11 research outputs found
Preliminary results on the long term operation of RPCs with eco-friendly gas mixtures under irradiation at the CERN Gamma Irradiation Facility
Since 2019 a collaboration between researchers from various institutes and
experiments (i.e. ATLAS, CMS, ALICE, LHCb/SHiP and the CERN EP-DT group), has
been operating several RPCs with diverse electronics, gas gap thicknesses and
detector layouts at the CERN Gamma Irradiation Facility (GIF++). The studies
aim at assessing the performance of RPCs when filled with new eco-friendly gas
mixtures in avalanche mode and in view of evaluating possible ageing effects
after long high background irradiation periods, e.g. High-Luminosity LHC phase.
This challenging research is also part of a task of the European AidaInnova
project.
A promising eco-friendly gas identified for RPC operation is the
tetrafluoruropropene (CHF, commercially known as HFO-1234ze)
that has been studied at the CERN GIF++ in combination with different
percentages of CO. Between the end of 2021 and 2022 several beam tests have
been carried out to establish the performance of RPCs operated with such
mixtures before starting the irradiation campaign for the ageing study.
Results of these tests for different RPCs layouts and different gas mixtures,
under increasing background rates are presented here, together with the
preliminary outcome of the detector ageing tests
Scavenger receptor-mediated uptake of cell-penetrating peptide nanocomplexes with oligonucleotides.
Cell-penetrating peptides (CPPs) are short cationic peptides that penetrate cells by interacting with the negatively charged plasma membrane; however, the detailed uptake mechanism is not clear. In contrary to the conventional mode of action of CPPs, we show here that a CPP, PepFect14 (PF14), forms negatively charged nanocomplexes with oligonucleotides and their uptake is mediated by class-A scavenger receptors (SCARAs). Specific inhibitory ligands of SCARAs, such as fucoidin, polyinosinic acid, and dextran sulfate, totally inhibit the activity of PF14-oligonucleotide nanocomplexes in the HeLa pLuc705 splice-correction cell model, while nonspecific, chemically related molecules do not. Furthermore, RNA interference (RNAi) knockdown of SCARA subtypes (SCARA3 and SCARA5) that are expressed in this cell line led to a significant reduction of the activity to <50%. In line with this, immunostaining shows prevalent colocalization of the nanocomplexes with the receptors, and electron microscopy images show no binding or internalization of the nanocomplexes in the presence of the inhibitory ligands. Interestingly, naked oligonucleotides also colocalize with SCARAs when used at high concentrations. These results demonstrate the involvement of SCARA3 and SCARA5 in the uptake of PF14-oligonucleotide nanocomplexes and suggest for the first time that some CPP-based systems function through scavenger receptors, which could yield novel possibilities to understand and improve the transfection by CPPs
The Response of Small Business Owners to Changes in Monetary Policy
The small business sector of the economy accounts for half of private gross domestic product and well over half of private sector employment. Little is known about how these firms and the banks that serve them are affected by changes in monetary policy. Using data from the monthly surveys of the members of the National Federation of Independent Business, the impact of unexpected (between meeting) Federal Reserve announcements on owner expectations and hiring and spending plans are examined. Using interviews filled out during the month, “before” and “after” groups are analyzed to assess the impact of Federal Reserve announcements on firm behavior. Narrowing the analysis period to just days before and after Federal Reserve announcements permits the assessment of owner responses uncontaminated by other events. Changes in owner expectations and spending and hiring plans are shown to be translated into subsequent changes in actual spending and hiring that are often the opposite of what is suggested by conventional economic theory. Firms that do not use debt respond in the same way as those regularly active in credit markets. The results provide additional insight and richness to our understanding of the transmission channels through which monetary policy impacts the real economy.Business Economics (2009) 44, 23–37. doi:10.1057/be.2008.6