429 research outputs found
WDX-Analysis of the New Superconductors RO(1-x)F(x)FeAs and Its Consequences on the Electronic Phase Diagram
Polycrystalline samples of RO1-xFxFeAs (0 < x < 0.25) (R = La, Sm, Gd) were
investigated by wavelength-dispersive X-ray spectroscopy (WDX) in the electron
microscope to determine the composition of the samples, in particular the
fluorine content. It was found that the measured fluorine content can deviate
considerably from the initial weight. In the lanthanum compound LaO1-xFxFeAs,
we found good agreement mainly for x > 0.05, but for x < 0.05 the fluorine
hardly goes into the sample. For the samarium compound we measured less than
half the fluorine in the sample as initially weighed at all fluorine
concentrations. These measured values are taken into account when drawing the
electronic phase diagrams of LaO1-xFxFeAs and SmO1-xFxFeAs. This leads to a
more consistent picture of both of the diagrams in comparison to the plot of
the initial weight.Comment: 5 pages, 4 figures, Accepted for publication in Journal of
Superconductivity and Novel Magnetis
Physical secure optical communication based on private chaotic spectral phase encryption/decryption
Wideband complex-enhanced chaos generation using a semiconductor laser subject to delay-interfered self-phase-modulated feedback
Security-enhanced chaotic communications with optical temporal encryption based on phase modulation and phase-to-intensity conversion
Local-to-regional methane emissions from the Upper Silesian Coal Basin (USCB) quantified using UAV-based atmospheric measurements
Coal mining accounts for ~12% of the total anthropogenic methane (CH4) emissions worldwide. The Upper Silesian Coal Basin (USCB), Poland, where large quantities of CH4 are emitted to the atmosphere via ventilation shafts of underground hard coal (anthracite) mines, is one of the hot spots of methane emissions in Europe. However, coal bed CH4 emissions into the atmosphere are poorly characterized. As part of the carbon dioxide and CH4 mission 1.0 (CoMet 1.0) that took place in May-June 2018, we flew a recently developed active AirCore system aboard an unmanned aerial vehicle (UAV) to obtain CH4 and CO2 mole fractions 150-300m downwind of five individual ventilation shafts in the USCB. In addition, we also measured δ13C-CH4, δ2H-CH4, ambient temperature, pressure, relative humidity, surface wind speed, and surface wind direction. We used 34 UAV flights and two different approaches (inverse Gaussian approach and mass balance approach) to quantify the emissions from individual shafts. The quantified emissions were compared to both annual and hourly inventory data and were used to derive the estimates of CH4 emissions in the USCB. We found a high correlation (R2Combining double low line0.7-0.9) between the quantified and hourly inventory data-based shaft-averaged CH4 emissions, which in principle would allow regional estimates of CH4 emissions to be derived by upscaling individual hourly inventory data of all shafts. Currently, such inventory data is available only for the five shafts we quantified. As an alternative, we have developed three upscaling approaches, i.e., by scaling the European Pollutant Release and Transfer Register (E-PRTR) annual inventory, the quantified shaft-averaged emission rate, and the shaft-averaged emission rate, which are derived from the hourly emission inventory. These estimates are in the range of 256-383ktCH4yr-1 for the inverse Gaussian (IG) approach and 228-339ktCH4yr-1 for the mass balance (MB) approach. We have also estimated the total CO2 emissions from coal mining ventilation shafts based on the observed ratio of CH4/CO2 and found that the estimated regional CO2 emissions are not a major source of CO2 in the USCB. This study shows that the UAV-based active AirCore system can be a useful tool to quantify local to regional point source methane emissions
Local-to-regional methane emissions from the Upper Silesian Coal Basin (USCB) quantified using UAV-based atmospheric measurements
Coal mining accounts for ~12% of the total anthropogenic methane (CH4) emissions worldwide. The Upper Silesian Coal Basin (USCB), Poland, where large quantities of CH4 are emitted to the atmosphere via ventilation shafts of underground hard coal (anthracite) mines, is one of the hot spots of methane emissions in Europe. However, coal bed CH4 emissions into the atmosphere are poorly characterized. As part of the carbon dioxide and CH4 mission 1.0 (CoMet 1.0) that took place in May-June 2018, we flew a recently developed active AirCore system aboard an unmanned aerial vehicle (UAV) to obtain CH4 and CO2 mole fractions 150-300m downwind of five individual ventilation shafts in the USCB. In addition, we also measured δ13C-CH4, δ2H-CH4, ambient temperature, pressure, relative humidity, surface wind speed, and surface wind direction. We used 34 UAV flights and two different approaches (inverse Gaussian approach and mass balance approach) to quantify the emissions from individual shafts. The quantified emissions were compared to both annual and hourly inventory data and were used to derive the estimates of CH4 emissions in the USCB. We found a high correlation (R2Combining double low line0.7-0.9) between the quantified and hourly inventory data-based shaft-averaged CH4 emissions, which in principle would allow regional estimates of CH4 emissions to be derived by upscaling individual hourly inventory data of all shafts. Currently, such inventory data is available only for the five shafts we quantified. As an alternative, we have developed three upscaling approaches, i.e., by scaling the European Pollutant Release and Transfer Register (E-PRTR) annual inventory, the quantified shaft-averaged emission rate, and the shaft-averaged emission rate, which are derived from the hourly emission inventory. These estimates are in the range of 256-383ktCH4yr-1 for the inverse Gaussian (IG) approach and 228-339ktCH4yr-1 for the mass balance (MB) approach. We have also estimated the total CO2 emissions from coal mining ventilation shafts based on the observed ratio of CH4/CO2 and found that the estimated regional CO2 emissions are not a major source of CO2 in the USCB. This study shows that the UAV-based active AirCore system can be a useful tool to quantify local to regional point source methane emissions.</p
