Auswahl der wissenschaftlichen Literatur zum Thema „Bauer Chemical Co“

A base-promoted amidation of 1-aryl-2,2,2-trifluoroethanones with amines via Haller–Bauer reaction has been developed. This reaction directly transforms aryl trifluoroethanone into amides without the use of stoichiometric chemical oxidants or transition-metal catalysts.

The preferred imaging techniques for the observation of physical and chemical processes at solid surfaces with high temporal and spatial resolution are low-energy electron microscopy (LEEM), mirror electron microscopy (MEM) and photoemission electron microscopy (PEEM). In these techniques the energy transfer to the surface during the imaging process itself is small so that surface processes such as adsorption, diffusion, chemical reactions etc. remain largely undisturbed.LEEM, MEM and PEEM, which all can be performed in an ultra-high-vacuum surface microscope of the Bauer/Telieps type, have been applied to the study of CO/O reaction-diffusion fronts on a Pt(100) surface saturated with CO. These fronts develop after admission of oxygen to the surface (10-6 mbar) at surface defects which provide adsorption sites for oxygen and thus initiate the autocatalytic oxidation process. The formed CO2 is instantaneously desorbed, freeing adsorption sites which are then occupied by oxygen from the gas phase. The front propagates over the whole surface, leaving behind an oxygen-covered region.

Some 2′,4′-difluorophenyl chalcones have been synthesized under microwave irradiation using aldol condensation between 2,4-difluoroacetophenone and substituted benzaldehydes using catalytic amount of hydroxyapatite. The yields of the chalcones are more than 85%. The purities of these synthesized chalcones were examined by their physical constants and spectroscopic data. The UV absorption maxima (λmax, nm), infrared stretches (ν, cm-1) of CO, fingerprint region of CHip/op, CH=CHop, C=Cop modes, NMR chemical shifts (δ, ppm) of vinyl proton, carbon and carbonyl carbons have been assigned and correlated with Hammett substituent constants, F and R parameters using single and multi-regression analysis. From the statistical analysis the effect of substituent on the above spectral frequencies can be discussed. The antimicrobial activities of these synthesized chalcones have been screened using Bauer-Kirby method.

Some 2′,4′-difluorophenyl chalcones have been synthesized under microwave irradiation using aldol condensation between 2,4-difluoroacetophenone and substituted benzaldehydes using catalytic amount of hydroxyapatite. The yields of the chalcones are more than 85%. The purities of these synthesized chalcones were examined by their physical constants and spectroscopic data. The UV absorption maxima (λmax, nm), infrared stretches (ν, cm-1) of CO, fingerprint region of CHip/op, CH=CHop, C=Cop modes, NMR chemical shifts (δ, ppm) of vinyl proton, carbon and carbonyl carbons have been assigned and correlated with Hammett substituent constants, F and R parameters using single and multi-regression analysis. From the statistical analysis the effect of substituent on the above spectral frequencies can be discussed. The antimicrobial activities of these synthesized chalcones have been screened using Bauer-Kirby method.

Background: The main aim of this study was to monitor the antimicrobial resistant pattern of Salmonella isolates to select proper antibiotic & prevent drug resistance in Salmonella species. Material and Methods: Total 250 blood culture bottles were collected from patients clinically suspected enteric fever and loaded to BACTEC 9050. Out of them 200 signalled positive samples were inoculated on chocolate and Mac Conkey agar plates and incubated overnight at 370 C in the incubator and identified by colony characteristics, procedures like Gram staining, wet preparation for motility and bio-chemical reactions like oxidase test, catalase test, triple sugar iron agar, Citrate test, using Salmonella antisera like Poly O, O-9, and H-d. The clinical isolates were subjected to antibiotic sensitivity test on Mueller-Hinton agar, using modified Kirby Bauer disc diffusion method as per Clinical Laboratory Standard Institute (CLSI) guidelines. Results: Total 61 Salmonella were isolated. 49 were Salmonella typhi and 12 were Salmonella paratyphi. Overall rate of resistance of 49 S. typhi isolates was 2 % to ampicillin, 4 % to Azithromycin, 4 % to fluoroquinolones and 2 % to co-trimoxazole. S. paratyphi isolates were 100% sensitive to ampicillin, co-trimoxazole, chloramphenicol and 3rd generation cephalosporins. Conclusion: Enteric fever is one such infection which poses challenges in antimicrobial resistance. Continuous surveillance is important to track bacterial resistance and to treat infections in a cost-effective manner.

