bluuebunny/crossref_metadata_2025 huggingface dataset:
Crack Hysteresis Phenomena in Polycrystalline NMC811 Secondary Particles
Authors: Parks Huw Christopher William , Wade Aaron , Heenan Thomas M.M. , Tan Chun , Llewellyn Alice V. , Reid Hamish Thomas , Ziesche Ralf , Marathe Shashidhara , Rau Christoph , Brett Dan J L , Shearing Paul R , Jervis Rhodri
Published: September 2023

Using X-ray tomography, we can predict and study the factors that govern fracture behaviour and cracking in NMC811 particles as a function of potential. Cracking and fracturing is known to cause a decline in battery performance, as regions become disintegrated from the conductive matrix. However, electrochemically induced cracking can be difficult to assess due to complicated sample preparation methods required. An in-situ study that accurately determines the onset of cracking during delithiation from the layered structure is crucial to characterize voltage-induced fracturing in battery particles. Tomography has been extensively used to non-destructively image cracks in li-ion battery materials at the electrode and particle level, making it an ideal candidate for in-situ studies that preserve the electrode during charging and discharging. However, accurately, and reliably tracking operational cracking without the influence of pre-existing cracks is highly challenging, requiring the highest resolutions possible for 3D imaging techniques and small sample geometries while maintaining realistic electrochemical performance. In this study, we present a technique using in-situ synchrotron X-ray computed tomography (CT) and nano-scale CT to completely attribute particle cracking to electrochemical stimulation, corroborated with high-resolution imaging. We demonstrate the cracking hysteresis phenomenon that occurs in NMC811 secondary particles during the first cycle, using a rapid detection algorithm that calculates the extent of cracking in battery particles, even when cracking is not resolvable as compared to nano CT. The results show unprecedented material statistics for understanding and predicting fracture behaviour in battery particles.

Figure 1
Highly Conductive Solid Electrolytes for Fluoride Battery Application
Authors: Mineshige Atsushi , Sugiura Maiko
Published: September 2023

Recently, fluoride batteries are attracting attention as electrochemical high-energy-density storage devices. There are various types of fluoride ion conductors such as fluorite-type, tysonite-type, and fluorite-related-type and so on. Among them, MSnF4-type fluorides (M: Pb, Ba) have high ion conductivity, and are good candidates for electrolyte materials to be used in fluoride batteries. Up to now, the highest conductivity among fluoride ion conductors was obtained for PbSnF4 with the fluorite-related-type structure, exhibiting pure and high ion conductivity of 2x10-2 S cm-1 at room temperature. In the present study, BaSnF4 (BSF) was prepared by using mechanical milling (MM) process, and its ion conducting behavior was reinvestigated.

A BSF pellet was prepared via MM process, followed by a thermal annealing at 573 K, and it was found that the pellet was a tetragonal BSF phase. Crystal structure and ion conducting pathway of tetragonal BSF prepared by the MM method could be clarified by the neutron diffraction experiment on the basis of a [−SnBaBaSn−]-layered structure along c axis with three nonequivalent fluorine sites: F1, F2, and F3 [1]. According to an impedance analysis, the fluoride ion conductivity of the obtained BSF pellet was 2.6x10-3 S cm-1 at 298 K. Conductivity decreased after pulverization compared to the original one due to an increase in the grain boundary resistance. However, it was largely improved by compaction higher than 434 MPa. Furthermore, conductivity retrieved by the heating up to 423 K under dry Ar atmosphere, and the conductivity was 2.1x10-3 S cm-1 at 298 K after 607 MPa compaction and heat treatment to 423 K. Therefore, BSF green compact exhibiting high conductivity to be applied to the high performance fluoride batteries could be obtained by suppressing the grain boundary resistance.

This work was supported by the RISING2 (JPNP16001) and RISING3 (JPNP21006) project, NEDO, Japan.

Reference

[1] K. Mori et al., J. Phys. Chem. C 2021, 125, 23, 12568.
Optimized Graphene Hydrogels for Electrochemical Applications from High-Concentration GO/Gnp Dispersions
Authors: Chamberland Joshua P , Sellathurai Andrew J , Parent J Scott , Barz Dominik PJ
Published: September 2023

As the world combats climate change, energy storage solutions will be required to bridge the gap between the supply and demand of renewable energy sources. Supercapacitors have a higher power density and cyclic stability than batteries, making them more useful for selected applications. These devices utilize high surface area electrode materials, such as graphene, with enough active sites for sufficient ion adsorption to occur. Graphene hydrogels self-assemble via the hydrothermal reduction of graphene oxide (GO) dispersions. These three-dimensional structures have high specific surface areas while avoiding the use of binders. Binders usually negatively impact the conductivity of the material and require the use of conductive additives which lower specific performance data. As such, graphene hydrogels are attractive as a supercapacitor electrode material.

