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Université de Fribourg

Handling (nano)silver as antimicrobial agent: therapeutic window, dissolution dynamics, detection methods and molecular interactions

Abram, Sarah‐Luise ; Fromm, Katharina M.

In: Chemistry – A European Journal, 2020, vol. 26, no. 48, p. 10948–10971

Silver is an antimicrobial agent well known since antiquity. With the emergence of multiresistant bacteria, it has come back into the focus of research, and ionic as well as nano‐sized silver have been studied in vitro and in vivo. The results are controversial, silver being discussed as the “silver bullet” or a “wolf in sheep's clothing”. A thorough search of literature from...

Université de Fribourg

Assessing the impact of diagenesis on foraminiferal geochemistry from a low latitude, shallow-water drift deposit

Stainbank, Stephanie ; Spezzaferri, Silvia ; Boever, Eva De ; Bouvier, Anne-Sophie ; Chilcott, Colin ; Leau, Erica S.de ; Foubert, Anneleen ; Kunkelova, Tereza ; Pichevin, Laetitia ; Raddatz, Jacek ; Rüggeberg, Andres ; D.Wright, James ; M.Yu, Siyao ; Zhang, Manlin ; Kroon, Dick

In: Earth and Planetary Science Letters, 2020, vol. 545, p. 116390

Due to their large heat and moisture storage capabilities, the tropics are fundamental in modulating both regional and global climate. Furthermore, their thermal response during past extreme warming periods, such as super interglacials, is not fully resolved. In this regard, we present high-resolution (analytical) foraminiferal geochemical (δ18O and Mg/Ca) records for the last 1800 kyr from...

Université de Fribourg

A nano-rattle SnO2@carbon composite anode material for high-energy Li-ion batteries by melt diffusion impregnation

Maharajan, Sivarajakumar ; Kwon, Nam Hee ; Brodard, Pierre ; Fromm, Katharina M.

In: Nanomaterials, 2020, vol. 10, no. 4, p. 804

The huge volume expansion in Sn-based alloy anode materials (up to 360%) leads to a dramatic mechanical stress and breaking of particles, resulting in the loss of conductivity and thereby capacity fading. To overcome this issue, SnO2@C nano- rattle composites based on < 10 nm SnO2 nanoparticles in and on porous amorphous carbon spheres were synthesized using a silica template and tin melting...

Université de Fribourg

Macro- and micro-fauna from cold seeps in the Palmahim Disturbance (Israeli off-shore), with description of Waisiuconcha corsellii n.sp. (Bivalvia, Vesicomyidae)

Basso, D. ; Beccari, V. ; Almogi-Labin, A. ; Hyams-Kaphzan, O. ; Weissman, A. ; Makovsky, Y. ; Rüggeberg, A. ; Spezzaferri, Silvia

In: Deep Sea Research Part II: Topical Studies in Oceanography, 2020, vol. 171, p. 104723

Chemosymbiotic micro- and macro-fauna related to cold-seep sites were recovered in the Palmahim Disturbance (PD), offshore Israel, during EU EUROFLEETS2 SEMSEEP Cruise, by box-coring and Remotely Operated Vehicle (ROV) dives. No live macrofauna was identified in the collected sediments, with the exception of the seep-related crustacean Calliax lobata (de Gaillande and Lagardère, 1966)....

Université de Fribourg

Foraminiferal-based biotic indices to assess the ecological quality status of the Gulf of Gabes (Tunisia): Present limitations and future perspectives

Kateb, Akram El ; Stalder, Claudio ; Martínez-Colón, Michael ; Mateu-Vicens, Guillem ; Francescangeli, Fabio ; Coletti, Giovanni ; Stainbank, Stephanie ; Spezzaferri, Silvia

In: Ecological Indicators, 2020, vol. 111, p. 105962

Biotic indices are tools to assess the ecological status of marine systems, and can be based on different metrics (such as ecological groups, specific diversity). The present study applies five biotic indices based on living (stained) benthic foraminiferal assemblages to assess ecological conditions in a wide area of the Mediterranean Sea in the heavily polluted Gulf of Gabes and along the...

Université de Fribourg

Chemistry of alkaline earth metals: It is not all ionic and definitely not boring!

Fromm, Katharina M.

In: Coordination Chemistry Reviews, 2020, vol. 408, p. 213193

Some scientists might consider group 2 chemistry as “boring, closed shell and all ionic, aqueous chemistry, where everything is known! It is not worth investigating”. How wrong they are! Far from forming only purely ionic compounds, this review will shed light on some spectacular molecules, showing that alkaline earth metal ions can behave similar to transition metal ions. After general...

Université de Fribourg

Nitrogen-doped carbons with hierarchical porosity via chemical blowing towards long-lived metal-free catalysts for acetylene hydrochlorination

Kaiser, Selina K. ; Song, Kyung Seob ; Mitchell, Sharon ; Coskun, Ali ; Pérez‐Ramírez, Javier

In: ChemCatChem, 2020, vol. 12, no. 7, p. 1922-1925

Porous nitrogen‐doped carbons (NCs) are sustainable alternatives to the toxic mercury‐based acetylene hydrochlorination catalysts applied in the manufacture of polyvinyl chloride. However, the application of NCs as metal‐free catalysts is hampered by their insufficient durability under industrially relevant process conditions. In particular, pore blockage leads to accelerated...

Université de Fribourg

Revision of the planktonic foraminiferal biostratigraphy of the Voirons Flysch (Chablais Prealps, Haute-Savoie, France)

Ragusa, Jérémy ; Ospina-Ostios, Lina Maria ; Spezzaferri, Silvia ; Kindler, Pascal

In: Swiss Journal of Geosciences, 2018, vol. 111, no. 3, p. 461–473

The ages obtained from planktonic foraminiferal assemblages retrieved from two exposures in the Gurnigel Flysch and from the re-examination of similar material gathered by previous researchers from the Voirons Flysch reveal only minor discrepancies with previous studies based on nannofossil biostratigraphy. In contrast, major divergences between this work and previous studies on the Voirons...

Université de Fribourg

The Planktonic foraminifera Globigerinoides eoconglobatus n. sp. in a glacial–interglacial context: IODP359 Sites U1467 and U1468

Stainbank, Stephanie ; Spezzaferri, Silvia ; Kroon, Dick ; Leau, Erica S. de ; Rüggeberg, Andres

In: Swiss Journal of Geosciences, 2018, vol. 111, no. 3, p. 511–522

Here we define a new morphospecies of planktonic foraminifera Globigerinoides eoconglobatus n. sp., identified from International Ocean Discovery Program (IODP) expedition 359 samples from drift deposits of the Maldives, Inner Sea. Through biostratigraphic analysis, we infer it may be the direct ancestor of Globigerinoides conglobatus evolving from Globigerinoides obliquus in the Late Miocene...