bluuebunny/crossref_metadata_2025_split huggingface dataset:
The g-Extra Edge-Connectivity of Balanced Hypercubes
Authors: Wei Yulong , Li Rong-hua , Yang Weihua 
Published: July 2021

The [Formula: see text]-extra edge-connectivity is an important measure for the reliability of interconnection networks. Recently, Yang et al. [Appl. Math. Comput. 320 (2018) 464–473] determined the [Formula: see text]-extra edge-connectivity of balanced hypercubes [Formula: see text] and conjectured that the [Formula: see text]-extra edge-connectivity of [Formula: see text] is [Formula: see text] for [Formula: see text]. In this paper, we confirm their conjecture for [Formula: see text] and [Formula: see text], and disprove their conjecture for [Formula: see text] and [Formula: see text], where [Formula: see text].
(Invited) Near Infrared Imaging of Cellular Signaling
Authors: Kruss Sebastian 
Published: July 2021

Cells use molecules to exchange information. A very prominent example is neurotransmitter signaling between neuronal cells or paracrine signaling between blood cells or bacteria. However, it is up to date difficult to visualize signaling processes between cells with high spatial, temporal and chemical resolution. We are interested in developing fluorescent sensors/probes that overcome these limitations and answer novel biological questions.
For that purpose we use near infrared (NIR) fluorescent single-walled carbon nanotubes (SWCNTs). SWCNTs fluoresce in the nIR tissue transparency window (900 nm -1700 nm) and do not bleach. They are chemically modified to render them selective for biological signaling molecules. In this context, we developed different chemical strategies that include screening for artificial binding motifs, aptamers and nanobodies. Using these strategies we created sensors for the neurotransmitters dopamine/serotonin, reactive oxygen species and bacterial signaling molecule. These sensors change their fluorescence in the presence of the target molecule and detect down to single molecules. Fast parallel imaging of many of those sensors provides a NIR image (>900 nm) of the neurotransmitter concentration around cells. This technique was used to image hot spots of dopamine release from primary dopaminergic under electrical stimulation and assess the heterogeneity of release sites. Neurotransmitters are not only relevant in the neuronal system but as well in the periphery e.g. in blood cells. In this context, we imaged for the first time how human blood platelets release serotonin after activation and resolved the location and the time scale of release. Finally, such sensors resolve signaling between bacteria and even detect them. These results illustrate that tailored SWCNTs are powerful tools for quantitative chemical imaging of biological processes.
Preclinical Imaging and Spectroscopy in the NIR-II Window with Indocyanine Green (ICG) and Single-Walled Carbon Nanotubes
Authors: Chung Wendy , Galassi Thomas , Harvey Jackson , Baker Hanan , Rioux David , Beaulieu Ouellet Émilie , Moreno Maria , Heller Daniel A. 
Published: July 2021

We developed a near-infrared small animal imaging system, IR VIVO, that provides real-time images, videos and spectral imaging in the NIR-I and shortwave infrared (SWIR or NIR-II) regions. We found that SWIR wavelengths can give optimal resolution for in vivo optical imaging of deep organs in mice up to 3 cm due to the low tissue autofluorescence, scattering and absorption of light at these wavelengths. We also showed how this higher penetration depth can enable the detection of small wavelength changes in the emission of carbon nanotube-based sensors implanted in vivo using a continuously tunable filter.
First, we demonstrated superior image clarity and penetration depth at NIR-II wavelengths (1000-1700 nm) in vivo using an FDA approved dye, indocyanine green (ICG) in a mouse. We used 780 nm excitation, detection using a Zephir 1.7 InGaAs camera and 1250 nm long-pass emission filter. We found low tissue autofluorescence at 1250 nm. The ICG dye imaging resulted in superior visualization of microvasculature, perfusion, measurement of hearst rate, respiratory rate, hepatobiliary and intestinal contractions. Further anatomical and functional imaging was carried out by looking at the kinetics of ICG, resulting in the identification of different organs.
Second, In vivo near-infrared hyperspectral imaging of carbon nanotubes was conducted using a continuously-tunable filter in the imager. A diffraction volume Bragg grating (VBG), was used to provide narrow-band wavelength selection. Coupled with a homogeneous global illumination, spectrally-defined images were acquired in the entire field of view. The result was a dataset containing both 2D spatial information and the full spectrum for each point in the image. We conducted near-infrared hyperspectral imaging of single-walled carbon nanotubes to measure small wavelength changes of the nanotubes implanted into live mice. Hyperspectral measurements of carbon nanotube sensors for lipids in the liver as well as implantable sensors for doxorubicin were conducted, facilitating liver disease monitoring and drug pharmacokinetics measurements.
Finally, we believe wide-area NIR-II imaging and spectral/hyperspectral measurements have broad potential applications for the use of carbon nanotubes and other NIR-I/II materials in basic materials/biology, translational, and clinical work, including sensor arrays, point-of-care measurements, implants, whole small animal imaging and intraoperative/surgical imaging.
(Invited) Photostability of Core-Shell Structures at Low Temperature
Authors: Orcin-Chaix Lucile , Campidelli Stephane , Rondin Loic , Chassagneux Yannick , Voisin Christophe , Lauret Js 
Published: July 2021

