Combined EXAFS, XRD, DRIFTS, and DFT Study of Nano Copper Based Catalysts for CO2 Hydrogenation

Highly monodispersed CuO nanoparticles (NPs) were synthesized via continuous hydrothermal flow synthesis (CHFS) and then tested as catalysts for CO2 hydrogenation. The catalytic behavior of unsupported 11 nm sized nanoparticles from the same batch was characterized by diffuse reflectance infrared fourier transform spectroscopy (DRIFTS), extended X-ray absorption fine structure (EXAFS), X-ray diffraction (XRD), and catalytic testing, under CO2/H2 in the temperature range 25–500 °C in consistent experimental conditions. This was done to highlight the relationship among structural evolution, surface products, and reaction yields; the experimental results were compared with modeling predictions based on density functional theory (DFT) simulations of the CuO system. In situ DRIFTS revealed the formation of surface formate species at temperatures as low as 70 °C. DFT calculations of CO2 hydrogenation on the CuO surface suggested that hydrogenation reduced the CuO surface to Cu2O, which facilitated the formation of formate. In situ EXAFS supported a strong correlation between the Cu2O phase fraction and the formate peak intensity, with the maxima corresponding to where Cu2O was the only detectable phase at 170 °C, before the onset of reduction to Cu at 190 °C. The concurrent phase and crystallite size evolution were monitored by in situ XRD, which suggested that the CuO NPs were stable in size before the onset of reduction, with smaller Cu2O crystallites being observed from 130 °C. Further reduction to Cu from 190 °C was followed by a rapid decrease of surface formate and the detection of adsorbed CO from 250 °C; these results are in agreement with heterogeneous catalytic tests where surface CO was observed over the same temperature range. Furthermore, CH4 was detected in correspondence with the decomposition of formate and formation of the Cu phase, with a maximum conversion rate of 2.8% measured at 470 °C (on completely reduced copper), supporting the indication of independent reaction pathways for the conversion of CO2 to CH4 and CO that was suggested by catalytic tests. The resulting Cu NPs had a final crystallite size of ca. 44 nm at 500 °C and retained a significantly active surface

Synergistic Effect of Co and Mn Co-Doping on SnO2 Lithium-Ion Anodes

The incorporation of transition metals (TMs) such as Co, Fe, and Mn into SnO2 substantially improves the reversibility of the conversion and the alloying reaction when used as a negative electrode active material in lithium-ion batteries. Moreover, it was shown that the specific benefits of different TM dopants can be combined when introducing more than one dopant into the SnO2 lattice. Herein, a careful characterization of Co and Mn co-doped SnO2 via transmission electron microscopy coupled with energy-dispersive X-ray spectroscopy and X-ray diffraction including Rietveld refinement is reported. Based on this in-depth investigation of the crystal structure and the distribution of the two TM dopants within the lattice, an ex situ X-ray photoelectron spectroscopy and ex situ X-ray absorption spectroscopy were performed to better understand the de-/lithiation mechanism and the synergistic impact of the Co and Mn co-doping. The results specifically suggest that the antithetical redox behaviour of the two dopants might play a decisive role for the enhanced reversibility of the de-/lithiation reaction

Three-dimensional Magnetic Resonance Imaging–based Printed Models of Prostate Anatomy and Targeted Biopsy-proven Index Tumor to Facilitate Patient-tailored Radical Prostatectomy—A Feasibility Study

