Acquired Bracket Pellicle Modulation Via Exposure To Histatin 3

Objectives: To investigate the effect of histatin 3 on the protein pellicle formation on the orthodontic bracket surface. Methods: Our study consisted of 4 sample groups. A sample of human parotid saliva without histatin functioned as a control group. Other groups were immersed with or without histatin 3 and human parotid saliva. Each group was incubated for 2 hours in their respective substrate at 37°C. The acquired pellicle from each group was harvested, then analyzed with SDS-PAGE and LC-ESI-MS/MS. Results: Thirty-nine proteins were identified in the control group, 18 were identified in group 2, and 21 were identified in group 3. Thirteen proteins were common to all groups. Groups immersed in histatin 3 and human parotid saliva showed an increase in the percentage of proteins exhibiting antimicrobial activities and immune response. Conclusions: There were functional differences in the protein pellicle formed on the orthodontic bracket, suggesting that exposure to histatin 3 may alter pellicle formation. However, structural differences were limited due to redundant characteristics of salivary proteins

Search for intermediate-mass black hole binaries in the third observing run of Advanced LIGO and Advanced Virgo

International audienceIntermediate-mass black holes (IMBHs) span the approximate mass range 100−105 M⊙, between black holes (BHs) that formed by stellar collapse and the supermassive BHs at the centers of galaxies. Mergers of IMBH binaries are the most energetic gravitational-wave sources accessible by the terrestrial detector network. Searches of the first two observing runs of Advanced LIGO and Advanced Virgo did not yield any significant IMBH binary signals. In the third observing run (O3), the increased network sensitivity enabled the detection of GW190521, a signal consistent with a binary merger of mass ∼150 M⊙ providing direct evidence of IMBH formation. Here, we report on a dedicated search of O3 data for further IMBH binary mergers, combining both modeled (matched filter) and model-independent search methods. We find some marginal candidates, but none are sufficiently significant to indicate detection of further IMBH mergers. We quantify the sensitivity of the individual search methods and of the combined search using a suite of IMBH binary signals obtained via numerical relativity, including the effects of spins misaligned with the binary orbital axis, and present the resulting upper limits on astrophysical merger rates. Our most stringent limit is for equal mass and aligned spin BH binary of total mass 200 M⊙ and effective aligned spin 0.8 at 0.056 Gpc−3 yr−1 (90% confidence), a factor of 3.5 more constraining than previous LIGO-Virgo limits. We also update the estimated rate of mergers similar to GW190521 to 0.08 Gpc−3 yr−1.Key words: gravitational waves / stars: black holes / black hole physicsCorresponding author: W. Del Pozzo, e-mail: [email protected]† Deceased, August 2020

Open data from the first and second observing runs of Advanced LIGO and Advanced Virgo

Advanced LIGO and Advanced Virgo are monitoring the sky and collecting gravitational-wave strain data with sufficient sensitivity to detect signals routinely. In this paper we describe the data recorded by these instruments during their first and second observing runs. The main data products are gravitational-wave strain time series sampled at 16384 Hz. The datasets that include this strain measurement can be freely accessed through the Gravitational Wave Open Science Center at http://gw-openscience.org, together with data-quality information essential for the analysis of LIGO and Virgo data, documentation, tutorials, and supporting software