13,491 research outputs found
Modelação espacial da tendência do bosque na Serra da Gardunha
A modelação da tendência espacial do bosque à escala regional baseada na
cartografia actual local, teve como objectivo estabelecer padrões possíveis para
a gestão equilibrada do bosque e da implantação de novos cerejais
Human epicardial adipose tissue expresses a pathogenic profile of adipocytokines in patients with cardiovascular disease
Introduction: Inflammation contributes to cardiovascular disease and is exacerbated with
increased adiposity, particularly omental adiposity; however, the role of epicardial fat is poorly
understood.
Methods: For these studies the expression of inflammatory markers was assessed in epicardial fat
biopsies from coronary artery bypass grafting (CABG) patients using quantitative RT-PCR. Further,
the effects of chronic medications, including statins, as well as peri-operative glucose, insulin and
potassium infusion, on gene expression were also assessed. Circulating resistin, CRP, adiponectin
and leptin levels were determined to assess inflammation.
Results: The expression of adiponectin, resistin and other adipocytokine mRNAs were
comparable to that in omental fat. Epicardial CD45 expression was significantly higher than control
depots (p < 0.01) indicating significant infiltration of macrophages. Statin treated patients showed
significantly lower epicardial expression of IL-6 mRNA, in comparison with the control abdominal
depots (p < 0.001). The serum profile of CABG patients showed significantly higher levels of both
CRP (control: 1.28 ± 1.57 μg/mL vs CABG: 9.11 ± 15.7 μg/mL; p < 0.001) and resistin (control:
10.53 ± 0.81 ng/mL vs CABG: 16.8 ± 1.69 ng/mL; p < 0.01) and significantly lower levels of
adiponectin (control: 29.1 ± 14.8 μg/mL vs CABG: 11.9 ± 6.0 μg/mL; p < 0.05) when compared to
BMI matched controls.
Conclusion: Epicardial and omental fat exhibit a broadly comparable pathogenic mRNA profile,
this may arise in part from macrophage infiltration into the epicardial fat. This study highlights that
chronic inflammation occurs locally as well as systemically potentially contributing further to the
pathogenesis of coronary artery disease
Distinct Contributions of Median Raphe Nucleus to Contextual Fear Conditioning and Fear-Potentiated Startle
Ascending 5-HT projections from the
median raphe nucleus (MRN), probably to the
hippocampus, are implicated in the acquisition
of contextual fear (background stimuli), as
assessed by freezing behavior. Foreground cues
like light, used as a conditioned stimulus (CS) in
classical fear conditioning, also cause freezing
through thalamic transmission to the amygdala.
As the MRN projects to the hippocampus and
amygdala, the role of this raphe nucleus in fear
conditioning to explicit cues remains to be
explained. Here we analyzed the behavior of
rats with MRN electrolytic lesions in a
contextual conditioning situation and in a fear-potentiated
startle procedure. The animals
received MRN electrolytic lesions either before
or on the day after two consecutive training
sessions in which they were submitted to 10
conditioning trials, each in an experimental
chamber (same context) where they. received
foot-shocks (0.6 mA, 1 sec) paired to a 4-sec
light CS. Seven to ten days later, the animals
were submitted to testing sessions for assessing
conditioned fear when they were placed for five
shocks, and the duration of contextual freezing
was recorded. The animals were then submitted
to a fear-potentiated startle in response to a 4-sec
light-CS, followed by white noise (100 dB, 50 ms). Control rats (sham) tested in the same
context showed more freezing than did rats
with pre- or post-training MRN lesions. Startle
was clearly potentiated in the presence of light CS in the sham-lesioned animals. Whereas pretraining
lesions reduced both freezing and fear-potentiated
startle, the post-training lesions
reduced only freezing to context, without
changing the fear-potentiated startle. In a
second experiment, neurotoxic lesions of the
MRN with local injections of N-methyl-D-aspartate
or the activation of 5-HT1A somatodendritic
auto-receptors of the MRN by
microinjections of the 5-HT1A receptor agonist
8-hydroxy- 2-(di-n-propylamino)tetralin (8-OH-DPAT)
before the training sessions also reduced
the amount of freezing and the fear-potentiated
startle. Freezing is a prominent response of
contextual fear conditioning, but does not seem
to be crucial for the enhancement of the startle
reflex by explicit aversive cues. As fear-potentiated
startle may be produced in posttraining
lesioned rats that are unable to freeze
to fear contextual stimuli, dissociable systems
seem to be recruited in each condition. Thus,
contextual fear and fear-potentiated startle are
conveyed by distinct 5-HT-mediated circuits of
the MRN
Can cholinium chloride form eutectic solvents with organic chloride-based salts?