The use of carbon nanotubes as single emitters is currently developing. Being made only of surface
atoms carbon nanotubes are very sensitive to their environment. A fingerprint of this sensitivity is the
variation with time of their emission intensity (blinking) and energy (spectral jitter) in low temperature
experiments. To improve the stability of nanotubes, we have synthesized core-double shell structures
where two shells of polymers are rolled around the nanotube [1]. Here, we will show the influence of
these shells on the stability of both the emission intensity and energy [2].
[1] L. Orcin-Chaix et al, Journal of Material Chemistry C 6, 4786 (2018)
[2] L. Orcin-Chaix et al, ACS Appl. Nano Mater. 3, 7291-7296 (2020).
(Invited) Toward Spectral Homogeneity in Guanine Functionalized SWCNTs
Authors: Soltani Nima , Bachilo Sergei M. , Weisman R. Bruce 
Published: July 2021

Different chiralities of single-walled carbon nanotubes (SWCNTs) have distinct electronic and optical properties, with a range of band gaps that make them appropriate for several opto-electronic applications. Due to the unusually high mobility of charge carriers in SWCNTs,1 semiconducting SWCNTs may find use as logic gates in future high-speed nano-electronic circuits. With this in mind, controlled modulation of the optical and electronic properties of individual carbon nanotubes may be valuable in optoelectronic and nano-bioelectronic applications.
It was recently discovered that when SWCNTs coated with single-stranded DNA are exposed to singlet oxygen, the guanine nucleobases in the DNA coatings form covalent bonds to the nanotube sidewalls.2 This alters the nanotube electronic and optical properties, allowing spatial and energetic control through selection of the DNA base sequence. However, the functionalized products display undesired spectral broadening interpreted as excess inhomogeneity compared to the pristine SWCNT reactants.
Here we will present the results of efforts to understand and reduce this inhomogeneity. Our study has used molecular dynamics simulations of ssDNA – SWCNT hybrid structures, as well as analysis of experimental data. We have explored the effects of varied reaction conditions, including temperature, ionic strength, and pH on product yields and spectra. An unexpected inverse dependence of functionalization density on reaction temperature was uncovered. We will also present photophysical results extracted from spectral data via statistical modeling, including the energy depth of localized exciton quantum wells created by functionalization. The analysis points to fluorescence red shifts that reflect the random number of functionalization sites felt by excitons.

Dürkop, T.; Getty, S. A.; Cobas, E.; Fuhrer, M. S. Extraordinary Mobility in Semiconducting Carbon Nanotubes. Nano Lett.
2004, 4, 35-39.

