bluuebunny/crossref_metadata_2025_split huggingface dataset:
Click Chemistry on Defects to Create Multifunctional Fluorescent Carbon Nanotubes
Authors: Kruss Sebastian 
Published: May 2020

Single-walled carbon nanotubes (SWCNT) are versatile materials for imaging and sensing in the near infrared (nIR) range. Non-covalent adsorption with (bio)polymers such as DNA is a powerful approach to functionalize SWCNTs. This approach lead to a broad range of biosensors. However, covalent approaches would be beneficial for many applications because of higher stability and photophysical signal transduction. One route to covalent functionalization is reactions with diazonium salts that create covalent defects and a red-shifted peak in the nIR fluorescence spectrum attributed to a formerly dark exciton.
Here, we used novel synthesized diazonium salts to create defects that can be easily further functionalized with click chemistry reactions (Thiol-en and azid-alkine). The modified SWCNTs were additionally non-covalently wrapped in biopolymers for solubilization and characterized via nIR spectroscopy and atomic force microscopy (AFM). Using this approach we covalently conjugated diverse molecules including small aliphatic molecules, peptides, DNA and nanobodies to the SWCNT backbone. Successful functionalization was verified by conjugation of organic visible fluorophores and single SWCNT colocalization. Additionally, these multifunctional SWCNTs were used as building block for biosensors that detect disease markers.
In summary, we present a general approach to conjugate a broad range of molecules to SWCNTs using defect chemistry and demonstrate applications in biosensing.
(Invited) Environmental Impact of Carbon Nanotubes & Graphene and Related Materials (GRMs)
Authors: Flahaut Emmanuel , Evariste Lauris , Liné Clarisse , Mottier Antoine , Mouchet Florence , Barret Maialen , Pinelli Eric , Galibert Anne Marie , Soula Brigitte , Larue Camille , Gauthier Laury 
Published: May 2020

Carbon nanomaterials (and especially carbon nanotubes) are often cited first when people are asked about "nanoparticles" in general. For some people, they represent a huge potential of applications due to their extraordinary properties (or more realistically because of their unique combination of different properties), while some others will mention first the (potential) related toxicity issues.
We will quickly review different aspects related to the potential environmental toxicity of carbon nanomaterials and will summarize our main results in this field. In particular, we have identified that the impact of carbon nanomaterials with very different morphologies ranging from zero-D (nanodiamonds) to 2D (few-layer graphene, graphene oxide) can be generalized when the metric used for the comparison of the data is the surface (m²/L) instead of the weight (g/L) [1]. We will illustrate in the specific case of graphene oxide how the modification of surface chemistry (reduction) can be used to significantly decrease the risk during handling and use, in the framework of a "safer(r) by design" strategy [2].
Finally, we will give a brief overview of our recent work on the impact of carbon nanotubes on plants grown in contaminated soils.
REFERENCES:
[1] A. Mottier, F. Mouchet, C. Laplanche, S. Cadarsi, L. Lagier, J-C. Arnault, H. Girard, V. Léon, E. Vazquez, C. Sarrieu, E. Pinelli, L. Gauthier, E. Flahaut, Nano Letters, 16 (6), (2016), 3514-3518, "Surface area of carbon nanoparticle: a dose-metric for a more realistic ecotoxicological assessment"

[2] L. Evariste, L. Lagier, P. Gonzalez, A. Mottier, F. Mouchet, S. Cadarsi, P. Lonchambon, G. Daffe, G. Chimowa, C. Sarrieu, A-M. Galibert, C. Matei Ghimbeu, E. Pinelli, E. Flahaut, L. Gauthier, Nanomaterials, 9, (2019), 584:1-16, "Thermal reduction of Graphene Oxide mitigates its in vivo genotoxicity toward Xenopus laevis tadpoles"
(Invited) Synthesis and Optical Properties of Graphene Quantum Dots
Authors: Lavie Julien , Zhao Shen , Orcin-Chaix Lucile , Liu Thomas , Rondin Loïc , Lauret Jean-Sébastien , Campidelli Stephane 
Published: May 2020

