Background: Initial systemic therapy for patients with metastatic colorectal cancer (mCRC) is usually based on two- or three-drug chemotherapy regimens with fluoropyrimidine (5-fluorouracil (5-FU) or capecitabine), oxaliplatin and/or irinotecan, combined with either anti-VEGF (bevacizumab) or, for RAS wild-type (WT) tumors, anti-EGFR antibodies (panitumumab or cetuximab). Recommendations for patients who are not eligible for intensive combination therapies are limited and include fluoropyrimidine plus bevacizumab or single agent anti-EGFR antibody treatment. The use of a monochemotherapy concept of trifluridine/ tipiracil in combination with monoclonal antibodies is not approved for first-line therapy, yet.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
June 2021
Carbon chains with an odd number of C atoms are reactive intermediates with a high biradical character. Here we report a joint experimental and computational investigation of the dynamics of diphenylpropynylidene, CH-C-CH, in dichloromethane and ethanol. The biradical is generated by ultraviolet light from 1,3-diphenyldiazopropyne.
View Article and Find Full Text PDFWe report the generation, spectroscopic characterization, and computational analysis of the first free (non-stabilized) organometallic bismuthinidene, BiMe. The title compound was generated from BiMe by controlled homolytic Bi-C bond cleavage in the gas phase. Its electronic structure was characterized by a combination of photoion mass-selected threshold photoelectron spectroscopy and DFT as well as multi-reference computations.
View Article and Find Full Text PDFTolane (diphenylacetylene, CH) was studied by picosecond time-resolved photoionisation and photoelectron imaging in a supersonic jet. The low-energy part of the B← S REMPI spectrum is very similar to an earlier LIF spectrum, however additional bands were observed at higher energies above the fluorescence cut-off. For a number of bands the dynamics were investigated via pump-probe photoionisation and photoelectron spectroscopy.
View Article and Find Full Text PDFA recent review on the photoionisation of the CH isomer ortho-benzyne suggests that bands reported in earlier photoelectron spectra might be due to side products or contaminations, while computations raise doubts, whether the cation has a planar geometry. We therefore reinvestigate the photoionisation of ortho-benzyne, generated by pyrolysis from benzocyclobutenedione, by photoion mass-selected threshold photoelectron (ms-TPE) spectroscopy using synchrotron radiation. The experiments are accompanied by a theoretical study that investigates the structure of the ortho-benzyne cation systematically as a function of the computational method, up to CASPT2(11,14) ab initio computations.
View Article and Find Full Text PDFPeptide hormones are powerful regulators of various biological processes. To guarantee continuous availability and function, peptide hormone secretion must be tightly coupled to its biosynthesis. A simple but efficient way to provide such regulation is through an autocrine feedback mechanism in which the secreted hormone is "sensed" by its respective receptor and initiates synthesis at the level of transcription and/or translation.
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