bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrochemical study of N-acetyl neuraminic acid at gold-modified screen-printed carbon electrodes for a glycoprotein sensor of SARS-CoV-2
Authors: Syaifie Putri Hawa , Nasution Mochammad Arfin Fardiansyah , Rahmawati Isnaini , Saepudin Endang , Ivandini Tribidasari Anggraningrum 
Published: January 2024

Abstract
An electrochemical sensor of SARS-CoV-2 spike glycoprotein S1 has been developed using N-acetyl neuraminic acid (Neu5Ac) as the biosensing agent based on the interaction between Neu5Ac with the N-terminal domain of spike glycoprotein S1. Gold-modified screen-printed carbon electrodes (Au-SPCEs), prepared by electrochemical deposition of gold particles on a screen-printed carbon electrode surface, were used to detect the presence of the SARS-CoV-2 from the change in the electrochemical behavior of Neu5Ac. Cyclic voltammetry of Neu5Ac in phosphate buffer solution pH 7.6 using Au-SPCEs yielded a couple of oxidation and reduction peaks at potentials of +0.6 and 0.1 V (vs Ag/AgCl), respectively. The currents of both peaks linearly increased with the Neu5Ac concentrations in the range from 0 to 200 µM. A sensitivity of 0.77 mA/mM and 0.47 mA/mM for reduction and oxidation currents were observed, respectively, with estimated detection limits (LODs) of 51.05 µM and 35.77 µM. In the presence of SARS-CoV-2 spike glycoprotein S1, these current peaks decreased. At an optimum contact time of 30 min, a linear correlation to the current change of the reduction peaks was observed for the spike glycoprotein S1 over the concentration range 0 to 0.01 µg/mL. An estimated LOD of 0.7 ng/mL could be achieved with excellent stability (2.18% RSD value for n = 10), indicating that the sensor is promising for use in real applications of SARS-CoV-2 spike glycoprotein S1 detection.
Synthesis and physical properties of doubly-annulated [10]cycloparaphenylene
Authors: Sun Liansheng , Kayahara Eiichi , Nishinaga Tohru , Ball Melissa , Paley Daniel , Nuckolls Colin , Yamago Shigeru 
Published: January 2024

Abstract
A doubly annulated cycloparaphenylene (CPP), in which two [N]paraphenylenes share one benzene unit by meta (m)-connection, m-,m-phenylene-[2N]CPP with N = 5 (2a), was synthesized by double annulation between a CPP precursor and 1,5-dibromo-2,4-diiodobenzene followed by reductive aromatization. The structure of 2a was confirmed by NMR, mass spectroscopy, and single crystal X-ray diffraction analysis. As 2a has a figure-eight structure, it can have a twisted Möbius topology. However, the X-ray analysis clearly reveals a non-twisted Hückel topology in a solid state. The photophysical and electrochemical properties of 2a were also clarified. The studies proved that, while 2a can also be seen as ortho (o)-,o- or para (p)-,p-connected [10]CPP, 2a has an meta (m)-,m-connected electronic structure. The theoretical calculations also support this conclusion.
Effective synthesis of 1,4-diarylbutadienes via reductive desulfonylation of 1,3-butadienyl sulfones by proper choice of regioisomeric π-expanded pyrene photocatalysts
Authors: Watanabe Hikaru , Sato Takuma , Sumita Michiki , Shiroyama Mei , Sugawara Daichi , Tokuyama Tomoki , Okuda Yasuhiro , Wakamatsu Kan , Orita Akihiro 
Published: January 2024