At present, alloying the Pt with 3d-transition metal, such as Co, has been demonstrated as an efficacious approach in enhancing the activity of the cathodic catalysts and diminishing the cost of Pt through ligand effect and strain effect. However, these catalysts were facing with a substantial challenge of the limited durability, primarily attributed to the leaching of the 3d-transition metal under the rigorous electrochemical conditions for the proton exchange membrane fuel cells (PEMFCs)[1]. Herein, we applied both operando conventional XAS and high energy resolution fluorescence detection (HERFD) XAS to identify the electro-chemical behaviors of subsize (about 2.5 nm) PtxCoy alloy catalysts with different Co content and associated with the Pt1Co3@Pt core-shell (CS) nanostructure catalysts obtained by simple displacement reaction. We find that the introduction of Co helps to modify the structure of PtCo alloy catalysts and benefit the activity, however, the increase content of Co brings to the heavier oxidation of Pt, which accelerate the degradation of the PtCo alloy catalysts. While the structure with Pt-rich shell suggested a high tolerance to the Pt oxidation which benefits both stability and activity. Based on these findings, we demonstrate the significance of designing PtCo CS nanostructure with high Co content to achieve optimal performance in PEMFCs. Our research provides valuable insights in designing the catalysts combined with operando XAS analysis and paves the way for the development for the large-scale application for PEMFCs. For the typical synthesis of PtCox alloy catalysts, the Pt(acac)2 and Co(acac)3 were used as Pt and Co precursors. 4mL ethanol was added to the pre-mixed Pt and Co precursors and heated up to 60 °C with magnetic stirring. After the precursors completely dissolved, certain amount of Vulcan 72 was added into the solution. Then repeat ultrasonication and magnetic stirring in 60 °C until the solution converted into slurry statement, dried the product in 30 °C over night. Next, the above well-milled products were treated at 700 °C for 2h in Ar atmosphere to transfer into alloy particles. According to the introduced ratio between Pt and Co, the catalysts were noted as Pt3Co1, Pt1Co1, and Pt1Co3. The contribution of CS nanostructure of Pt1Co3 was applied by simple displacement reaction using H2PtCl6 solution as Pt source. The production was annealed in H2 for 30 min. Operando conventional XAS (at BL36XU in Spring 8) was performed to investigate the electronic statement and structure changes during the operation. Operando HERFD XAS (at BL39XU in Spring 8) further identified the formation of metal Pt with chemisorbed O and Pt oxidation during the polarization varying different Co content and Pt-rich shell. The electronic performance of PtCo alloy catalysts was evaluated in rotating disk electrode, gas diffusion electrode, and membrane electrode assembly, which exhibited a higher performance (about 5 times higher than Pt/C) for Pt1Co3@Pt catalyst. Fig. 1a shows the STEM mapping results for Pt1Co3@Pt catalysts, the linear scanning profile is shown in the mix-image, and the signal intensity between the Pt L-edge and Co K-edge indicates the Pt-rich shell and Pt and Co core structure, which suggested the successful synthesis of Pt-rich shell with high Co content. To further analyze the electronic-behavior for the catalysts, the operando HERFD-XAS analysis was performed on Pt1Co3 and Pt1Co3@Pt catalysts, which provides a higher signal-to-noise ratio and detailed information about the electronic statement of Pt atom[2]. As shown in Figure 1b and c, the main Pt L3-edge white line intensity continuously increased and positively shifted, which suggested the increasing coverage of chemisorbed O or OH onto the Pt surface and the generation of oxidic component at high polarization potential for Pt1Co3 catalyst. While less changes were shown in Pt1Co3@Pt catalyst, which implied the formation of Pt-rich shell could help to suppress the oxidation of Pt in PtCo alloy catalysts and benefit the catalytic performance. References [1] Z.P. Wu, D.T. Caracciolo, Y. Maswadeh, et al. Nat. Commun. 12 (2021) 859. [2] M. Bauer, Phys.Chem.Chem.Phys. 16 (2014) 13827. Fig. 1 (a) STEM-mapping image for Pt1Co3@Pt catalysts and its linear-scanning mapping result for Pt L-edge (red) and Co K-edge (green), operando HERFD XAS analysis for (b) Pt1Co3 and (c) Pt1Co3@Pt catalysts varying different polarization potential (vs. RHE) in O2-satureated 0.1 M HClO4 solution. Figure 1