The outstanding electronic, optical and mechanical properties of graphene strongly inspire the scientific community at both the fundamental and applicative levels. However, the key issue that needs to be addressed is the control and the modification of the electronic properties of graphene, and notably the opening of a sizable bandgap. For the last decade, a great attention has been paid to the size reduction of graphene using conventional top-down approaches (lithography and etching, thermal treatments and oxidation of bulk materials) to fabricate graphene quantum dots (GQDs)1 or graphene nanoribbons (GNRs).2 However, top-down approaches do not permit to manipulate the structure of the material at the atomic scale. In particular, they do not allow a sufficient control of the morphology and oxidation state of the edges, which drastically impact the properties. In order to truly control, with the required level of precision, the morphology and the composition of the materials and of its edges, the bottom-up approach is the relevant way to proceed.3,4

Recently, we reported on the synthesis and single photon emission properties of triangular-shaped GQDs.5 While, this initial report focused on functionalized nanoparticles, we now turn to non-functionalized graphene quantum dots that are in terms of structure closer to real graphene. Here, we described the synthesis, the dispersion and optical properties of a series of rod-shaped particles and we studied the structure-properties relationship in these graphene quantum dots. To this end, we designed a series of GQDs with a given edge type and by changing only one parameter (one dimension, namely the length or the width – Figure 1), we expect to follow simply the evolution of the optical properties.
References.
1. Haque, E.; Kim, J.; Malgras, V.; Reddy, K. R.; Ward, A. C.; You, J.; Bando, Y.; Hossain, M. S. A.; Yamauchi, Y. Recent Advances in Graphene Quantum Dots: Synthesis, Properties, and Applications. Small Methods
2018,
2, 1800050.
2. Xu, W.; Lee, T.-W. Recent progress in fabrication techniques ofgraphene nanoribbons. Mater. Horiz.
2016,
3, 186-207.
3. Narita, A.; Wang, X. Y.; Feng, X.; Müllen, K. New advances in nanographene chemistry. Chem. Soc. Rev.
2015,
44, 6616-6643.
4. Narita, A.; Chen, Z.; Chen, Q.; Müllen, K. Solution and on-surface synthesis of structurally defined graphene nanoribbons as a new family of semiconductors. Chem. Sci.
2019,
10, 964-975.
5. Zhao, S.; Lavie, J.; Rondin, L.; Orcin-Chaix, L.; Diederichs, C.; Roussignol, P.; Chassagneux, Y.; Voisin, C.; Müllen, K.; Narita, A.; Campidelli, S.; Lauret, J.-S. Single photon emission from graphene quantum dots at room temperature. Nat. Commun.
2018,
9, 3470.

Figure 1
(Invited) Modulation of the Fermi Level in Single-Walled Carbon Nanotubes By Chromophore Encapsulation
Authors: Chambard Romain , Izard Nicolas , Aznar Raymond , Jousselme Bruno , Campidelli Stephane , Sato Yuta , Suenaga Kazu , Lauret Jean-Sébastien , Bantignies Jean-Louis , Alvarez Laurent 
Published: May 2020

