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Research Project
Centro de Química Estrutural
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Ionic liquid-based semi-interpenetrating polymer network (sIPN) membranes for CO2 separation
Publication . Gouveia, Andreia S.L.; Bumenn, Edwin; Rohtlaid, K.; Michaud, A.; Vieira, T.M.; Delgado Alves, Vitor; Tomé, L.C.; Plesse, C.; Marrucho, Isabel M.
This work explores the preparation of ionic liquid (IL)-based semi-interpenetrating polymer network (sIPN)
membranes composed of poly(ethylene oxide) (PEO) network and linear nitrile butadiene rubber (NBR),
incorporating up to 66 wt% of three ILs with a common cation ([C2mim]+) and different anions ([C(CN)3]–,
[NTf2]– and [FSI]–). All sIPN/IL membranes were characterized by Fourier-transform infrared (FT-IR) spectroscopy,
thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and puncture tests. Ideal
CO2/N2 and CO2/H2 separation performances of the prepared sIPN/IL membranes were investigated at T = 20 ◦C
and 35 ◦C, respectively, and 1 bar of feed pressure.
The incorporation of both [C2mim][NTf2] and [C2mim][FSI] ILs allowed to obtain sIPN/IL membranes with
higher IL contents (66 wt%) compared to previously reported PIL–IL membranes with similar IL structures (40 wt
%). The membranes containing [NTf2]– and [C(CN)3]– anions showed improved thermal stability compared to
the neat PEO/NBR sIPN, being thermally stable up to 300 ◦C. Although sIPN/IL membrane mechanical properties
were affected by the incorporation of IL, all membranes revealed high elongation properties (elongation upon
puncture = 68–170%), mainly due to the presence of NBR component in the sIPN structure. The highest CO2/N2
permselectivity was obtained for the sIPN/66 wt% [C2mim][C(CN)3] membrane, while the sIPN/66 wt%
[C2mim][FSI] membrane revealed the highest CO2 and N2 permeabilities. The incorporation of 66 wt% of
[C2mim][FSI] into the sIPN also showed superior CO2/H2 separation performance, with a CO2 permeability of
727 Barrer and a CO2/H2 permselectivity of 10.9
Sphingolipid domains in the plasma membrane of fungal cells : Interplay with membrane proteins and antifungal resistance
Publication . Santos, Filipa C.; Almeida, Rodrigo F. M. de
Plasma membrane (PM) carries out multiple functions a tightly regulated dynamic organization into specialized domains of different size, stability, and composition. Sphingolipids are a major class of lipids of PM being crucial for its structure and function. A specific type of ergosterol-depleted PM domains in fungi, where lipids are tightly packed in a very rigid gel phase, comprises the sphingolipid-enriched domains (SLEDs). In this work, the presence of SLEDs in a mold, Neurospora crassa, was disclosed, as well as their involvement in the response to the antifungal staurosporine. A comparison with the budding yeast Saccharomyces cerevisiae was performed, taking into consideration the known differences between their PM sphingolipidomes. The studies with N. crassa were performed in conidial suspensions along different time points of conidial germination, using several fluorescence spectroscopy techniques and a multiprobe approach.
S. cerevisiae living cells were studied in mi-exponential phase. To evaluate the impact of changing sphingolipid composition in the organization of the two main yeast PM compartments, MCC (arginine/ H+ symporter Can1p) and MCP (H+ ATPase Pma1p), the time-resolved fluorescence properties of Can1p tagged with GFP and Pma1p tagged with mRFP, respectively, were studied by FLIM in wt and a mutant strain with a different sphingolipid profile, ipt1∆.
IPT1 deletion strongly affects the rigidity of gel domains and Pma1p PM distribution, whereas no significant alterations could be perceived neither in ergosterol-enriched domains nor Can1p distribution.
Thus, this work strongly suggests that proper SLEDs hydrophobic chain packing is required for an adequate organization of the MCP, but not MCC.
Finally, considering that the PM is crucial for antifungal action, a biophysical connection between SLEDs and antifungal activity was explored in S. cerevisiae.
Shedding Light on Metals Release from ChestnutWood toWine Spirit Using ICP-MS
Publication . Catarino, Sofia; Thanasi, Vasiliki; Morin, Gael; Anjos, Ofélia; Fernandes, Tiago A.; Caldeira, Ilda; Fargeton, Laurent; Boissier, Benjamin; Canas, Sara
Possible effects caused by mineral elements during wine spirit ageing are diverse. In this
study, the evolution of the mineral composition of wine spirit during ageing with chestnut (Castanea
sativa Mill.) wood was investigated. A wine distillate was aged in 250 L wooden barrels (traditional
ageing) and in 50 L glass demijohns with wood staves and micro-oxygenation (alternative ageing).