Na-ion batteries based on non-aqueous electrolytes represent an inexpensive and sustainable alternative to their Li-ion counterparts [1,2]. The cost advantage is particularly apparent at the present time as the prices of battery grade Li and Co precursor salts have spiraled upwards in the last 18 months. Faradion Limited is a UK-based company, founded in 2011 and from December 2021, part of Reliance Industries Limited of India*. It is commercializing its Na-ion battery technology in a number of large format applications. It has identified and developed a wide range of inexpensive and proprietary active materials and non-aqueous electrolyte systems which offer low manufacturing costs as well as outstanding electrochemical performance and intrinsic safety. Over the past 10 years the company has incorporated these materials into full-scale Na-ion cells to a point where battery performance characteristics such as energy density, rate capability and cycle life are competitive with commercial Li-ion technologies. The Faradion Na-ion prototype cells demonstrate low-capacity fade on cycling, coupled to low polarization and excellent columbic and energy (round-trip) efficiency and may be configured for both energy and power applications. The use of Al for both current collectors serves as an additional and significant cost and safety benefit and allows the cells to be stored and transported at 0 V (i.e. physically shorted) [3]. The Faradion Na-ion cells are manufactured on commercial Li-ion production lines using proven battery designs [4,5]. Pouch, cylindrical and prismatic cell designs have all been demonstrated successfully [6]. Faradion has worked with its commercial partners to scale-up its Na-ion cell chemistry to the 40 Wh and 90 Wh pouch cell level – see for example, figure 1. These cells deliver a cell level specific energy of over 150 Wh/kg and have been incorporated into a range of demonstrator energy storage applications, including E-bike, residential, renewables, telecoms and automotive [6]. Faradion’s technology roadmap indicates that a specific energy in excess of 190 Wh/kg will be accessible in the near future. Other key attributes such as low precursor costs, material sustainability and excellent temperature range, confirm that Faradion’s Na-ion battery technology will prove commercially successful in a range of large format applications [7]. Reference s: [1] J. Barker, M.Y. Saidi and J. Swoyer, Electrochem. Solid-State Chem. 6 (2003) A1 [2] K. Kubota and S. Komaba, J. Electrochem. Soc., 162 (2015) A2538. doi.org/10.1149/2.0151514jes [3] (a) A. Rudola, C.J. Wright and J. Barker, Energy Materials Advances, 2021 Article ID 9798460. doi.org/10.34133/2021/9798460 (b) J. Barker and C.J. Wright, Assignee: Faradion Limited. US Patent #11159027 [4] A. Bauer, J. Song, S. Vail, W. Pan, J. Barker and Y. Lu, Adv. Energy Materials, 1 2018, 1702869. doi.org/10.1002/aenm.201702869 [5] For example, J. Barker and R.J. Heap, Assignee: Faradion Limited, US Patent#9774035, US Patent #9917307, US Patent #1019628, US Patent #10115966, US Patent #10050271, US Patent #10399863 [6] (a) American Chemical Society, Chemical & Engineering News, July 20, 2015, Vol. 93, Issue 29. (b) American Chemical Society, Chemical & Engineering News, May 24, 2022, Vol. 100, Issue 19 [7] A. Rudola et al. J. Mater Chem A, 2021, 9, 8279-8302. doi.org/10.1039/D1TA00376C Footnote: [*] In late 2021, Faradion Limited was acquired by Reliance New Energy Systems Limited (RNESL), a wholly owned subsidiary of Reliance Industries Limited (RIL) of India. Figure 1