The one-dimensional structure of single-walled carbon nanotubes renders these materials ideal for optoelectronic applications as they can transport electrons or holes with quasi-ballistic features and as they display optical absorption and near-infrared emission (thanks to van Hove singularities). Nevertheless, functionalities can to be added to nanotube to both improve and control the physical properties. To this aim, chromophore encapsulation into host single-walled carbon nanotubes allows to create hybrid nano-systems with tunable opto-electronic properties. Up to now, we have been confining different kinds of molecules,1-4 either absorbing in the blue/green range, being electron donor (quaterthiophene derivatives (4T) and tetramethyl-paraphenylenediamine (TMPD)) or electron acceptor (tetracyanoquinodimethane (TCNQ)), or absorbing in the red visible range (phthalocyanine (MPc)).
In this study, we investigate, at both the macroscopic and the individual scales, the electronic and the optical properties of our hybrid systems by means of Raman and photoluminescence spectroscopies.
From Raman measurements, a significant charge transfer from the confined dye to the nanotube is evidenced. Experiments also suggest a photo-activated electron transfer for small diameter (~9 Å) semiconducting and metallic tubes. The main relevant parameters that govern the charge transfer are the nanotube diameter and the electronic properties of both the nanotube (metallic or semiconducting) and the chromophores (electron donor or acceptor).
Photoluminescence experiments clearly demonstrate changes on the emission properties after encapsulation. The intensities can be increased or reduced depending on the nature of the confined chromophores (electron donor or acceptor). These behaviors are consistent with a charge transfer.
Therefore, Raman and photoluminescence experiments strongly suggest charge transfer between the confined molecules and the nanotubes, leading to a Fermi level shift which governs the radiative de-excitation efficiency and the electron-phonon coupling.

References

[1] L. Alvarez et al, J. Phys. Chem. C, 119, (2015), pp. 5203−5210
[2] Y. Almadori et al, J. Phys. Chem. C; 118, (2014), pp. 19462−19468
[3] A. Belhboub et al, J. Phys. Chem. C; 120, (2016), pp. 28802−28807
[4] Y. Almadori et al, Carbon 149, (2019), pp. 772-780
Revealing the Nanoscale Dynamics of the Extracellular Space in the Living Brain
Authors: Godin Antoine G , Dannée Noemie , Groc Laurent , Cognet Laurent 
Published: May 2020

The brain is a highly dynamic structure with the extracellular space taking up almost a quarter of its volume. Signalling molecules, neurotransmitters and nutrients transit via the extracellular space, which constitutes a key microenvironment for cellular communication and clearance of toxic metabolites. Nevertheless, the extracellular space has not been characterized in detail in intact living samples because of the lack of appropriate tools allowing its study. Recent technological advances enhancing the luminescence properties and biocompatibility of carbon nanotubes opened the door to super-resolution imaging in the near-infrared in vivo. The luminescence efficiencies of single carbon nanotubes excited via various excitation strategies were compared and optimized for tissue imaging (e.g., targeting various excitonic transitions and through upconversion). The effects of tissue scattering, absorption, autofluorescence, and temperature increase induced by excitation light were systematically examined [1]. Using carbon nanotube tracking, we revealed the hidden structure and viscoelastic properties of the extracellular space of brain slices [2]. Local morphological and viscosity maps of the extracellular space of brain acute slices were reconstructed. A diversity of extracellular space dimensions down to ~40 nm and local viscosity maps were obtained. The rheological properties of the extracellular space are affected by chemical alterations of the extracellular matrix of the brains of live animals. Interestingly, these alterations are local and highly inhomogeneous in space. Probing the viscoelastic properties of the extracellular space is paramount to understand the spatiotemporal dynamics that regulate the cellular mechanisms ultimately influencing fundamental aspects of cell biology. These technological advances constitute the first milestone to generate super-resolution microscopy applications in the near-infrared to investigate live biological samples in situ.

References:

(1) Danné N* & Godin AG* et al. (2018) Comparison of the resonant excitations and upconversion luminescence of individual carbon nanotubes for biological tissue studies.
ACS Photonics 5 (2) 359-364. *ND and AGG contributed equally to this work.
(2) Godin AG et al. (2017) Single-nanotube tracking reveals the nanoscale organization of the extracellular space in the live brain.
Nature Nanotechnology 12 (3) 238-24.
(Invited) Magnetism and Electrochemistry of Fullerene-Based Composites
Authors: Wang Xiao , Dong Peipei , Feng Yongqiang 
Published: May 2020