Recently, graphene nanoplatelet (GNP) dispersions stabilized by small amounts of GO were used to form more cost-effective and better-performing hydrogels. Though GO/GNP hydrogels are a suitable alternative to those formed from dispersions of GO, the formulation of this material has yet to be optimized. In this work, we investigate the formation of GO/GNP hydrogels by assessing the influence of several input parameters on the specific surface area and mechanical stability of the hydrogel structure. A set of experiments based on a design of experiments is used. Based on the results, an optimized hydrogel is formed and characterized. Compared to typical hydrogels formed from dispersions of GO, the optimized GO/GNP hydrogel leads to significant improvements in both the specific surface area and conductivity of the material. When used in a supercapacitor, low internal resistance and high stability are observed while volumetric capacitance is increased by up to over 400%.
(Invited) Rapid, Large Area Preparation of Few-Layer Graphene Films Using Xenon Flash Lamp Pyrolysis for High-Performance Structural Micro-Supercapacitors
Authors: Bhardwaj Ayush , Okoroanyanwu Uzodinma , Watkins James
Published: September 2023

Graphene offers excellent electrical conductivity and very high surface area, which holds great promise for energy storage applications including supercapacitors. Current preparation methods for graphene require relatively long processing times, extremely high temperatures within controlled atmospheres, and/or involve multi-step reactions that present challenges for high throughput fabrication of graphene-based energy storage devices. We report a novel photothermal route to large-scale production of graphene within milliseconds using a commercially available polymers (polybenzoxazine, polyacrylonitrile and polyaniline) and a high intensity xenon flash lamp on various substrates, including carbon fibers, at ambient conditions. The xenon flash lamp provides large-area illumination and a wide emission band (300 nm –1100 nm) that was used to convert the polymeric material directly into few layer graphene upon millisecond exposures. The precursor material is heated to extremely high temperatures in a fraction of a second – a duration that is much shorter than the timescale for thermal equilibrium. This enabled the conversion of the polymeric material into few layer graphene in air and at room temperature, and without thermally damaging the substrate. Conversion to few-layer graphene was strongly dependent on pulse energy and the local temperature which was controlled via pulse power modulation. The obtained graphene composites at optimized conditions exhibited excellent conductivity (0.1 ohm-cm) with ID/IG ratio of 0.3 (Figure 1a). Particularly, graphene derived from polyaniline resulted in the formation of macroporous network (Figure 1b) with good adhesion to the carbon fiber, all of which facilitate the transport of ions through the material. The fabricated supercapacitor devices exhibited a very high areal capacitance of 200 mF/cm2 at 10 mV/s with retention of more than 70% of their capacitance, even at scan rates up to 100 mV/s. Moreover, mechanically, and structurally stable graphene derived from polyaniline on carbon fiber was utilized for the preparation of structural energy storage devices. We assembled symmetric structural supercapacitor comprised of carbonaceous material (carbon fiber and few-layer graphene) and polymer gel electrolyte. This resulted in the preparation of large area device (40 cm2) as shown in the Figure 1c with the capacitance exceeding 2000 mF and almost complete retention of capacitance after 5000 cycles.

The preparation of high-quality graphene via photothermal pyrolysis of polymer is amenable to high throughput processing, enabling large-scale production of high performance structural electrochemical energy storage devices.

Figure 1
Solar Cell Application of 1D Heterostructure Based on Single-Walled CNT
Authors: Qiu Xiyang , Zhang Bowen , Wang Shuhui , Zheng Yongjia , Otsuka Keigo , Xiang Rong , Maruyama Shigeo
Published: September 2023

The experimental synthesis of one-dimensional (1D) van der Waals heterostructures, first introduced in 2020 [1], has attracted much research attention. Discussions upon this coaxial stack of different atomic layers are not only limited to synthesis and characteristics, but also extended to applications. Many unique properties of the 1D van der Waals heterostructures, such as the adjustable band gap, strong quenching of photoluminescence of MoS2 by inner single-walled CNT, enable this structure to be a potential active layer material for solar cells [2].

For the synthesis of 1D van der Waals heterostructures, we first use dispersed high-purity semiconducting single-walled carbon nanotubes (s-SWCNT) solution obtained from Kataura group [3] as inner tube material. With an anodic aluminum oxide (AAO) membrane filter and HCl, we managed to fabricate a free-standing s-SWCNT film [4]. Then following our established CVD process [5], we are wrapping this inner s-SWCNT tube with an insulating boron nitride layer, and a semiconducting MoS2 layer. After that, the as-prepared 1D van der Waals heterostructures film will be utilized for solar cell fabrication.

The solar cell is adopting an n-i-p structure, in the order of glass-ITO-SnO2-Active layer-Spiro-Au. After spin-coating and annealing SnO2 (electron transporting layer) onto ITO-patterned glass, the 1D van der Waals heterostructure film is laminated on the SnO2 layer. Spiro (hole transporting layer) will be then spin-coated onto the film. Finally, gold is vapor-deposited onto the device in a vacuum chamber, as the top electrode [6].

Through photocurrent measurement of 1D van der Waals structure film using Esko film, a mixture of metallic-SWCNT and s-SWCNT, we found it is photosensitive with exposure to light and laser. The 1D van der Waals structure film using high-purity s-SWCNT is then expected to generate higher photocurrent, the experimental result will be updated in the future. By the IV measurement of the solar cell, we observed the photovoltaic effect of the device. Moreover, this new conceptual solar cell is believed to possess many advantages at the same time, such as flexibility, durability, non-toxicity, and sustainability [2]. However, further research on the choices of materials and optimizations of device parameters is still required in order to reach sufficient power conversion efficiency as a photovoltaic device.

