Quantity and clinical relevance of circulating endothelial progenitor cells in human ovarian cancer

<p>Abstract</p> <p>Background</p> <p>Circulating bone marrow-derived endothelial progenitor cells (EPCs) have been reported to participate in tumor angiogenesis and growth; however, the role of circulating EPCs in tumor progression is controversial. The role of circulating EPCs in ovarian cancer progression and angiogenesis has not yet been investigated.</p> <p>Methods</p> <p>The number of circulating EPCs in the peripheral blood in 25 healthy volunteers and 42 patients with ovarian cancer was determined by flow cytometry. EPCs were defined by co-expression of CD34 and vascular endothelial growth factor receptor 2 (VEGFR2). In addition, we determined CD34 and VEGFR2 mRNA levels by real-time reverse transcription-polymerase chain reaction. Plasma levels of vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9) were determined by enzyme-linked immunosorbent assay.</p> <p>Results</p> <p>Circulating levels of EPCs were significantly increased in ovarian cancer patients, correlating with tumor stage and residual tumor size. Higher levels of EPCs were detected in patients with stage III and IV ovarian cancer than in patients with stage I and II disease. After excision of the tumor, EPCs levels rapidly declined. Residual tumor size greater than 2 cm was associated with significantly higher levels of EPCs. In addition, high circulating EPCs correlated with poor overall survival. Pretreatment CD34 mRNA levels were not significantly increased in ovarian cancer patients compared with healthy controls; however, VEGFR2 expression was increased, and plasma levels of VEGF and MMP-9 were also elevated.</p> <p>Conclusions</p> <p>Our results demonstrate the clinical relevance of circulating EPCs in ovarian cancer. EPCs may be a potential biomarker to monitor ovarian cancer progression and angiogenesis and treatment response.</p

Crystal structure of the ethyl 2,4-dihydroxy-6-methylbenzoate from Illicium difengpi K.I.B et K.I.M.

The title compound, C10H12O4, was isolated from Illicium difengpi K.I.B et K.I.M. An intramolecular O—H...O hydrogen bond stabilizes the molecular conformation. In the crystal, the compound forms offset slanted stacks of alternating inversion-related molecules along the a axis direction. Intermolecular O—H...O hydrogen bonds link the molecules into double strands parallel to the [101] direction

CO2 hydrogenation to methanol over Rh/In2O3–ZrO2 catalyst with improved activity

The In2O3 supported rhodium catalyst has been previously confirmed to be active for CO2 hydrogenation to methanol. In this work, the In2O3–ZrO2 solid solution was prepared and employed to support the rhodium catalyst. The deposition-precipitation method was applied to make the Rh catalyst highly dispersed. The catalyst characterization confirms that the use of ZrO2 optimizes and stabilizes the oxygen vacancies of In2O3, which causes the enhanced adsorption and activation of CO2. The highly dispersed Rh catalyst remarkably improves the hydrogenation ability of the In2O3–ZrO2 support. Compared to Rh/In2O3, the In2O3–ZrO2 supported Rh catalyst shows significantly higher activity with high methanol selectivity. For instance, at 300 °C and 5 MPa, the methanol selectivity over Rh/In2O3–ZrO2 reaches 66.5% with a space-time yield (STY) of methanol of 0.684 gMeOH h-1 gcat-1 and a CO2 conversion of 18.1%. The methanol selectivity and methanol STY at 300 °C is 19% and 26% higher than that of the Rh/In2O3 catalyst

Research on the noise characteristics of a closed-loop 87Rb atom comagnetometer

Spin-based comagnetometers have essential applications in studying new physical effects such as the fifth force, Lorentz violations, and spin-gravity interactions. In this paper, a transfer function model of the spin precession phase (frequency) is derived to analyze the comagnetometer's noise mechanism. The theory combined with experiments reveals that the output frequency noise of the spin oscillator above 5 Hz is mainly phase noise from the phase-locked loop. The noise below 5 Hz is mainly from the biased magnetic field noise. When building a comagnetometer using two spin oscillators, the symmetry of the spin oscillator is significant. When the intrinsic physical parameters cannot be symmetrical, the comagnetometer's common-mode suppression capability to magnetic field fluctuations can be enhanced by optimizing the control parameters. In addition, the closed-loop control of Bz can significantly weaken the effect of system asymmetry in the low-frequency band. Finally, when considering the comagnetometer system in nuclear magnetic resonance gyroscopes, a trade-off between the bandwidth and sensitivity can be achieved using theory. This paper is an excellent reference for both the research and application of comagnetometers

Modeling and Simulation Investigations on Microstructure Evolution during Additive Manufacturing of AlSi10Mg Alloy