Endohedral metallofullerenes (EMFs), a negatively sp
2-hybridized spherical carbon surface containing alternating hexagons and pentagons doped with metal ion(s) or cluster inside, have attracted more and more interests owing to their unique nesting structures and alluring chemical/physical properties. Herein, we will discuss several typical spin-active endohedral metallofullerenes. To steer the electron spin of paramagnetic fullerene molecules, a solid-state spin system was constructed via encapsulating paramagnetic fullerenes into the pores of metal-organic frameworks (MOFs) forming a EMF/MOF compostie, and an axisymmetric paramagnetic property was found. This kind of solid spin system can be used as a probe for nanoscale nuclear magnetic resonance or for motion imaging of a single biomolecule.
Besides, as a representative allotrope of carbon, fullerene-based composite also exhibit fascinating electrochemistry, e.g., serving as electrocatalyst. In this work, a novel hybrid electrocatalyst comprising fullerene carbon dot (FQD)-decorated cobalt nickel layered double hydroxide (CoNi-LDH) nanosheets anchored on porous nickel foam (NF) is elaborately fabricated. The obtained FQD/CoNi-LDH/NF exhibits superior electrocatalytic activity for hydrogen and oxygen evolution as well as urea oxidation under ambient atmosphere. Both experiment and density functional theory (DFT) calculations demonstrate that the charge transfer from FQD to CoNi-LDH could account for the excellent catalytic performance of the newly-synthesized catalyst, and the decorated FQD finely modulates the electronic structure of CoNi-LDH, favoring the adsorption of active hydrogen atom, and thus promote the catalytic process. The present work would provide useful guidance for designing and developing fullerene-based electrocatalysts for hydrogen production.
(Invited) Visualizing the Dynamics of Metallofullerenes with Variable Temperature Single Crystal X-Ray Diffraction
Authors: Liu Fupin , Spree Lukas , Popov Alexey A. 
Published: May 2020

The empty interior space of fullerenes is ready to hold atoms/clusters to become endohedral fullerenes. Metal ions can be encapsulated in various fullerene cages, known as metallofullerenes. The interplay between the encapsulated metal ions and the fullerene cage carbon atoms is fundamental to understanding these molecules. Recently, we succeeded on the visualization of the dynamics of Dy2@Ih
(7)-C80-CH2Ph in the crystal lattice1 as well as M3N@Ih
(7)-C80 (M3N = Ho2LuN or Lu3N) in the crystal lattice of co-crystals with nickel octaethylporphyrin2 by variable temperature X-ray diffraction, see the following figure for the comparison of the equivalent atomic displacement parameters of heavy atoms. In this contribution, the details of the observed temperature dependent dynamics of the metallofullerenes will be discussed.
1. Liu, F.; Velkos, G.; Krylov, D. S.; Spree, L.; Zalibera, M.; Ray, R.; Samoylova, N. A.; Chen, C.-H.; Rosenkranz, M.; Schiemenz, S.; Ziegs, F.; Nenkov, K.; Kostanyan, A.; Greber, T.; Wolter, A. U. B.; Richter, M.; Büchner, B.; Avdoshenko, S. M.; Popov, A. A., Air-stable redox-active nanomagnets with lanthanide spins radical-bridged by a metal–metal bond. Nat. Commun.
2019,
10, 571.
2. Liu, F.; Spree, L., Molecular Spinning Top: Visualizing the Dynamics of M3N@C80 with Variable Temperature Single Crystal X-ray Diffraction. Chem. Commun.
2019,
55, 13000-13003.

Figure 1
“All Our Wisdom is Stored in the Trees” - Degrading BCR-ABL with Berberis Vulgaris
Authors: Elf Shannon Elisabeth 
Published: May 2020

Abstract
Treating BCR-ABL–positive chronic myeloid leukemia remains impeded by the development of clinical resistance to imatinib. It has been demonstrated that berberine, a plant alkaloid, has activity against imatinib-resistant BCR-ABL mutants by inducing autophagic degradation of BCR-ABL, thereby preventing the acquisition of drug-resistant mutations.
See related article by Yin et al., p. 4040
Caracterização dos contaminantes do minério de ferro do depósito mineral da Serra do Sapo, Conceição do Mato Dentro, Minas Gerais
Authors: Morais Fernando Prudencio , Silva Rosaline Cristina Figueiredo e , Rosiére Carlos Alberto , Dias Geraldo Sarquis 
Published: May 2020

