Concomitant Crystallization in Propylene/Ethylene Random Copolymer with Strong Flow at Elevated Temperatures

Flow-induced crystallization of α- and γ-phases was studied for a propylene/ethylene random copolymer with 3.4 mol % ethylene at two high temperatures of 132 and 142 °C by combining a pressure-driven slit flow device with real-time synchrotron wide-angle X-ray diffraction. At 132 °C, it was found that both α- and γ-phases were generated at shear stresses ranging from 0.091 to 0.110 MPa and that the γ-phase always appeared later than the α-phase. However, for 142 °C and the same stresses, only the α-phase formed. Only upon cooling the partially crystallized copolymer did the γ-phase emerge. The lack of γ-crystals obtained at 142 °C is opposite to the behavior reported for quiescent crystallization under pressure, for which increasing temperature results in more and even pure γ-crystals. In the current study, the absence of γ-phase at 142 °C is tentatively associated with lack of epitaxial nucleation on α-lamellae and to relatively low growth rate of γ-crystals

Comparison of long and short axis quantification of left ventricular volume parameters by cardiovascular magnetic resonance, with ex-vivo validation

<p>Abstract</p> <p>Background</p> <p>The purpose of the study was to compare the accuracy and evaluation time of quantifying left ventricular (LV), left atrial (LA) volume and LV mass using short axis (SAX) and long axis (LAX) methods when using cardiovascular magnetic resonance (CMR).</p> <p>Materials and methods</p> <p>We studied 12 explanted canine hearts and 46 patients referred for CMR (29 male, age 47 ± 18 years) in a clinical 1.5 T CMR system, using standard cine sequences. In standard short axis stacks of various slice thickness values in dogs and 8 mm slice thickness (gap 2 mm) in patients, we measured LV volumes using reference slices in a perpendicular, long axis orientation using certified software. Volumes and mass were also measured in six radial long axis (LAX) views.</p> <p>LV parameters were also assessed for intra- and inter-observer variability. In 24 patients, we also analyzed reproducibility and evaluation time of two very experienced (> 10 years of CMR reading) readers for SAX and LAX.</p> <p>Results</p> <p>In the explanted dog hearts, there was excellent agreement between ex vivo data and LV mass and volume data as measured by all methods for both, LAX (r²= 0.98) and SAX (r²= 0.88 to 0.98). LA volumes, however, were underestimated by 13% using the LAX views. In patients, there was a good correlation between all three assessed methods (r²≥ 0.95 for all). In experienced clinical readers, left-ventricular volumes and ejection fraction as measured in LAX views showed a better inter-observer reproducibility and a 27% shorter evaluation time.</p> <p>Conclusion</p> <p>When compared to an ex vivo standard, both, short axis and long axis techniques are highly accurate for the quantification of left ventricular volumes and mass. In clinical settings, however, the long axis approach may be more reproducible and more time-efficient. Therefore, the rotational long axis approach is a viable alternative for the clinical assessment of cardiac volumes, function and mass.</p

Modelling ecotoxicity impacts in vineyard production : Addressing spatial differentiation for copper fungicides

Unidad de excelencia María de Maeztu MdM-2015-0552Altres ajuts: OLCA-Pest project financially supported by ADEME (GA No. 17-03-C0025). Programa CERCA - Generalitat de CatalunyaApplication of plant protection products (PPP) is a fundamental practice for viticulture. Life Cycle Assessment (LCA) has proved to be a useful tool to assess the environmental performance of agricultural production, where including toxicity-related impacts for PPP use is still associated with methodological limitations, especially for inorganic (i.e. metal-based) pesticides. Downy mildew is one of the most severe diseases for vineyard production. For disease control, copper-based fungicides are the most effective and used PPP in both conventional and organic viticulture. This study aims to improve the toxicity-related characterization of copper-based fungicides (Cu) for LCA studies. Potential freshwater ecotoxicity impacts of 12 active ingredients used to control downy mildew in European vineyards were quantified and compared. Soil ecotoxicity impacts were calculated for specific soil chemistries and textures. To introduce spatial differentiation for Cu in freshwater and soil ecotoxicity characterization, we used 7 European water archetypes and a set of 15,034 non-calcareous vineyard soils for 4 agricultural scenarios. Cu ranked as the most impacting substance for potential freshwater ecotoxicity among the 12 studied active ingredients. With the inclusion of spatial differentiation, Cu toxicity potentials vary 3 orders of magnitude, making variation according to water archetypes potentially relevant. In the case of non-calcareous soils ecotoxicity characterization, the variability of Cu impacts in different receiving environments is about 2 orders of magnitude. Our results show that Cu potential toxicity depends mainly on its capacity to interact with the emission site, and the dynamics of this interaction (speciation). These results represent a better approximation to understand Cu potential toxicity impact profiles, assisting decision makers to better understand copper behavior concerning the receiving environment and therefore how restrictions on the use of copper-based fungicides should be considered in relation to the emission site

