Basics of factorization in a scalar Yukawa field theory

The factorization theorems of quantum chromodynamics (QCD) apply equally well to most simple quantum field theories that require renormalization but where direct calculations are much more straightforward. Working with these simpler theories is convenient for stress-testing the limits of the factorization program and for examining general properties of the parton density functions (pdfs) or other correlation functions that might be necessary for a factorized description of a process. With this view in mind, we review the steps of factorization in a real scalar Yukawa field theory for both deep inelastic scattering (DIS) and semi-inclusive deep inelastic scattering (SIDIS) cross sections. In the case of SIDIS, we illustrate how to separate the small transverse momentum region, where transverse momentum dependent (TMD) pdfs are needed, from a purely collinear large transverse momentum region, and we examine the influence of subleading power corrections. We also review the steps for formulating TMD factorization in transverse coordinate space, and we study the effect of transforming to the well-known $b_*$-scheme. Within the Yukawa theory, we investigate the consequences of switching to a generalized parton model (GPM) approach, and compare with a fully factorized approach. Our results highlight the need to address similar or analogous issues in QCD.Comment: 39 pages, 46 figure

Cell salvage and donor blood transfusion during cesarean section: A pragmatic, multicentre randomised controlled trial (SALVO)

BACKGROUND: Excessive haemorrhage at cesarean section requires donor (allogeneic) blood transfusion. Cell salvage may reduce this requirement. METHODS AND FINDINGS: We conducted a pragmatic randomised controlled trial (at 26 obstetric units; participants recruited from 4 June 2013 to 17 April 2016) of routine cell salvage use (intervention) versus current standard of care without routine salvage use (control) in cesarean section among women at risk of haemorrhage. Randomisation was stratified, using random permuted blocks of variable sizes. In an intention-to-treat analysis, we used multivariable models, adjusting for stratification variables and prognostic factors identified a priori, to compare rates of donor blood transfusion (primary outcome) and fetomaternal haemorrhage ≥2 ml in RhD-negative women with RhD-positive babies (a secondary outcome) between groups. Among 3,028 women randomised (2,990 analysed), 95.6% of 1,498 assigned to intervention had cell salvage deployed (50.8% had salvaged blood returned; mean 259.9 ml) versus 3.9% of 1,492 assigned to control. Donor blood transfusion rate was 3.5% in the control group versus 2.5% in the intervention group (adjusted odds ratio [OR] 0.65, 95% confidence interval [CI] 0.42 to 1.01, p = 0.056; adjusted risk difference -1.03, 95% CI -2.13 to 0.06). In a planned subgroup analysis, the transfusion rate was 4.6% in women assigned to control versus 3.0% in the intervention group among emergency cesareans (adjusted OR 0.58, 95% CI 0.34 to 0.99), whereas it was 2.2% versus 1.8% among elective cesareans (adjusted OR 0.83, 95% CI 0.38 to 1.83) (interaction p = 0.46). No case of amniotic fluid embolism was observed. The rate of fetomaternal haemorrhage was higher with the intervention (10.5% in the control group versus 25.6% in the intervention group, adjusted OR 5.63, 95% CI 1.43 to 22.14, p = 0.013). We are unable to comment on long-term antibody sensitisation effects. CONCLUSIONS: The overall reduction observed in donor blood transfusion associated with the routine use of cell salvage during cesarean section was not statistically significant. TRIAL REGISTRATION: This trial was prospectively registered on ISRCTN as trial number 66118656 and can be viewed on http://www.isrctn.com/ISRCTN66118656

Nonviral transfection of endothelial progenitor cells

Objective: To define the potential of endothelial progenitor cells (EPCs) to internalize and express exogenous DNA by nonviral transfection. Liposome-mediated delivery of either non-coding (FITC-DNA) or coding (pEGFP C1) DNA sequences was compared in view of their potential use for therapeutic strategies. Methods: Peripheral blood mononuclear cells (PBMNCs) were isolated from healthy volunteers. 1X106/cm2 PBMNCs were plated in EGM2-MV on fibronectin-coated flasks. After 6 days of culture, adherent cells were incubated with DiI-AcLDL and FITC-UEA-I. Double-positive cells were identified as EPCs. EPCs were detached after 6 days of culture and seeded at 8X105 cells/cm2 the day before the transfection. Different cationic liposomes were used for the transfection: Ap41 (with FITC-DNA); PolyFect, Effectene and Superfect with plasmid DNA. DNA was added to liposomes and the mixture was incubated for 15 minutes at room temperature. EPCs were exposed to the transfection mixture for 4 hours (FITC-DNA) or 24 hours (plasmid-DNA). Thereafter, EPCs were detached and the detection of cells containing FITC-DNA or expressing GFP was performed by FACS. For the detection of FITC-DNA, EPCs were washed with glycine 0.2M pH 2.8 to remove any fluorescent extracellular complex. Results: After 6 days of culture an adherent population with an endothelial-like phenotype (EPCs) was obtained, as confirmed by AcLDL/UEA-I positivity. 82.5% of EPCs internalized FITC-DNA at the end of 4 hours transfection; the number increased to 88.2% 20 hours later. No EPCs expressed GFP, with none of the three transfectants. Moreover, PolyFect and SuperFect seemed to induce the detachment of some adherent cells, because an appreciable amount of floating cells at the end of transfection was observed. Conclusion: While the uptake of the complex FITC-DNA/liposome by EPCs was very efficient, the plasmid gene transfer had no success. This finding may be explained by a lack of genomic integration and a rapid degradation of the plasmid DNA

Metabolomics Using 1H-NMR of apoptosis and necrosis in HL60 leukemia cells: Differences between the two types of cell death and independence from the stimulus of apoptotis used.

High-resolution proton nuclear magnetic resonance (1HNMR) spectroscopy was used to examine and compare the metabolic variations that occur in cells of the HL60 promyelocytic leukemia cell line after induction of apoptosis by ionizing radiation and the antineoplastic drug doxorubicin as well as after induction of necrosis by heating. Apoptosis and necrosis were confirmed by fluorescence microscopy using the chromatin stain Hoechst 33258, agarose gel electrophoresis of DNA, and determination of caspase 3 enzymatic activity. The 1H-NMR experiments revealed that the spectra of both samples containing apoptotic cells were characterized by the same trend of several important metabolites. Specifically, an increase in CH2 and CH3 mobile lipids, principally of CH2, decreases in glutamine and glutamate, choline-containing metabolites, taurine and reduced glutathione were observed. By contrast, the sample containing necrotic cells presented a completely different profile of 1H-NMR metabolites since it was characterized by a significant increase in all the metabolites examined, with the exception of CH2 mobile lipids, which remain unchanged, and reduced glutathione, which decreased. The results suggest that variations in 1H-NMR metabolites are specific to apoptosis independent of the physical or chemical nature of the stimulus used to induce this mode of cell death, while cells dying from necrosis are characterized by a completely different behavior of the same metabolites