Os itabiritos do depósito mineral da Serra do Sapo estão localizados na região da Serra do Espinhaço Meridional e são descritos como parte da Formação Serra do Sapo, unidade superior do Grupo Serra da Serpentina, e estão sobrepostos aos xistos e aos filitos da Formação Meloso. Formações ferríferas com alto teor de Al e P ocorrem no contato com metassedimentos da unidade basal. Esses contatos são transicionais e geram uma rocha bandada, com níveis milimétricos a centimétricos contendo grande concentração de óxido de ferro. Essa litologia tem textura sedosa e ocorre sempre decomposta, sendo descrita como hematita-quartzo-mica xistos ou classificada como itabirito com alto teor de contaminantes (IFX). A classificação dos itabiritos é feita de acordo com o grau de decomposição intempérica da rocha. Formações ferríferas bandadas classificadas como itabiritos (IT), rocha sã, e que também apresentam altos teores de P como contaminante, são classificadas como itabirito com alto teor de fósforo (ITX). Estudos petrográficos identificaram muscovita, clorita e gibbsita como as principais fontes de Al para as amostras de IFX. Os altos teores de Al2O3 e P2O5 desses litotipos também são explicados pelo processo de formação supergênica, em que o espaço dos minerais lixiviados é preenchido por clorita e gibbsita. Para o ITX, os altos teores de P estão relacionados com minerais de apatita que ocorrem com maior frequência nesse litotipo. Dados geoquímicos de rocha total, quando normalizados ao Pos-Archean Australian Shale (PAAS), mostram que as amostras de IFX são enriquecidas em elementos terras raras leves (ETRL) se comparadas aos outros itabiritos. Essas amostras também são enriquecidas em elementos móveis como Ba e Sr. Isso indica que o enriquecimento
Aeromagnetometria e aerogamaespectrometria do Complexo Atuba e arredores, leste do estado do Paraná
Authors: Baldin Michelangelo Tissi , Salamuni Eduardo , Castro Luís Gustavo De 
Published: May 2020

As rochas do Complexo Atuba afloram na porção leste do Estado do Paraná e compreendem a região sul do Cinturão Ribeira. Situam-se a norte do Terreno Luís Alves e estão enquadradas no Terreno Curitiba. O objetivo desta pesquisa foi definir as unidades geológicas e o arcabouço estrutural da área de trabalho, junto ao mapeamento de falhas, fraturas e diques. A pesquisa foi desenvolvida por meio de aeromagnetometria e aerogamaespectrometria. A primeira permitiu interpretar os traçados de lineamentos e estabelecer o arcabouço estrutural da área de estudo, porém não conseguiu separar de forma definida o Complexo Atuba do Grupo Açungui. As grandes zonas de cisalhamento definidas pela Zona de Cisalhamento (ZC) Lancinha-Cubatão e ZC Curitiba estão encobertas e mascaradas pelos diques básicos mesozoicos. Os lineamentos com direção NE-SW são escassos e correspondem às falhas e às fraturas observadas principalmente no domínio do Complexo Atuba e da Bacia Sedimentar de Curitiba. As orientações NW-SE aparecem em grande proporção e estão relacionadas às falhas e aos diques. O método gamaespectrométrico possibilitou observar dispersão dos elementos K, Th e U, caracterizando as unidades litológicas e detectando a presença de intrusões ígneas. De acordo com esse método, foi possível identificar quatro domínios diferentes, formados pelo Complexo Atuba, pela Formação Capiru, pela Formação Guabirotuba e por granitos neoproterozoicos.
PKG1α Cysteine-42 Redox State Controls mTORC1 Activation in Pathological Cardiac Hypertrophy
Authors: Oeing Christian U. , Nakamura Taishi , Pan Shi , Mishra Sumita , Dunkerly-Eyring Brittany L. , Kokkonen-Simon Kristen M. , Lin Brian L. , Chen Anna , Zhu Guangshuo , Bedja Djahida , Lee Dong Ik. , Kass David A. , Ranek Mark J. 
Published: May 2020