Zheng, Y.; Bachilo, S. M.; Weisman, R. B. Controlled Patterning of Carbon Nanotube Energy Levels by Covalent DNA Functionalization. ACS Nano
2019, 13, 8222-8228.
(Invited) Combining Absorption, Wavelength-Dependent Raman and Fluorescence-Excitation Spectroscopy with High-Resolution Transmission Electron Microscopy for Determining the Chiral Purity of Sorted SWCNT Samples
Authors: Cambré Sofie , Forel Salome , Castan Alice , Defillet Joeri , Levshov Dmitry , Fossard Frederic , Wenseleers Wim , Loiseau Annick 
Published: July 2021

Single-wall carbon nanotubes (SWCNTs) possess unique electronic and optical properties that depend strongly on their exact chiral structure. Recent progress in the structure sorting of specific SWCNT chiralities, with increasing chiral purity[1], demands an effective characterization methodology to be developed to accurately determine the chiral composition of any SWCNT chirality. Very often, optical spectroscopy is used to assess the chiral composition of a sample, but absorption cross-sections, PL quantum efficiencies and Raman cross-sections are all depending on the exact chiral structure,[2] and can be strongly influenced by other factors such as the specific internal and external environment of the SWCNTs.[3] In this work, we systematically compare the chirality distribution obtained from 3 different optical spectroscopic techniques, i.e. absorption, wavelength-dependent Raman and fluorescence-excitation spectroscopy with the chirality distribution obtained from high-resolution transmission electron microscopy for both chirality-sorted and unsorted SWCNT samples. This combined approach demonstrates the importance of using a multi-technique characterization strategy for a reliable determination of SWCNT chirality distribution.[4]
[1] J.A. Fagan, Nanoscale Adv. 1, 3307 (2019) and references therein
[2] V.N. Popov, Nano Lett. 4, 1795 (2004)
[3] S. Cambré et al, Angew. Chem. – Int Ed. 50, 2764 (2011); ACS nano 6, 2649 (2012)
[4] A. Castan et al, Carbon 171, 968 (2021)
(Invited) Tailoring of Single-Walled Carbon Nanotube Luminescence as Photoswitchable Near-Infrared Emitters
Authors: Godin Antoine , Setaro Antonio , Gandil Morgane , Haag Rainer , Adeli Mohsen , Reich Stephanie , Cognet Laurent 
Published: July 2021

Single-molecule localization microscopy (SMLM) has set a new paradigm in the field of optical imaging by delivering super-resolution images i.e. with resolution much better than the diffraction limit. We demonstrated over the last years that such approaches can be designed to understand basic excitonic processes in carbon nanotubes [1-2]. In the field of bioimaging, SMLM is currently limited to the visible or far-red range, missing the near-infrared region where biological tissues are however the most transparent. One reason for this is that single-molecule emitter optical properties still need to be tailored in the near-infrared, including photoswitching capabilities which is a basic ingredient to achieve single-molecule SMLM. To fill this gap, optical imaging of single-wall carbon nanotubes can first be greatly facilitated in brain tissues by covalent functionalization of luminescent defects, reducing the required excitation light intensity by one order of magnitude [3]. In addition, we have introduced a novel type of hybrid nanomaterials consisting of single-wall carbon nanotubes covalently functionalized with photo-switching molecules that are used to control the intrinsic luminescence of the single nanotubes in the near-infrared (beyond 1 µm) [4]. Through the control of photoswitching, we demonstrate super-localization imaging of nanotubes unresolved by diffraction limited microscopy opening the route toward SMLM in the near-infrared for biological applications. Photocontrol of individual near-infrared emitters will also be highly desirable for elementary optical molecular switches or information storage elements since most communication data transfer protocols are established in this spectral range.