Freshwater ecotoxicity assessment of pesticide use in crop production : Testing the influence of modeling choices

Unidad de excelencia María de Maeztu MdM-2015-0552Altres ajuts: Programa CERCA - Generalitat de CatalunyaPesticides help to control weeds, pests, and diseases contributing, therefore, to food availability. However, pesticide fractions not reaching the intended target may have adverse effects on the environment and the field ecosystems. Modeling pesticide emissions and the link with characterizing associated impacts is currently one of the main challenges in Life Cycle Assessment (LCA) of agricultural systems. To address this challenge, this study takes advantage of the latest recommendations for pesticide emission inventory and impact assessment and frames a suitable interface for those LCA stages and the related mass distribution of pesticide avoiding a temporal overlapping. Here, freshwater ecotoxicity impacts of the production of feed crops (maize, grass, winter wheat, spring barley, rapeseed, and peas) in Denmark were evaluated during a 3-year period, testing the effects of inventory modeling and the recent updates of the characterization method (USEtox). Potential freshwater ecotoxicity impacts were calculated in two functional units reflecting crop impact profiles per ha and extent of cultivation, respectively. Ecotoxicity impacts decreased over the period, mainly because of the reduction of insecticides use (e.g., cypermethrin). Three different emission modeling scenarios were tested; they differ on the underlining assumptions and data requirements. The main aspects influencing impact results are the interface between inventory estimates and impact assessment, and the consideration of intermedia processes, such as crop growth development and pesticide application method. Impact scores for AS2 were higher than RS and AS1, but the differences in the crops ranking was less apparent. On the other hand, the influence on the estimation of impacts for individual AIs was considerable and statistical differences were found in the impact results modeled in scenarios RS and AS2. Thereby indicating the effect of inventory models on ecotoxicity impact assessment

A bias in cosmic shear from galaxy selection: results from ray-tracing simulations

We identify and study a previously unknown systematic effect on cosmic shear measurements, caused by the selection of galaxies used for shape measurement, in particular the rejection of close (blended) galaxy pairs. We use ray-tracing simulations based on the Millennium Simulation and a semi-analytical model of galaxy formation to create realistic galaxy catalogues. From these, we quantify the bias in the shear correlation functions by comparing measurements made from galaxy catalogues with and without removal of close pairs. A likelihood analysis is used to quantify the resulting shift in estimates of cosmological parameters. The filtering of objects with close neighbours (a) changes the redshift distribution of the galaxies used for correlation function measurements, and (b) correlates the number density of sources in the background with the density field in the foreground. This leads to a scale-dependent bias of the correlation function of several percent, translating into biases of cosmological parameters of similar amplitude. This makes this new systematic effect potentially harmful for upcoming and planned cosmic shear surveys. As a remedy, we propose and test a weighting scheme that can significantly reduce the bias.Comment: 9 pages, 9 figures, version accepted for publication in Astronomy & Astrophysic

Deficient neural encoding of speech sounds in term neonates born after fetal growth restriction

Infants born after fetal growth restriction (FGR) an obstetric condition defined as the failure to achieve the genetic growth potential are prone to neurodevelopmental delays, with language being one of the major affected areas. Yet, while verbal comprehension and expressive language impairments have been observed in FGR infants, children and even adults, specific related impairments at birth, such as in the ability to encode the sounds of speech, necessary for language acquisition, remain to be disclosed. Here, we used the frequency-following response (FFR), a brain potential correlate of the neural phase locking to complex auditory stimuli, to explore the encoding of speech sounds in FGR neonates. Fifty-three neonates born with FGR and 48 controls born with weight adequate-for-gestational age (AGA) were recruited. The FFR was recorded to the consonant-vowel stimulus (/da/) during sleep and quantified as the spectral amplitude to the fundamental frequency of the syllable and its signal-to-noise ratio (SNR). The outcome was available in 45 AGA and 51 FGR neonates, yielding no differences for spectral amplitudes. However, SNR was strongly attenuated in the FGR group compared to the AGA group at the vowel region of the stimulus. These findings suggest that FGR population present a deficit in the neural pitch tracking of speech sounds already present at birth. Our results pave the way for future research on the potential clinical use of the FFR in this population, so that if confirmed, a disrupted FFR recorded at birth may help deriving FGR neonates at risk for postnatal follow-ups

The factor H binding protein of Neisseria meningitidis interacts with xenosiderophores in vitro.

