bluuebunny/crossref_metadata_2025 huggingface dataset:
Soluble C-type lectin-like receptor 2 in stroke (CLECSTRO) study: protocol of a multicentre, prospective cohort of a novel platelet activation marker in acute ischaemic stroke and transient ischaemic attack
Authors: Uchiyama Shinichiro , Suzuki-Inoue Katsue , Wada Hideo , Okada Yasushi , Hirano Teruyuki , Nagao Takehiko , Kinouchi Hiroyuki , Itabashi Ryo , Hoshino Haruhiko , Oki Koichi , Honma Yutaka , Ito Nobuo , Sugimori Hiroshi , Kawamura Masahide
Published: September 2023

Introduction

Soluble C-type lectin-like receptor 2 (sCLEC-2) is a new biomarker for platelet activation, which can be easily measured by usual blood collection. We conducted the CLECSTRO, a prospective, observational cohort study, to evaluate the clinical implications of sCLEC-2 in patients with acute ischaemic stroke (AIS) and transient ischaemic attack (TIA).

Methods and analysis

The participants are patients with AIS/TIA and control patients required for differentiation from AIS/TIA. The target population is 600, including the patients and controls, who would be recruited from eight stroke centres across Japan. The inclusion criteria are AIS within 24 hours of onset and a modified Rankin Scale (mRS) score of 0–2, TIA within 7 days of onset, and contemporary patients required for differentiation from AIS/TIA. Plasma sCLEC-2 will be measured by high-sensitive chemiluminescent enzyme immunoassay using residual blood samples from routine laboratory examinations at the first visit in all patients and 7 days later or at discharge in patients with AIS/TIA. The outcomes include plasma levels of sCLEC-2 in patients with AIS/TIA and controls, sCLEC-2/D-dimer ratio in non-cardioembolic and cardioembolic AIS/TIA, correlation of sCLEC-2 with recurrence or worsening of stroke, severity of stroke, infarct size, ABCD2score in TIA and outcome (mRS) at 7 days and 3 months.

Ethics and dissemination

This study was approved by the Ethical Committee of the University of Yamanashi as the central ethical committee in agreement with the ethical committees of all collaborative stroke centres. Informed consent will be obtained by an opt-out form from the patients at each stroke centre according to the Ethical Guidelines for Medical and Biological Research Involving Human Subjects by the Japanese Ministry of Health, Labour and Welfare.

Trial registration numbers

NCT05579405, UMIN000048954
Immediate analgesic effect of acupuncture intervention within 10 min during acute migraine attacks: protocol of a randomised controlled trial
Authors: Huang Ya , Li Qifu , Huang Gaoyangzi , Pei Xianmei , Chen Ziwen , Tang Xing , Zhang Renrui , Zhao Si-Wen , Liu Zili , Sun Jinbo , Guo Taipin , Liang Fan-rong
Published: September 2023

Introduction

Migraine is a widespread neurological disorder characterised by recurrent moderate-to-severe headaches. These headaches can seriously affect patients’ daily life and work, especially during acute attacks when patients often need immediate pain relief. This study aims to assess the immediate analgesic effect of acupuncture for 10 min during acute migraine attacks.

Methods and analysis

The study will randomly divide 80 participants into either the acupuncture group or the sham acupuncture group with an allocation ratio of 1:1. Each group will receive 10 min of treatment, and the post-treatment evaluation will be performed after 0, 0–2, 4, 6, 8 and 10 min of acupuncture. The primary outcome is the pain Visual Analogue Scale (VAS) score assessed before and after treatment at 10 min. Additionally, secondary outcomes include the pain VAS score assessed at 0–2, 4, 6 and 8 min, blinding assessment and treatment effectiveness expectations scale. Data will be collected at baseline time and the end of treatment (after 10 min). Adverse events during each treatment period will be collected and recorded.

Ethics and dissemination

Ethics approval was obtained from the Ethics Committee of the Second Affiliated Hospital of Yunnan University of Chinese Medicine (2022–008). All participants will provide written informed consent before randomisation. The results of this study will be published in a peer-reviewed journal and presented at conferences.

Trial registration number

Chinese Clinical Trial Registration Center (ChiCTR2200066976).
Optimal measurement of gastric emptying of solids in gastroparesis or functional dyspepsia: evidence to establish standard test
Authors: Camilleri Michael , Zheng Ting , Vosoughi Kia , Lupianez-Merly Camille , Eckert Deborah , Busciglio Irene , Burton Duane , Dilmaghani Saam
Published: September 2023

Objective

Symptoms in gastroparesis (Gp) and functional dyspepsia (FD) overlap; using egg protein substitute to measure gastric emptying of solids (GES), ~40% of patients are reclassified from Gp to FD, and vice versa. Our aim was to assess inter-individual and intra-individual coefficients of variation (COV) in GES in symptomatic patients with Gp or FD with documented slow or normal GES, respectively.

Design

Scintigraphic GES (T1/2and GE% at 2 and 4 hours) using a 320 kcal real egg meal (30% fat) was tested in the following: single measurements in 20 patients with diabetes mellitus (10 each type 1 and type 2); repeat GES to estimate COVintrameasured: 3 days apart in 9 Gp, 4 weeks apart in 21 Gp and 18 with FD with normal GE assigned to placebo and in 70 patients at 94.3 weeks (median) apart.

Results

COVinterfor GE% at 4 hours and GE T1/2were respectively 14.2% and 23.5% in FD and 27.5% and 33% in Gp; COVintrafor GE% at 4 hours and GE T1/2up to 4 weeks apart were 23.4% and 37.9% in FD and 20.1% and 33% in Gp. GE% at 2 hours showed less consistent results. However, >85% retained original diagnosis as normal or delayed. From clinical GES to baseline research for Gp group, repeat GES (after treatment) showed the COVintrafor GE% at 4 hours was 37.3% at median 94.3 weeks, with 26/70 changed diagnoses.

Conclusion

The 320 kcal (30% fat) GES scintigraphic test provides consistent diagnosis in >85% and should be the standard test for suspected gastric emptying disorders.
Gene of the month: GATA3
Authors: Qiang Zekai , Jubber Ibrahim , Lloyd Kirsty , Cumberbatch Marcus , Griffin Jon
Published: September 2023

GATA binding protein 3 (GATA3) is a zinc-finger pioneer transcription factor involved in diverse processes. GATA3 regulates gene expression through binding nucleosomal DNA and facilitating chromatin remodelling. Post-translational modifications modulate its activity. During development, GATA3 plays a key role in cell differentiation. Mutations inGATA3are linked to breast and bladder cancer. GATA3 expression is a feature of the luminal subtype of bladder cancer and has implications for immune status and therapeutic response. It also has clinical relevance in squamous cell carcinomas and soft tissue sarcomas. This paper reviews the structure and function of GATA3, its role in cancer and its use and pitfalls as an immunohistochemical marker.
Effects of sodium chloride crystallization on shear characteristics of road base aggregates under unsaturated state
Authors: Ye Xingchi , Cao Zhigang , Gu Chuan , Cai Yuanqiang , Wang Jun
Published: September 2023

The precipitation and intrusion of sodium chloride into pavement structures is inevitable in coastal regions, which can affect the mechanical properties of the road base courses. To investigate this problem, samples with sodium chloride solution were cured in a thermostatic chamber until they reached the specified states of sodium chloride precipitation within the pores. A critical crystallization degree ( ωc) was discovered by computerized tomography scan, corresponding to the start of the formation of porous salt crust cementing the soil particles. A series of unsaturated large-scale triaxial shear tests were then conducted under various states of salt crystallization. The results showed that in the early stages of crystallization (i.e., ω < ωc), the peak stress and internal friction angle decreased with ω because of the coating and lubricating effects of salt powders, while the apparent cohesion remained constant. When ω > ωc, owing to the increasing adsorption and cementation effects of the salt crust, rapid growth was observed for the peak stress, internal friction angle, and apparent cohesion of the road base aggregates. Considering the influence of salt precipitation, a modified shear strength criterion that can predict the shear strength of the salinized road base aggregates was formulated.
Investigating the deformation characteristics of balloon-type CLT shearwall
Authors: Xing Dalu , Casagrande Daniele , Doudak Ghasan
Published: September 2023

Balloon-type cross-laminated timber (CLT) shearwalls represent a valuable alternative to traditional platform-type construction for use as lateral load resisting systems in mid-rise mass timber buildings. Limited information is available on the behaviour of balloon-type shearwalls, and the system is not included in design codes and standards. The research aims to investigate the lateral deformation contribution and kinematic behaviour of balloon-type CLT shearwall system. A simplified analytical model to establish the lateral displacement of shearwalls is presented and discussed. The methodology involves a validated finite element model, and the result of sensitivity analysis is used to develop the analytical model. The study revealed that the stiffness of hold-downs and vertical joints, and aspect ratio of panels and vertical loads are contributing factors influencing lateral stiffness. The proposed analytical model was verified against 45 cases implemented in numerical models yielding an average error in the prediction of top lateral displacement of less than 4.7%.
Causal viscous Universe in Sáez–Ballester theory
Authors: Singh Sanasam Surendra , Kumrah Leishingam , Alam Md Khurshid , Singh Laishram Kapil , Devi Lambamayum Anjana
Published: September 2023

In this work, the authors examine the dynamics of viscous Universe in the Sáez–Ballester theory of gravity. The solutions of the Friedmann–Robertson–Walker field equations have been derived within the framework of full causal theories presented by Israel and Stewart using simple parametrization of scale factor a( t), i.e., power law relation a( t) = a0 tα and exponential law a( t) = b0eβ t. The power law cosmological model shows that the Universe transitioned from early cosmic deceleration to the present cosmic acceleration, and the exponential cosmological model shows the accelerated expansion of the Universe. It has been discovered that as time passes, energy density and viscosity decrease while temperature rises. Energy conditions are also investigated in which the strong energy condition is violated. The behaviour of the cosmological parameters such as the Hubble parameter, energy density, pressure, coefficient of viscosity, and state-finder parameter has been presented graphically.
Time-of-flight spectroscopy of ultracold neutrons at the PSI UCN source
Authors: Bison G. , Chen W. , Chiu P. -J. , Daum M. , Doorenbos C. B. , Kirch K. , Kletzl V. , Lauss B. , Pais D. , Rienäcker I. , Schmidt-Wellenburg P. , Zsigmond G.
Published: September 2023

The ultracold neutron (UCN) source at the Paul Scherrer Institute (PSI) provides high intensities of storable neutrons for fundamental physics experiments. The neutron velocity spectrum parallel to the beamline axis was determined by time-of-flight spectroscopy using a neutron chopper. In particular, the temporal evolution of the spectrum during neutron production and UCN storage in the source storage volume was investigated and compared to Monte Carlo simulation results. A softening of the measured spectrum from a mean velocity of 7.7(1)–5.1(1) $$\hbox {m s}^{-1}$$

m

s

-
1

occurred within the first 30 $$\hbox {s}$$
s
after the proton beam pulse had impinged on the spallation target. A spectral hardening was observed over longer time scales of one measurement day, consistent with the effect of surface degradation of the solid deuterium moderator.
Ultra-low radioactivity flexible printed cables
Authors: Arnquist Isaac J. , di Vacri Maria Laura , Rocco Nicole , Saldanha Richard , Schlieder Tyler , Patel Raj , Patil Jay , Perez Mario , Uka Harshad
Published: September 2023

Flexible printed cables and circuitry based on copper-polyimide materials are widely used in experiments looking for rare events due to their unique electrical and mechanical characteristics. However, past studies have found copper-polyimide flexible cables to contain 400-4700 pg 238U/g, 16-3700 pg 232Th/g, and 170-2100 ng natK/g, which can be a significant source of radioactive background for many current and next-generation ultralow background detectors. This study presents a comprehensive investigation into the fabrication process of copper-polyimide flexible cables and the development of custom low radioactivity cables for use in rare-event physics applications. A methodical step-by-step approach was developed and informed by ultrasensitive assay to determine the radiopurity in the starting materials and identify the contaminating production steps in the cable fabrication process. Radiopure material alternatives were identified, and cleaner production processes and treatments were developed to significantly reduce the imparted contamination. Through the newly developed radiopure fabrication process, fully-functioning cables were produced with radiocontaminant concentrations of 20-31 pg 238U/g, 12-13 pg 232Th/g, and 40-550 ng natK/g, which is significantly cleaner than cables from previous work and sufficiently radiopure for current and next-generation detectors. This approach, employing witness samples to investigate each step of the fabrication process, can hopefully serve as a template for investigating radiocontaminants in other material production processes.
An Arabic Probabilistic Parser Based on a Property Grammar
Authors: Bensalem Raja , Haddar Kais , Blache Philippe
Published: September 2023

The specificities of Arabic parsing, such as agglutination, vocalization, and the relatively order-free words in Arabic sentences, remain major issues to consider. To promote its robustness, such parseing should define different types of constraints. Property Grammar (PG) formalism verifies the satisfiability of the constraints directly on the units of the structure, thanks to its properties (or relations). In this context, we propose to build a probabilistic parser with syntactic properties, using a PG, and we measure the production rules in terms of different implicit information and in particular the syntactic properties. We experimented with our parser on the treebank ATB, using the parsing algorithm CYK, and we obtained encouraging results. Our method is also automatic for implementation of most property types. Its generalization for other languages or corpus domains (using treebanks) could be a good perspective. Its combination with pre-trained models of BERT may also make our parser faster.
Online Self-Disclosure, Social Support, and User Engagement During the COVID-19 Pandemic
Authors: Lee Jooyoung , Rajtmajer Sarah , Srivatsavaya Eesha , Wilson Shomir
Published: September 2023

We investigate relationships between online self-disclosure and received
social support and user engagement
during the COVID-19 crisis. We crawl a total of 2,399 posts and 29,851 associated comments from the
r/COVID19_support
subreddit and manually extract fine-grained personal information categories and types of social support sought from each post. We develop a BERT-based ensemble classifier to automatically identify types of support offered in users’ comments. We then analyze the effect of personal information sharing and posts’ topical, lexical, and sentiment markers on the acquisition of support and five interaction measures (submission scores, the number of comments, the number of unique commenters, the length and sentiments of comments). Our findings show that: (1) users were more likely to share their age, education, and location information when seeking both informational and emotional support as opposed to pursuing either one; (2) while personal information sharing was positively correlated with receiving informational support when requested, it did not correlate with emotional support; (3) as the degree of self-disclosure increased, information support seekers obtained higher submission scores and longer comments, whereas emotional support seekers’ self-disclosure resulted in lower submission scores, fewer comments, and fewer unique commenters; and (4) post characteristics affecting
audience response
differed significantly based on types of support sought by post authors. These results provide empirical evidence for the varying effects of self-disclosure on acquiring desired support and user involvement online during the COVID-19 pandemic. Furthermore, this work can assist support seekers hoping to enhance and prioritize specific types of
social support and user engagement
.
Feature Selection for Efficient Local-to-global Bayesian Network Structure Learning
Authors: Yu Kui , Ling Zhaolong , Liu Lin , Li Peipei , Wang Hao , Li Jiuyong
Published: September 2023

Local-to-global learning approach plays an essential role in Bayesian network (BN) structure learning. Existing local-to-global learning algorithms first construct the skeleton of a DAG (directed acyclic graph) by learning the MB (Markov blanket) or PC (parents and children) of each variable in a dataset, then orient edges in the skeleton. However, existing MB or PC learning methods are often computationally expensive especially with a large-sized BN, resulting in inefficient local-to-global learning algorithms. To tackle the problem, in this article, we link feature selection with local BN structure learning and develop an efficient local-to-global learning approach using filtering feature selection. Specifically, we first analyze the rationale of the well-known Minimum-Redundancy and Maximum-Relevance (MRMR) feature selection approach for learning a PC set of a variable. Based on the analysis, we propose an efficient F2SL (feature selection-based structure learning) approach to local-to-global BN structure learning. The F2SL approach first employs the MRMR approach to learn the skeleton of a DAG, then orients edges in the skeleton. Employing independence tests or score functions for orienting edges, we instantiate the F2SL approach into two new algorithms, F2SL-c (using independence tests) and F2SL-s (using score functions). Compared to the state-of-the-art local-to-global BN learning algorithms, the experiments validated that the proposed algorithms in this article are more efficient and provide competitive structure learning quality than the compared algorithms.
Post-growth Human–Computer Interaction
Authors: Sharma Vishal , Kumar Neha , Nardi Bonnie
Published: September 2023

Human–Computer Interaction (HCI) researchers have increasingly been questioning computing’s engagement with unsustainable and unjust economic growth, pushing for identifying alternatives. Incorporating
degrowth,
post-development,
and
steady-state
approaches,
post-growth
philosophy offers an alternative not rooted in growth but in improving quality of life. It recommends an equitable reduction in resource use through sensible distributive practices where fulfillment is based on values including solidarity, cooperation, care, social justice, and localized development. In this paper, we describe opportunities for HCI to take a post-growth orientation in research, design, and practice to reimagine the design of sociotechnical systems toward advancing sustainable, just, and humane futures. We aim for the critiques, concerns, and recommendations offered by post-growth to be integrated into transformative HCI practices for technology-mediated change.
Measures of Information Leakage for Incomplete Statistical Information: Application to a Binary Privacy Mechanism
Authors: Sakib Shahnewaz Karim , Amariucai George T , Guan Yong
Published: September 2023

Information leakage
is usually defined as the logarithmic increment in the adversary’s probability of correctly guessing the legitimate user’s private data or some arbitrary function of the private data when presented with the legitimate user’s publicly disclosed information. However, this definition of information leakage implicitly assumes that both the privacy mechanism and the prior probability of the original data are entirely known to the attacker. In reality, the assumption of complete knowledge of the privacy mechanism for an attacker is often impractical. The attacker can usually have access to only an approximate version of the correct privacy mechanism, computed from a limited set of the disclosed data, for which they can access the corresponding un-distorted data. In this scenario, the conventional definition of leakage no longer has an operational meaning. To address this problem, in this article, we propose novel meaningful information-theoretic metrics for information leakage when the attacker has
incomplete information
about the privacy mechanism—we call them
average subjective leakage
,
average confidence boost
, and
average objective leakage
, respectively. For the simplest, binary scenario, we demonstrate how to find an optimized privacy mechanism that minimizes the worst-case value of either of these leakages.
Manipulating the Destiny of Wild Populations Using CRISPR
Authors: Raban Robyn , Marshall John M. , Hay Bruce A. , Akbari Omar S.
Published: September 2023

Genetic biocontrol aims to suppress or modify populations of species to protect public health, agriculture, and biodiversity. Advancements in genome engineering technologies have fueled a surge in research in this field, with one gene editing technology, CRISPR, leading the charge. This review focuses on the current state of CRISPR technologies for genetic biocontrol of pests and highlights the progress and ongoing challenges of using these approaches.
Metal Organic Complexation in Seawater: Historical Background and Future Directions
Authors: Moffett James W. , Boiteau Rene M.
Published: September 2023

The speciation of most biologically active trace metals in seawater is dominated by complexation by organic ligands. This review traces the history of work in this area, from the early observations that showed surprisingly poor recoveries using metal preconcentration protocols to the present day, where advances in mass spectroscopy and stable isotope geochemistry are providing new insights into the structure, origin, fate, and biogeochemical impact of organic ligands. Many long-standing hypotheses about the specific biological origin of ligands such as siderophores in seawater are finally being validated. This work has revealed the complexity of organic complexation, with multiple ligands and, in some cases, timescales of ligand exchange that are much slower than originally thought. The influence of organic complexation on scavenging is now a key parameter in biogeochemical models of biologically essential metals, especially iron. New insights about the sources and sinks of ligands are required to enhance the usefulness of these models.
Diffuse Pleural Mesothelioma: Advances in Molecular Pathogenesis, Diagnosis, and Treatment
Authors: Febres-Aldana Christopher A. , Fanaroff Rachel , Offin Michael , Zauderer Marjorie G. , Sauter Jennifer L. , Yang Soo-Ryum , Ladanyi Marc
Published: September 2023

Diffuse pleural mesothelioma (DPM) is a highly aggressive malignant neoplasm arising from the mesothelial cells lining the pleural surfaces. While DPM is a well-recognized disease linked to asbestos exposure, recent advances have expanded our understanding of molecular pathogenesis and transformed our clinical practice. This comprehensive review explores the current concepts and emerging trends in DPM, including risk factors, pathobiology, histologic subtyping, and therapeutic management, with an emphasis on a multidisciplinary approach to this complex disease.
Metacognition and Confidence: A Review and Synthesis
Authors: Fleming Stephen M.
Published: September 2023

Determining the psychological, computational, and neural bases of confidence and uncertainty holds promise for understanding foundational aspects of human metacognition. While a neuroscience of confidence has focused on the mechanisms underpinning subpersonal phenomena such as representations of uncertainty in the visual or motor system, metacognition research has been concerned with personal-level beliefs and knowledge about self-performance. I provide a road map for bridging this divide by focusing on a particular class of confidence computation: propositional confidence in one's own (hypothetical) decisions or actions. Propositional confidence is informed by the observer's models of the world and their cognitive system, which may be more or less accurate—thus explaining why metacognitive judgments are inferential and sometimes diverge from task performance. Disparate findings on the neural basis of uncertainty and performance monitoring are integrated into a common framework, and a new understanding of the locus of action of metacognitive interventions is developed.
Fabrication of a Co-Ni/TiO2 Core-Shell Sensor for Label-Free Quantification of Human Serum Albumin in Hepatitis C Virus Patients
Authors: Sultan Noor , Alam Ayub , Fatima Batool , Shafi Sameera , Hussain Dilshad , Sarwar Zohaib , Wasim Muhammad , Majeed Saadat , Yar Ahmad , Najam-ul-Haq Muhammad
Published: September 2023

Liver cirrhosis is a life-threatening disorder characterized by severe hepatitis C. Early detection of hepatitis C is crucial since HCV infection has few symptoms, and the patient may remain unaware for many years. The early-stage detection can assist in the treatment and prevent further virus transmission. Abnormally varying albumin concentrations in hepatitis C patients can lead to hypoalbuminemia. Herein, a novel Co-Ni/TiO2 core–shell-based electrochemical sensor is developed for facile and ultra-sensitive human serum albumin (HSA) detection in HCV patients. Co-Ni/TiO2 core shells are fabricated via coprecipitation and hydrothermal methods and used for non-enzymatic detection albumin with high sensitivity, selectivity, and lower detection limits. Cyclic voltammetry, chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS) is performed for albumin detection via Co-Ni/TiO2 modified GCE at different scan rates, pH, and concentrations. The linear range and limit of detection (LOD) obtained for the Co-Ni/TiO2 electrode are 0–30 μM and 0.019 μM, respectively. The utility of Co-Ni/TiO2 electrodes is extended to HSA sensing from HCV-infected patients. Albumin recovery at room temperature ranged from 81.0% to 91.3% in diluted human serum samples. The developed electrochemical analysis method is superior for HSA detection and can be a tool for clinical diagnosis in the future.
Understanding the Electrolyte Chemistry Induced Enhanced Stability of Si Anodes in Li-Ion Batteries based on Physico-Chemical Changes, Impedance, and Stress Evolution during SEI Formation
Authors: Tripathi Rashmi , Yesilbas Göktug , Lamprecht Xaver , Gandharapu Pranay , Bandarenka Aliaksandr S. , Dusane Rajiv O. , Mukhopadhyay Amartya
Published: September 2023

The volume expansion/contraction of Si-based anodes during electrochemical lithiation/delithiation cycles causes a loss in mechanical integrity and accrued instability of the solid electrolyte interphase (SEI) layer, culminating into capacity fade. Electrolyte additives like fluoroethylene carbonate (FEC) improve SEI stability, but the associated causes still under debate. This work reveals some of the roles of FEC via post-mortem observations/analyses, operando stress measurements and a comprehensive study of the impedance associated with the formation/evolution of SEI during lithiation/delithiation. Usage of 10 vol.% FEC as electrolyte additive leads to significant improvements in cyclic stability, Coulombic efficiency and facilitates smoother/compact/crack-free surface/SEI, in contrast to the cracked/pitted/uneven surface upon non-usage of FEC. Operando stress measurements during SEI formation reveal compressive stress development, followed by loss in mechanical integrity, upon non-usage of electrolyte additive, in contrast to insignificant stress development associated with SEI formation upon usage of FEC. The EIS model proposed here facilitates good fit with the impedance data at all states-of-charges, with the SEI resistance and capacitance exhibiting expected variations with cycling and the SEI resistance progressively decreasing with cycle number in the presence of FEC. By contrast, in the absence of FEC, severe fluctuations observed with the SEI resistance and capacitance indicate instability.
Improvement of Low-Cost Commercial Carbon Screen-Printed Electrodes Conductivities with Controlled Gold Reduction Towards Thiol Modification
Authors: Partanen Kristin , Lee Dianne S. , Omoboye Adekunle , McEleney Kevin , Chen Rebecca X. Y. , She Zhe
Published: September 2023

Effectively detecting bacteria in the environment is crucial for researchers to make informed decisions about the safety of public areas, such as lakes. This led to an increased need in the development of portable handheld devices, capable of on-the-spot chemical and biological sensing applications. Specific interests lie in electrochemical biosensors and screen-printed electrodes (SPEs) due to the decreased costs, an ability to integrate with handheld devices, and their user-friendly nature. Together, these qualities make the devices more accessible in resource-poor settings. Two of the most common substrates used to fabricate SPEs are carbon and gold. Carbon SPEs are effective in sensing applications yet challenged when attempting to covalently attach biomolecules to the surface. Gold SPEs have higher affinity towards biomolecules and improve the sensitivity, selectivity, and stability of a device; yet they can be costly. A carbon SPE modified with gold may be an ideal candidate to create an efficient low-cost device, using electrochemical gold deposition. In this study, electrochemical gold deposition on SPEs is explored to enhance the surface area and conductivity towards sensing applications. These SPEs were then modified with a thiol-based self-assembled monolayer (SAM) which demonstrates this technique could be used for further modification towards biosensing.
(Invited) Formation of Organic Color Centers in Air-Suspended Carbon Nanotubes Using Vapor-Phase Reaction
Authors: Kozawa Daichi , Wu Xiaojian , Ishii Akihiro , Fortner Jacob , Otsuka Keigo , Xiang Rong , Inoue Taiki , Maruyama Shigeo , Wang YuHuang , Kato Yuichiro K.
Published: September 2023

Organic color centers in single-walled carbon nanotubes have demonstrated exceptional ability to generate single photons at room temperature in the telecom range. Combining the color centers with pristine air-suspended nanotubes would be desirable for improved performance, but all current synthetic methods occur in solution which makes them incompatible. Here we demonstrate the formation of color centers in air-suspended nanotubes using a vapor-phase reaction [1]. Functionalization is directly verified by photoluminescence spectroscopy, with unambiguous statistics from more than a few thousand individual nanotubes. The color centers show strong diameter-dependent emission, which can be explained with a model for chemical reactivity considering strain along the tube curvature. We also estimate the defect density by comparing the experiments with simulations based on a one-dimensional exciton diffusion equation. Our results highlight the influence of the nanotube structure on vapor-phase reactivity and emission properties, providing guidelines for the development of high-performance near-infrared quantum light sources.

This work is supported in part by MIC (SCOPE JP191503001 to Y.K.K.), JSPS (JP18H05329, JP20H00220 to S.M., JP20H02558 to Y.K.K., JP20K15112, JP22H01893 to D.K., JP20K15137 to K.O.), MEXT (Nanotechnology Platform JPMXP09F19UT0077), NSF (RAISE-TAQS PHY-1839165 to Y.H.W.), and JST (CREST JPMJCR20B5 to S.M.). D.K. acknowledges support from RIKEN Special Postdoctoral Researcher Program. K.O. is supported by JSPS Research Fellowship. We thank the Advanced Manufacturing Support Team at RIKEN for technical assistance.

[1] D. Kozawa, X. Wu, A. Ishii, J. Fortner, K. Otsuka, R. Xiang, T. Inoue, S. Maruyama, Y. Wang, and Y. K. Kato, Nature Commun. 13, 2814 (2022).
(Invited) Advanced Carbon Nanotube Fluorescence Spectrometry for Novel Applications
Authors: Weisman R. Bruce , Cherukuri Tonya , Bachilo Sergei M. , Meng Wei , Nagarajaiah Satish
Published: September 2023

Instrumental advances in near-IR fluorescence spectroscopy are enabling new types of measurements involving single-wall carbon nanotubes (SWCNTs). Two unique systems will be described. The first is a two-dimensional fluorescence-detected circular dichroism (FDCD) spectrometer. In this, SWCNT samples are excited by a spectrally selected supercontinuum laser beam that is switched between left- and right-circular polarization in an electro-optic modulator. Near-infrared sample fluorescence emitted in the backward direction is captured and directed to a scanning monochromator with a cooled InGaAs single-channel detector. After amplification and high precision digitization, the modulated signal component is extracted by computer-based phase sensitive detection. The system can measure a sample’s E22 circular dichroism in four spectral modes: 1) conventional FDCD, with scanned visible excitation wavelength and spectrally integrated (zero-order grating) emission detection; 2) Emission-specific FDCD, with scanned visible excitation wavelengths and selected emission wavelength; 3) Emission-scanned FDCD, with selected visible excitation wavelength and scanned emission wavelengths; 4) Excitation-Emission FDCD, with excitation and emission wavelengths both scanned to give two-dimensional data sets. This instrument can spectroscopically resolve enantiomer signals from a single (n,m) species in a racemic SWCNT sample.

In a parallel project, developments in SWCNT fluorescence spectrometry are advancing nanotube-based strain measurement technology toward commercialization. Because SWCNT emission wavelengths vary systematically with axial strain, nanotubes in a thin coating on a specimen can serve as optically interrogated strain gauges. We apply this effect to measure strain maps through hyperspectral imaging of SWCNT fluorescence. A rotated band pass filter is used to capture a set of images in multiple spectral slices, from which a custom computer program deduces strain at each of ~105 image pixels and compiles strain maps. We will describe how this apparatus has evolved from a lab prototype into a compact portable system that can make measurements in industrial settings.
Quantifying Free Carriers in Doped SWCNTs: An Optical and Magnetic Resonance Approach
Authors: Hermosilla Palacios Martha Alejandra , Martinez Marissa , Blackburn Jeff , Spokoyny Alexander
Published: September 2023

Single-walled carbon nanotubes (SWCNTs) have become increasingly important for opto-electronic devices due to their strong optical absorption, tunable carrier densities, and large carrier mobilities. To produce electricity in applications like photovoltaics and sensors, after light absorption the bound exciton must be separated into free charges carriers. However, the nature of charges in s-SWCNTs is still unclear and a way to quantify them has remained elusive. To better understand free carriers in doped semiconducting SWCNTs we employ a new class of molecular charge-transfer dopants, functionalized dodecaborane (DDB) molecules, to tune the charge carrier density. These DDB dopants form delocalized hole charge carriers on the SWCNTs due to the spatial separation between nanotube surface and the boron cluster containing the negative counterion. Importantly, the fluorine-decorated DDB dopants have strong 19F resonances, characteristic of the negatively charged molecules, that can quantify the absolute concentrations of DDB- and SWCNT+. As such, we use a combined approach of steady state optical spectroscopy and 19F NMR studies. Optical spectroscopy allows to track the excitonic absorption quenching and trion signature due to charge carrier density while correlating it to the concentration of carriers extracted from NMR experiments. This combined methodology allows for quantitative determination of a molar extinction coefficient for free carriers in semiconducting SWCNTs. This molar extinction coefficient can then be used in further studies to determine the yield and mobility of free carriers generated in a variety of samples and applications, for example at a heterojunction in photovoltaic devices, to determine quantitative charge transfer efficiencies and dynamics.
(Invited) Macroscopically Aligned Carbon Nanotubes for Photonics, Electronics, and Thermoelectrics
Authors: Doumani Jacques , Gao Weilu , Kono Junichiro
Published: September 2023

The remarkable flexibility, stable chemical structure, and extraordinary thermal, electrical, and optical properties of carbon nanotubes (CNTs) are promising for a variety of applications in flexible and/or high-temperature electronics, optoelectronics, and thermoelectrics, including wearables, refractory photonics, and waste heat harvesting. However, the long-standing goal in the preparation of CNT ensembles is how to maintain the extraordinary properties of individual CNTs on a macroscopic scale. The polydispersity and randomness remain two main challenges. Here, we will discuss different methods for creating macroscopically aligned CNTs, including spontaneous formation of wafer-scale aligned CNT films via controlled vacuum filtration and production of ultrahigh-conductivity CNT fibers and films through solution spinning and coating. We will then describe the optical, dc and ac electrical, thermal, and thermoelectric properties of these materials. These results are promising for device applications in various fields such as flexible CNT broadband detectors, spectrally selective thermal emitters, and thermoelectric devices.
(Invited) Designer Polymer Dispersants for Sorting, and Assembly of Carbon Nanotube Arrays
Authors: Gopalan Padma , Oliveras Santos Stephanie , Li Songying (Frederick) , Arnold Michael Scott
Published: September 2023

Conjugated polymers have been extensively utilized to isolate semiconducting single walled carbon nanotubes (s-CNTs) in organic solvents creating a high-purity s-CNT “ink”. To overcome inter-CNT π–π interactions to individualize and disaggregate s-CNTs, typically dispersing agents are necessary. Solution deposition of s-CNTs from these inks onto target substrates to create a monolayer of CNT arrays is actively being explored to fabricate FETs with superior performance compared to conventional silicon and gallium arsenide-based FETs. A wide range of deposition and alignment of s-CNTs on substrates has been explored by methods such as Langmuir-Blodgett/Schaefer, vacuum filtration, electric fields, shear, evaporation, 3D printing, and at liquid/liquid interfaces. While significant progress has been made in deposition and alignment of CNTs on wafer-scale, achieving a controllable pitch in a perfectly aligned dense array of CNTs is still a challenge.

Following the initial discovery of dispersants such as aromatic conjugated polymers which interact non-covalently with CNTs and sort CNT soot into high-purity, electronics-grade s-CNT inks, the vast community now uses polymers such as polyfluorene and polythiophene homo and copolymers with other monomers. We have focused in this study on revisiting some of the design rules for these conjugated polymer dispersants to incorporate additional functions such as self-assembly dictated pitch control and improving the yield and selectivity of the sorting process. We have investigated ABA triblock copolymers where B is the conjugated block and A is a non-conjugated coil block to study its effect on dispersion and sorting of CNTs. Though these types of ABA di and triblocks have been investigated in the literature for modulation of the photophysical properties of the B block, their use for sorting of s-CNTs is largely unexplored. In this study, Arc CNT or HiPCO soot was mixed with the ABA triblock at various B block: CNT ratio’s and its dispersion and sorting characteristics were studied. Our studies show that the A coil block greatly improves the sorting efficiency while maintaining the semiconducting selectivity. The selectivity of the ABA triblocks towards s-CNT chiralities is similar to the conjugated B block alone. Furthermore, the ABA architecture allows for much lower degree of polymerization for the B block that what is commonly accepted in the literature. Our results show a generalizable polymer dispersant design where the pitch of the assembled CNT arrays can be potentially controlled.
Influence of Excess Conjugated Wrapping Polymer in Semiconducting Single-Walled Carbon Nanotube Dispersions
Authors: Mirka Brendan , Rice Nicole , Williams Phillip , Tousignant Mathieu , Boileau Nicholas , Bodnaryk William , Fong Darryl , Adronov Alex , Lessard Benoit
Published: September 2023

Single-walled carbon nanotubes (SWNTs) are promising nanomaterials for incorporation into organic electronic devices (OEDs), with the potential to fabricate flexible devices while exploiting inexpensive solution-processing techniques. As-synthesized SWNTs are insoluble and comprised of a mixture of metallic and semiconducting SWNTs (sc-SWNTs), necessitating dispersal and purification before integration into OEDs. Refinement of conjugated polymer extraction techniques has allowed for the isolation of sc-SWNTs from metallic in a reproducible and scalable manner. The availability of highly-pure sc-SWNT materials has facilitated the production of thin-film transistors (TFTs) with very high charge carrier mobilities, outperforming organic small molecule and polymer semiconductors. However, the realization of commercial OED applications of polymer-sorted sc-SWNTs have not yet been achieved, partially due to the prohibitive time and materials costs associated with purifying sc-SWNTs.

Current protocols for dispersing sc-SWNTs with conjugated polymers involve three broad steps: (1) dispersion of bulk SWNT material, (2) removal of non-dispersed carbonaceous materials, and (3) removal of excess polymer through filtration or centrifugation. The final step of removal of excess polymer is time-consuming and wasteful, but viewed as necessary for preparing high-performing TFTs, as the conjugated polymer has much lower performance compared to SWNTs.

In this study we performed the first systematic investigation of the effect of excess polymer on SWNT TFT performance. Three SWNT concentrations were investigated, with varying ratios of excess polymer added to each. TFT device performance was monitored using several metrics, including: mobility, threshold voltage, on/off ratios and hysteresis. Characterization of large numbers of replicate TFT devices determined that below a threshold amount of excess polymer the presence of excess polymer did not have a negative impact on device performance. Detailed analysis of the sc-SWNT films through Raman spectroscopy and atomic force microscopy (AFM) confirmed that a simple rinsing step was sufficient to remove all the unbound conjugated polymer from the substrate surface without affecting the sc-SWNT network. The volume of solvent required for the rinsing step was substantially lower than that required for filtration or centrifugation steps. Furthermore, at higher SWNT concentrations the excess polymer prevented nanotube bundling, resulting in moderate improvements in both mobility and on/off ratios. Our results were reproducible for two different conjugated polymer sc-SWNT systems, demonstrating the versatility of this procedure.
(Invited) 3D Aromaticity in Borane and Carborane Derivatives
Authors: Solà Miquel , Poater Jordi , Tu Deshuang , Yan Hong , Viñas Clara , Teixidor Francesc
Published: September 2023

We will start discussing the difference between 3D aromatic species and those that should be described as 2D-aromatic with three-dimensional molecular structures (abbr. 2D-aromatic-in-3D) and not as truly 3D-aromatic [1]. Then, we will show the connection between archetypal polycyclic aromatic hydrocarbons (PAH) and closo boranes to conclude that the 4n+2 Wade-Mingos rule for three-dimensional closo boranes is connected to the (4n+2)π Hückel rule for bidimensional PAHs [2]. Next, we will analyze the aromaticity of closo and nido boranes and carboranes. Quantum chemical calculations reveal that the nido cage retains part of the aromatic character that characterizes the closo borane cages [2]. Then, we will elaborate on the aromaticity in benzenoids (2D aromatic) linked to carboranes (3D aromatic) [3]. And finally, we will apply the Clar’s π-sextet model to explain the extrusion of benzenoids linked to cobaltabis(dicarbollide), [3,3’-Co(1,2-C2B9H11)2]- [4].

References

1) El Bakouri, O.; Szczepanik, D. W.; Jorner, K.; Ayub, R.; Bultinck, P.; Solà, M.; Ottosson, H. J. Am. Chem. Soc.
2022, 144, 8560-8575

2) a) Poater, J.; Solà, M.; Viñas, C.; Teixidor, F. Angew.
Chem. Int. Ed.
2014, 53, 12191-12195. b) Poater, J.; Solà, M.; Viñas, C.; Teixidor, F. Chem. Eur. J.
2016, 22, 7437-7443.

3) a) Poater, J.; Viñas, C.; Solà, M.; Teixidor, F. Nat.
Commun.
2022, 13, 3844. b) Sun, F.; Tan, S.; Lu, C.; Tu, D.; Poater, J.; Solà, M.; Yan, H.; submitted for publication.

4) Poater, J.; Viñas, C.; Olid, D.; Solà, M.; Teixidor, F. Angew.
Chem. Int. Ed.
2022, 61, e202200672.

Figure 1
(Invited) On-Surface Synthesis of Π-Conjugated Polymers
Authors: Ecija David
Published: September 2023

On-surface synthesis has emerged as a powerful strategy to design unprecedented nanomaterials. In this talk, I will revise our recent achievements regarding the synthesis of one-dimensional π-conjugated polymers, featuring emerging physical properties such as non-trivial topology or pi-based magnetism.1-6

References

[1] Advanced Materials 33, 2170349, 2021

[2] Angewandte Chemie International Edition 59, 17594-17599, 2020

[3] Nature communications 11, 1-8, 2020

[4] Nature Nanotechnology 15, 437-443, 2020

[5] Chemical Communications 56, 15309-15312, 2021

[6] Angewandte Chemie International Edition 58, 6781-6781, 2019