The high melting point of a large number of organic salts with potential ionic liquid-like properties,
hinders their applicability as solvents. Considering the success of cholinium chloride on lowering the
melting temperature of several substances and its success on forming deep eutectic solvents, this work
studies its mixing with organic chlorides to lower their melting points producing eutectic ionic liquids.
The solid-liquid phase diagrams for binary mixtures composed of cholinium chloride and ten organic
halides were experimentally measured. Surprisingly, cholinium chloride presented, for all these systems,
significant positive deviations from ideal liquid behaviour that restricted its ability to lower the melting
points of these mixtures. Only for mixtures with ammonium chloride, tetramethylammonium chloride,
bis(2-hydroxyethyl)dimethylammonium chloride or cholinium bromide was cholinium chloride able to
significantly lower the melting point of the mixture, but without reaching values close to room temperature
(298 K). For a better understanding of the results obtained, the solid-liquid phase diagrams of
four alkylammonium chloride-based mixtures were experimentally assessed and used to show that
these compounds are better than cholinium chloride at inducing negative deviations from ideality,
leading to greater melting point depressions.This work was developed in the scope of the project CICECO e
Aveiro Institute of Materials, POCI-01-0145-FEDER-007679
(Ref. FCT UID/CTM/50011/2013) and Associate Laboratory LSRELCM,
POCI-01-0145-FEDER-006984 (Ref. FCT UID/EQU/50020/2019), and project MultiBiorefinery (POCI-01-0145-FEDER-016403), all financed by national funds through the FCT/MCTES (PIDDAC) and when appropriate co-financed by FEDER under the
PT2020 Partnership Agreement. FCT is also acknowledged for
funding the project DeepBiorefinery (PTDC/AGRTEC/1191/2014).
The authors acknowledge the European Research Council under the
European Union's Seventh Framework Programme (FP7/
2007 e 2013)/ERC grant agreement no. 337753. M.A.R.M. acknowledges
financial support from NORTE-01-0145-FEDER-000006 -
funded by NORTE2020 through PT2020 and ERDF. L.P.S. acknowledges
FCT for her PhD grant (SFRH/BD/135976/2018).info:eu-repo/semantics/publishedVersio
Indirect assessment of the fusion properties of choline chloride from solid-liquid equilibria data
The temperature and enthalpy of fusion of choline chloride -[Ch]Cl- are not directly measurable since this compound decomposes upon melting. Yet, given the wide use of this compound in the preparation of deep eutectic solvents (DES), its thermophysical fusion properties are very important for a better understanding of these mixtures and the thermodynamic description of their solid-liquid phase diagrams. In this work, the fusion properties of choline chloride were estimated using the solubility curves of choline chloride in ten different ionic compounds, forming simple binary eutectic mixtures with quasi-ideal liquid phases. Experimental solid-liquid equilibria data for these systems -[Ch] Cl + ionic compounds- were measured, and the ideality of the systems assessed through the quantification of the activity coefficients and their comparison in each pair of binary solutions. The values estimated for the fusion properties of choline chloride are T fus,[Ch]Cl = 597 ± 7 K and Δ fus H [Ch]Cl = 4300 ± 600 J mol −1 . These were additionally checked by thermodynamic consistency tests and by the prediction of the solid-liquid curves with COSMO-RS model. The results obtained with both procedures allow us to guarantee the usefulness and robustness of the estimated data.This work was developed in the scope of the project CICECOAveiro
Institute of Materials, POCI-01-0145-FEDER-007679
(Ref. FCT UID/CTM/50011/2013) and Project POCI-01-0145-FEDER-
006984 e Associate Laboratory LSRE-LCM, both funded by FEDER
