A perovskite oxide with high conductivities in both air and reducing atmosphere for use as electrode for solid oxide fuel cells

Electrode materials which exhibit high conductivities in both oxidising and reducing atmospheres are in high demand for solid oxide fuel cells (SOFCs) and solid oxide electrolytic cells (SOECs). In this paper, we investigated Cu-doped SrFe0.9Nb0.1O3−δ finding that the primitive perovskite oxide SrFe0.8Cu0.1Nb0.1O3−δ (SFCN) exhibits a conductivity of 63 Scm−1and 60 Scm−1 at 415 °C in air and 5%H2/Ar respectively. It is believed that the high conductivity in 5%H2/Ar is related to the exsolved Fe (or FeCu alloy) on exposure to a reducing atmosphere. To the best of our knowledge, the conductivity of SrFe0.8Cu0.1Nb0.1O3−δ in a reducing atmosphere is the highest of all reported oxides which also exhibit a high conductivity in air. Fuel cell performance using SrFe0.8Cu0.1Nb0.1O3−δ as the anode, (Y2O3)0.08(ZrO2)0.92 as the electrolyte and La0.8Sr0.2FeO3−δ as the cathode achieved a power density of 423 mWcm−2 at 700 °C indicating that SFCN is a promising anode for SOFCs

Conductivity and redox stability of new double perovskite oxide Sr 1.6 K 0.4 Fe 1+ x Mo 1− x O 6− δ (x= 0.2, 0.4, 0.6)

A series of new perovskite oxides Sr1.6K0.4Fe1+xMo1−xO6−δ (x = 0.2, 0.4, 0.6) were synthesised by solid state reaction method. Synthesis of Sr1.6K0.4Fe1+xMo1−xO6−δ (x = 0.2, 0.4, 0.6) was achieved above 700 °C in 5 % H2/Ar, albeit with the formation of impurity phases. Phase stability upon redox cycling was only observed for sample Sr1.6K0.4Fe1.4Mo0.6O6−δ. Redox cycling of Sr1.6K0.4Fe1+xMo1−xO6−δ (x = 0.2, 0.4, 0.6) demonstrates a strong dependence on high temperature reduction to achieve high conductivities. After the initial reduction at 1200 °C in 5 %H2/Ar, then re-oxidation in air at 700 °C and further reduction at 700 °C in 5 %H2/Ar, the attained conductivities were between 0.1 and 58.4 % of the initial conductivity after reduction 1200 °C in 5 %H2/Ar depending on the composition. In the investigated new oxides, sample Sr1.6K0.4Fe1.4Mo0.6O6−δ is most redox stable also retains reasonably high electrical conductivity, ~70 S/cm after reduction at 1200 °C and 2–3 S/cm after redox cycling at 700 °C, indicating it is a potential anode for SOFCs

Deregulation of MYCN, LIN28B and LET7 in a Molecular Subtype of Aggressive High-Grade Serous Ovarian Cancers

Molecular subtypes of serous ovarian cancer have been recently described. Using data from independent datasets including over 900 primary tumour samples, we show that deregulation of the Let-7 pathway is specifically associated with the C5 molecular subtype of serous ovarian cancer. DNA copy number and gene expression of HMGA2, alleles of Let-7, LIN28, LIN28B, MYC, MYCN, DICER1, and RNASEN were measured using microarray and quantitative reverse transcriptase PCR. Immunohistochemistry was performed on 127 samples using tissue microarrays and anti-HMGA2 antibodies. Fluorescence in situ hybridisation of bacterial artificial chromosomes hybridized to 239 ovarian tumours was used to measure translocation at the LIN28B locus. Short interfering RNA knockdown in ovarian cell lines was used to test the functionality of associations observed. Four molecular subtypes (C1, C2, C4, C5) of high-grade serous ovarian cancers were robustly represented in each dataset and showed similar pattern of patient survival. We found highly specific activation of a pathway involving MYCN, LIN28B, Let-7 and HMGA2 in the C5 molecular subtype defined by MYCN amplification and over-expression, over-expression of MYCN targets including the Let-7 repressor LIN28B, loss of Let-7 expression and HMGA2 amplification and over-expression. DICER1, a known Let-7 target, and RNASEN were over-expressed in C5 tumours. We saw no evidence of translocation at the LIN28B locus in C5 tumours. The reported interaction between LIN28B and Let-7 was recapitulated by siRNA knockdown in ovarian cancer cell lines. Our results associate deregulation of MYCN and downstream targets, including Let-7 and oncofetal genes, with serous ovarian cancer. We define for the first time how elements of an oncogenic pathway, involving multiple genes that contribute to stem cell renewal, is specifically altered in a molecular subtype of serous ovarian cancer. By defining the drivers of a molecular subtype of serous ovarian cancers we provide a novel strategy for targeted therapeutic intervention