Abstract
For the reductive desulfonylation of 1,3-butadienyl sulfones, we synthesized 1,3,6,8-tetra(phenylethynyl)pyrenes possessing (S)-citronellyloxy groups on the terminal phenyl rings at the ortho-, meta-, and para-positions to serve as photocatalysts. All of these pyrenes exhibited catalytic activity in the reductive desulfonylation of butadienyl sulfones when exposed to either green (514 nm) or blue LEDs (447 nm) in the presence of the sacrificial reducing agent i-Pr2NEt. The photocatalytic activities of these compounds could be fine-tuned by altering the position of the (S)-citronellyloxy group. Under green LEDs illumination, the ortho-(S)-citronellyloxy pyrene photocatalyst (S)-1 proved to be the most effective in the reductive desulfonylation of 1,4-diphenylbutadien-1-yl sulfone 4b to produce 1,4-diphenylbutadiene (5b) with an 88% yield. On the other hand, in the reductive desulfonylation of 1,2-diphenyethen-1-yl sulfone 4a, the para-(S)-citronellyloxy photocatalyst (S)-3 demonstrated high performance, producing stilbene (5a) with a 92% yield. Furthermore, the trio of pyrene photocatalysts proved to be highly efficient in promoting the reductive desulfonylation of functionalized dienyl sulfones as well as π-expanded dienyl sulfones. By judiciously selecting the suitable photocatalyst from the trio of (S)-1-3, these desulfonylation reactions could be rapidly and effectively accomplished.
Neutral Nazarov reaction using protic solvents as activators
Authors: Iwata Takayuki , Funatsu Shingo , Kajiwara Kohei , Shiota Yoshihito , Yoshizawa Kazunari , Shindo Mitsuru 
Published: January 2024

Abstract
Herein, we report a neutral Nazarov reaction using protic solvents instead of strong acids as activators. The key to the success of this reaction lies in the rational design of the divinyl ketone substrates. In particular, the introduction of electron-donating groups (EDGs) at the β- and β′-positions of the carbonyl group in the divinyl ketone increases the Lewis basicity dramatically, an EDG at α-position promotes the cyclization, and the presence of a phenoxy group at β-position enables the irreversible elimination of phenol from the cyclized intermediate, thus shifting the reversible cyclization to the product side. This phenol-releasing reaction can be applied to clip chemistry to target acidic biological environments.
Pd(II) and Pt(II) terpyridyl complexes: topoisomerase I inhibition and cytotoxicity
Authors: Nakai Misaki , Asano Kyohei , Shimada Kouyou , Kanno Keiko , Nakabayashi Yasuo , Alba Laurenzo , Funahashi Yasuhiro , Yano Shigenobu , Ishida Hitoshi 
Published: January 2024

Abstract
Pd(II) and Pt(II) terpyridyl complexes [MCl(terpy-COOH)]Cl where M = Pd(1) or Pt(2); terpy-COOH = 2,2′:6′,2″-terpyridine-4′-carboxylic acid] were synthesized. The Pd(II) complex was rapidly hydrolyzed because a Pd(II) ion was active in ligand substitution, while hydrolysis of the Pt(II) complex was slow because of its inactivity. Their topoisomerase inhibitory activity was examined: the Pd complex showed higher activity than the Pt complex. The complexes also bound with calf thymus DNA (ct-DNA): the binding constant of 1 was about twice as large as that of 2. The model studies suggested that the Pd complex coordinated faster with the His residue, to which topoisomerase bound phosphate ester, than the Pt complex. The cytotoxicity against HeLa cells was evaluated by adding bovine serum albumin (BSA): the Pd complex 1 was more cytotoxic than cisplatin, while no cytotoxicity was observed for the Pt complex 2. The binding constants of 2 with BSA were confirmed to be similar to those of 1. It is fascinating that the Pd complex, which has been conventionally considered to have low anticancer activity, shows higher cytotoxicity than the Pt complex with the same structure.
Intersystem crossing as vibronically induced phonon emission and absorption processes: a unified view of nonradiative transitions in a molecule
Authors: Ota Wataru , Uejima Motoyuki , Haruta Naoki , Sato Tohru 
Published: January 2024