[1] R. Xiang et al., Science
367, 537–542 (2020)

[2] R. Xiang et al., Natl Sci Open
1, 3 (2022)

[3] J. Cui et al., ACS Appl. Nano Mater
2, 1, 343–350 (2019)

[4] C. Zhang et al., ACS Nano
16, 11, 18630–18636 (2022)

[5] M. Liu et al., ACS Nano
15, 5, 8418–8426 (2021)

[6] J.-M. Choi et al, Adv. Funct. Mater.
32, 2204594 (2022)
Flexible Hydrophilic Carbon Nanotube Fibers As Microelectrodes for Neuroscience
Authors: Alvarez Noe T , Ruhunage Chethani
Published: September 2023

Implantable micro electrodes are generally employed to record and stimulate electrical activity of neurons in the nervous system. Most of the electrodes available today are made of metals and silicon that lack required flexibility resulting on a mechanical mismatch between soft tissues and rigid metals which induces faster biofouling and inconsistent performance for long-term applications. Biofouling triggered by inflammatory responses dramatically affect the performance of neural electrodes, resulting in decreased signal sensitivity and consistency over time. Thus, long-term clinical applications require electrically conducting flexible electrode materials with reduced dimensions and antibiofouling properties. These characteristics reduce the degree of inflammatory reactions and increase lifetime of neural electrodes. Carbon nanotubes (CNTs) are well known for their flexibility, electrical conductivity and chemical inertness. This talk will report the use of CNT fibers for neural stimulation and recording, and subsequent covalent functionalization of CNT fibers and films surfaces with hydrophilic, antibiofouling phosphorylcholine (PC) molecules. The electrochemical and spectroscopic characteristics, impedance properties, hydrophilicity, and in vitro antifouling nature of the functionalized CNT surfaces will be presented. The hydrophilicity of the functionalized CNT films was demonstrated by a decrease in the static contact angle from 134.4° ± 3.9° before to 15.7° ± 1.5° after one, and fully wetting after three functionalization cycles respectively. In addition, the extent of protein absorption on the functionalized CNT films were significantly lower than that on the non-functionalized CNT film. Surprisingly, the faradic charge-transfer properties and impedance of the CNT assemblies were preserved after functionalization with PC molecules. These functionalized CNT assemblies are promising for the development of low-impedance neural electrodes with higher hydrophilicity and protein-fouling resistance to inhibit inflammatory responses.
Real-Time Macrophage Phenotype Identification Using Single Walled Carbon Nanotubes and Machine Learning
Authors: Nadeem Aceer , Roxbury Daniel
Published: September 2023

Macrophages play a critical role in the immune system, as both pro and anti-inflammatory immune cells these are the first line of defense from foreign bodies. Although methods for identifying Macrophage Phenotype (M1, M2) currently exist, these methods are limiting to factors like time, cost, operational training, and sample size. Cost and time effective identification of macrophage phenotypes can not only lead to better therapeutic research but also help in creating a platform for real time monitoring of the wound healing process as well as other (macrophage related) disease progression.

Single Walled Carbon Nanotubes are ideal optical biosensors due to their intrinsic near-Infrared (nIR) emission, which is highly sensitive, easily tunable and indefinitely photostable. Due to such desirable properties, non-covalent functionalization of these fluorescent nanotubes has resulted in them being used as in vitro and in vivo sensors for numerous applications. Even so, the full extent of nanotube applicability is yet to be explored due to their underdeveloped potential as next generation bioimaging and bio-sensing probes. Here we demonstrate a platform using DNA functionalized Single Walled Carbon Nanotubes and machine learning to identify macrophage phenotype with 99% accuracy and effectively estimate the number of each polarization state in a sample.
Optical Nanosensors for the Detection of Quaternary Ammonium Compounds
Authors: Dewey Hannah , Sultana Nigar , Budhathoki-Uprety Januka
Published: September 2023

Quaternary ammonium compounds (QACs) are common active ingredients in chemical disinfectants, household cleaners, cosmetics, pesticides, etc. Recently QACs have been detected in human blood and breast milk during the COVID-19 pandemic. Humans can be exposed to QACs through dermal adsorption during application, hand-to-mouth ingestion of disinfectant residues, and inhalation of indoor air upon treatment with disinfectant spray. Exposure to these chemicals can cause respiratory illness such as asthma and chronic obstructive pulmonary disease, increase inflammatory cytokines, decrease mitochondrial function, and disrupt cholesterol biosynthesis. However, the complete biological fate of QACs is currently unknown. Therefore, a real-time continuous monitoring system in complex biological environments is crucial to learn the long-term effects of QACs on human health.

Photoluminescent single-walled carbon nanotubes (SWCNTs) are great candidates for developing optical probes to monitor biological systems due to their outstanding photophysical properties in the tissue-transparent near-infrared spectral region, high sensitivity, and high stability. Furthermore, nanotube-based sensors exhibit a great potential for an implantable, real-time, wireless optical detection technology. Herein, we developed a carbon nanotube-based optical sensor for the detection of QACs in complex solution. Our findings from this research could provide a basis for engineering an optical detection technology to gain insight on the long-term effects of QACs to human health.
(Invited) Bio-Applications of Carbon Nanotubes for NIR Imaging Probes and Guided Bone Regeneration Membranes
Authors: Okazaki Toshiya
Published: September 2023

Single-walled carbon nanotubes (CNTs) have been expected for biological and medical applications because of their unique optical and chemical properties. One of the promising applications is imaging probes because CNTs show fluorescence in the near-infrared (NIR) region, which is highly transparent for biomaterials. We have reported the synthesis method of the epoxide-type oxygen-doped CNTs (Ep-CNTs) and their application as a near-infrared fluorescent probe [1-3]. Treated (6, 5) nanotubes show photoluminescence at ~1280 nm, which corresponds to the most transparent regions for biomaterials [1]. Immunoassay and fluorescence vascular angiography of mice were demonstrated by using the produced Ep-CNTs as infrared fluorescent labels [1,3] and imaging agents [1,2], respectively. From a practical point of view, the biodistributions of the Ep-CNTs imaging probe after administration to mice were investigated in detail [2]. In addition, the biological responses of mice following administration, which are relevant to safety, were also introduced [2].