In this prospective single-center feasibility study, we demonstrate that the use of three-dimensional (3D)-printed prostate models support nerve-sparing radical prostatectomy (RP) and intraoperative frozen sectioning (IFS) in ten men suffering from intermediate- and high-risk prostate cancer (PC), of whom seven harbored pT3 disease. Patient-specific 3D resin models were printed based on preoperative multiparametric magnetic resonance imaging (mpMRI) to provide an exact 3D impression of significant tumor lesions. RP and IFS were planned in a patient-tailored fashion. The 36-region Prostate Imaging Reporting and Data System (PI-RADS) v2.0 scheme was used to compare the MRI/3D print with whole-mount histopathology. In all cases, localization of the index lesion was correctly displayed by MRI and the 3D model. Localization of significant PC lesions correlated significantly (Pearson`s correlation coefficient of 0.88; p <  0.001). In addition, a significant correlation of the width, length, and volume of the tumor and prostate gland, derived from the printed model and histopathology, was found, using Pearson's correlation analyses and Bland-Altman plots. In conclusion, 3D-printed prostate models correlate well with final pathology and can be used to tailor RP. PATIENT SUMMARY: The use of three-dimensional (3D)-printed prostate models based on preoperative magnetic resonance imaging (MRI) may improve prostatectomy outcome. This study confirmed the accuracy of 3D-printed prostates compared with pathology from radical prostatectomy specimens. Thus, MRI-derived 3D-printed prostate models can assist in prostate cancer surgery

Synthesis of cerium, zirconium, and copper doped zinc oxide nanoparticles as potential biomaterials for tissue engineering applications

A novel eco-friendly high throughput continuous hydrothermal flow system was used to synthesise phase pure ZnO and doped ZnO in order to explore their properties for tissue engineering applications. Cerium, zirconium, and copper were introduced as dopants during flow synthesis of ZnO nanoparticles, Zirconium doped ZnO were successfully synthesised, however secondary phases of CeO and CuO were detected in X-ray diffraction (XRD). The nanoparticles were characterised using X-ray diffraction, Brunauer-Emmett-Teller (BET), Dynamic Light scattering Measurements, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and RAMAN spectroscopy was used to evaluate physical, chemical, and structural properties. The change in BET surface area was also significant, the surface area increased from 11.35 (ZnO_2) to 26.18 (ZrZnO_5). However. In case of CeZnO_5 and CuZnO_5 was not significant 13.68 (CeZnO_5) and 12.16 (CuZnO_5) respectively. Cell metabolic activity analysis using osteoblast-like cells (MG63) and human embryonic derived mesenchymal stem cells (hES-MP) demonstrated that doped ZnO nanoparticles supported higher cell metabolic activity compared to cells grown in standard media with no nanoparticles added, or pure zinc oxide nanoparticles. The ZrZnO_5 demonstrated the highest cell metabolic activity and non-cytotoxicity over the duration of 28 days as compared to un doped or Ce or Cu incorporated nanoparticles. The current data suggests that Zirconium doping positively enhances the properties of ZnO nanoparticles by increasing the surface area and cell proliferation. Therefore, are potential additives within biomaterials or for tissue engineering applications

Enhancer Remodeling during Adaptive Bypass to MEK Inhibition Is Attenuated by Pharmacologic Targeting of the P-TEFb Complex

Targeting the dysregulated BRaf-MEK-ERK pathway in cancer has increasingly emerged in clinical trial design. Despite clinical responses in specific cancers using inhibitors targeting BRaf and MEK, resistance develops often involving non-genomic adaptive bypass mechanisms. Inhibition of MEK1/2 by trametinib in triple negative breast cancer (TNBC) patients induced dramatic transcriptional responses, including upregulation of receptor tyrosine kinases (RTKs) comparing tumor samples before and after one week of treatment. In preclinical models MEK inhibition induced genome-wide enhancer formation involving the seeding of BRD4, MED1, H3K27 acetylation and p300 that drives transcriptional adaptation. Inhibition of P-TEFb associated proteins BRD4 and CBP/p300 arrested enhancer seeding and RTK upregulation. BRD4 bromodomain inhibitors overcame trametinib resistance, producing sustained growth inhibition in cells, xenografts and syngeneic mouse TNBC models. Pharmacological targeting of P-TEFb members in conjunction with MEK inhibition by trametinib is an effective strategy to durably inhibit epigenomic remodeling required for adaptive resistance

Bio-inspired CO₂ conversion by iron sulfide catalysts under sustainable conditions

The mineral greigite presents similar surface structures to the active sites found in many modern-day enzymes. We show that particles of greigite can reduce CO2 under ambient conditions into chemicals such as methanol, formic, acetic and pyruvic acid. Our results also lend support to the Origin of Life theory on alkaline hydrothermal vents