Proton-Exchange Membrane Fuel Cells (PEMFCs) are electrochemical devices with potential applications in mobility and stationary energy storage. Last decades have seen a growing interest in the research, the development and the small-scale industrialization of PEMFC. However, PEMFC requires Pt as catalyst for both electrochemical reactions. From the geological point of view, Pt is a scarce element, while between 7 to 12 t of mineral must be extracted to obtain 31.1 g of Pt. Moreover, Pt is considered as a critical raw material by the E.U. with a high supply shortage/breakdown risk.1 The recycling might be a feasible way how to face the current and future supply issues and to secure the access to resources. Although there are currently no legal obligation regarding the PEMFCs recycling, it is highly probable that regulations close to those already existing for batteries will be soon applied, implementing mandatory collection and recycling targets for spent PEMFCs. Finally, this might also be a way to decrease the costs and the environmental impacts of the PEMFCs’ sector as the use of Pt affects both its cost and is considered as a burden from the environmental point of view.2,3 Recycling it might be a feasible option to counteract these issues in a comparable manner to (i) an increase of the Pt catalyst durability, (ii) a decrease of its loading and (iii) its substitution by less noble metals. While the three latter pathways are already widely studied by different research teams, the recycling option has not attracted, up to now, significant attention and will be the scope of this presentation. Two different recycling approaches might be used to recover Pt. Pyrometallurgy is based on thermal treatment of metals, namely their reduction and smelting, while hydrometallurgy is a chemical approach consisting in metals dissolution and further purification. Each of them has its own pros and cons, whereas both approaches can be combined. Both have also been exploited for MEA recycling. Within our research group hydrometallurgical approach has been applied to MEA recycling. This approach is traditionally composed of several successive steps: pretreatment (including shredding and grinding), leaching, separation and purification followed by the final recovery. We have progressively exploited several manners to dissolve platinum. The Pt/C catalyst might be dissolved at room temperature by combining appropriate concentrations of oxidizing and complexing agents. We have namely achieved very high leaching yield when using either H2O2 (3%) and HNO3 (5%) as oxidizer diluted in concentrated HCl playing the role of the complexing agent.4 We have further demonstrated that electro-assisted leaching of Pt might also be feasible if an appropriate electrolyte is combined to the appropriate choice of oxidation and reduction potential that are applied alternatively. Once the Pt is dissolved its purification might be carried out via ion exchange or solvent extraction.4 These operations might also be feasible for its separation from Co in case of Pt3Co alloys presence in the spent MEAs.5,6 Finally, the recovery of Pt might be carried out by precipitation or Pt/C catalyst might be synthetized in a closed-loop manner.5 Two different approaches have been attempted within our research team and both of them have provided a catalyst which exhibited similar performance to a reference Pt/C catalyst in a single-cell PEMFC.5 Moreover, the environmental benefits of the recycling process have been assessed using the LCA methodology.5,7 The results show that primary platinum production remains the most impacting stage, even when MEA recycling is considered. Moreover, the assessment reveals that the MEA life-cycle impacts can be reduced significantly if electrodes recycling is carried out, while the main impact categories decrease is proportional to the platinum recycling rate. References 1 European Commission, Study on the Critical Raw Materials for the EU 2023 - Final Report, 2023. 2 M. Miotti, J. Hofer and C. Bauer, Int. J. Life Cycle Assess., 2017, 22, 94–110. 3 A. Simons and C. Bauer, Appl. Energy, 2015, 157, 884–896. 4 L. Duclos, L. Svecova, V. Laforest, G. Mandil and P.-X. Thivel, Hydrometallurgy, 2016, 160, 79–89. 5 L. Duclos, R. Chattot, L. Dubau, P. X. Thivel, G. Mandil, V. Laforest, M. Bolloli, R. Vincent and L. Svecova, Green Chem., 2020, 22, 1919–1933. 6 M. Gras, L. Duclos, N. Schaeffer, V. Mogilireddy, L. Svecova, Eric Chaînet, I. Billard and N. Papaiconomou, ACS Sustain. Chem. Eng., 2020, 8, 15865–15874. 7 L. Duclos, M. Lupsea, G. Mandil, L. Svecova, P.-X. Thivel and V. Laforest, J. Clean. Prod., 2017, 142, 2618–2628.

