Three Cs detection method using Wi-Fi radio wave statistics.

Many infection preventing measures have been taken in COVID-19 situation. In particular, the approach called Three Cs avoidance is drawing attention. Three Cs means closed spaces, crowded places, and close-contact settings. This approach is taken in many business scenes regardless of individual situation. Such Three Cs are effective, but it is difficult for humans to always be aware of them. Various detection systems have been proposed to help understanding Three Cs situation. Most of them use cameras, CO2 sensors and so on. However, such system is costly due to introduce new equipment. Therefore, we propose a method for detecting Three Cs using only the existing widely used Wi-Fi equipment. Our method introduces unique detection parameters and performs statistical evaluation. As a result of constructing the system and evaluating it, we confirmed that it was possible to detect Three Cs with an accuracy of 86% or more.

Antibacterial effect of indene on Helicobacter pylori correlates with specific interaction between its compound and dimyristoyl-phosphatidylethanolamine.

Recent studies by our group have suggested that the vitamin D3 decomposition product VDP1 [(1R,3aR,7aR)-1-[(1R)-1,5-dimethylhexyl]octahydro-7a-methyl-4H-inden-4-one] confers the potent bactericidal action to Helicobacter pylori by targeting the membranal dimyristoyl-phosphatidylethanolamine (di-14:0 PE). In this study we synthesized a new VDP1 derivative to advance further investigation as for the correlative relationship between VDP1 structure and anti-H. pylori activity or PE vesicle collapse induction activity. The derivative VD3-7 [(1R,7aR)-4-fluoro-7a-methyl-1-((R)-6-methylheptan-2-yl)octahydro-1H-indene] retained a fluorine atom in place of the oxygen atom of VDP1. The fluorination of the carbonyl portion of VDP1 forfeited the effective anti-H. pylori activity. We, therefore, prepared Coomassie brilliant blue (CBB)-containing unilamellar vesicles consisting of various PE molecular species, and examined the vesicle collapse induction activity of either VDP1 or VD3-7 by detecting the CBB eluted from the PE unilamellar vesicles. VDP1 strongly induced CBB elution from the unilamellar vesicles of rectus-PE retaining the same two fatty acid side-chains shorter than carbon numbers 14, indicating that VDP1 specifically disrupted the vesicular conformation of those PE unilamellar vesicles. Meanwhile, VD3-7 had no influence on the structural stability of any PE unilamellar vesicles. This study obtained additional evidence that VDP1 acts as a bactericidal agent on H. pylori by targeting the membranal di-14:0 PE.

Indene Compounds Synthetically Derived from Vitamin D Have Selective Antibacterial Action on Helicobacter pylori.

Helicobacter pylori infects the human stomach and is closely linked with the development of gastric cancer. When detected, this pathogen can be eradicated from the human stomach using wide-spectrum antibiotics. However, year by year, H. pylori strains resistant to the antibacterial action of antibiotics have been increasing. The development of new antibacterial substances effective against drug-resistant H. pylori is urgently required. Our group has recently identified extremely selective bactericidal effects against H. pylori in (1R,3aR,7aR)-1-[(1R)-1,5-dimethylhexyl]octahydro-7a-methyl-4H-inden-4-one (VDP1) (otherwise known as Grundmann's ketone), an indene compound derived from the decomposition of vitamin D3 and proposed the antibacterial mechanism whereby VDP1 induces the bacteriolysis by interacting at least with PtdEtn (dimyristoyl-phosphatidylethanolamine [di-14:0 PtdEtn]) retaining two 14:0 fatty acids of the membrane lipid constituents. In this study, we synthesized new indene compounds ((1R,3aR,7aR)-1-((2R,E)-5,6-dimethylhept-3-en-2-yl)-7a-methyloctahydro-4H-inden-4-one [VD2-1], (1R,3aR,7aR)-1-((S)-1-hydroxypropan-2-yl)-7a-methyloctahydro-1H-inden-4-ol [VD2-2], and (1R,3aR,7aR)-7a-methyl-1-((R)-6-methylheptan-2-yl)octahydro-1H-inden-4-ol [VD3-1]) using either vitamin D2 or vitamin D3 as materials. VD2-1 and VD3-1 selectively disrupted the di-14:0 PtdEtn vesicles without destructing the vesicles of PtdEtn (dipalmitoyl-phosphatidylethanolamine) retaining two 16:0 fatty acids. In contrast, VD2-2, an indene compound lacking an alkyl group, had no influence on the structural stability of both PtdEtn vesicles. In addition, VD2-1 and VD3-1 exerted extremely selective bactericidal action against H. pylori without affecting the viability of commonplace bacteria. Meanwhile, VD2-2 almost forfeited the bactericidal effects on H. pylori. These results suggest that the alkyl group of the indene compounds has a crucial conformation to interact with di-14:0 PtdEtn of H. pylori membrane lipid constituents whereby the bacteriolysis is ultimately induced.