More recently, we found that CNTs exhibit high compatibility with bone tissue [4]. The guided bone regeneration (GBR) technique is commonly applied to reconstruct alveolar bone and treat peri-implant bone defects. It was found that CNT-based membrane for GBR exhibits high strength to provide a space for bone formation and provide cellular shielding to induce osteogenesis.

In this meeting, we will report above biological and medical applications of CNTs in detail.

1. Y. Iizumi, M. Yudasaka, J. Kim, H. Sakakita, T. Takeuchi, T. Okazaki, Oxygen-doped carbon nanotubes for near-infrared fluorescent labels and imaging probes, Sci. Rep., 8, 6272 (2018).

2. T. Takeuchi, Y. Iizumi, M. Yudasaka, S. K. Kondoh, T. Okazaki, Characterization and biodistribution analysis of oxygen-doped single-walled carbon nanotubes used as in vivo fluorescence imaging probes, Bioconjugate Chem., 30, 1323−1330 (2019). (Cover Article)

3. K. Kojima, Y. Iizumi, M. Zhang, T. Okazaki, Streptavidin-conjugated oxygen-doped single-walled carbon nanotubes as near-infrared labels for immunoassays, Langmuir, 38, 1509-1513 (2022).

4. Y. Xu, E. Hirata, Y. Iizumi, N. Ushijima, K. Kubota, S. Kimura, Y. Maeda, T. Okazaki, A. Yokoyama, Single-walled Carbon Nanotube Membranes Accelerate Active Osteogenesis in Bone Defects: Potential of Guided Bone Regeneration Membranes, ACS Biomater. Sci. Eng., 8, 1667-1675 (2022).
(Invited) Tackling Leakage, Drift, and Variation in Printed Carbon Nanotube-Based Electronic Biosensors
Authors: Franklin Aaron D
Published: September 2023

Semiconducting carbon nanotubes (CNTs) have been pursued for use in electronic biosensors for decades. Their all-surface molecular structure, sizeable semiconducting bandgap, and solution-phase compatibility make them highly sensitive and versatile options for transducing target bioelectrical signals. However, amid the thousands of reports on CNT-based electronic biosensors, very little attention has been given to identifying (let alone addressing) the impact of leakage current, signal drift, and device-to-device variation. This talk will present recent results focused on tackling these issues with specific emphasis on printed CNT-based biosensors. For instance, a variety of passivation strategies were studied to determine the role of leakage current for CNT transistor-based biosensors (i.e., bioFETs or ion-sensitive FETs), revealing that a bilayer epoxy/high-k dielectric stack was most effective at minimizing unwanted leakage current. The influence of signal drift will also be demonstrated, likely playing a significant role in many previous reports of CNT-based biosensors characterized by sequential concentration spikes. Finally, strategies for addressing device-to-device variation in these biosensors will be discussed, including the motivation for a printed thin-film device rather than a single-CNT configuration. Two things seem certain about this field: 1) the promise of CNT-based biosensors continues to suggest they are worth ongoing pursuit, and 2) there is much work remaining towards achieving a reproducible, reliable electronic biosensing technology from CNTs.
Alignment of DNA Wrapped Single Walled Carbon Nanotubes Sensors
Authors: Sadak Omer , Iverson Nicole M
Published: September 2023

Single walled carbon nanotubes (SWNT) that are well aligned have a broad range of applications, including solar cells, sensors, transistors, and optoelectronic devices. Alignment of SWNT is typically performed either during SWNT fabrication or out of post-processed SWNT solutions through vacuum filtration, spin-coating, electromagnetic fields, surfactant-aided microfluidic alignment techniques or concentration-dependent shear alignment. Alignment of SWNT during fabrication requires a lot of time and money and precludes the ability to wrap the SWNT with DNA, which is what creates the SWNT’s sensing capabilities. Unfortunately, most of these techniques have not been widely adopted since it is labor-intensive, difficult to reproduce or hard to scale up. We developed a scalable method to align DNA wrapped SWNT through heat activation without altering the SWNT’s wrapping and sensing capabilities. This research will pave the way for the development of both research and industrial scale aligned SWNT from aqueous solutions for next-generation of SWNT based optical sensors.
(Invited) Engineering Single Wall Carbon Nanotubes for Sub-Cellular Drug Delivery
Authors: Islam Mohammad
Published: September 2023