References

[1] Cognet et al Nanoletters, 8 (2008) 749 - 753.
[2] Danné et al. ACS Nano, 12 (2018) 6059
[3] Mandal et al. Scientific Reports, 10 (2020) 5286
[4] Godin et al Science Advances, 5, (2019) eaax1166
(Invited) Light Emission Modulation from Individual Single-Walled Carbon Nanotubes By Chromophore Encapsulation
Authors: Chambard Romain , Izard Nicolas , Jousselme Bruno , Sato Yuta , Kazu Suenaga , Jean-Louis Bantignies , Patrick Hermet , Alvarez Laurent 
Published: July 2021

The one-dimensional structure of single-walled carbon nanotubes (NT) display optical absorption and near-infrared emission (thanks to van Hove singularities). 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 chromophores,1-4 absorbing from the blue/ green (400/500 nm) range (tetracyanoquinodimethane (TNCQ), quaterthiophene derivatives (4T) and tetramethyl-paraphenylenediamine (TMPD)) to the red (700 nm) range (phthalocyanine (MPc)). In addition then can be either electron donor (4T, TMPD) or acceptor (TNCQ).
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.
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) and on the NT diameter.
From Raman measurements, a significant charge transfer from the confined dye to the nanotube is evidenced. The main relevant parameters that govern the charge transfer are the nanotube diameter and the nature of the chromophores (electron donor or acceptor).
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.
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
The Impact of Fiber Arrangement on Power Density and Electrodeposition in Porous Ag-Trab Electrodes
Authors: Cross Nicholas , Hall Derek M , Lvov Serguei , Logan Bruce , Rau Matthew 
Published: July 2021

As the need for a sharp reduction in carbon emissions continues to grow, many researchers are looking to electrochemical technologies to provide sustainable power to the grid. One promising technology is the silver thermally regenerative ammonia battery (Ag-TRAB), which is a new approach for converting low-grade waste heat (<100 °C) to electrical power. These hybrid flow batteries are charged using energy derived from waste heat, rather than electrical power, and can be cycled hundreds of times without a decrease in performance. The Ag-TRAB uses silver as the active metal ion for deposition and dissolution on each half of the battery and porous carbon as the electrode material, driven by ammonia added into only one chamber. Following a discharge cycle, ammonia is removed using waste heat, and a new cycle is initiated using the ammonia added to the opposite electrolyte chamber. Design factors that impact operational conditions and performance are needed to improve reliability and electrode utilization. For example, the structure of the porous electrodes could alter silver deposition rates and porosities of the electrodes during operation, leading to preferential flow paths from clogging of pores that would impact cycle longevity and power.
A 2D numerical model was created using COMSOL Multiphysics to study the relationship between fluid flow, electrode structure, and electrodeposition in the porous electrodes using cylinders in cross-flow to represent the internal structure of a porous carbon fiber electrode. Lower void fractions resulted in 2.5% higher power density, but less uniform deposition and the pores clogging 3-5 times faster due to nonuniform deposition normal to the membrane boundary. It was found that the electric field resultant from the void fraction and fiber arrangement was critical to the performance of the electrode. The electrode microstructure can be modified to better distribute the deposition rate relative to the pore size to allow for higher power output for a longer discharge time before the pores begin to clog. An electrode with variable void fraction increased the peak power by 7.5% but the pores clogged 23% faster compared to homogenous void fraction.
(Invited) Fluorescence Quenching Microscopy for Imaging 2D Materials: An Update
Authors: Huang Jiaxing 
Published: July 2021

Fluorescence quenching microscopy (FQM) was initially developed for high throughput imaging of graphene based sheets on arbitrary substrates under a common fluorescence microscopy. It takes advantages of the long range, energy transfer-based fluorescence quenching effect of graphene-based materials, and can obtain images with high contrast and high layer resolution comparable to those of scanning electron microscopy (SEM) and atomic force microscopy (AFM). FQM was later applied to image other strongly quenching sheets such as transitional metal dichalcogenides.
The high-contrast optical imaging of nearly transparent 2D materials such as clays and some oxides sheets has been an outstanding challenge; yet it is a critical research capability needed in the synthesis and processing of these materials, which have shown promise in a number of applications including barrier coatings, membranes, and composites. Using delaminated silicate clay and titania sheets as model system, here we show that these weakly quenching, nearly transparent 2D sheets can also be readily imaged by FQM based on a new mechanism with SEM and AFM level of contrast and layer resolutions. When different 2D materials are co-deposited, FQM not only differentiates them readily based on their quenching capabilities, but also can resolve their vertical stacking sequence based on the contrast of their overlapped areas.
(Invited) Fundamentals and Applications of Hexagonal Boron Nitride Ionogels
Authors: Hersam Mark C 
Published: July 2021