Prehospital transdermal glyceryl trinitrate in patients with ultra-acute presumed stroke (RIGHT-2): an ambulance-based, randomised, sham-controlled, blinded, phase 3 trial

Background High blood pressure is common in acute stroke and is a predictor of poor outcome; however, large trials of lowering blood pressure have given variable results, and the management of high blood pressure in ultra-acute stroke remains unclear. We investigated whether transdermal glyceryl trinitrate (GTN; also known as nitroglycerin), a nitric oxide donor, might improve outcome when administered very early after stroke onset. Methods We did a multicentre, paramedic-delivered, ambulance-based, prospective, randomised, sham-controlled, blinded-endpoint, phase 3 trial in adults with presumed stroke within 4 h of onset, face-arm-speech-time score of 2 or 3, and systolic blood pressure 120 mm Hg or higher. Participants were randomly assigned (1:1) to receive transdermal GTN (5 mg once daily for 4 days; the GTN group) or a similar sham dressing (the sham group) in UK based ambulances by paramedics, with treatment continued in hospital. Paramedics were unmasked to treatment, whereas participants were masked. The primary outcome was the 7-level modified Rankin Scale (mRS; a measure of functional outcome) at 90 days, assessed by central telephone follow-up with masking to treatment. Analysis was hierarchical, first in participants with a confirmed stroke or transient ischaemic attack (cohort 1), and then in all participants who were randomly assigned (intention to treat, cohort 2) according to the statistical analysis plan. This trial is registered with ISRCTN, number ISRCTN26986053. Findings Between Oct 22, 2015, and May 23, 2018, 516 paramedics from eight UK ambulance services recruited 1149 participants (n=568 in the GTN group, n=581 in the sham group). The median time to randomisation was 71 min (IQR 45–116). 597 (52%) patients had ischaemic stroke, 145 (13%) had intracerebral haemorrhage, 109 (9%) had transient ischaemic attack, and 297 (26%) had a non-stroke mimic at the final diagnosis of the index event. In the GTN group, participants’ systolic blood pressure was lowered by 5·8 mm Hg compared with the sham group (p<0·0001), and diastolic blood pressure was lowered by 2·6 mm Hg (p=0·0026) at hospital admission. We found no difference in mRS between the groups in participants with a final diagnosis of stroke or transient ischaemic stroke (cohort 1): 3 (IQR 2–5; n=420) in the GTN group versus 3 (2–5; n=408) in the sham group, adjusted common odds ratio for poor outcome 1·25 (95% CI 0·97–1·60; p=0·083); we also found no difference in mRS between all patients (cohort 2: 3 [2–5]; n=544, in the GTN group vs 3 [2–5]; n=558, in the sham group; 1·04 [0·84–1·29]; p=0·69). We found no difference in secondary outcomes, death (treatment-related deaths: 36 in the GTN group vs 23 in the sham group [p=0·091]), or serious adverse events (188 in the GTN group vs 170 in the sham group [p=0·16]) between treatment groups. Interpretation Prehospital treatment with transdermal GTN does not seem to improve functional outcome in patients with presumed stroke. It is feasible for UK paramedics to obtain consent and treat patients with stroke in the ultraacute prehospital setting. Funding British Heart Foundation

Retrospective evaluation of whole exome and genome mutation calls in 746 cancer samples

Funder: NCI U24CA211006Abstract: The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) curated consensus somatic mutation calls using whole exome sequencing (WES) and whole genome sequencing (WGS), respectively. Here, as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, which aggregated whole genome sequencing data from 2,658 cancers across 38 tumour types, we compare WES and WGS side-by-side from 746 TCGA samples, finding that ~80% of mutations overlap in covered exonic regions. We estimate that low variant allele fraction (VAF < 15%) and clonal heterogeneity contribute up to 68% of private WGS mutations and 71% of private WES mutations. We observe that ~30% of private WGS mutations trace to mutations identified by a single variant caller in WES consensus efforts. WGS captures both ~50% more variation in exonic regions and un-observed mutations in loci with variable GC-content. Together, our analysis highlights technological divergences between two reproducible somatic variant detection efforts

Fabrication of solid oxide fuel cell based on doped ceria electrolyte by one-step sintering at 800 degrees C