Single wall carbon nanotubes (SWCNTs) have been rigorously studied and engineered for a myriad of applications including drug delivery due to their unique, desirable properties. Since SWCNTs bundle in aqueous media and the bundling substantially diminishes their desirable properties along with inducing cytotoxicity, strategies to disperse individually SWCNTs with therapeutic molecules and biologic excipients have been heavily investigated. However, a handful of studies has been performed to understand the interactions between therapeutic molecules and excipients with SWCNT interface as well as the mechanism of intracellular release for therapeutic effects. Additionally, little attention has been paid to how cell type and cell metabolic activity level influence internalization of SWCNTs with different lengths. In this talk, I will discuss cell type, cell metabolic activity, and SWCNT length dependent cellular processing of SWCNTs dispersed with diverse biocompatible dispersing agents. Our results demonstrate that proper choice of dispersing agent can allow for interaction with F-actin, accumulation in the endoplasmic reticulum for eventual expulsion, or accumulation in cell nucleus. Further, macrophages with relatively high cell metabolic activity level compared to other cell types such as fibroblasts have shown to internalize significantly higher amount of SWCNTs per cell. The total mass of SWCNTs internalized per cell increases with a decrease in SWCNT length. Lastly, I will discuss our recent effort to create a ternary complex of SWCNTs, drug, and protein for intracellular delivery and release of model drugs. To overcome the limitation of the existing methods being only plausible for model drugs that are soluble in aqueous solutions, we developed a facile schema to assemble stepwise various combinations of therapeutic molecules and excipients on SWCNTs in different solvents using a preformed SWCNT network. These ternary complexes allow dialing in delivery of therapeutic molecules and excipients to achieve desired cell viability reduction. These findings allow for the development of new SWCNT-based biological applications as they establish important parameters of biomolecule adsorption on SWCNTs, SWCNT internalization and subcellular processing, which are crucial for applications ranging from drug delivery to cell type-specific modulation.
Carbon Nanotube Optical Reporters for Cancer Drug Discovery
Authors: Heller Daniel A. , Ruiz Stephen , Jena Prakrit , Horoszko Christopher , Tylawsky Daniel E , Gwynne Declan
Published: September 2023

The identification of therapeutic vulnerabilities in cancers has been substantially aided by tools that advance the monitoring of cellular processes and analytes. Our laboratory has developed optical sensors using carbon nanotubes to detect intracellular analytes, including a reporter for lipids that specifically accumulate in the lysosome. Using this reporter, we found that certain cancer cell lines exhibit lysosomal lipid dysfunction and accumulation. We screened a library of lipid-modulating experimental therapeutics using the lipid reporter, finding that the inhibition of some classes of phospholipase enzymes can abrogate the accumulation of lipids in the lysosomes. Follow-up studies found that certain phospholipase enzymes have a protective role in regulating redox stress, and if inhibited can induce cell death in cancer cell lines and in vivo. Our work demonstrated that a carbon nanotube reporter that provides a new type of intracellular measurement can enable target and discovery efforts for the treatment of cancer.
Carbon Nanotube-Based Nanosensor Reports Lysosomal pH and Autophagy Activation in vivo
Authors: Kim Mijin , Chen Chen , Randall Ewelina , Lee Seungyeop , An Heeseon , Heller Daniel A.
Published: September 2023

One of the major challenges in studying biological systems is the dearth of robust tools available to monitor dynamic biological processes in live cells and animals. For example, current techniques to measure autophagy are either ex vivo or involve conventional fluorophores/fluorescent proteins, which can be used for in vitro measurements but present problems in vivo. In this presentation, we show the development of optical nanosensors that non-invasively monitor autophagy-associated lysosomal pH changes. The sensor technology is based on quantum-defect-modified fluorescent carbon nanotubes, often called organic color centers (OCCs). OCC fluorescence is bright, photostable, and optically tunable by the chemical nature of the color center. We designed the OCC-nanosensors to be sensitive and selective to endolysosomal pH. Their unique chemical and photophysical properties enabled dynamic and quantitative measurements of lysosomal pH in live cells and in vivo. We will discuss how we utilize these capabilities to facilitate previously inaccessible mechanistic insights in the fields of cancer biology.
Development of SWIR Clinical Imaging and Spectroscopic Instruments
Authors: Blais-Ouellette Sebastien , Rioux David , Marcet Stephane , Chung Wendy
Published: September 2023

The last decade saw a tremendous evolution of nanocarbon-based biosensors. Most often based on SWIR, or NIR-II (1 - 1.7µm) fluorescence, these novel technologies prompted the development of new imaging and spectroscopic instruments. As these nanosensors are moving from basic and preclinical research to medical and veterinary applications, the instrumentation has to be adapted to large animals, including humans. This talk will focus on the challenges and promises of clinical fluorescence spectrometers and imagers for the SWIR window.
Red and Blue Emissive Graphene Quantum Dots for Biomedical Applications
Authors: Kost Veronika , Mauro Diandra , Da Ros Tatiana
Published: September 2023

Graphene quantum dots (GQDs) are a promising class of carbon nanomaterials characterized by unique photophysical and photochemical properties, which can be adjusted by using adapt preparation methods.1 Despite the wide range of synthesis routes suitable for GQDs production, achieving reproducible and properly controllable synthesis remains a challenging task.2,3

GQDs are characterized by high solubility in water, high biocompatibility, and low toxicity, which determine their wide application in bioimaging, biosensing, drug delivery, diagnosis, and therapy of cancer, and other more.4-7

Their synthesis was carried out by ultrasonic top-down technique starting from graphene oxide or using a bottom up approach starting from different precursors, including melamine and its polymer, or a mixture of citric acid, boric acid, and urea. The synthesis conditions, as well as ratios of the reagents, were varied to get control over the structure, size, and composition and, as a consequence, their photophysical properties.