Ionogel electrolytes based on ionic liquids (ILs) and a gelling solid matrix are an attractive alternative to conventional liquid electrolytes for electronic and energy storage applications. In particular, ILs offer several advantages as an electrolyte including nonflammability, nonvolatility, high electrochemical stability, and high ionic conductivity. Moreover, combining ILs with a gelling solid matrix leads to a solid-state electrolyte that is sufficiently mechanically robust to replace both the liquid electrolyte and separator in a single component, thus allowing easier packaging, streamlined manufacturing, and minimal risk of leakage [1]. For ionogel electrolytes, hexagonal boron nitride (hBN) is an especially desirable solid matrix due to its excellent chemical and thermal stability in addition to its mechanical robustness [2]. This talk will address recent efforts to realize high-performance hBN/IL ionogel electrolytes using hBN that has been solution-exfoliated into two-dimensional nanosheets using ethyl cellulose (EC) stabilizing polymers [3]. In addition to the intrinsic advantages of hBN, EC-exfoliated hBN nanosheets significantly enhance both ionic conductivity (> 1 mS/cm) and mechanical strength (storage modulus > 1 MPa) compared to conventional hBN microparticles, providing additional competitive advantages for energy storage applications [4]. The high thermal stability of hBN/IL ionogel electrolytes also enables safe, high-rate operation (up to 10C charge/discharge rate) at high temperatures up to 175 °C, which represents the highest operating temperature to date for solid-state lithium-ion batteries. Since hBN ionogels can also be formulated into printable inks [5], they are particularly promising for printed devices including electrolyte-gated thin-film transistors, supercapacitors, and batteries.
[1] A. C. M. de Moraes, et al., ACS Applied Materials & Interfaces, 12, 8107 (2020).
[2] W. J. Hyun, et al., Advanced Energy Materials, 10, 2002135 (2020).
[3] A. C. M. de Moraes, et al., Advanced Functional Materials, 29, 1902245 (2019).
[4] W. J. Hyun, et al., ACS Nano, 13, 9664 (2019).
[5] W. J. Hyun, et al., Faraday Discussions, DOI: 10.1039/C9FD00113A (2020).
Design of 3D Printed Batteries with Printable Water-in-Salt Gel Polymer Electrolyte
Authors: Yen Dean , Lin Cheng-Hung , Chen-Wiegart Yu-chen Karen Karen 
Published: July 2021

3D printing, also known as additive manufacturing (AM), has emerged as a promising strategy to design and fabricate future energy storage devices. The benefits of 3D printed batteries include versatile, adaptable shape and geometry, enhanced performance with new architectural design, and the ability to integrate printing power sources with other 3D printable devices. Although significant progress has been reported, current 3D printed batteries design still presents several limitations. The printed battery cells may use a solid electrolyte, which can only be operated at an elevated temperature, or use a conventional organic liquid electrolyte, which is toxic and flammable. The use of oxygen and moisture-sensitive electrolytes especially presents challenges for packing and sealing 3D printable batteries.
To overcome these challenges, this work incorporated the latest developments in aqueous batteries into a novel 3D printable battery that can be fabricated directly in an ambient environment that is also more environmentally friendly in nature. Specifically, a gel polymer electrolyte (GPE) with a water-in-salt (WIS) concept was introduced in our 3D printed batteries. The WIS concept, using a highly concentrated electrolyte, offers a larger operation voltage compared with conventional aqueous batteries, whereas the GPEs formulation enables the printability and easier packaging than liquid counterparts. By combining the advantages of both WIS and GPE, the resulting 3D printable batteries show promise for much more simplified processing conditions, as well as performance. The structural, (electro-)chemical, and morphological evolution of the printed batteries are being investigated by synchrotron X-ray techniques and electrochemical analysis. Overall, our research explores the possibility for an easier and more environmentally friendly way to build 3D printable, customizable batteries for future technologies.