Microstructure has significant effects on the mechanical properties of AlSi10Mg alloy. Therefore, an in-depth understanding of microstructure evolution, such as dendrite and Al-Si eutectic, is of great significance to obtain the desirable microstructure and manage the performance of AlSi10Mg components. In the current work, an integrated dendrite and eutectic evolution model based on the cellular automaton–finite difference (CA-FD) method, taking account of solute distribution, growth kinetics, and nucleation mechanism, was established. Microstructures of the as-built selective laser melted (SLMed) samples were characterized by optical microscopy (OM), scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD) techniques, and the experimental results showed that the microstructure consisted of Al grains and Al-Si eutectic networks in the individual melt pool. Dendrite growth, solute redistribution in ternary alloy and dendritic morphologies with different cooling rates were numerically investigated. In addition, the proposed model was also applied to predict the Al-Si eutectic evolution, and eutectic morphologies under eutectic undercooling in a range of 5 K to 20 K were also simulated. The simulated results indicated that dendrites were refined with the increasing of the cooling rates, and Al-Si eutectic morphology was sensitive to eutectic undercooling such that higher eutectic undercooling refined the eutectic microstructures. Model validations were performed, and the experimental results agreed well with the simulation results, indicating that the proposed model can successfully reproduce both dendrite and eutectic microstructures

Modeling and Simulation Investigations on Microstructure Evolution during Additive Manufacturing of AlSi10Mg Alloy

Microstructure has significant effects on the mechanical properties of AlSi10Mg alloy. Therefore, an in-depth understanding of microstructure evolution, such as dendrite and Al-Si eutectic, is of great significance to obtain the desirable microstructure and manage the performance of AlSi10Mg components. In the current work, an integrated dendrite and eutectic evolution model based on the cellular automaton&ndash;finite difference (CA-FD) method, taking account of solute distribution, growth kinetics, and nucleation mechanism, was established. Microstructures of the as-built selective laser melted (SLMed) samples were characterized by optical microscopy (OM), scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD) techniques, and the experimental results showed that the microstructure consisted of Al grains and Al-Si eutectic networks in the individual melt pool. Dendrite growth, solute redistribution in ternary alloy and dendritic morphologies with different cooling rates were numerically investigated. In addition, the proposed model was also applied to predict the Al-Si eutectic evolution, and eutectic morphologies under eutectic undercooling in a range of 5 K to 20 K were also simulated. The simulated results indicated that dendrites were refined with the increasing of the cooling rates, and Al-Si eutectic morphology was sensitive to eutectic undercooling such that higher eutectic undercooling refined the eutectic microstructures. Model validations were performed, and the experimental results agreed well with the simulation results, indicating that the proposed model can successfully reproduce both dendrite and eutectic microstructures

Probing Surface Structures of CeO₂, TiO₂, and Cu₂O Nanocrystals with CO and CO₂ Chemisorption

CO and CO₂ chemisorption on uniform CeO₂, TiO₂, and Cu₂O nanocrystals with various morphologies were comprehensively studied with in-situ diffuse reflectance infrared Fourier transform spectroscopy. The formed adsorbates were observed to be morphology dependent. CO or CO₂ chemisorbed at the metal cation sites, and bidentate and bridged carbonates involving the O sites are sensitive to the surface composition and the local coordination environments of surface metal cations and O anions and can be correlated well with the surface structures of facets exposed on oxide nanocrystals. Carbonate and carbonite species formed by CO chemisorption can probe the different facets of CeO₂. Carbonate species formed by CO chemisorption can probe the different facets of TiO₂. Adsorbed CO and carbonate species formed by CO chemisorption can probe the different facets of Cu₂O, and adsorbed CO₂ formed by CO₂ chemisorption can also probe the different facets of Cu₂O. These results demonstrate chemisorption of probing molecules as a convenient technique to identify surface structures of different facets of oxide nanocrystals and lay the foundations of surface structures for the fundamental understanding of catalysis and other surface-mediated functions of CeO₂, TiO₂, and Cu₂O nanocrystals

Nanoscale optical pulse limiter enabled by refractory metallic quantum wells.

The past several decades have witnessed rapid development of high-intensity, ultrashort pulse lasers, enabling deeper laboratory investigation of nonlinear optics, plasma physics, and quantum science and technology than previously possible. Naturally, with their increasing use, the risk of accidental damage to optical detection systems rises commensurately. Thus, various optical limiting mechanisms and devices have been proposed. However, restricted by the weak optical nonlinearity of natural materials, state-of-the-art optical limiters rely on bulk liquid or solid media, operating in the transmission mode. Device miniaturization becomes complicated with these designs while maintaining superior integrability and controllability. Here, we demonstrate a reflection-mode pulse limiter (sub-100 nm) using nanoscale refractory films made of Al2O3/TiN/Al2O3 metallic quantum wells (MQWs), which provide large and ultrafast Kerr-type optical nonlinearities due to the quantum size effect of the MQW. Functional multilayers consisting of these MQWs could find important applications in nanophotonics, nonlinear optics, and meta-optics