Rationale:
Stimulated PKG1α (protein kinase G-1α) phosphorylates TSC2 (tuberous sclerosis complex 2) at serine 1365, potently suppressing mTORC1 (mechanistic [mammalian] target of rapamycin complex 1) activation by neurohormonal and hemodynamic stress. This reduces pathological hypertrophy and dysfunction and increases autophagy. PKG1α oxidation at cysteine-42 is also induced by these stressors, which blunts its cardioprotective effects.

Objective:
We tested the dependence of mTORC1 activation on PKG1α C42 oxidation and its capacity to suppress such activation by soluble GC-1 (guanylyl cyclase 1) activation.

Methods and Results:

Cardiomyocytes expressing wild-type (WT) PKG1α (PKG1α
WT
) or cysteine-42 to serine mutation redox-dead (PKG1α
CS/CS
) were exposed to ET-1 (endothelin 1). Cells expressing PKG1α
WT
exhibited substantial mTORC1 activation (p70 S6K [p70 S6 kinase], 4EBP1 [elF4E binding protein-1], and Ulk1 [Unc-51-like kinase 1] phosphorylation), reduced autophagy/autophagic flux, and abnormal protein aggregation; all were markedly reversed by PKG1α
CS/CS
expression. Mice with global knock-in of PKG1α
CS/CS
subjected to pressure overload (PO) also displayed markedly reduced mTORC1 activation, protein aggregation, hypertrophy, and ventricular dysfunction versus PO in PKG1α
WT
mice. Cardioprotection against PO was equalized between groups by co-treatment with the mTORC1 inhibitor everolimus. TSC2-S1365 phosphorylation increased in PKG1α
CS/CS
more than PKG1α
WT
myocardium following PO. TSC2
S1365A/S1365A
(TSC2 S1365 phospho-null, created by a serine to alanine mutation) knock-in mice lack TSC2 phosphorylation by PKG1α, and when genetically crossed with PKG1α
CS/CS
mice, protection against PO-induced mTORC1 activation, cardiodepression, and mortality in PKG1α
CS/CS
mice was lost. Direct stimulation of GC-1 (BAY-602770) offset disparate mTORC1 activation between PKG1α
WT
and PKG1α
CS/CS
after PO and blocked ET-1 stimulated mTORC1 in TSC2
S1365A
-expressing myocytes.

Conclusions:
Oxidation of PKG1α at C42 reduces its phosphorylation of TSC2, resulting in amplified PO-stimulated mTORC1 activity and associated hypertrophy, dysfunction, and depressed autophagy. This is ameliorated by direct GC-1 stimulation.
Group-size preferences in a shoaling cichlid
Authors: Durrer Loris , Taborsky Michael , Frommen Joachim G. 
Published: May 2020

Abstract
Group size is an important criterion in social decisions. Accordingly, assessing quantities is common in many animals. In fishes, studies on numerical abilities focus on a limited range of species. Arguably, cichlids show the greatest variability of social patterns among vertebrates. Nevertheless, knowledge about their quantitative abilities is scarce. Here we use the Lake Tanganyika cichlid Lamprologus callipterus to scrutinize the quantitative abilities of fish in the context of shoaling. Females chose between different numbers of conspecifics, varying in absolute and relative number differences. In half of the trials both shoals were composed of familiar sisters, while all fish were unfamiliar non-kin in the other half. Test fish consistently preferred the larger of two shoals, irrespective of the ratios. Their activity differed significantly between familiarity/relatedness treatments, indicating recognition of this parameter. L. callipterus therefore has fine-tuned discrimination skills, adding to the evidence that quantitative abilities are widespread in fishes.