Encapsulation process sterilizes and preserves surgical instruments

Ethylene oxide is blended with an organic polymer to form a sterile material for encapsulating surgical instruments. The material does not bond to metal and can be easily removed when the instruments are needed

Process for preparing sterile solid propellants Patent

Using ethylene oxide in preparation of sterilized solid rocket propellants and encapsulating material

Optimal cellular mobility for synchronization arising from the gradual recovery of intercellular interactions

Cell movement and intercellular signaling occur simultaneously during the development of tissues, but little is known about how movement affects signaling. Previous theoretical studies have shown that faster moving cells favor synchronization across a population of locally coupled genetic oscillators. An important assumption in these studies is that cells can immediately interact with their new neighbors after arriving at a new location. However, intercellular interactions in cellular systems may need some time to become fully established. How movement affects synchronization in this situation has not been examined. Here we develop a coupled phase oscillator model in which we consider cell movement and the gradual recovery of intercellular coupling experienced by a cell after movement, characterized by a moving rate and a coupling recovery rate respectively. We find (1) an optimal moving rate for synchronization, and (2) a critical moving rate above which achieving synchronization is not possible. These results indicate that the extent to which movement enhances synchrony is limited by a gradual recovery of coupling. These findings suggest that the ratio of time scales of movement and signaling recovery is critical for information transfer between moving cells.Comment: 18 single column pages + 1 table + 5 figures + Supporting Informatio

Evidences on the role of the lid loop of γ-glutamyltransferases (GGT) in substrate selection

\u3b3-Glutamyltransferase (GGT) catalyzes the transfer of the \u3b3-glutamyl moiety from a donor substrate such as glutathione to water (hydrolysis) or to an acceptor amino acid (transpeptidation) through the formation of a \u3b3-glutamyl enzyme intermediate. The vast majority of the known GGTs has a short sequence covering the glutamate binding site, called lid-loop. Although being conserved enzymes, both B. subtilis GGT and the related enzyme CapD from B. anthracis lack the lid loop and, differently from other GGTs, both accept poly-\u3b3-glutamic acid (\u3b3-PGA) as a substrate. Starting from this observation, in this work the activity of an engineered mutant enzyme containing the amino acid sequence of the lid loop from E. coli GGT inserted into the backbone of B. subtilis GGT was compared to that of the lid loop-deficient B. subtilis GGT and the lid loop-carrier E. coli GGT. Results indicate that the absence of the lid loop seems not to be the sole structural feature responsible for the recognition of a polymeric substrate by GGTs. Nevertheless, time course of hydrolysis reactions carried out using oligo-\u3b3-glutamylglutamines as substrates showed that the lid loop acts as a gating structure, allowing the preferential selection of the small glutamine with respect to the oligomeric substrates. In this respect, the mutant B. subtilis GGT revealed to be more similar to E. coli GGT than to its wild-type counterpart. In addition, the transpeptidase activity of the newly produced mutant enzyme revealed to be higher with respect to that of both E. coli and wild-type B. subtilis GGT. These findings can be helpful in selecting GGTs intended as biocatalysts for preparative purposes as well as in designing mutant enzymes with improved transpeptidase activity

The third KV62 radar scan: Searching for hidden chambers adjacent to Tutankhamun's tomb

The existence of hidden chambers and corridors adjacent to Tutankhamun’s tomb (code name KV62) hasbeen long debated. In 2015 it was suggested that these chambers may host the as yet undiscovered burialof Nefertiti. In order to test this hypothesis, two Ground Penetrating Radar (GPR) surveys, conductedin 2015 and 2016 from inside KV62, were carried out, but gave contradictory results. To solve theseuncertainties and obtain a more confident and conclusive response, a third GPR survey was conductedby our team in February 2018. The results of this third radar scan are reported in this article. Three GPRsystems with multiple frequency bands (from 150 MHz to 3000 MHz) and very dense spatial samplingwere adopted. After careful data processing, no evidence of marked discontinuities due to the passagefrom natural rock to artificial blocking walls were found in the radargrams. It is therefore concluded thatthere are no hidden chambers immediately adjacent to the Tomb of Tutankhamun