A new design of highly granular hadronic calorimeter using Glass Resistive Plate Chambers (GRPCs) with embedded electronics has been proposed for the future International Linear Collider (ILC) ...experiments. It features a 2-bit threshold semi-digital read-out. Several GRPC prototypes with their electronics have been successfully built and tested in pion beams. The design of these detectors is presented along with the test results on efficiency, pad multiplicity, stability and reproducibility.
The importance of aromatic CO, CN, and CS bonds necessitates increasingly efficient strategies for their formation. Herein, we report a biomimetic approach that converts phenolic CH bonds into ...CO, CN, and CS bonds at the sole expense of reducing dioxygen (O2) to water (H2O). Our method hinges on a regio‐ and chemoselective copper‐catalyzed aerobic oxygenation to provide ortho‐quinones. ortho‐Quinones are versatile intermediates, whose direct catalytic aerobic synthesis from phenols enables a mild and efficient means of synthesizing polyfunctional aromatic rings.
The direct approach: Polyfunctional aromatic rings have been generated by direct functionalization of CH bonds to CO, CN, and CS bonds at the sole expense of reducing O2 to H2O. The method hinges on a regio‐ and chemoselective, copper‐catalyzed aerobic oxygenation of phenols to provide ortho‐quinones (see scheme), thus mimicking the ubiquitous biosynthetic pathway of melanogenesis.
The oxidation of phenols is the subject of extensive investigation, but there are few catalytic aerobic examples that are chemo- and regioselective. Here we describe conditions for the ...ortho-oxygenation or oxidative coupling of phenols under copper (Cu)-catalyzed aerobic conditions that give rise to ortho-quinones, biphenols or benzoxepines. We demonstrate that each product class can be accessed selectively by the appropriate choice of Cu(I) salt, amine ligand, desiccant and reaction temperature. In addition, we evaluate the effects of substituents on the phenol and demonstrate their influence on selectivity between ortho-oxygenation and oxidative coupling pathways. These results create an important precedent of catalyst control in the catalytic aerobic oxidation of phenols and set the stage for future development of catalytic systems and mechanistic investigations.
We describe a selective aerobic oxidation of meta‐biaryl phenols that enables rapid access to functionalized phenanthrenes. Aerobic oxidations attract interest due to their efficiency, but remain ...underutilized in complex molecule settings due to challenges of selectivity. We discuss these issues in the context of Cu catalysis, and highlight the advantages of confining oxygen activation and substrate oxidation to the catalyst's inner‐coordination sphere. This gives rise to predictable selectivity that we use for a concise synthesis of the aporphine dehydronornuciferine.
A breath of fresh air: A selective aerobic oxidation of meta‐biaryl phenols under copper catalysis enables rapid access to functionalized phenanthrenes. The predictable selectivity provided by this method is utilized for a concise synthesis of the aporphine dehydronornuciferine.
Summary Background The prevalence of hepatitis E virus (HEV) genotype 3 infections in the English population (including blood donors) is unknown, but is probably widespread, and the virus has been ...detected in pooled plasma products. HEV-infected donors have been retrospectively identified through investigation of reported cases of possible transfusion-transmitted hepatitis E. The frequency of HEV transmission by transfusion and its outcome remains unknown. We report the prevalence of HEV RNA in blood donations, the transmission of the virus through a range of blood components, and describe the resulting morbidity in the recipients. Methods From Oct 8, 2012, to Sept 30, 2013, 225 000 blood donations that were collected in southeast England were screened retrospectively for HEV RNA. Donations containing HEV were characterised by use of serology and genomic phylogeny. Recipients, who received any blood components from these donations, were identified and the outcome of exposure was ascertained. Findings 79 donors were viraemic with genotype 3 HEV, giving an RNA prevalence of one in 2848. Most viraemic donors were seronegative at the time of donation. The 79 donations had been used to prepare 129 blood components, 62 of which had been transfused before identification of the infected donation. Follow-up of 43 recipients showed 18 (42%) had evidence of infection. Absence of detectable antibody and high viral load in the donation rendered infection more likely. Recipient immunosuppression delayed or prevented seroconversion and extended the duration of viraemia. Three recipients cleared longstanding infection after intervention with ribavirin or alteration in immunosuppressive therapy. Ten recipients developed prolonged or persistent infection. Transaminitis was common, but short-term morbidity was rare; only one recipient developed apparent but clinically mild post-transfusion hepatitis. Interpretation Our findings suggest that HEV genotype 3 infections are widespread in the English population and in blood donors. Transfusion-transmitted infections rarely caused acute morbidity, but in some immunosuppressed patients became persistent. Although at present blood donations are not screened, an agreed policy is needed for the identification of patients with persistent HEV infection, irrespective of origin, so that they can be offered antiviral therapy. Funding Public Health England and National Health Service Blood and Transplant.
IEEE Trans.Nucl.Sci.49:1904-1908,2002 The GLAST Balloon Flight Engineering Model (BFEM) represents one of 16 towers
that constitute the Large Area Telescope (LAT), a high-energy (>20 MeV)
gamma-ray ...pair-production telescope being built by an international partnership
of astrophysicists and particle physicists for a satellite launch in 2006. The
prototype tower consists of a Pb/Si pair-conversion tracker (TKR), a CsI
hodoscopic calorimeter (CAL), an anti-coincidence detector (ACD) and an
autonomous data acquisition system (DAQ). The self-triggering capabilities and
performance of the detector elements have been previously characterized using
positron, photon and hadron beams. External target scintillators were placed
above the instrument to act as sources of hadronic showers. This paper provides
a comprehensive description of the BFEM data-reduction process, from receipt of
the flight data from telemetry through event reconstruction and background
rejection cuts. The goals of the ground analysis presented here are to verify
the functioning of the instrument and to validate the reconstruction software
and the background-rejection scheme.
Azophenols are important chromophores and reagents in organic synthesis, with applications as pigments and molecular switches. Here, we describe a catalytic aerobic process that couples phenols and ...hydrazines or hydrazides for their synthesis. The key aromatic C−N bond is formed by condensation between the hydrazine or hydrazide and an ortho‐quinone, which triggers a redox‐isomerization to install the azo‐functionality. Notable features include rapid access to highly functionalized azophenols with a range of electronic configurations, including “push–pull” systems, conditions that employ simple, unactivated substrates, occurrence at room temperature using an earth‐abundant and commercially available copper catalyst, and production of water as the only stoichiometric byproduct.
A bio‐inspired coupling of phenols and hydrazines or hydrazides that draws inspiration from melanogenesis and collagen biosynthesis is developed for the mild and efficient synthesis of ortho‐azo phenols. The method hinges on the catalytic aerobic dearomatization of phenols to ortho‐quinones, which are versatile coupling partners for C−N bond formation.
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