The nanomaterials from GO presented excitation wavelength-independent photoluminescent behavior in the red region when excited in the range from UV till yellow light (300-550 nm). The emission maximum was observed at 647 nm when irradiated at 400 nm, while the one diriving from the bottom up strategies showed different fluorescence properties, with very interesting quantum yield. These properties let us consider these nanomaterials promising for investigating biological systems both in vitro and in vivo.

References

1) Tian et al. Mater. Today Chem. 2018, 10, 221–258.

2) Miao Nano Today. 2020, 33, 100879.

3) Moon et al. Nat. Commun. 2021,12, 5879.

4) Hadad et al. Nano Research, 2021, 14, 674-683.

5) Bayda et al. Nanoscale Adv., 2021, 3, 5183-5221.

6) Ding et al. Carbon, 2020, 167, 322-344.

7) She et al. Carbon, 2022, 191, 636-645.
Graphene Quantum Dots for siRNA Delivery in Gene Silencing Cancer Therapy
Authors: Valimukhametova Alina , Lee Bong Han , Gries Klara , Akkaraju Giridhar , Naumov Anton V.
Published: September 2023

Small interfering RNA (siRNA) technology in particular has become an advantageous tool in gene therapy for cancer treatment. However, the primary obstacle to this method is the inability of gene transfection of the cells on their own, their lack of stability in blood, and the lack of monitoring capabilities able to track gene delivery. Recently, graphene quantum dots (GQDs) have emerged as a platform allowing targeted drug delivery and fluorescence image-tracking in the visible and near-infrared regions. These capabilities can aid in overcoming obstacles to siRNA gene delivery. Here, for the first time, we have utilized biocompatible nitrogen and neodymium-doped graphene quantum dots (GQDs) for the delivery of Kirsten rat sarcoma virus (KRAS) and epidermal growth factor receptor (EGFR) siRNAs. The non-covalent loading of siRNA on GQDs was estimated by electrophoretic mobility shift assay and zeta potential. Successful siRNA delivery was confirmed by testing protein expression levels and using visible and near-infrared confocal fluorescence microscopy. The results show that GQDs/siRNA complex is biocompatible at the concentrations of 375-750 ug/mL and leads to protein knockdown in Hela cells at nanomolar siRNA concentrations. This shows the promising potential of GQDs for the delivery of siRNA and genes in general, complemented by multiwavelength image-tracking.
Guanine Functionalization for Improved ssDNA-Nanotube Colloidal Stability
Authors: Goerzen Dana , Kim Mijin , Zheng Ming , Heller Daniel A.
Published: September 2023

Single-stranded DNA wrapped carbon nanotubes (ssDNA-CNT) have emerged as a promising technology for the sensitive detection of analytes in live cell and in vivo imaging applications. ssDNA wrapping permits the dispersion of individual nanotubes, biocompatibility, cellular uptake, and acts as a molecular mask conferring specific molecular interactions with analytes of interest. However, due to the non-covalent nature of ssDNA-CNT interactions, the polymeric coating can be stripped after introduction to biofluids, causing nanotube aggregation. This results in the fluorescent quenching of nanotube response and limits the ability to probe longitudinal changes in analyte levels. To address this experimental limitation, we evaluate the effect of rose Bengal-mediated guanine functionalization on long-term colloidal stability and functionality of ssDNA-CNT-based sensors in biofluids.
(Third Place Poster Award) Computational Assessment of the Optoelectronic Structure and Biomolecular Complexation of Graphene Quantum Dots
Authors: Topkiran Ugur C. , Valimukhametova Alina , Naumov Anton V.
Published: September 2023

With novel materials getting smaller and their size falling to the nanometer scale, it becomes harder to fully characterize them by only using the experimental apparatus at hand. Therefore, taking advantage of computational methods proves to be trustworthy in filling those gaps and in aiding our experimental data to get a better understanding of the nanomaterials’ structural and electronic properties. Graphene quantum dots (GQDs) have recently become one of the flagships of carbon nanotechnology due to their remarkable physical properties and, when functionalized, an ability to become water soluble, biocompatible and capable of fluorescence in the visible and near-infrared. This makes them perspective carriers for therapeutic delivery and image-tracking. In order to assess the advantages of their utilization for a variety of bioapplications, we have investigated optical properties of doped GQDs and their interactions with biomolecules using a variety of molecular simulation approaches. True atomic ground state of the N-GQD is achieved via performing first-principle calculations based on density functional theory (DFT). DFT calculations also unrevealed the contributions of each functional group within the structure to HOMO–LUMO band edges. The adsorption of biomolecules and genes on the GQD surface has been further investigated with regards of the GQD structure, complementing experimental results that verify gene and drug complexation.

