► In the present work, we have successfully synthesized BaZr
0.025Ti
0.975O
3 at various sintering temperatures. ► The composition has been prepared using solid state reaction technique. ► The ...composition showed enhanced properties at various sintering temperatures.
In this study, structural, dielectric and ferroelectric properties of BaZr
0.025Ti
0.975O
3 ferroelectric ceramics have been investigated. The compound was synthesized using solid state reaction technique. It is observed that the synthesized compound have perovskite crystal structure. As the sintering temperature increases from 1200
°C to 1250
°C and 1300
°C, the average grain size increases from 0.62
μm to 2.82
μm and 3.20
μm respectively. Moreover, the domains with “water-mark” and “lamellar” features are observed in SEM micrographs. The dielectric measurements as a function of temperature show a decrease in Curie temperature on increasing the sintering temperature. The decrease in Curie temperature is attributed to the decreased tolerance factor of the perovskite ABO
3 structure. There is enormous increase in the permittivity with the increase in grain size. The coercive field decreases and the remanent polarization increases as the grain size increases.
The repeatability and reproducibility of radiomic features extracted from CT scans need to be investigated to evaluate the temporal stability of imaging features with respect to a controlled scenario ...(test-retest), as well as their dependence on acquisition parameters such as slice thickness, or tube current. Only robust and stable features should be used in prognostication/prediction models to improve generalizability across multiple institutions. In this study, we investigated the repeatability and reproducibility of radiomic features with respect to three different scanners, variable slice thickness, tube current, and use of intravenous (IV) contrast medium, combining phantom studies and human subjects with non-small cell lung cancer. In all, half of the radiomic features showed good repeatability (ICC > 0.9) independent of scanner model. Within acquisition protocols, changes in slice thickness was associated with poorer reproducibility compared to the use of IV contrast. Broad feature classes exhibit different behaviors, with only few features appearing to be the most stable. 108 features presented both good repeatability and reproducibility in all the experiments, most of them being wavelet and Laplacian of Gaussian features.
The oxygen reduction reaction at a manganese dioxide cathode in alkaline medium is studied using cyclic voltammetry and by measuring volume of oxygen consumed at the cathode. The performance of the ...manganese dioxide cathode is also determined in the presence of fuel and an alkali mixture with a standard Pt/Ni anode in a flowing alkaline-electrolyte fuel cell. The fuels tested are methanol, ethanol and sodium borohydride (1
M), while 3
M KOH is used as the electrolyte. The performance of the fuel cell is measured in terms of open-circuit voltage and current–potential characteristics. A single peak in the cyclic voltammogram suggests that a four-electron pathway mechanism prevails during oxygen reduction. This is substantiated by calculating the number of electrons involved per molecule of oxygen that are reacted at the MnO
2 cathode from the oxygen consumption data for different fuels. The results show that the power density of the fuel cell increases with increase in MnO
2 loading to a certain limit but then decreases with further loading. The maximum power density is obtained at 3
mg
cm
−2 of MnO
2 for each of the three different fuels.
► NaCl crystals has been used as space holder. ► Variation of NaCl:Ti ratio varies porosity (65–80%). ► NaCl is cubic but the cells are spherical. ► Two types of pores: micro and macro pores are ...obtained. ► Foams are suitable for bones scaffolds and engineering applications.
Open cell Titanium-foam (Ti-foam) with varying porosities (65–80%) was prepared using sodium chloride (NaCl) particles as space holder through powder metallurgy route. In order to ensure sufficient handling strength in cold compacted pallets, 2wt.% polyvinyl alcohol (PVA) solutions (5wt.% PVA in water) was mixed with the mixture of Ti and NaCl powders prior to cold compaction. After sintering, NaCl salt was removed by dissolving it in hot water. Detailed Energy dispersive X-ray (EDX) analysis and X-ray diffraction studies of the prepared Ti-foams were conducted to examine any physical and chemical changes in the phase constituents. The micro-architectural characteristics, density vis-a-vis porosity, and compressive deformation behavior of the synthesized foams were evaluated to examine their suitability as biomaterial and engineering applications.