Abstract
An analytical expression for the nonradiative rate constant is derived based on Fermi's golden rule within the mixed-spin crude adiabatic (CA) approximation. The mixed-spin CA basis is defined by a set of eigenstates for the electronic Hamiltonian that comprises the nonrelativistic electronic Hamiltonian and spin-orbit coupling clumped at the reference nuclear configuration. The mixed-spin basis differs from the pure-spin basis defined by a set of eigenstates for the nonrelativistic electronic Hamiltonian. The mixed-spin CA representation provides a unified view of the nonradiative transitions; both internal conversion and intersystem crossing (ISC) are regarded as vibronically induced phonon emission and absorption processes. The analytical expression enables us to determine important vibrational modes that are responsible for phonon emission/absorption (promoting modes) and accepting excitation energy (accepting modes) according to the selection rule of vibronic coupling. An advantage of the CA representation is that the spatial distribution of vibronic coupling is elucidated based on its density form, i.e. vibronic coupling density, which can be applied to theoretical molecular designs with controlled nonradiative processes. The calculated ISC rate constant for tetracene reproduces the experimental result well.
Pinpoint-fluorinated polycyclic aromatic hydrocarbons (F-PAHs) and their heteroaromatic analogs: syntheses, reactivities, and properties
Authors: Fuchibe Kohei , Fujita Takeshi , Ichikawa Junji 
Published: January 2024

Abstract
Pinpoint-fluorinated polycyclic aromatic hydrocarbons (F-PAHs) and their heteroaromatic analogs, which are regioselectively substituted by one or two fluorine atoms, were systematically synthesized by Friedel–Crafts cyclization of fluoroalkenes (2-trifluoromethyl-1-alkenes, 1,1-difluoro-1-alkenes, 1,1,2-trifluoro-1-alkenes, and 1,1-difluoroallenes) that were Al(III)-mediated, Pd(II)-catalyzed, and In(III)-catalyzed. The key feature of these reactions is ring closures that proceed via α-fluorine-stabilized CF2 cations and related species. Using an array of synthesized F-PAHs and their heteroaromatic analogs, their chemical reactivities and physical properties were investigated. (i) The reactivities of F-PAHs and their heteroaromatic analogs were used for further ring construction. (ii) The crystal structures of F-PAHs revealed that the planarity of their π-conjugated systems was not compromised because of the low steric demand of fluorine atoms. (iii) The introduction of fluorine atom(s) into PAH molecules increased their solubility in organic solvents, which was best exemplified by the high solubility of 6-fluoropicene (5.3 wt%) and 6,7-difluoropicene (5.4 wt%) in THF. (iv) One of the F-PAHs, 13-fluoropicene exhibited p-type semiconducting behavior (mobility 6.6 × 10−2 cm2/Vs by vacuum deposition; 1.3 × 10−4 cm2/Vs by spin casting using toluene as a solvent). (v) The HOMO–LUMO energy gaps of the F-PAHs were smaller than those of the corresponding fluorine-free PAH (i.e. picene) by 0.02 to 0.26 eV, and the HOMO and LUMO energy levels were lowered by 0.10 to 0.22 and 0.12 to 0.41 eV, respectively.
Pyrene-fused dioxaborine-based merocyanines with high brightness, photostability, and fluorogenic function for deep-skin tissue imaging of a living mouse
Authors: Nishihara Haruka , Watanabe Mai , Kawakami Ryosuke , Murakami Masamoto , Seki Hitomi , Osaki Katsuki , Tsuda Teruko , Imamura Takeshi , Hadano Shingo , Watanabe Shigeru , Niko Yosuke 
Published: January 2024