through COMPETE2020 - Programa Operacional Competitividade e
Internacionalizaç~ao (POCI) e and by national funds through FCT -
Fundaç~ao para a Ci^encia e a Tecnologia. M.A.R.M acknowledges FCT
for her PhD grant (SFRH/BD/87084/2012). J.O. and L.F. thank the
financing provided by the Spanish Government, Ministerio de
Economia y Competitividad (MINECO), under the project CTQ2012-
37114 and the short-stay grant EEBB-I-16-11792.info:eu-repo/semantics/publishedVersio
Adjusting MtDNA quantification in whole blood for peripheral blood platelet and leukocyte counts
Alterations of mitochondrial DNA copy number (mtDNAcn) in the blood (mitochondrial to nuclear DNA ratio) appear associated with several systemic diseases, including primary mitochondrial disorders, carcinogenesis, and hematologic diseases. Measuring mtDNAcn in DNA extracted from whole blood (WB) instead of from peripheral blood mononuclear cells or buffy coat may yield different results due to mitochondrial DNA present in platelets. The aim of this work is to quantify the contribution of platelets to mtDNAcn in whole blood mtDNAcn(WB)] and to propose a correction formula to estimate leukocytes'' mtDNAcn mtDNAcn(L)] from mtDNAcn(WB). Blood samples from 10 healthy adults were combined with platelet-enriched plasma and saline solution to produce artificial blood preparations. Aliquots of each sample were combined with five different platelet concentrations. In 46 of these blood preparations, mtDNAcn was measured by qPCR. MtDNAcn(WB) increased 1.07 (95%CI 0.86, 1.29; p<0.001) per 1000 platelets present in the preparation. We proved that leukocyte count should also be taken into account as mtDNAcn(WB) was inversely associated with leukocyte count; it increased 1.10 (95%CI 0.95, 1.25, p<0.001) per unit increase of the ratio between platelet and leukocyte counts. If hematological measurements are available, subtracting 1.10 the platelets/leukocyte ratio from mtDNAcn(WB) may serve as an estimation for mtDNAcn(L). Both platelet and leukocyte counts in the sample are important sources of variation if comparing mtDNAcn among groups of patients when mtDNAcn is measured in DNA extracted from whole blood. Not taking the platelet/leukocyte ratio into account in whole blood measurements, may lead to overestimation and misclassification if interpreted as leukocytes'' mtDNAcn
Quantification of the secretory glycoproteins of the subcommissural organ by a sensitive sandwich ELISA with a polyclonal antibody and a set of monoclonal antibodies against the bovine Reissner's fiber
The subcommissural organ (SCO) is an ependymal brain gland that releases glycoproteins into the ventricular cerebrospinal fluid where they condense to form the Reissner's fiber (RF). We have developed a highly sensitive and specific two-antibody sandwich enzyme-linked immunosorbent assay (ELISA) for the quantification of the bovine SCO secretory material. The assay was based on the use of the IgG fraction of a polyclonal antiserum against the bovine RF as capture antibody and a pool of three peroxidase-labeled monoclonal antibodies that recognize non-overlapping epitopes of the RF glycoproteins as detection antibody. The detection limit was 1 ng/ml and the working range extended from 1 to 4000 ng/ml. The calibration curve, generated with RF glycoproteins, showed two linear segments: one of low sensitivity, ranging from 1 to 125 ng/ml, and the other of high sensitivity between 125 and 4000 ng/ml. This assay was highly reproducible (mean intra- and interassay coefficient of variation 2.2% and 5.3%, respectively) and its detectability and sensitivity were higher than those of ELISAs using exclusively either polyclonal or monoclonal antibodies against RF glycoproteins. The assay succeeded in detecting and measuring secretory material in crude extracts of bovine SCO, culture medium supernatant of SCO explants and incubation medium of bovine RF; however, soluble secretory material was not detected in bovine cerebrospinal fluid
