Photon counting - the wholly digital treatment of the signal from a photomultiplier tube (PMT) or another electromagnetic radiation detector - has not until now been employed in commercial ...spectrometric air pollution analyzers. Photon counting produces significant performance improvements over current methods. Gain stability, or the insensitivity of instrument responses to outside influences such as temperature, is increased by more than an order of magnitude. The improved sensitivity enables much lower concentrations of sulfur dioxide and nitric oxide to be detected, and the linear dynamic range is extended at both low and high gas concentrations.
We present Herschel observations from the Herschel Gould Belt Survey and SCUBA-2 science verification observations from the JCMT Gould Belt Survey of the B1 clump in the Perseus molecular cloud. We ...determined the dust emissivity index using four different techniques to combine the Herschel PACS+SPIRE data at 160 - 500 microns with the SCUBA-2 data at 450 microns and 850 microns. Of our four techniques, we found the most robust method was to filter-out the large-scale emission in the Herschel bands to match the spatial scales recovered by the SCUBA-2 reduction pipeline. Using this method, we find beta ~ 2 towards the filament region and moderately dense material and lower beta values (beta > 1.6) towards the dense protostellar cores, possibly due to dust grain growth. We find that beta and temperature are more robust with the inclusion of the SCUBA-2 data, improving estimates from Herschel data alone by factors of ~ 2 for beta and by ~ 40% for temperature. Furthermore, we find core mass differences of < 30% compared to Herschel-only estimates with an adopted beta = 2, highlighting the necessity of long wavelength submillimeter data for deriving accurate masses of prestellar and protostellar cores.
The questionnaire surveyed OR staff on themes such as design, security, and workload. Surgical nurses had greater expectations for their roles and functions in the new facility. Levels of physical ...comfort improved; however, mood was not affected positively.
Alkylation of the substituted cycloalkanones
14
a-d and
30
with (Z)-1-bromo-4-methyl-3-trimethylstannyl-2-pentene (
13
) produced compounds
15
a-d and
33
, which were readily converted into the ...corresponding enol trifluoromethane-sulfonates (triflates)
16
a-d and
34
. Intramolecular Pd(O)-catalyzed coupling of the vinylstannane and enol triflate functions in
16
a-d and
34
provided the dienes
17
a-d and
35
. The annulation product
35
served as a suitable starting material for the total syntheses of the dolastane diterpenoids (±)-(5S,12R,14S)-dolasta-1(15),7,9-trien-14-ol (
2
) and (±)-amijitrienol (
3
). The key steps of the synthesis of (±)-2 involved the stereoselective methylation of the ketone
44
(readily derived from
35
) to provide
46
and the Barbier type ring closure of
47
to provide the target compound. For the synthesis of (±)-3, the notable conversions included the reductive transformation of the diene
35
into the alkene
53
, the aldol condensation of the ketone
54
with 4-trimethylstannyl-4-pentenal (
55
), the chemo- and stereoselective reduction of the dione
58
, and the one-pot conversion of the keto vinylstannane
63
into the triene
65
, via the intermediate
64
.
Neonatal cleft lip repair is no longer an unusual procedure and several series have been published to date. We present our 3-year experience from the anesthesiologist's point of view. Preoperative ...evaluation, perioperative management, and postoperative problems are described. A thorough preoperative evaluation in order to exclude associated malformations (especially cardiac) and experience in neonatal anesthesia are essential for the sake of safety.
