Search results for "hell"
showing 10 items of 1035 documents
Controlling the semi-permeability of protein nanocapsules influences the cellular response to macromolecular payloads.
2021
Nanocapsules are an excellent platform for the delivery of macromolecular payloads such as proteins, nucleic acids or polyprodrugs, since they can both protect the sensitive cargo and target its delivery to the desired site of action. However, the release of macromolecules from nanocapsules remains a challenge due to their restricted diffusion through the nanoshell compared to small molecule cargo. Here, we designed degradable protein nanocapsules with varying crosslinking densities of the nanoshell to control the release of model macromolecules. While the crosslinking did not influence the degradability of the capsules by natural proteases, it significantly affected the release profiles. F…
Evolution of nacre: biochemistry and proteomics of the shell organic matrix of the cephalopod Nautilus macromphalus.
2009
12 pages; International audience; In mollusks, one of the most widely studied shell textures is nacre, the lustrous aragonitic layer that constitutes the internal components of the shells of several bivalves, a few gastropods, and one cephalopod: the nautilus. Nacre contains a minor organic fraction, which displays a wide range of functions in relation to the biomineralization process. Here, we have biochemically characterized the nacre matrix of the cephalopod Nautilus macromphalus. The acid-soluble matrix contains a mixture of polydisperse and discrete proteins and glycoproteins, which interact with the formation of calcite crystals. In addition, a few bind calcium ions. Furthermore, we h…
Molecular modularity and asymmetry of the molluscan mantle revealed by a gene expression atlas
2018
15 pages; International audience; Background: Conchiferan molluscs construct a biocalcified shell that likely supported much of their evolutionary success.However, beyond broad proteomic and transcriptomic surveys of molluscan shells and the shell-forming mantle tissue,little is known of the spatial and ontogenetic regulation of shell fabrication. In addition, most efforts have been focused onspecies that deposit nacre, which is at odds with the majority of conchiferan species that fabricate shells using acrossed-lamellar microstructure, sensu lato. Results: By combining proteomic and transcriptomic sequencing with in situhybridization we have identified a suite of gene products associated …
Proteomics of CaCO3 biomineral-associated proteins: how to properly address their analysis.
2013
8 pages; International audience; In a recent editorial (Proc. Natl. Acad. Sci., 2013 110, E2144-E2146) and elsewhere, questions have been raised regarding the experimental practices in relation to the proteomic analysis of organic matrices associated to the biomineralized CaCO3 skeletons of metazoans such as molluscan shells and coral skeletons. Indeed, although the use of new high sensitivity MS technology potentially allows to identify a greater number of proteins, it is also equally (or even more) sensitive to contamination of residual proteins from soft tissues, which are in close contact with the biomineral. Based on our own past and present experimental know-how-observations that are …
Nacre calcification in the freshwater mussel Unio pictorum: carbonic anhydrase activity and purification of a 95 kDa calcium-binding glycoprotein.
2008
9 pages; International audience; The formation of the molluscan shell is finely tuned by macromolecules of the shell organic matrix. Previous results have shown that the acid-soluble fraction of the nacre matrix of the freshwater paleoheterodont bivalve Unio pictorum shell displays a number of remarkable properties, such as calcium-binding activity, the presence of extensive glycosylations and the capacity to interfere at low concentration with in vitro calcium carbonate precipitation. Here we have found that the nacre-soluble matrix exhibits a carbonic anhydrase activity, an important function in calcification processes. This matrix is composed of three main proteinaceous discrete fraction…
Metal stresses modify soluble proteomes and toxin profiles in two Mediterranean strains of the distributed dinoflagellate Alexandrium pacificum
2022
WOS:000789651000009; HABs involving Alexandrium pacificum have been reported in metal-contaminated ecosystems, suggesting that this distributed species adapts to and/or can tolerate the effects of metals. Modifications in soluble proteomes and PST contents were characterized in two Mediterranean A. pacificum strains exposed to mono- or polymetallic stresses (zinc, lead, copper, cadmium). These strains were isolated from two anthropized locations: Santa Giusta Lagoon (Italy, SG C10-3) and the Tarragona seaport (Spain, TAR C5-4F). In both strains, metals primarily downregulated key photosynthesis proteins. Metals also upregulated other proteins involved in photosynthesis (PCP in both strains)…
Proton, Hydroxide Ion, and Oxide Ion Affinities of Closed-Shell Oxides: Importance for the Hydration Reaction and Correlation to Electronic Structure
2019
Phenomenologically, the enthalpy of the dissociative water incorporation (hydration) of oxides is often found to be more favorable for more basic oxides. In the present work, we investigate proton,...
Self-care and total care: the twofold return of care in twentieth-century thought
2020
The paper studies two fundamentally different forms in which the concept of care makes its comeback in twentieth-century thought. We make use of a distinction made by Peter Sloterdijk, who argues that the ancient and medieval ‘ascetic’ ideal of self-enhancement through practice has re-emerged in the nineteenth and twentieth centuries, particularly in the form of a rehabilitation of the Hellenistic notion of self-care (epimeleia heautou) in Michel Foucault’s late ethics. Sloterdijk contrasts this return of self-care with Martin Heidegger’s concept of being-in-the-world as ‘total care’ (Sorge), an utterly ‘secularized’ understanding of the human being as irreducibly world-embedded that reject…
Orthotrichum mazimpakanum sp. nov. and O. anodon (Orthotrichaceae), two similar species from California
2011
Abstract Studies of herbarium samples and field surveys in Southern California during the fall of 2008 led to the discovery of several new collections of mosses lacking exostome teeth belonging to Orthotrichum Hedw. subgenus Pulchella (Schimp.) Vitt. Some of them are ascribable to O. anodon F. Lara, Garilleti & Mazimpaka even though they display a set of characters not noticed before, considerably broadening the morphological variability of this species and making necessary an updated description. Other materials, from scattered localities along a wide latitudinal range, correspond to a here described new species, Orthotrichum mazimpakanum Garilleti & F. Lara, differentiated by a set of una…
Orthotrichum anodon (Orthotrichaceae), a new species from California, and its relationships to otherOrthotrichawith puckered capsule mouths
2006
A new Orthotrichum species, O. anodon F. Lara, Garilleti & Mazimpaka, is described. The new taxon is included in subgenus Pulchella (Schimp.) Vitt, and is characterised by its immersed, cylindrical capsules, with eight short exothecial bands that constrict the capsule mouth when dry; the lack of exostome teeth; the endostome having 16 hyaline and papillose segments; and the leaves lingulate to ovate lanceolate, with obtuse apices. Its distinction from and relationships with similar species within the genus, are discussed.