304 research outputs found
Design of new highly functional polymer grafted polyhipes for proteins immobilization
PolyHIPE have proven to be useful in a large variety of applications included column filtration/separation, supported organic chemistry, as media for tissue engineering and 3D cell culture.1 The ability to conveniently modify pHIPE surfaces with functional groups is essential to opening new applications areas. The most promising method to conveniently modify pHIPE surface with a high density of functional groups is the âgrafting fromâ approach. Stable polymer brushes covalently attached to the surface posses excellent mechanical and chemical robustness and offer the flexibility to introduce a large variety of functional monomers.2 We developed a new and unique pHIPE platform by incorporation of a polymerizable monomer with amino group into the HIPE available for different post in situ polymerization. The pHIPE with amino groups on the surface (pHIPE-NH2) can be directly used for the ring opening polymerization of amino acids N-carboxyanhydrates (NCAs) monomers to make pHIPE-g-polypeptide (such as pHIPE-g-poly(L-Benzyl Glutamate)) or easily converted to an atom transfer radical polymerization (ATRP) initiator for activators generated electron transfer (AGET) ATRP of tert-Butyl acrylate monomers. The polymers grafted can be deprotected to form pHIPE-g-poly(glutamic acid) or pHIPE-g-poly(acrylic acid) with reactive groups, on the surface of the pHIPE, available for further bioconjugation
Cross-national and multilevel correlates of partner violence:an analysis of data from population-based surveys
Background On average, intimate partner violence aff ects nearly one in three women worldwide within their lifetime.
But the distribution of partner violence is highly uneven, with a prevalence of less than 4% in the past 12 months in
many high-income countries compared with at least 40% in some low-income settings. Little is known about the
factors that drive the geographical distribution of partner violence or how macro-level factors might combine with
individual-level factors to aff ect individual womenâs risk of intimate partner violence. We aimed to assess the role that
womenâs status and other gender-related factors might have in defi ning levels of partner violence among settings.
Methods We compiled data for the 12 month prevalence of partner violence from 66 surveys (88 survey years) from
44 countries, representing 481 205 women between Jan 1, 2000, and Apr 17, 2013. Only surveys with comparable
questions and state-of-the-art methods to ensure safety and encourage violence disclosure were used. With linear
and quantile regression, we examined associations between macro-level measures of socioeconomic development,
womenâs status, gender inequality, and gender-related norms and the prevalence of current partner violence at a
population level. Multilevel modelling and tests for interaction were used to explore whether and how macro-level
factors aff ect individual-level risk. The outcome for this analysis was the population prevalence of current partner
violence, defi ned as the percentage of ever-partnered women (excluding widows without a current partner), aged
from 15 years to 49 years who were victims of at least one act of physical or sexual violence within the past 12 months.
Findings Gender-related factors at the national and subnational level help to predict the population prevalence of
physical and sexual partner violence within the past 12 months. Especially predictive of the geographical distribution
of partner violence are norms related to male authority over female behaviour (0·102, p<0·0001), norms justifying
wife beating (0·263, p<0·0001), and the extent to which law and practice disadvantage women compared with men in
access to land, property, and other productive resources (0·271, p<0·0001). The strong negative association between
current partner violence and gross domestic product (GDP) per person (â0·055, p=0·0009) becomes non-signifi cant
in the presence of norm-related measures (â0·015, p=0·472), suggesting that GDP per person is a marker for social
transformations that accompany economic growth and is unlikely to be causally related to levels of partner violence.
We document several cross-level eff ects, including that a girlâs education is more strongly associated with reduced
risk of partner violence in countries where wife abuse is normative than where it is not. Likewise, partner violence is
less prevalent in countries with a high proportion of women in the formal work force, but working for cash increases
a womanâs risk in countries where few women work.
Interpretation Our fi ndings suggest that policy makers could reduce violence by eliminating gender bias in ownership
rights and addressing norms that justify wife beating and male control of female behaviour. Prevention planners
should place greater emphasis on policy reforms at the macro-level and take cross-level eff ects into account when
designing interventions
Protein immobilization on highly functional polymer grafted polyHIPEs
PolyHIPE have proven to be useful in a large variety of applications included column filtration/separation, supported organic chemistry, as media for tissue engineering and 3D cell culture.[1] We developed a new pHIPE platform by incorporation of a polymerizable monomer with amino group into the HIPE available for different post polymerizations.[2] The pHIPE with amino groups on the surface (pHIPE-NH2) can be directly used for the ring opening polymerization of amino acids N-carboxyanhydrates (NCAs) to obtain pHIPE-g- polypeptides or easily converted to an atom transfer radical polymerization (ATRP) initiator for activators generated electron transfer (AGET) ATRP of tert-butyl acrylate. The polymers grafted were deprotected to form or pHIPE-g-poly(acrylic acid) with reactive groups on the surface of the pHIPE, available for bioconjugation of fluorescent proteins such as enhanced green fluorescent protein (eGFP
SYNTHESIS OF STAR POLY(4-VINYLPYRIDINE) ARCHITECTURE BY NITROXIDE MEDIATED POLYMERISATION
This study proposed multifunctional alkoxyamine 2-({tert-butyl [[1-
(diethoxyphosphoryl)-2,2-dimethylpropyl]amino}oxy)-2-methylpropanoic acid
(MAMA-SG1) initiators for the âgrafting-fromâ method to obtain star architecture of
poly 4-vinylpyridine (P4VP) from JEFFAMINEÂź. The structure of macroinitiator
was confirmed by amide bond present in NMR and FTIR spectroscopy.
