Thermodynamic analysis and optimization of RWGS processes for solar syngas production from CO2

Process systems were investigated for syngas production from CO₂ and renewable energy (solar) by the reverse water‐gas shift (RWGS) and the reverse water‐gas shift chemical looping (RWGS‐CL) process. Thermodynamic analysis and optimization was performed to maximize the solar‐to‐syngas (StS) efficiency η_StS. Special emphasis was laid on product gas separation. For RWGS‐CL, maximum StS efficiencies of 14.2 and 14.4% were achieved without and with heat integration, respectively. The StS efficiency is dictated by the low overall efficiency of H₂ production. RWGS‐CL is most beneficial for the production of pure CO, where the StS efficiency is one percent point higher compared to that of the RWGS process with heat integration. Heat integration leads to significant reductions in external heat demand since most of the gas phase process heat can be integrated. The StS efficiencies for RWGS and RWGS‐CL achieve the same level as the reported values for solar thermochemical syngas production. © 2016 American Institute of Chemical Engineers AIChE J, 63: 15–22, 2017     

Synthesis and characterization of polyurethane/titanium dioxide nanocomposites obtained by in situ polymerization

The development of new polymeric and polymeric based materials is fundamental to meet the market demands. This work aims the synthesis and characterization of polyurethane/titanium dioxide nanocomposite, using low cost commercial raw materials. Nanocomposites were synthesized by in situ polymerization reactions in which titanium dioxide were added in the following proportions, by weight, in relation to the mass obtained from the pure polymer: 0.5, 1.0, 2.0, 3.0, 5.0, 7.0, and 10.0 %. These reactions were based in poli (ε-caprolactone) and 1,6-diisocyanatohexane. The materials were characterized by infrared spectroscopy Fourier transform, scanning electron microscopy, differential scanning calorimetry analysis, thermogravimetric analysis, dynamic mechanical thermal analysis, and UV–Vis spectroscopy. Based on the obtained results it was concluded that the nanocomposites synthesized by in situ polymerization presented, in general, thermal properties (degradation temperature) and mechanical properties higher than the pure polymer.     

Impact of an Altered Wnt1/β-Catenin Expression on Clinicopathology and Prognosis in Clear Cell Renal Cell Carcinoma

In renal cell carcinoma (RCC), single members of the Wnt/β-catenin signaling cascade were recently identified to contribute to cancer progression. However, the role of Wnt1, one of the key ligands in β-catenin regulation, is currently unknown in RCC. Therefore, alterations of the Wnt1/β-catenin axis in clear cell RCC (ccRCC) were examined with regard to clinicopathology, overall survival (OS) and cancer specific survival (CSS). Corresponding ccRCCs and benign renal tissue were analyzed in 278 patients for Wnt1 and β-catenin expression by immunohistochemistry in tissue microarrays. Expression scores, including intensity and percentage of stained cells, were compared between normal kidney and ccRCCs. Data was categorized according to mean expression scores and correlated to tumor and patients’ characteristics. Survival was analyzed according to the Kaplan-Meier and log-rank test. Univariable and multivariable Cox proportional hazard regression models were used to explore the independent prognostic value of Wnt1 and β-catenin. In ccRCCs, high Wnt1 was associated with increased tumor diameter, stage and vascular invasion (p ≤ 0.02). High membranous β-catenin was associated with advanced stage, vascular invasion and tumor necrosis (p ≤ 0.01). Higher diameter, stage, node involvement, grade, vascular invasion and sarcomatoid differentiation (p ≤ 0.01) were found in patients with high cytoplasmic β-catenin. Patients with a high cytoplasmic β-catenin had a significantly reduced OS (hazard ratio (HR) 1.75) and CSS (HR 2.26), which was not independently associated with OS and CSS after adjustment in the multivariable model. Increased ccRCC aggressiveness was reflected by an altered Wnt1/β-catenin signaling. Cytoplasmic β-catenin was identified as the most promising candidate associated with unfavorable clinicopathology and impaired survival. Nevertheless, the shift of membranous β-catenin to the cytoplasm with a subsequently increased nuclear expression, as shown for other malignancies, could not be demonstrated to be present in ccRCC.     

Identification and Optimization of the First Highly Selective GLUT1 Inhibitor BAY‐876

Despite the long‐known fact that the facilitative glucose transporter GLUT1 is one of the key players safeguarding the increase in glucose consumption of many tumor entities even under conditions of normal oxygen supply (known as the Warburg effect), only few endeavors have been undertaken to find a GLUT1‐selective small‐molecule inhibitor. Because other transporters of the GLUT1 family are involved in crucial processes, these transporters should not be addressed by such an inhibitor. A high‐throughput screen against a library of ～3 million compounds was performed to find a small molecule with this challenging potency and selectivity profile. The N‐(1H‐pyrazol‐4‐yl)quinoline‐4‐carboxamides were identified as an excellent starting point for further compound optimization. After extensive structure–activity relationship explorations, single‐digit nanomolar inhibitors with a selectivity factor of >100 against GLUT2, GLUT3, and GLUT4 were obtained. The most promising compound, BAY‐876 [N⁴‐[1‐(4‐cyanobenzyl)‐5‐methyl‐3‐(trifluoromethyl)‐1H‐pyrazol‐4‐yl]‐7‐fluoroquinoline‐2,4‐dicarboxamide], showed good metabolic stability in vitro and high oral bioavailability in vivo.     

A Highly Potent and Cellularly Active β‐Peptidic Inhibitor of the p53/hDM2 Interaction

New and improved : The incorporation of a 6‐chlorotryptophan (6‐Cl‐Trp) into a β‐peptide (M)‐3₁₄ helix leads to a high‐affinity hDM2 inhibitor, as demonstrated by fluorescence fluctuation analysis at single molecule resolution. When conjugated to penetratin, the newly derived hDM2 binder specifically inhibits tumour cell growth in vitro.