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191.
Lars H. Eng Mona B.-M. Lewin Halina Y. Neujahr 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1993,56(3):317-324
The periplasmic hydrogenase (hydrogen: ferricytochrome-c3 oxido-reductase EC 1.12.2.1) from Desulfovibrio desulfuricans (NCIMB 8372) was isolated and the catalytic properties of the enzyme determined with different electron mediators. In the direction of H2-oxidation with the physiological electron mediator cytochrome c3, the value of the apparent second order rate constant (kcat/Km) is close to that expected for a diffusion-controlled reaction. In H2-production however, the value of kcat/Km with cytochrome c3 is almost 200 times lower. When methyl viologen is used as mediator, the value of kcat/Km is the same in both directions and is intermediate to the values obtained with cytochrome c3. The close to optimum value of kcat/Km in H2-oxidation with cytochrome c3 as electron acceptor is discussed with respect to the biological role of this and related hydrogenases. H2-production occurred with the hydrogenase in a system where the mediator was reduced with either of three photosensitizers (proflavin, 5-deazariboflavin, Zn-tetraphenyl porphyrin sulphonate) upon illumination. The efficiency of different mediators is discussed. 相似文献
192.
The theory of characteristic modes is invoked to illuminate some features found in the radar scattering by the symmetric wire cross. Results discussed here may help to clarify conflicting literature on this subject. 相似文献
193.
Katarzyna Wegrzynowska-Drzymalska Kinga Mylkie Pawel Nowak Dariusz T. Mlynarczyk Dorota Chelminiak-Dudkiewicz Halina Kaczmarek Tomasz Goslinski Marta Ziegler-Borowska 《International journal of molecular sciences》2022,23(14)
In recent years, new cross-linkers from renewable resources have been sought to replace toxic synthetic compounds of this type. One of the most popular synthetic cross-linking agents used for biomedical applications is glutaraldehyde. However, the unreacted cross-linker can be released from the materials and cause cytotoxic effects. In the present work, dialdehyde starch nanocrystals (NDASs) were obtained from this polysaccharide nanocrystal form as an alternative to commonly used cross-linking agents. Then, 5–15% NDASs were used for chemical cross-linking of native chitosan (CS), gelatin (Gel), and a mixture of these two biopolymers (CS-Gel) via Schiff base reaction. The obtained materials, forming thin films, were characterized by ATR-FTIR, SEM, and XRD analysis. Thermal and mechanical properties were determined by TGA analysis and tensile testing. Moreover, all cross-linked biopolymers were also characterized by hydrophilic character, swelling ability, and protein absorption. The toxicity of obtained materials was tested using the Microtox test. Dialdehyde starch nanocrystals appear as a beneficial plant-derived cross-linking agent that allows obtaining cross-linked biopolymer materials with properties desirable for biomedical applications. 相似文献
194.
Diana Sawicka Agnieszka Hryniewicka Sylwia Gohal Anna Sadowska Anna Pryczynicz Katarzyna Guziska-Ustymowicz Emilia Sokoowska Jacek W. Morzycki Halina Car 《International journal of molecular sciences》2022,23(13)
Imidazolium salts (IMSs) are the subject of many studies showing their anticancer activities. In this research, a series of novel imidazolium salts substituted with lithocholic acid (LCA) and alkyl chains of various lengths (S1–S10) were evaluated against colon cancer cells. A significant reduction in the viability and metabolic activity was obtained in vitro for DLD-1 and HT-29 cell lines when treated with tested salts. The results showed that the activities of tested agents are directly related to the alkyl chain length, where S6–S8 compounds were the most cytotoxic against the DLD-1 line and S4–S10 against HT-29. The research performed on the xenograft model of mice demonstrated a lower tendency of tumor growth in the group receiving compound S6, compared with the group receiving 5-fluorouracil (5-FU). Obtained results indicate the activity of S6 in the induction of apoptosis and necrosis in induced colorectal cancer. LCA-based imidazolium salts may be candidates for chemotherapeutic agents against colorectal cancer. 相似文献
195.
Dr. Carlotta Figliola Dr. Halina Anton Christophe Sutter Camille Chériaux Alexandra Sutter Dr. Valérie Mazan Dr. Mourad Elhabiri Prof. Dr. Pascal Didier Prof. Dr. Denis Jacquemin Dr. Gilles Ulrich 《Chembiochem : a European journal of chemical biology》2023,24(12):e202300139
Photodynamic therapy (PDT) is a photochemistry-based medical treatment combining light at a specific wavelength and a photosensitizer (PS) in the presence of oxygen. Application of PDT as a conventional treatment is limited and clearly the approval in clinics of new PS is challenging. The selective accumulation of the PS in the targeted malignant cells is of paramount importance to reduce the side effects that are typical of the current worldwide approved PS. Here we report a new series of aniline- and iodine-substituted BODIPY derivatives ( 1 – 3 ) as promising lysosome-targeting and pH-responsive theranostic PS, which displayed a significant in vitro light-induced cytotoxicity, efficient imaging properties and low dark toxicity (for 2 and 3 ). These compounds were obtained in few reproducible synthetic steps and good yields. Spectroscopic and electrochemical measurements along with computational calculations confirmed the quenching of the emissive properties of the PS, while both fluorescence and 1O2 emission were obtained only under acidic conditions inducing amine protonation. The pKa values and pH-dependent emissive properties of 1 – 3 being established, their cellular uptake and activation in the lysosomal vesicles (pH≈4-5) were confirmed by their co-localization with the commercial LysoTracker deep red and light-induced cytotoxicity (IC50 between 0.16 and 0.06 μM) against HeLa cancer cells. 相似文献