Knowledge Transfer and Accomodation Effects in Multinational Corporations: Evidence from European Subsidiaries

Foreign subsidiaries in multinational corporations (MNCs) possess knowledge that has different sources (e.g., the firm itself or various sources in the environment). How such sources influence knowledge transfer is not well understood. Drawing on the “accommodation effect” from cognitive psychology, the authors argue that accumulation of externally sourced knowledge in a subsidiary may reduce the value of transferring that subsidiary’s knowledge to other parts of the MNC. The authors develop a parsimonious model of intrafirm knowledge transfer and test its predictions against a unique data set on subsidiary knowledge development that includes the sources of subsidiary knowledge and the extent of knowledge transfer to other MNC units. The authors show that a high level of externally sourced knowledge in a subsidiary is associated with a high level of knowledge transfer from that subsidiary only if a certain tipping point of internally sourced knowledge has been surpassed. This suggests that subsidiary knowledge stocks that are balanced in terms of their origins tend to be more valuable, congruous, and fungible, and therefore more likely to be transferred to other MNC units

Three-dimensional Numerical Modeling and Computational Fluid Dynamics Simulations to Analyze and Improve Oxygen Availability in the AMC Bioartificial Liver

A numerical model to investigate fluid flow and oxygen (O(2)) transport and consumption in the AMC-Bioartificial Liver (AMC-BAL) was developed and applied to two representative micro models of the AMC-BAL with two different gas capillary patterns, each combined with two proposed hepatocyte distributions. Parameter studies were performed on each configuration to gain insight in fluid flow, shear stress distribution and oxygen availability in the AMC-BAL. We assessed the function of the internal oxygenator, the effect of changes in hepatocyte oxygen consumption parameters in time and the effect of the change from an experimental to a clinical setting. In addition, different methodologies were studied to improve cellular oxygen availability, i.e. external oxygenation of culture medium, culture medium flow rate, culture gas oxygen content (pO(2)) and the number of oxygenation capillaries. Standard operating conditions did not adequately provide all hepatocytes in the AMC-BAL with sufficient oxygen to maintain O(2) consumption at minimally 90% of maximal uptake rate. Cellular oxygen availability was optimized by increasing the number of gas capillaries and pO(2) of the oxygenation gas by a factor two. Pressure drop over the AMC-BAL and maximal shear stresses were low and not considered to be harmful. This information can be used to increase cellular efficiency and may ultimately lead to a more productive AMC-BAL

Systems biology discoveries using non-human primate pluripotent stem and germ cells: novel gene and genomic imprinting interactions as well as unique expression patterns

The study of pluripotent stem cells has generated much interest in both biology and medicine. Understanding the fundamentals of biological decisions, including what permits a cell to maintain pluripotency, that is, its ability to self-renew and thereby remain immortal, or to differentiate into multiple types of cells, is of profound importance. For clinical applications, pluripotent cells, including both embryonic stem cells and adult stem cells, have been proposed for cell replacement therapy for a number of human diseases and disorders, including Alzheimer's, Parkinson's, spinal cord injury and diabetes. One challenge in their usage for such therapies is understanding the mechanisms that allow the maintenance of pluripotency and controlling the specific differentiation into required functional target cells. Because of regulatory restrictions and biological feasibilities, there are many crucial investigations that are just impossible to perform using pluripotent stem cells (PSCs) from humans (for example, direct comparisons among panels of inbred embryonic stem cells from prime embryos obtained from pedigreed and fertile donors; genomic analysis of parent versus progeny PSCs and their identical differentiated tissues; intraspecific chimera analyses for pluripotency testing; and so on). However, PSCs from nonhuman primates are being investigated to bridge these knowledge gaps between discoveries in mice and vital information necessary for appropriate clinical evaluations. In this review, we consider the mRNAs and novel genes with unique expression and imprinting patterns that were discovered using systems biology approaches with primate pluripotent stem and germ cells