250 research outputs found
Recommended from our members
Daytime CO2 urban surface fluxes from airborne measurements, eddy-covariance observations and emissions inventory in Greater London
Airborne measurements within the urban mixing layer (360 m) over Greater London are used to quantify CO2 emissions at the meso-scale. Daytime CO2 fluxes, calculated by the Integrative Mass Boundary Layer (IMBL) method, ranged from 46 to 104 μmol CO2 m−2 s−1 for four days in October 2011. The day-to-day variability of IMBL fluxes is at the same order of magnitude as for surface eddy-covariance fluxes observed in central London. Compared to fluxes derived from emissions inventory, the IMBL method gives both lower (by −37%) and higher (by 19%) estimates. The sources of uncertainty of applying the IMBL method in urban areas are discussed and guidance for future studies is given
Organic Aerosol source apportionment in London 2013 with ME-2:Exploring the solution space with annual and seasonal analysis
The multilinear engine (ME-2) factorization tool is being
widely used following the recent development of the Source Finder (SoFi)
interface at the Paul Scherrer Institute. However, the success of this tool,
when using the <i>a</i>Â value approach, largely depends on the inputs (i.e. target
profiles) applied as well as the experience of the user. A strategy to
explore the solution space is proposed, in which the solution that best
describes the organic aerosol (OA) sources is determined according to the
systematic application of predefined statistical tests. This includes
trilinear regression, which proves to be a useful tool for comparing different
ME-2 solutions. Aerosol Chemical Speciation Monitor (ACSM) measurements were
carried out at the urban background site of North Kensington, London from
March to December 2013, where for the first time the behaviour of OA sources
and their possible environmental implications were studied using an ACSM.
Five OA sources were identified: biomass burning OA (BBOA), hydrocarbon-like
OA (HOA), cooking OA (COA), semivolatile oxygenated OA (SVOOA) and
low-volatility oxygenated OA (LVOOA). ME-2 analysis of the seasonal data sets
(spring, summer and autumn) showed a higher variability in the OA sources
that was not detected in the combined March–December data set; this
variability was explored with the triangle plots <i>f</i>44 : <i>f</i>43 <i>f</i>44 : <i>f</i>60, in which a
high variation of SVOOA relative to LVOOA was observed in the <i>f</i>44 : <i>f</i>43
analysis. Hence, it was possible to conclude that, when performing source
apportionment to long-term measurements, important information may be lost
and this analysis should be done to short periods of time, such as
seasonally. Further analysis on the atmospheric implications of these OA
sources was carried out, identifying evidence of the possible contribution
of heavy-duty diesel vehicles to air pollution during weekdays compared to
those fuelled by petrol
What to expect from electronic patient record system implementation; lessons learned from published evidence
Background:Â Numerous studies have examined specific factors related to success, failure and implications of Electronic patient record (EPR) system implementations, but usually limited to specific aspects. Â Objective: To review the published peer-reviewed literature and present findings regarding factors important in relation to successful EPR implementations and likely impact on subsequent clinical activity.Method:Â Literature reviewResults:Â 312 potential articles were identified on initial search of which 117 were relevant and included in the review. Several factors were related to implementation success, such as good leadership and management, infrastructure support, staff training and focus on workflows and usability. In general, EPR implementation is associated with improvements in documentation, and screening performance, and reduced prescribing errors, whereas there are minimal available data in other areas such as effects on clinical patient outcomes. The peer-reviewed literature appears to under-represent a range of technical factors important for EPR implementations, such as data migration from existing systems and impact of organisational readiness.Conclusion: The findings presented here represent synthesis of data from peer-reviewed literature in the field and should be of value to provide the evidence-base for organisations considering how best to implement an EPR system
Porcine iGb3s gene silencing provides minimal benefit for clinical xenotransplantation
Background
The Galα(1,3)Gal epitope (α-GAL), created by α-1,3-glycosyltransferase-1 (GGTA1), is a major xenoantigen causing hyperacute rejection in pig-to-primate and pig-to-human xenotransplantation. In response, GGTA1 gene-deleted pigs have been generated. However, it is unclear whether there is a residual small amount of α-Gal epitope expressed in GGTA1−/− pigs. Isoglobotrihexosylceramide synthase (iGb3s), another member of the glycosyltransferase family, catalyzes the synthesis of isoglobo-series glycosphingolipids with an α-GAL-terminal disaccharide (iGb3), creating the possibility that iGb3s may be a source of α-GAL epitopes in GGTA1−/− animals. The objective of this study was to examine the impact of silencing the iGb3s gene (A3GalT2) on pig-to-primate and pig-to-human immune cross-reactivity by creating and comparing GGTA1−/− pigs to GGTA1−/−- and A3GalT2−/−-double-knockout pigs.
Methods
We used the CRISPR/Cas 9 system to target the GGTA1 and A3GalT2 genes in pigs. Both GGTA1 and A3GalT2 genes are functionally inactive in humans and baboons. CRISPR-treated cells used directly for somatic cell nuclear transfer produced single- and double-gene-knockout piglets in a single pregnancy. Once grown to maturity, the glycosphingolipid profile (including iGb3) was assayed in renal tissue by normal-phase liquid chromatography. In addition, peripheral blood mononuclear cells (PBMCs) were subjected to (i) comparative cross-match cytotoxicity analysis against human and baboon serum and (ii) IB4 staining for α-GAL/iGb3.
Results
Silencing of the iGb3s gene significantly modulated the renal glycosphingolipid profile and iGb3 was not detected. Moreover, the human and baboon serum PBMC cytotoxicity and α-GAL/iGb3 staining were unchanged by iGb3s silencing.
Conclusions
Our data suggest that iGb3s is not a contributor to antibody-mediated rejection in pig-to-primate or pig-to-human xenotransplantation. Although iGb3s gene silencing significantly changed the renal glycosphingolipid profile, the effect on Galα3Gal levels, antibody binding, and cytotoxic profiles of baboon and human sera on porcine PBMCs was neutral
- …