Interplay between liver and blood stages of Plasmodium infection dictates malaria severity via γδ T cells and IL-17-promoted stress erythropoiesis
© 2023 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Plasmodium replicates within the liver prior to reaching the bloodstream and infecting red blood cells. Because clinical manifestations of malaria only arise during the blood stage of infection, a perception exists that liver infection does not impact disease pathology. By developing a murine model where the liver and blood stages of infection are uncoupled, we showed that the integration of signals from both stages dictated mortality outcomes. This dichotomy relied on liver stage-dependent activation of Vγ4+ γδ T cells. Subsequent blood stage parasite loads dictated their cytokine profiles, where low parasite loads preferentially expanded IL-17-producing γδ T cells. IL-17 drove extra-medullary erythropoiesis and concomitant reticulocytosis, which protected mice from lethal experimental cerebral malaria (ECM). Adoptive transfer of erythroid precursors could rescue mice from ECM. Modeling of γδ T cell dynamics suggests that this protective mechanism may be key for the establishment of naturally acquired malaria immunity among frequently exposed individuals.We would like to acknowledge Freddy Frischknecht (Integrative Parasitology Center for Infectious Diseases, Heidelberg) for providing the Plasmodium berghei lisp2− parasite line, Immo Prinz (Hannover Medical School, Hannover) for providing genetically modified mouse lines, Ana Parreira (iMM-JLA, Portugal) and Geoff McFadden’s lab (School of BioSciences, University of Melbourne, Australia) for mosquito rearing and infection with Plasmodium parasites, Helena Pinheiro (iMM-JLA, Portugal) for assistance with graphical design, Inês Bento and Miguel Prudêncio for critically reviewing this manuscript, and the Flow Cytometry and Rodent Facilities teams (iMM-JLA, Portugal) for their assistance. Work at iMM-JLA was supported by Fundação para a Ciência e a Tecnologia. Portugal (PTDC/MED-IMU/28664/2017) and the “La caixa” Banking Foundation, Spain (HR17-00264-PoEMM) grants attributed to Â.F.C. and M.M.M., respectively. Work at the Department of Microbiology and Immunology, The University of Melbourne, Australia, was funded by the National Health and Medical Research Council, Australia (1113293, 1154457) and the Australian Research Council, Australia (CE140100011). Â.F.C., S.M., J.L.G., M.I.M., R.M.R., and K.S. were supported by Fundação para a Ciência e a Tecnologia, Portugal (DL57/2016/CP1451/CT0004, DL57/2016/CP1451/CT0010, PD/BD/139053/2018, PD/BD/135454/2017, PTDC/MAT-APL/31602/2017, and CEECIND/00697/2018, respectively), P.L. was supported by Conselho Nacional de Desenvolvimento Científico e Tenológico, Brazil (SN/CGEFO/CNPQ 201801/2015-9), and A.T.T. was supported in part by Alfred P. Sloan Foundation Fellowship (FG-2020-12949).info:eu-repo/semantics/publishedVersio
Khuri-Treiman equations for 3π decays of particles with spin
Khuri-Treiman equations have proven to be a useful theoretical tool in the analysis of three-body decays, especially into the 3π final state. In this work we present in full detail the necessary generalization of the formalism to study the decays of particles with arbitrary spin, parity, and charge conjugation. To this extent, we find it most convenient to work with helicity amplitudes instead of the so-called invariant amplitudes, especially when dealing with the unitarity relations. The isobar expansions in the three possible (s-, t-, and u-) final channels are related with the appropriate crossing matrices. We pay special attention to the kinematical singularities and constraints of the helicity amplitudes, showing that these can be derived by means of the crossing matrix
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