RESUMO
Objective: To compare the effectiveness of "semiocclusive dressing (SOD)" treatment using plastic wrap or low-adherent absorbent wound dressings with that of occlusive dressing (OD) treatment for National Pressure Injury Advisory Panel stage III/IV pressure injuries in the inflammatory phase. Approach: This 12-week, open-label, randomized controlled trial was conducted at one hospital and three care facilities. Seventy-seven participants were enrolled; 40 comprised the SOD group and 37 comprised the OD group. The primary outcome was the surface area reduction. Secondary outcomes included the Bates-Jensen Wound Assessment Tool (BWAT) score reductions, incidence of adverse events, and material cost. This trial met the recommendations of the CONSORT 2010 statement. Results: The surface area reduction of the SOD group was greater than that of the OD group throughout the study period. The significant interaction was revealed between treatment and time course (p < 0.0001). The 95% confidence interval of the difference at 12 weeks was 3.4 to 21.9. The median BWAT score reduction of the SOD group at 12 weeks was 23, and that of the OD group was 18.5 (p = 0.0077). The incidence of adverse events was comparable between groups. The OD treatment cost was 3.0 times higher than the SOD treatment cost (p = 0.0012). Innovation: Because the SOD does not completely occlude the wound, excess exudate drains from the wound. Therefore, SOD can treat the wound with abundant exudate effectively and safely. Conclusion: SOD treatment is more effective and less expensive than OD treatment for stage III/IV pressure injuries. Clinical Trial Registration: UMIN Clinical Trials Registry [UMIN000023412]. Registered on July 31, 2016.
RESUMO
The intramolecular Diels-Alder reaction (IMDA) is a powerful method for regioselective and stereoselective construction of functionalised decalin skeletons, and the recent discovery of enzymes that catalyse IMDA cycloaddition in biosynthesis has generated considerable interest. This study focused on the role of the absolute configuration of the C-6 carbon of the substrate polyene in the stereocontrol of the IMDA reaction catalysed by Fsa2 and Phm7, which construct different enantiomeric decalin skeletons. Their enantiomeric precursor polyenes were synthesised and subjected to enzymatic or thermal IMDA reactions to isolate various diastereomeric decalines and determine their absolute configuration. Furthermore, density functional theory calculations were performed to elucidate the stereocontrol mechanism underlying the formation of decalin. The results showed that Fsa2 exhibits the same equisetin-type stereoselectivity for enantiomeric substrates regardless of the 6-methyl group configuration of the substrate, while Phm7 shows two types of stereoselectivity depending on the configuration of the 6-methyl group. We also found a unique stereochemistry-activity relationship in antibacterial activity for decalin diastereomers, including new derivatives. This study provides new insights into the stereoselectivity of DAase, which is important in the synthesis of natural product skeletons.
RESUMO
We report infrared (IR) and electronic spectra of benzene-ammonia cluster radical cations [C(6)H(6)(NH(3))(n)](+) (n = 1 and 2) in the gas phase to explore cluster structures and chemical reactivity of the simplest aromatic radical cation with base (nucleophile) molecules. The electronic spectra in the visible region indicate that these cluster cations no longer have the benzene cation chromophore as a result of an intracluster reaction. Analyses of the IR spectra, on the basis quantum chemical calculations and the vibration-internal rotation analysis, reveal that both [C(6)H(6)(NH(3))(1,2)](+) form σ-complex structures, in which the ammonia moiety is covalently bonded to the benzene moiety due to the intracluster nucleophilic addition. For [C(6)H(6)(NH(3))(2)](+), it is also shown that the second ammonia molecule solvates the σ-complex core via a N-H···N hydrogen bond. Such σ-complex structures are generally supposed to be a key intermediate of aromatic substitution reactions. The observed mass spectra and energetics calculations, however, show that [C(6)H(6)(NH(3))(n)](+) systems are inert for aromatic substitutions. The present experimental observations indicate the inherent stability of these σ-complex structures, even though they do not show the aromatic substitution reactivity.