations provide a promising guideline for constructing efficient water oxidation.
Fulltext Two orders of magnitude enhancement in oxygen evolution reactivity on amorphous Ba0.5Sr0.5Co0.8Fe0.2O3-δ nanofilms with tunable oxidation state

Chen G, Zhou W, Guan D, Sunarso J, Zhu Y, Hu X, et al.

Sci Adv, 2017 06;3(6):e1603206.
PMID: 28691090 DOI: 10.1126/sciadv.1603206

Perovskite oxides exhibit potential for use as electrocatalysts in the oxygen evolution reaction (OER). However, their low specific surface area is the main obstacle to realizing a high mass-specific activity that is required to be competitive against the state-of-the-art precious metal-based catalysts. We report the enhanced performance of Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) for the OER with intrinsic activity that is significantly higher than that of the benchmark IrO2, and this result was achieved via fabrication of an amorphous BSCF nanofilm on a surface-oxidized nickel substrate by magnetron sputtering. The surface nickel oxide layer of the Ni substrate and the thickness of the BSCF film were further used to tune the intrinsic OER activity and stability of the BSCF catalyst by optimizing the electronic configuration of the transition metal cations in BSCF via the interaction between the nanofilm and the surface nickel oxide, which enables up to 315-fold enhanced mass-specific activity compared to the crystalline BSCF bulk phase. Moreover, the amorphous BSCF-Ni foam anode coupled with the Pt-Ni foam cathode demonstrated an attractive small overpotential of 0.34 V at 10 mA cm-2 for water electrolysis, with a BSCF loading as low as 154.8 μg cm-2.

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