Figure 1
The Effect of G. applanatum Crude Polysaccharide Extract on Proinflammatory Cytokines and Proapoptotic Caspases in HeLa Cell Line: An In Vitro Study
Authors: A’yun Qurrotu , Susilo Raden Joko Kuncoroningrat , Hayaza Suhailah , Fikriyah Nur’aini , Musthoza Fina Syifa’una , Islamatasya Ufairanisa , Rohmatika Aulia Umi , Winarni Dwi , Wahyuningsih Sri Puji Astuti , Doong Ruey-an , Karsari Deya , Yanti Aristika Dinar , Fahmi Mochammad Zakki , Darmanto Win
Published: September 2023

Polysaccharide extracts exhibit promise as potential anticancer agents. Among the fungi rich in polysaccharide content, G. applanatum stands out; however, its anticancer activity necessitates further investigation. This study aims to explore the impact of G. applanatum crude polysaccharide (GACP) extract by assessing its effects on cell viability, levels of proinflammatory cytokines such as TNF-α, IFN-γ, IL-2, and IL-12, and levels of proapoptotic markers including caspase-3 and caspase-9, as well as the percentages of necrosis and apoptosis in the HeLa cell line. Employing the HeLa cell line as a research model, four groups were studied: KN (media and DMSO), K+ (doxorubicin 10 μg/mL), P1 (G. applanatum extract 200 μg/mL), and P2 (G. applanatum extract 400 μg/mL). The G. applanatum extract was obtained via boiling distilled water. Anticancer activity was evaluated through the MTT test (3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide) conducted over three treatment durations (24, 48, and 72 hours). Cytokine levels and caspase-3 and caspase-9 levels were assessed using the ELISA test. Cell apoptosis was determined using the Annexin V-PI biomarker and analyzed through flow cytometry. The MTT test exhibited optimal results at the 48-hour treatment mark. Cytokine level analysis revealed significant reductions in TNF-α, IFN-γ, IL-2, and IL-12 levels (

p

 < 0.005). Concurrently, caspase-3 and caspase-9 levels exhibited substantial increases (

p

 < 0.005). Flow cytometry highlighted the highest percentage of apoptosis in HeLa cells. In conclusion, G. applanatum’s polysaccharide extract demonstrates potential as an anticancer and therapeutic agent for cancer treatment.
Super Enhancer Regulatory Gene FYB1 Promotes the Progression of T Cell Acute Lymphoblastic Leukemia by Activating IGLL1
Authors: Zhang Kunlong , Lu Jun , Fang Fang , Zhang Yongping , Yu Juanjuan , Tao Yanfang , liu Wenyuan , Lu Lihui , Zhang Zimu , Chu Xinran , Wang Jianwei , Li Xiaolu , Tian Yuanyuan , Li Zhiheng , Li Qian , Sang Xu , Ma Li , Wang Ningling , Pan Jian , Hu Shaoyan
Published: September 2023

Background. Arising from T progenitor cells, T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematologic malignant tumor, accounting for 15% of childhood ALL and 25% of adult ALL. Composing of putative enhancers in close genomic proximity, super enhancer (SE) is critical for cell identity and the pathogenesis of multiple cancers. Belonging to the cytosolute linker protein group, FYB1 is essential for TCR signaling and extensively studied in terms of tumor pathogenesis and metastasis. Dissecting the role of FYN binding protein 1 (FYB1) in T-ALL holds the potential to improve the treatment outcome and prognosis of T-ALL. Methods. In this study, SEs were explored using public H3K27ac ChIP-seq data derived from T-ALL cell lines, AML cell lines and hematopoietic stem and progenitor cells (HSPCs). Downstream target of FYB1 gene was identified by RNA-seq. Effects of shRNA-mediated downregulation of FYB1 and immunoglobulin lambda-like polypeptide 1 (IGLL1) on self-renewal of T-ALL cells were evaluated in vitro and/or in vivo. Results. As an SE-driven gene, overexpression of FYB1 was observed in T-ALL, according to the Cancer Cell Line Encyclopedia database. In vitro, knocking down FYB1 led to comprised growth and enhanced apoptosis of T-ALL cells. In vivo, downregulation of FYB1 significantly decreased the disease burden by suppressing tumor growth and improved survival rate. Knocking down FYB1 resulted in significantly decreased expression of IGLL1 that was also an SE-driven gene in T-ALL. As a downstream target of FYB1, IGLL1 exerted similar role as FYB1 in inhibiting growth of T-ALL cells. Conclusion. Our results suggested that FYB1 gene played important role in regulating self-renewal of T-ALL cells by activating IGLL1, representing a promising therapeutic target for T-ALL patients.
Delayed Anaphylactic Reaction to Midazolam in the Absence of Immediate Respiratory or Skin Manifestations
Authors: Winegarner Andrew , Kendall Mark C. , Stephen Mekhala , Siddiqui Afreen
Published: September 2023

Anaphylaxis, a type 1 hypersensitivity reaction, is a feared but uncommon complication of medications administered in the perioperative period. The incidence of perioperative hypersensitivity reactions has been reported to range from 1 in 20,000 to 1 in 1,361. Anesthesiologists are well aware of common causes of hypersensitivity such as paralytics and antibiotics; however, less common triggers of anaphylaxis need to be considered as well. Midazolam, a short acting benzodiazepine metabolized by cytochrome P450 enzymes, is considered very safe with a minimal risk profile. Previous reports have described adverse reactions to occur within seconds to minutes following the administration of midazolam. We describe a patient with no known history of asthma or allergies who underwent elective hydrocelectomy with spinal analgesia without incident until 42 minutes later at the conclusion of the procedure, when they experienced circulatory collapse necessitating immediate emergency treatment. This case emphasizes the necessity to improve knowledge and awareness of delayed hypersensitivity reactions following the administration of perioperative medications such as midazolam.
Metaverse Banking Service: Are We Ready to Adopt? A Deep Learning-Based Dual-Stage SEM-ANN Analysis
Authors: Nguyen Luan-Thanh , Duc Dang Thi Viet , Dang Tri-Quan , Nguyen Dang Phong
Published: September 2023