Furthermore, the macroinitiator was used to polymerise 4VP. P4VP from
JEFFAMINE-SG1 shows a monomodal peak in the SEC chromatogram, indicating
more control polymerisation process
Molecular environment and reactivity in gels and colloidal solutions under identical conditions
A PEG-Tyr block copolymer forms a kinetically stable colloidal solution in water at room temperature which undergoes an irreversible conversion to a gel phase upon heating. A micellar solution and a gel can therefore be studied under identical experimental conditions. This made it possible to compare physical properties and chemical reactivity of micelles and gels in identical chemical environments and under identical conditions. EPR spectra of the spin-labelled copolymer showed that tyrosine mobility in gels was slightly reduced compared to micelles. Chemical reactivity was studied using photochemical degradation of tyrosine and tyrosine dimerization, in the absence and in the presence of an Fe(iii) salt. The reactivity trends were explained by reduced tyrosine mobility in the gel environment. The largest reactivity difference in gels and micelles was observed for bimolecular dityrosine formation which was also attributed to the reduction in molecular mobility
Metaphor Identification beyond Discourse Coherence
In this paper, we propose an account of metaphor identification on the basis of contextual coherence. In doing so, we build on previous work by Nicholas Asher and Alex Lascarides that appeals to rhetorical relations in order to explain discourse structure and the constraints on the interpretation of metaphor that follow from it. Applying this general idea to our problem, we will show that rhetorical relations are sometimes insufficient and sometimes inadequate for deciding whether a given utterance is a case of metaphor. They are insufficient, since rhetorical relations fall short at times of providing a basis for disambiguating between literal and metaphorical interpretations. In such cases, contextual information other than previous discourse needs to enter the picture. To this effect, we bring the idea of external consistency into play. Beyond that, though, we will argue that rhetorical relations are sometimes inadequate to account for coherence, if conceived as relations among sentences only. The reason is that extra-linguistic elements of the situation in which the sentence is uttered may be crucial for getting at the preferred interpretation. To account for these cases, we allow rhetorical relations to connect both with previous discourse and with extra-linguistic situations. In our final refinement of the notion of contextual coherence, we forfeit any appeal to rhetorical relations in favour of Questions Under Discussion (QUD). We defend the view that this account does not only explain the same sort of cases. What is more, it solves the issue of metaphor identification in impoverished contexts
Protocol TOP-Study (tacrolimus organ perfusion): a prospective randomized multicenter trial to reduce ischemia reperfusion injury in transplantation of marginal liver grafts with an "ex vivo" tacrolimus perfusion
Background: Critical organ shortage results in the utilization of extended donor criteria (EDC) liver grafts. These marginal liver grafts are prone to increased ischemia reperfusion injury (IRI) which may contribute to deteriorated graft function and survival. Experimental data have shown that the calcineurin inhibitor tacrolimus exerts protective effects on hepatic IRI when applied intravenously or directly as a hepatic rinse. Therefore, the aim of the present study is to examine the effects of an ex vivo tacrolimus perfusion on IRI in transplantation of EDC liver grafts.
Methods/Design: The TOP-Study (tacrolimus organ perfusion) is a randomized multicenter trial comparing the ex vivo tacrolimus perfusion of marginal liver grafts with placebo. We hypothesize that a tacrolimus rinse reduces IRI, potentially improving organ survival following transplantation of EDC livers. The study includes livers with two or more EDC, according to Eurotransplant International Foundationâs definition of EDC livers. Prior to implantation, livers randomized to the treatment group are rinsed with tacrolimus at a concentration of 20 ng/ml in 1000 ml Custodiol solution and in the placebo group with Custodiol alone. The primary endpoint is the maximum serum alanine transamninase (ALT) level within the first 48 hours after surgery; however, the study design also includes a 1-year observation period following transplantation. The TOP-Study is an investigator-initiated trial sponsored by the University of Munich Hospital. Seven other German transplant centers are participating (Berlin, Frankfurt, Heidelberg, Mainz, MĂŒnster, Regensburg, TĂŒbingen) and aim to include a total of 86 patients.
Discussion: Tacrolimus organ perfusion represents a promising strategy to reduce hepatic IRI following the transplantation of marginal liver grafts. This treatment may help to improve the function of EDC grafts and therefore safely expand the donor pool in light of critical organ shortage.
Trial register: EudraCT number: 2010-021333-31, ClinicalTrials.gov identifier: NCT0156409
A randomized controlled trial
Objective We report on the effect of hemoadsorption therapy to reduce
cytokines in septic patients with respiratory failure. Methods This was a
randomized, controlled, open-label, multicenter trial. Mechanically ventilated
patients with severe sepsis or septic shock and acute lung injury or acute
respiratory distress syndrome were eligible for study inclusion. Patients were
randomly assigned to either therapy with CytoSorb hemoperfusion for 6 hours
per day for up to 7 consecutive days (treatment), or no hemoperfusion
(control). Primary outcome was change in normalized IL-6-serum concentrations
during study day 1 and 7. Results 97 of the 100 randomized patients were
analyzed. We were not able to detect differences in systemic plasma IL-6
levels between the two groups (n = 75; p = 0.15). Significant IL-6
elimination, averaging between 5 and 18% per blood pass throughout the entire
treatment period was recorded. In the unadjusted analysis, 60-day-mortality
was significantly higher in the treatment group (44.7%) compared to the
control group (26.0%; p = 0.039). The proportion of patients receiving renal
replacement therapy at the time of enrollment was higher in the treatment
group (31.9%) when compared to the control group (16.3%). After adjustment for
patient morbidity and baseline imbalances, no association of hemoperfusion
with mortality was found (p = 0.19). Conclusions In this patient population
with predominantly septic shock and multiple organ failure, hemoadsorption
removed IL-6 but this did not lead to lower plasma IL-6-levels. We did not
detect statistically significant differences in the secondary outcomes
multiple organ dysfunction score, ventilation time and time course of
oxygenation
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