Lysosomal Ca2+ homeostasis is implicated in disease and controls many lysosomal functions. A key in understanding lysosomal Ca2+ signaling was the discovery of the two‐pore channels (TPCs) and their ...potential activation by NAADP. Recent work concluded that the TPCs function as a PI(3,5)P2 activated channels regulated by mTORC1, but not by NAADP. Here, we identified Mg2+ and the MAPKs, JNK and P38 as novel regulators of TPC2. Cytoplasmic Mg2+ specifically inhibited TPC2 outward current, whereas lysosomal Mg2+ partially inhibited both outward and inward currents in a lysosomal lumen pH‐dependent manner. Under controlled Mg2+, TPC2 is readily activated by NAADP with channel properties identical to those in response to PI(3,5)P2. Moreover, TPC2 is robustly regulated by P38 and JNK. Notably, NAADP‐mediated Ca2+ release in intact cells is regulated by Mg2+, PI(3,5)P2, and P38/JNK kinases, thus paralleling regulation of TPC2 currents. Our data affirm a key role for TPC2 in NAADP‐mediated Ca2+ signaling and link this pathway to Mg2+ homeostasis and MAP kinases, pointing to roles for lysosomal Ca2+ in cell growth, inflammation and cancer.
Synopsis
Lysosomal Ca2+ release is mediated by the TPC2 channel, which is activated by both NAADP and PI(3,5)P2. This activation is under further control by the intracellular concentration of Mg2+ and MAPK signaling.
Two‐pore channel 2 (TPC2) is regulated by both NAADP and PI(3,5)P2.
NAADP and PI(3,5)P2 show a synergistic effect on TPC2 activation in vivo.
TPC2 activity is negatively regulated by both Mg2+ cations and MAPK signaling.
Lysosomal Ca2+ release is mediated by the TPC2 channel, which is activated by both NAADP and PI(3,5)P2. This activation is under further control by the intracellular concentration of Mg2+ and MAPK signaling.
The present paper reports the dependence of wear behavior on sintering mechanism for iron (Fe) – alumina (Al2O3) metal matrix nanocomposites fabricated via Powder Metallurgy (P/M) technique. ...Nanocomposite composition was taken as 10 wt % Al2O3 and 90 wt % Fe. Synthesized green specimens were sintered in an argon atmosphere in the temperature range of 900–1100 °C for 1–3 h. XRD pattern of sintered nanocomposite reveals the formation of iron aluminate (FeAl2O4) phase beside presence of iron (Fe) and trace amount of aluminium oxide (Al2O3). Iron aluminate phase is formed as a result of reactive sintering between iron and alumina particles. Wear and coefficient of friction behavior of nanocomposite specimens were investigated under a load of 0.5, 1.0 and 2.0 kg with a constant sliding velocity of 4 m/s and sliding time of 1 h. It is found from these studies that the wear properties in nanocomposite specimen depends on the sintering temperature and sintering time respectively.
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•Present paper investigates the wear behavior of Fe - 10% Al2O3 MMNCs.•Wear properties are dependent on density and hardness of the specimens.•Wear behavior of the specimens varies with iron aluminate phase formation.•Wear mechanism maps in present case shows the microploughing effect.•All the synthesized nanocomposite specimens showed improved wear rate incomparison to pure iron specimen.
Purpose: The aim of the present study was to perform molecular characterisation of the blaNDM plasmids and to understand the mechanism of its spread among pathogenic bacteria. Materials and Methods: ...Seventy-six non-repetitive carbapenem-resistant isolates which were collected during Nov 2011 to April 2013 from four hospitals in Chennai were analyzed for the presence of the blaNDM gene by PCR. Further, the genetic context of the blaNDM gene was analyzed by PCR specific to ISAba125 and bleMBL gene. One of the blaNDM plasmid was completely sequenced in the Illumina HiSeq platform. Results: Twenty-three isolates consisting of 8 Escherichia coli, 8 Klebsiella pneumoniae, 3 Klebsiella oxytoca, 3 Acinetobacter baumanii and 1 Pseudomonas aeruginosa were found to carry the blaNDM gene. In 18 isolates the blaNDM gene was associated with a bleMBL gene and the ISAba125 element. The complete sequencing of pNDM-MGR194 revealed an IncX3 replication type plasmid, with a length of 46,253 bp, an average GC content of 47% and 59 putative ORFs. The iteron region contained the blaNDM5 gene and the bleMBL, trpF and dsbC genes downstream and an IS5 inserted within the ISAba125 element upstream. Conclusion: This is the first report where the blaNDM gene insertion in a plasmid is not accompanied by other resistance gene determinants. These observations suggest that the IncX3 plasmid pNDM-MGR194 is an early stage in the dissemination of the blaNDM.
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