Documentation of the EVENT-HMMS Experiment 2012 – Microclimatological effects of rain-out shelters within EVENT II
Synthesis and Characterization of 40 wt % Ce₀.₉Pr₀.₁O₂−δ−60 wt % NdxSr₁₋ₓFe₀.₉Cu₀.₁O₃−δ Dual-Phase Membranes for Efficient Oxygen Separation
Dense, H₂- and CO₂-resistant, oxygen-permeable 40 wt % Ce₀.₉Pr₀.₁O₂–δ–60 wt % NdₓSr₁₋ₓFe₀.₉Cu₀.₁O₃−δdual-phase membranes were prepared in a one-pot process. These Nd-containing dual-phase membranes have up to 60% lower material costs than many classically used dual-phase materials. The Ce₀.₉Pr₀.₁O₂−δ–Nd₀.₅Sr₀.₅Fe₀.₉Cu₀.₁O₃−δ sample demonstrates outstanding activity and a regenerative ability in the presence of different atmospheres, especially in a reducing atmosphere and pure CO₂ atmosphere in comparison with all investigated samples. The oxygen permeation fluxes across a Ce₀.₉Pr₀.₁O₂−δ–Nd₀.₅Sr₀.₅Fe₀.₉Cu₀.₁O₃−δ membrane reached up to 1.02 mL min⁻¹ cm⁻² and 0.63 mL min⁻¹ cm⁻² under an air/He and air/CO₂ gradient at T = 1223 K, respectively. In addition, a Ce₀.₉Pr₀.₁O₂–δ–Nd₀.₅Sr₀.₅Fe₀.₉Cu₀.₁O₃–δ membrane (0.65 mm thickness) shows excellent long-term self-healing stability for 125 h. The repeated membrane fabrication delivered oxygen permeation fluxes had a deviation of less than 5%. These results indicate that this highly renewable dual-phase membrane is a potential candidate for long lifetime, high temperature gas separation applications and coupled reaction–separation processes
Cytochrome P450 27C1 Level Dictates Lung Cancer Tumorigenicity and Sensitivity towards Multiple Anticancer Agents and Its Potential Interplay with the IGF-1R/Akt/p53 Signaling Pathway
Cytochrome P450 enzymes (CYP450s) exert mighty catalytic actions in cellular metabolism and detoxication, which play pivotal roles in cell fate determination. Preliminary data shows differential expression levels of CYP27C1, one of the "orphan P450s" in human lung cancer cell lines. Here, we study the functions of CYP27C1 in lung cancer progression and drug endurance, and explore its potential to be a diagnostic and therapeutic target for lung cancer management. Quantitative real-time PCR and immunoblot assays were conducted to estimate the transcription and protein expression level of CYP27C1 in human lung cancer cell lines, which was relatively higher in A549 and H1975 cells, but was lower in H460 cells. Stable CYP27C1-knockdown A549 and H1975 cell lines were established, in which these cells showed enhancement in cell proliferation, colony formation, and migration. In addition, aberrant IGF-1R/Akt/p53 signal transduction was also detected in stable CYP27C1-knockdown human lung cancer cells, which exhibited greater tolerance towards the treatments of anticancer agents (including vinorelbine, picropodophyllin, pacritinib, and SKLB610). This work, for the first time, reveals that CYP27C1 impacts lung cancer cell development by participating in the regulation of the IGF-1R/Akt/p53 signaling pathway, and the level of CYP27C1 plays indispensable roles in dictating the cellular sensitivity towards multiple anticancer agents
Differential roles for lysyl oxidase (like), family members in chronic obstructive pulmonary disease; from gene and protein expression to function:from gene and protein expression to function
Chronic obstructive pulmonary disease (COPD) is characterized by long-term airflow obstruction with cigarette smoke as a key risk factor. Extracellular matrix (ECM) alterations in COPD may lead to small airway wall fibrosis. Altered collagen cross-linking, potentially mediated by the lysyl oxidase (LO) family of enzymes (LOX, LOXL1-4), orchestrates disturbed ECM homeostasis. In this study, we investigated the effects of smoking status and presence and severity of COPD on LOs gene and protein expression in the airways and the impact of LOs inhibition on airway contraction in an ex vivo mouse model. We used gene expression data from bronchial brushings, airway smooth muscle (ASM) cells in vitro and immunohistochemistry in lung tissue to assess smoke- and COPD-associated differences in LOs gene and protein expression in the small airways. We found higher LOX expression in current- compared to ex-smokers and higher LOXL1 expression in COPD compared to non-COPD patients. LOX and LOXL2 expression were upregulated in COPD ASM cells treated with cigarette smoke extract. LOXL1 and LOXL2 protein levels were higher in small airways from current- compared to non-smokers. In COPD patients, higher LOXL1 and lower LOX protein levels were observed, but no differences for LOXL2, LOXL3, and LOXL4 protein were detected in small airways. Inhibiting LOs activity increased airway contraction in murine lung slices. COPD-associated changes in LOs, in particular LOX and LOXL1, may be related to smoking and contribute to impaired airway function, providing potential novel targets for preventing or treating small airways changes in COPD
- …