Abstract The YAP-TEAD protein-protein interaction (PPI) is a critical event known to mediate YAP oncogenic functions downstream of the Hippo pathway. Current advanced pharmacological agents which aim at inhibiting YAP-TEAD oncogenic function do so by engaging into the lipid pocket of TEAD. Thereby the consequences of a direct pharmacological disruption of the interface of YAP and TEADs remain unexplored. Here we report the identification of IAG933, the first molecule able to potently and directly disrupt the YAP/TAZ-TEADs PPI with suitable properties to enter in clinical trial. The path to drug discovery was established by structure-based optimization of a truncated natural YAP peptide allowing the pharmacophore mapping of TEAD coil binding site. Based on in silico screening, validated hit was optimized using structure- and property-based lead optimization yielding IAG933, whose chemical structure will be for the first time disclosed here. Biochemical and cellular assays demonstrate that IAG933 specifically abrogates the interaction between YAP/TAZ coactivators and all four TEAD isoforms, thus selectively inhibiting TEAD-driven transcriptional activity and inducing anti-cancer effects. At the epigenome level, YAP eviction from chromatin was observed upon treatment with IAG933, while leaving TEADs genomic occupancy unaffected. Concomitantly, engagement of co-repressor VGLL4 translated to a decrease in enhancer activity with rapid and progressive changes in transcription of Hippo target genes. In preclinical experiments, IAG933 linear pharmacokinetics was consistent with dose proportional TEAD transcriptional inhibition and anti-tumor efficacy in xenograft and primary-tumor derived malignant pleural mesothelioma models. Daily treatment with IAG933 elicited complete tumor regression in the MSTO-211H xenograft model at well-tolerated doses. In line with the current clinical strategy for IAG933, robust anti-tumor efficacy in cancer models bearing NF2 loss of function or expressing TAZ-fusions was observed. Moreover, we provide evidence for combination benefits of IAG933 with several MAPK/KRAS inhibitors, both in vitro and in vivo, in non-Hippo altered models including lung, pancreatic and colorectal cancer. Overall, our results provide a rationale of progressing IAG933 as a monotherapy in patients with Hippo-mutated cancers, and as a combination partner in MAPK-dependent cancers, with the potential to treat patient populations of high unmet medical need. Citation Format: Tobias Schmelzle, Emilie Chapeau, Daniel Bauer, Patrick Chene, Jason Faris, Cesar Fernandez, Pascal Furet, Giorgio Galli, Jiachang Gong, Stephanie Harlfinger, Francesco Hofmann, Eloisa Jimenez Nunez, Joerg Kallen, Thanos Mourikis, Laurent Sansregret, Paulo Santos, Clemens Scheufler, Holger Sellner, Markus Voegtle, Markus Wartmann, Peter Wessels, Frederic Zecri, Nicolas Soldermann. IAG933, a selective and orally efficacious YAP1/WWTR1(TAZ)-panTEAD protein-protein interaction inhibitor with pre-clinical activity in monotherapy and combinations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr LB319.

Abstract This chapter situates London and Bauer’s ‘little book’ in its historical context, beginning with the co-authors’ scientific backgrounds. London in particular did important work in physics, using quantum theory to explain chemical bonding and superconductivity for example. Working closely with the likes of Born, Sommerfeld, and, crucially, Schrödinger, London found himself at the heart of discussions over the foundations of the new theory. Notably he was part of the network of discussants used by Schrödinger to try out his ideas which subsequently found expression in his (in)famous ‘cat’ thought-experiment and in the notion of entanglement. However, London was also remarkable in having a strong background in philosophy, particularly phenomenology, and his student thesis on how we should conceive of scientific theories was actually published in the journal that Husserl founded. Even after he and his wife moved to Paris, where he met Bauer, London maintained his philosophical interests, holding long conversations with his friend Gurwitsch, for example, who went on to establish phenomenology as a discipline in the USA.