Ce(0.8)Gd(0.05)Y(0.15)O(1.9)(GYDC) electrolyte was prepared by a carbonate co-precipitation method. Lithium nitrate at 1, 1.5, 2 and 3 mol% was added to GYDC as sintering additive. 96% relative density was achieved for GYDC at sintering temperature of 800 degrees C with addition of 1.5 mol% LiNO(3). The conductivities of GYDC with sintering aids LiNO3 were measured by a.c. impedance spectroscopy and showed comparable values to that of pure GYDC sample sintered at 1400 degrees C. A single cell with 1.5 mol% LiNO(3) infiltrated GYDC electrolyte was fabricated by sintering at 800 degrees C for only 2 h. Lithiated NiO was synthesized by the glycine-nitrate combustion method and employed as cathode material. The cell was tested at temperatures from 500 to 575 degrees C and a maximum power density of 73 mW cm(-2) was obtained at 575 degrees C. These preliminary results indicate that LiNO(3) is a very effective sintering additive for intermediate temperature solid oxide fuel cell fabrication

Conductivity and redox stability of perovskite oxide SrFe1-xTixO3-δ (x≤ 0.3)

A solid solution with the cubic perovskite structure was observed for SrFe1-xTixO3-delta (x = 0-0.3), with an increase in the lattice parameters noted upon increasing dopant concentration. Material stability in air was observed for all compounds, with a decrease in conductivity noted upon increasing dopant concentration attributed to a reduction in charge carrier concentration. A reduction in weight proportional to the titanium content was observed upon exposure to 5% H-2/Ar, although reduction at 700 degrees C was observed to elicit a structural transitions and the formation of a secondary phase for samples SrFeO3-delta and SrFe0.9Ti0.1O3-delta respectively. Conductivity measurements at 600 degrees C demonstrated a larger decrease in the conductivity with increasing dopant concentration, while all investigated oxides are stable after reducing in 5% H-2/Ar at 600 degrees C. It was found that the conductivity of SrFe0.8Ti0.2O3-delta and SrFe0.7Ti0.3O3-delta in 5% H-2/Ar is insufficient to be used as anode for SOFCs. In the investigated compositions, SrFe0.9Ti0.1O3-delta exhibits desired conductivity and redox stability, reduced thermal expansion coefficient compared to SrFeO3-delta, which is a promising redox stable anode for IT-SOFCs. (C) 2015 Elsevier Masson SAS. All rights reserved.</p

Building a Low-Cost Streaming System : Streaming and Camera Operating System for Live Internet Productions

This thesis describes a research and development project for a working live streaming system for a small society. The goal was to develop a software based live streaming system and to find out the best possibilities to expand the system into wider scale live productions for the future purposes. The goal was to build a working and cost-efficient set up with a low budget. The streaming system was built based on four different software and simple cameras. A server computer was installed to keep and send the material as video-on-demand server and streaming server. The streaming software was installed to on a laptop computer that enabled the multi-camera directing, video mixing and streaming from one device. The website was built to offer streaming for multiple different devices and offers video on demand and live stream possibilities. The project was successful and reached the set goal. The streaming server is managing the data well, and the website visitors are able to see the streams live or later. The end result of the project, the live streaming system, is cost-efficient and simple. It supports good quality streaming with small equipment, but is easily enlarged for future purposes.Insinöörityönä tehtiin tutkimus ja toteutus järjestelmästä, jonka avulla voidaan toteuttaa suoria televisiolähetyksiä internetin välityksellä. Työ suunniteltiin kokouksiaan internetin välityksellä jakavalle yhdistykselle, ja työn tavoitteena oli toteuttaa tietokoneohjelmistoihin perustuva suoratoistojärjestelmä suoria televisiolähetyksiä varten. Tavoitteena oli suunnitella ja toteuttaa järjestelmä, joka on toimiva ja mahdollisimman kustannustehokas. Median suoratoistojärjestelmä rakennettiin neljää tietokoneohjelmistoa hyödyntäen. Projektia varten rakennettiin palvelintietokone, jonka tehtävänä oli toimia videoiden arkistointtietokoneena ja suoratoistopalvelimena. Suoratoistoa varten asennettiin erillinen tietokone, joka mahdollistaa monikameraohjaamisen, leikkaamisen ja materiaalin lähettämisen eteenpäin internetin välityksellä. Projekti oli onnistunut ja asetettu tavoite saavutettiin. Lopputuloksena oli toimiva lähetysjärjestelmä ja kotisivut, joista katsoja pystyy seuraamaan suoria internetlähetyksiä ja näkemään vanhoja nauhoitteita videoarkistosta