Sampling was performed after 21, 60, 180, 270, and 365 days of ageing. The elemental composition
of the wine spirits, including alkaline, alkaline earth metals, and heavy metals, was assessed by
quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS). For most of the elements, no
significant differences between wine spirits from distinct ageing modalities were observed. Ageing
time had significant effect on most of them, with different trends and distinct magnitude of changes,
depending on each specific element. The concentrations of the mineral elements found in the wine
spirits were very low, especially those of heavy metals, which is quite positive in terms of quality and
food safety. Novel information on metals released from chestnut wood to wine spirits confirms its
appropriateness for ageing this beverage
First report on the synergistic interaction between essential oils against the pinewood nematode Bursaphelenchus xylophilus
Publication . Faria, Jorge M. S.; Cavaco, Tomás; Gonçalves, Diogo; Barbosa, Pedro; Teixeira, Dora Martins; Moiteiro, Cristina; Inácio, Maria L.
Control of the pinewood nematode (PWN), the causal agent of pine wilt disease, can be
achieved through the trunk injection of nematicides; however, many pesticides have been linked
to environmental and human health concerns. Essential oils (EOs) are suitable alternatives due
to their biodegradability and low toxicity to mammals. These complex mixtures of plant volatiles
often display multiple biological activities and synergistic interactions between their compounds.
The present work profiled the toxicity of eight EOs against the PWN in comparison to their 1:1
mixtures, to screen for successful synergistic interactions. Additionally, the main compounds of the
most synergistic mixtures were characterized for their predicted environmental fate and toxicity to
mammals in comparison to emamectin benzoate, a commercial nematicide used against PWN. The
mixtures of Cymbopogon citratus with Mentha piperita and of Foeniculum vulgare with Satureja montana
EOs showed the highest activities, with half-maximal effective concentrations (EC50) of 0.09 and
0.05 L/mL, respectively. For these, complete PWN mortality was reached after only ca. 15 min or
2 h of direct contact, respectively. Their major compounds had a higher predicted affinity to air and
water environmental compartments and are reported to have very low toxicity to mammals, with
low acute oral and dermal toxicities. In comparison, emamectin benzoate showed lower nematicidal
activity, a higher affinity to the soil and sediments environmental compartments and higher reported
oral and dermal toxicity to mammals. Overall, uncovering synergistic activities in combinations
of EOs from plants of different families may prove to be a source of biopesticides with optimized
toxicity against PWNs.
Trace elements in soils of the Antarctic ice-free areas: Insights on natural geochemical values, anthropogenic impact and possible remobilisation upon permafrost thaw
Publication . Zilhão, Henrique; Cesário, Rute; Vieira, Gonçalo; Canário, João
Climate change is transforming the ice-free areas of Antarctica, leading to rapid changes in terrestrial ecosystems.
These areas represent <0.5% of the continent and coincide with the most anthropogenically pressured sites,
where the human footprint is a source of contamination. Simultaneously, these are the locations where
permafrost can be found, not being clear what might be the consequences following its degradation regarding
trace element remobilisation. This raises the need for a better understanding of the natural geochemical values of Antarctic soils as well as the extent of human impact in the surroundings of scientific research stations.
Permafrost thaw in the Western Antarctic Peninsula region and in the McMurdo Dry Valleys is the most likely to
contribute to the remobilisation of toxic trace elements, whether as the result of anthropogenic contamination or
due to the degradation of massive buried ice and ice-cemented permafrost. Site-specific locations across
Antarctica, with abandoned infrastructure, also deserve attention by continuing to be a source of trace elements
that later can be released, posing a threat to the environment. This comprehensive summary of trace element
concentrations across the continent's soils enables the geographical systematisation of published results for a
better comparison of the literature data. This review also includes the used analytical techniques and methods for trace element dissolution, important factors when reporting low concentrations. A new perspective in environmental monitoring is needed to investigate if trace element remobilisation upon permafrost thaw might be a tangible consequence of climate change.
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Funding agency
Fundação para a Ciência e a Tecnologia
Funding programme
6817 - DCRRNI ID
Funding Award Number
UIDB/00100/2020