Metaverse banking service is the transformation from online banking to a metaverse environment that allows customers to access banking services and interact with representatives in a virtual environment. The metaverse refers to a virtual realm that integrates physical reality with digital environments, enabling users to interact, socialize, and participate in a wide range of activities through the use of avatars and immersive technologies. While there are advantages to adopt the metaverse, the metaverse adoption researches are scarce and primarily focus on the game, education, and sport, providing limited attention to banking services. Furthermore, most adoption research using standard information technology/information system models has focused primarily on organizational context and adopted compulsorily. Metaverse banking service is mainly adopted voluntarily by users and for personal purposes. Thus, this leads to the difficulty in drawing meaningful conclusions toward metaverse adoption. The study addresses these issues by proposing a new unified theory of acceptance and use of the metaverse technology model (UTAUMT), which consists of metaverse performance expectancy (MPE), metaverse facilitating conditions (MFC), metaverse effort expectancy (MEE), and metaverse social influence (MSI) to determine metaverse banking service adoption. Moreover, metaverse trust (MET) and metaverse financial resources (MEF) are also incorporated to investigate complexity in the metaverse environment. The integrated model has been developed and validated through a pretest (face validity and content validity) and pilot test before applying to 491 metaverses-experienced users in Vietnam through a questionnaire approach. Partial least squares structural equation modelling-artificial neural network (PLS-SEM-ANN) has provided a comprehensive result as it can capture both linear and nonlinear relationships. The results from the model showed that only one of the proposed hypotheses between metaverse financial resources (MEF) and behavioural intention to use metaverse banking services (BIM) was not supported in this study and thus needed further investigation. The study contributes to the academic literature by proposing new constructs to assess users’ likelihood of adopting metaverse banking services. The result also assists bank managers in understanding metaverse banking adoption and makes them realize the metaverse banking services’ growth opportunity to pursue. Given the limited scope of the study focusing solely on Vietnam, it would be advantageous for future research on the cultural variations among users of mobile social commerce to incorporate a comparative analysis across multiple countries, with a particular emphasis on Asian nations.
Effect of Annealing on PL Intensity of NaYF4:Er3+, Yb3+/Ca2+ Phosphor and the Application to Temperature Sensor
Authors: Zhang Fuli , Guo Chunlai , Zhang Zhen , Chen Xu , Song Chunlei , Li Chengren
Published: September 2023

We have prepared NaYF4:Er3+/Yb3+/Ca2+ phosphors using the solvothermal method and discussed the influence of annealing on the crystal structure, morphology, and photoluminescence characteristics in this work. The results show that, with the increase of annealing temperature, the crystallization phase changes from a single cubic structure to a mixed phase of cubic and hexagonal phases and the morphology is also condensed from spherical particles to sheets. In particular, the PL intensity of the annealed phosphor becomes much stronger than that of the unannealed phosphor. An annealed NaYF4:Yb3+, Er3+/Ca2+ phosphor is selected as an example to investigate the performance of high temperature sensor based on the fluorescence intensity ratio between two green emissions. The measurement range and the maximum absolute sensitivity SA of the annealed sensor material are superior to the corresponding parameters of the same phosphor without annealing. The curve of relative sensitivity curve SR decreases as the ambient temperature increases, but that of the revolution δT presents an opposite trend. All the results show that the NaYF4:Er3+/Yb3+/Ca2+ phosphor is more suitable for application on the high temperature sensor after annealing.
Rheumatic Heart Disease in East Africa: A Systematic Review and Meta-Analysis
Authors: Mebrahtom Guesh , Hailay Abrha , Aberhe Woldu , Zereabruk Kidane , Haile Teklehaimanot
Published: September 2023

Background. Despite being a grave problem, there is little information on rheumatic heart disease’s prevalence in East Africa. Therefore, the purpose of this systematic review and meta-analysis was to estimate the pooled prevalence of rheumatic heart disease in East Africa. Materials and Methods. A computerized systematic search of using multiple database searching engines was performed in search of relevant English articles from the inception of the databases to December 2019. It was done in accordance with the preferred reporting items for systematic review and meta-analysis (PRISMA) standard. The funnel plot was used to assess publication bias. R and RStudio for Windows were used for all statistical analysis. The random-effect model was used for calculating the pooled estimate of the prevalence of rheumatic heart disease. Results. The database search retrieved 1073 papers, and 80 articles (78 cross-sectional and two cohort study designs) with a total of 184575 individuals were found to be appropriate for the review. In East Africa, the overall prevalence of rheumatic heart disease was 14.67% (95% CI: 13.99% to 15.35%). In Ethiopia, Uganda, Tanzania, and Sudan, respectively, the subgroup analysis of rheumatic heart disease pooled prevalence was 22% (95% CI: 13% to 36%), 11% (95%t CI: 5% to 20%), 9% (95%t CI: 5% to 16%), and 3% (95%t CI: 1% to 10%), while the pooled prevalence of rheumatic heart disease in adults was 20% (95% CI: 12% to 30%), and in children, it was 4% (95% CI: 2% to 8%). Conclusions. From this report, the prevalence of rheumatic heart disease in East Africa is very high, affecting about one in seven people. Therefore, future strategies should emphasize preventive measures at appropriate times to minimize the burden of this type of preventable heart disease.