The factor H binding protein (fHbp) is a key virulence factor of Neisseria meningitidis that confers to the bacterium the ability to resist killing by human serum. The determination of its three-dimensional structure revealed that the carboxyl terminus of the protein folds into an eight-stranded ߠbarrel. The structural similarity of this part of the protein to lipocalins provided the rationale for exploring the ability of fHbp to bind siderophores. We found that fHbp was able to bind in vitro siderophores belonging to the cathecolate family and mapped the interaction site by nuclear magnetic resonance. Our results indicated that the enterobactin binding site was distinct from the site involved in binding to human factor H and stimulates new hypotheses about possible multiple activities of fHbp.Full Tex

Pre-transplant donor-specific T-cell alloreactivity is strongly associated with early acute cellular rejection in kidney transplant recipients not receiving T-cell depleting induction therapy

Preformed T-cell immune-sensitization should most likely impact allograft outcome during the initial period after kidney transplantation, since donor-specific memory T-cells may rap- idly recognize alloantigens and activate the effector immune response, which leads to allo- graft rejection. However, the precise time-frame in which acute rejection is fundamentally triggered by preformed donor-specific memory T cells rather than by denovo activated na ï ve T cells is still to be established. Here, preformed donor-specific alloreactive T-cell re- sponses were evaluated using the IFN- γ ELISPOT assay in a large consecutive cohort of kidney transplant patients (n = 90), to assess the main clinical variables associated with cel- lular sensitization and its predominant time-frame impact on allograft outcome, and was fur- ther validated in an independent new set of kidney transplant recipients (n = 67). We found that most highly T-cell sensitized patients were elderly patients with particularly poor HLA class-I matching, without any clinically recognizable sensitizing events. While one-year inci- dence of all types of biopsy-proven acute rejection did not differ between T-cell alloreactive and non-alloreactive patients, Receiver Operating Characteristic curve analysis indicated the first two months after transplantation as the highest risk time period for acute cellular re- jection associated with baseline T-cell sensitization. This effect was particularly evident in young and highly alloreactive individuals that did not receive T-cell depletion immunosup- pression. Multivariate analysis confirmed preformed T-cell sensitization as an independent predictor of early acute cellular rejection. In summary, monitoring anti-donor T-cell sensiti- zation before transplantation may help to identify patients at increased risk of acute cellular rejection, particularly in the early phases after kidney transplantation, and thus guide decision-making regarding the use of induction therapy

XRCC2 R188H (rs3218536), XRCC3 T241M (rs861539) and R243H (rs77381814) single nucleotide polymorphisms in cervical cancer risk

Human Papillomavirus (HPV) is the main cause of cervical cancer and its precursor lesions. Transformation may be induced by several mechanisms, including oncogene activation and genome instability. Individual differences in DNA damage recognition and repair have been hypothesized to influence cervical cancer risk. The aim of this study was to evaluate whether the double strand break gene polymorphisms XRCC2 R188H G>A (rs3218536), XRCC3 T241M C>T (rs861539) and R243H G>A (rs77381814) are associated to cervical cancer in Argentine women. A case control study consisting of 322 samples (205 cases and 117 controls) was carried out. HPV DNA detection was performed by PCR and genotyping of positive samples by EIA (enzyme immunoassay). XRCC2 and 3 polymorphisms were determined by pyrosequencing. The HPV-adjusted odds ratio (OR) of XRCC2 188 GG/AG genotypes was OR = 2.4 (CI = 1.1-4.9, p = 0.02) for cervical cancer. In contrast, there was no increased risk for cervical cancer with XRCC3 241 TT/CC genotypes (OR = 0.48; CI = 0.2-1; p = 0.1) or XRCC3 241 CT/CC (OR = 0.87; CI = 0.52-1.4; p = 0.6). Regarding XRCC3 R243H, the G allele was almost fixed in the population studied. In conclusion, although the sample size was modest, the present data indicate a statistical association between cervical cancer and XRCC2 R188H polymorphism. Future studies are needed to confirm these findings.Fil: Perez, Luis Orlando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Crivaro, Andrea Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Barbisan, Gisela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Poleri, Lucía Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Golijow, Carlos Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentin