| 1. |
- De Colle, Mattia, et al.
(författare)
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Study of the Hydration Behavior of Synthetic Ferropericlase with LowIron Oxide Concentrations to Prevent Swelling in Steel Slags
- 2021
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Ingår i: Journal of Sustainable Metallurgy. - : Springer Nature. - 2199-3831 .- 2199-3823.
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Tidskriftsartikel (refereegranskat)abstract
- Steel slags generally swell when subjected to water or humidity, which prevents proper recycling in the cement or asphaltindustries. The MgO and CaO phases in steel slags are responsible for this phenomenon, as both minerals easily absorb waterto form their respective hydroxides. MgO is often present in steel slags in a solid solution with several oxides, constitutingthe so-called RO phase. This study investigates the hydration rate of an RO phase consisting of FeO and MgO called ferropericlase.The material was synthesized in a laboratory furnace by sintering a FeO–MgO powder mixture with varying initialFeO contents (approximately 10, 15, and 20 wt%). Thereafter, electron probe micro-analyzer (EPMA) and X-ray diffraction(XRD) spectroscopies were used to characterize the structure of the samples, which were mainly composed of ferropericlaseand an exsolution of magnesioferrite. Also, Mössbauer spectra showed that the total ferrous iron proportion (Fe2+/ΣFe) ofthe sintered samples was in the range of 0.55–0.72. To measure the hydration behavior, the samples in powder form werecured in an autoclave at an H2Opartial pressure of 2 atm. Thereafter, thermal gravimetric analysis (TGA) was performed tomeasure the amount of water absorbed during the autoclave curing from the mass drop associated with the dehydration ofthe hydroxide. The study found a linear correlation between the initial FeO content and the weight loss after TGA, with areduction down to 6% in the sample with an initial FeO content of 20 wt% content compared to pure MgO.
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| 2. |
- Kobayashi, Takayuki, et al.
(författare)
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Disease Outcome and Brain Metabolomics of Cyclophilin-D Knockout Mice in Sepsis
- 2022
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Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1661-6596 .- 1422-0067. ; 23:2
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Tidskriftsartikel (refereegranskat)abstract
- Sepsis-associated encephalopathy (SAE) is a diffuse brain dysfunction resulting from a systemic inflammatory response to infection, but the mechanism remains unclear. The mitochondrial permeability transition pore (MPTP) could play a central role in the neuronal dysfunction, induction of apoptosis, and cell death in SAE. The mitochondrial isomerase cyclophilin D (CypD) is known to control the sensitivity of MPTP induction. We, therefore, established a cecal ligation and puncture (CLP) model, which is the gold standard in sepsis research, using CypD knockout (CypD KO) mice, and analyzed the disease phenotype and the possible molecular mechanism of SAE through metabolomic analyses of brain tissue. A comparison of adult, male wild-type, and CypD KO mice demonstrated statistically significant differences in body temperature, mortality, and histological changes. In the metabolomic analysis, the main finding was the maintenance of reduced glutathione (GSH) levels and the reduced glutathione/oxidized glutathione (GSH/GSSG) ratio in the KO animals following CLP. In conclusion, we demonstrate that CypD is implicated in the pathogenesis of SAE, possibly related to the inhibition of MPTP induction and, as a consequence, the decreased production of ROS and other free radicals, thereby protecting mitochondrial and cellular function.
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| 3. |
- Mogi, Kazumasa, et al.
(författare)
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9-oxo-ODAs suppresses the proliferation of human cervical cancer cells through the inhibition of CDKs and HPV oncoproteins
- 2023
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Ingår i: Scientific Reports. - 2045-2322. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Mucosal human papillomavirus (HPV) subtypes 16 and 18 are causative agents of cervical cancer, a leading cause of cancer-related deaths among women worldwide. In Japan, eggplant calyx is a folk remedy used to treat common warts. 9-oxo-(10E,12E)-octadecadienoic acid, isolated from eggplant calyx, may have antitumor effects. This study investigated the antitumor effects of 9-oxo-(10E, 12Z)-octadecadienoic acid and 9-oxo-(10E,12E)-octadecadienoic acid (9-oxo-ODAs) on human cervical cancer cells. 9-oxo-ODAs suppressed the proliferation of human cervical cancer cell lines (HeLa, and SiHa) in a concentration-dependent manner (IC50 = 25–50 µM). FCM analysis revealed that 9-oxo-ODAs induced apoptosis. Transcriptome, proteomics, and enrichment analyses revealed that treatment with 9-oxo-ODAs significantly altered the cell cycle and p53 pathways and decreased cyclin-dependent kinase 1 (CDK1) protein expression. Real-time PCR analysis demonstrated that 9-oxo-ODAs reduced CDK1 mRNA expression in a concentration-dependent manner. In vitro, 9-oxo-ODAs reduced the HPV oncoprotein expression. In ex vivo human cervical cancer tissues, 9-oxo-ODAs decreased CDK1 expression and increased cleaved caspase 3, an apoptosis marker. Further, 9-oxo-ODAs showed the potential to suppressed metastatic formation and growth of cervical cancer in vivo. These findings suggest that 9-oxo-ODAs induce cell cycle arrest and apoptosis in HPV-positive human cervical cancer cells, and this process involves CDK1. Consequently, 9-oxo-ODAs may be potential therapeutic agents for cervical cancer.
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| 4. |
- Wang, Wei, et al.
(författare)
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In-situ real time observation of martensite transformation in duplex fcc+hcp cobalt based entropic alloys
- 2020
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Ingår i: Materialia. - : Elsevier BV. - 2589-1529. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- Athermal martensite transformation in duplex fcc+hcp Co-based entropic alloys during continuous cooling was investigated in-situ. The real time observation was carried out using high temperature confocal laser scanning microscopy (HT-CLSM). This technique enables the detection of the athermal fcc to hcp transformation in entropic alloys, which is not sensitively detected by conventional thermomechanical methods e.g. dilatometer. The martensite fraction increases with increasing martensite starting temperature, and vice versa. Meanwhile, the martensite starting temperature decreases with the increasing grain size. In addition, the morphology and nucleation sites for martensite formation is discussed. This is the first time the that HT-CLSM technique is utilized in the field of entropic alloys. This in-situ observation technique coupled with thermodynamic calculations may help in the design of entropic alloys through the tailoring of the desired microstructure.
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| 5. |
- Wang, Wei, et al.
(författare)
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Inclusion engineering in Co-based duplex entropic alloys
- 2021
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Ingår i: Materials & design. - : Elsevier BV. - 0264-1275 .- 1873-4197. ; 210
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Tidskriftsartikel (refereegranskat)abstract
- Co-based duplex entropic alloy is designed very recently to replace pure Co as a major component of the binder phase for cemented carbide cutting tools. This work aims to provide a fundamental study of oxide inclusion characteristics in the duplex fcc + hcp Co-based entropic alloys. It is found that the Co85-xCrxFe7.5Ni7.5 (x = 15, 30 at.%) alloys hold the highest liquidus (T-liq) and solidus (T-sol) temperatures, compare with the Co85-xCrxMn7.5Ni7.5 (x = 15, 30 at.%) and Co77.5-xCrxFe7.5Mn7.5Ni7.5 (x = 15, 30 at.%) alloys. For each grade, the increasing Cr content leads to a decrease of T-sol and T-liq temperatures. It is also noted that there is an approximate 100 degrees C of undercooling exists in each grade during the solidification. The stable oxide inclusion in the Co85-xCrxMn7.5Ni7.5 and Co77.5-xCrxFe7.5Mn7.5Ni7.5 alloys is the MnCr2O4 type, while Cr2O3 is the main stable inclusion in the Co85-xCrxFe7.5Ni7.5 alloy. Furthermore, the size range of the MnCr2O4 particles is larger than that of Cr2O3. The theoretical calculation shows that MnCr2O4 has a higher coagulation coefficient than Cr2O3 does. This is due to the influence of the thermo-physical parameters, i.e. the interfacial energy between the oxide and the alloy and the viscosity of liquid alloy. The theoretical calculation fits well with the experimental findings.
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| 6. |
- Wang, Yong, et al.
(författare)
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Combination of In Situ Confocal Microscopy and Calorimetry to Investigate Solidification of Super- and Hyper-Duplex Stainless Steels
- 2023
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Ingår i: Steel Research International. - : Wiley. - 1611-3683 .- 1869-344X. ; 94:11
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Tidskriftsartikel (refereegranskat)abstract
- The solidification processes of super- and hyper-duplex stainless steels (i.e., UNS S32750 and S 33 207) are investigated in situ by a high-temperature confocal laser scanning microscope (HT-CLSM) and differential scanning calorimetry (DSC). The variations of δ-ferrite phase fraction during solidification are measured quantitatively. The results show that liquid L→δ-ferrite transformation first occurs at a certain degree of supercooling during the solidification process of steel. UNS S3DSS 3207 with a higher Cr content can result in a higher nucleation temperature and faster growth of δ-ferrite compared to those of UNS S332750 steel. Moreover, both the liquidus (TL) and solidus temperatures (TS) are increased with the increasing Cr content, while TL increases greater than TS. Electron microscopies are used to quantify the fraction and composition of each phase. Scheil equation is employed to predict the distribution behavior of the main alloying elements in the solidification process, and the predicted results are consistent with the experimental findings. This study aims to provide real-time experimental insights into the solidification kinetics of state-of-the-art high-alloy-grade duplex steels and benefits for controlling the casting process in the real production of stainless steels.
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| 7. |
- Xu, Kai, et al.
(författare)
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Ground-state electron transfer in all-polymer donor-acceptor heterojunctions
- 2020
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Ingår i: Nature Materials. - : Springer Science and Business Media LLC. - 1476-4660 .- 1476-1122. ; 19:7, s. 738-744
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Tidskriftsartikel (refereegranskat)abstract
- Doping of organic semiconductors is crucial for the operation of organic (opto)electronic and electrochemical devices. Typically, this is achieved by adding heterogeneous dopant molecules to the polymer bulk, often resulting in poor stability and performance due to dopant sublimation or aggregation. In small-molecule donor–acceptor systems, charge transfer can yield high and stable electrical conductivities, an approach not yet explored in all-conjugated polymer systems. Here, we report ground-state electron transfer in all-polymer donor–acceptor heterojunctions. Combining low-ionization-energy polymers with high-electron-affinity counterparts yields conducting interfaces with resistivity values five to six orders of magnitude lower than the separate single-layer polymers. The large decrease in resistivity originates from two parallel quasi-two-dimensional electron and hole distributions reaching a concentration of ∼1013 cm–2. Furthermore, we transfer the concept to three-dimensional bulk heterojunctions, displaying exceptional thermal stability due to the absence of molecular dopants. Our findings hold promise for electro-active composites of potential use in, for example, thermoelectrics and wearable electronics.
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| 8. |
- Xuan, Changji, et al.
(författare)
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Wetting and spreading behavior of liquid iron on single crystal TiO2 substrate
- 2020
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Ingår i: Materials letters (General ed.). - : Elsevier. - 0167-577X .- 1873-4979. ; 258
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Tidskriftsartikel (refereegranskat)abstract
- This work reported the wetting and spreading behavior of pure iron droplet on single crystal TiO2 substrate. During the heating process, a "FeO center dot TiOx separated liquid phase" appeared at the temperature below the melting point of the pure iron, and completely covered the lower half of the iron droplet. The observed high-wetting behavior of the droplet is due to the spreading of the "separated liquid phase" rather than the iron droplet flow. According to both thermodynamic considerations and experimental measurements, the "separated liquid phase" is formed through the chemical interactions among the iron specimen, oxygen gas in the Ar atmosphere and TiO2 substrate.
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