Biodegradation kinetics of 4-fluorocinnamic acid by a consortium of Arthrobacter and Ralstonia strains

Arthrobacter sp. strain G1 is able to grow on 4-fluorocinnamic acid (4-FCA) as sole carbon source. The organism converts 4-FCA into 4-fluorobenzoic acid (4-FBA) and utilizes the two-carbon side-chain for growth with some formation of 4-fluoroacetophenone as a dead-end side product. We also have isolated Ralstonia sp. strain H1, an organism that degrades 4-FBA. A consortium of strains G1 and H1 degraded 4-FCA with Monod kinetics during growth in batch and continuous cultures. Specific growth rates of strain G1 and specific degradation rates of 4-FCA were observed to follow substrate inhibition kinetics, which could be modeled using the kinetic models of Haldane–Andrew and Luong–Levenspiel. The mixed culture showed complete mineralization of 4-FCA with quantitative release of fluoride, both in batch and continuous cultures. Steady-state chemostat cultures that were exposed to shock loadings of substrate responded with rapid degradation and returned to steady-state in 10–15 h, indicating that the mixed culture provided a robust system for continuous 4-FCA degradation

Carcinoma of the esophagus, esophagogastric junction, and stomach. Cooperation between pathology and surgery

Cooperation between pathology and surgery plays a decisive role in the treatment of carcinoma of the esophagus, esophagogastric junction, and stomach. Preoperatively, the carcinoma is confirmed and the histologic type, grading, type of extension (stomach) and immunohistochemical or molecular-biological parameters, if necessary, are determined. For exclusion or diagnosis of distant metastases, peritoneal carcinosis, or secondary tumors, further biopsies or cytological examinations may be required. All results contribute to the individualized treatment. In case of endoscopic treatment, the completeness of resection of the carcinoma and the depth of infiltration must be identified with extraordinary diligence. Postoperative proof of tumor, location, histological type, completeness of resection and safety margin have to be identified. Detailed T-status, N-status with declaration of the ratio of affected and nonaffected number of lymph nodes, location of affected lymph nodes, extracapsular lymph node spread, invasion of lymphatic and vascular vessels and perineural sheets are important parameters. The description of tumor regression after neoadjuvant treatment (histomorphological response) is of special interest

Bedeutung der GLUT-1 Expression für das primäre Magenkarzinom

Zeolites have been found to be promising sensor materials for a variety of gas molecules such as NH3, NOx, hydrocarbons, etc. The sensing effect results from the interaction of the adsorbed gas molecules with mobile cations, which are non-covalently bound to the zeolite lattice. The mobility of the cations can be accessed by electrical low-frequency (LF; mHz to MHz) and high-frequency (HF; GHz) impedance measurements. Recent developments allow in situ monitoring of catalytic reactions on proton-conducting zeolites used as catalysts. The combination of such in situ impedance measurements with diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), which was applied to monitor the selective catalytic reduction of nitrogen oxides (DeNOx-SCR), not only improves our understanding of the sensing properties of zeolite catalysts from integral electric signal to molecular processes, but also bridges the length scales being studied, from centimeters to nanometers. In this work, recent developments of zeolite-based, impedimetric sensors for automotive exhaust gases, in particular NH3, are summarized. The electrical response to NH3 obtained from LF impedance measurements will be compared with that from HF impedance measurements, and correlated with the infrared spectroscopic characteristics obtained from the DRIFTS studies of molecules involved in the catalytic conversion. The future perspectives, which arise from the combination of these methods, will be discussed