Abstract
Bright polymethine dyes, typified by carbocyanines, are employed in various fluorescence techniques such as the 3D visualization of living cell morphology and the tracking of extracellular vesicles in the blood vessels of a zebrafish. However, they often exhibit low photostability, particularly for dyes with red-shifted absorption/fluorescence wavelengths due to extended polymethine length, and limited photofunctionality. This limitation restricts their utility in specific applications requiring high-power excitation and/or a wash-free approaches. This study introduces novel merocyanine dyes, MCPY3 and MCPY5, comprising a newly developed pyrene-fused dioxaborine and polymethine chain. Despite their minimal polymethine lengths, their absorption/fluorescence wavelengths reside in the red to near infra-red regions due to the substantial π-conjugation system of pyrene. Moreover, they exhibit a considerably superior photostability to carbocyanine dyes and fluorogenic behavior between low (ON) and high (OFF) polar solvents, while maintaining brightness comparable to carbocyanine. Leveraging these advantages, the hydrophilic analogs of MCPY3, MCPY3S, were applied to two-photon microscopy imaging of the skin tissues on the finger of a living mouse. The dye clearly visualized the individual cell morphology in the epidermis and the elastin within the dermis, highlighting the potential of the new dye as a valuable tool for fundamental dermatological and histological studies.
Optimal design of hybrid renewable-energy microgrid system: a techno–economic–environment–social–reliability perspective
Authors: Gupta Manoj , Bhargava Annapurna 
Published: January 2024

Abstract
The main objective of this paper is to select the optimal model of a hybrid renewable-energy microgrid (MG) system for a village in India. The MG comprises solar photovoltaic (PV) modules, a wind turbine generator, a biomass generator, a battery bank, a diesel generator and an electric vehicle. The optimal model selection is based on technical, economic, environmental, social and reliability parameters. A novel spoonbill swarm optimization algorithm is proposed to select the best hybrid MG system. The optimization results are compared with particle swarm optimization, the genetic algorithm and the grasshopper optimization algorithm. The number or size of components of the optimized MG system is 215 PV modules, 92 kW of wind turbine generation, 25 kW of biomass generation, 267 batteries, 22 kW of electric vehicles and 30 kW of diesel generation. The optimized system was selected based on technical factors such as renewable dispersion (93.5%), the duty factor (5.85) and excess energy (15 975 kWh/year) as well as economic considerations including the net present cost (Rs. 34 686 622) and the cost of energy (9.3 Rs./kWh). Furthermore, environmental factors such as carbon emissions (396 348 kg/year) and atmospheric particulate matter (22.686 kg/year); social factors such as the human progress index (0.68411), the employment generation factor (0.0389) and local employment generation (15.64643); and reliability parameters including loss of power supply probability (0.01%) and availability index (99.99%) were considered during the selection process. The spoonbill swarm optimization algorithm has reduced the convergence time by 1.2 times and decreased the number of iterations by 0.83 times compared with other algorithms. The performance of the MG system is validated in the MATLAB® environment. The results show that the MG system is the optimal system considering technical, economic, environmental, social and reliability parameters. Additionally, the spoonbill swarm optimization algorithm is found to be more efficient than the other algorithms in terms of iteration time and convergence time.
A hybrid solar–biogas system for post-COVID-19 rural energy access
Authors: Overen Ochuko K , Obileke KeChrist , Meyer Edson L , Makaka Golden , Apeh Oliver O 
Published: January 2024

Abstract
Solar home systems for rural electrification are often designed with a limited energy supply, which presents a drawback for the technology. Furthermore, uncontrolled livestock faeces in rural communities constitute environmental sanitation and health risks. Livestock excrement can be used through a biogas digester to supplement solar energy to provide adequate and sustainable electricity access to underserved rural communities while achieving waste management. Therefore, this study presents a hybrid solar–biogas system for a more dynamic energy supply and waste management for post-Covid recovery plans in rural communities. A parametric research approach that involves the use of the Integrated Environment Solution Virtual Environment software application and mathematical models to design the desired household load and the hybrid system sizing is used in the study. The findings show that the daily household energy consumption was 6.6 kWh, equivalent to 206.40 kWh/month. A 1.2-kWp and 1.2-m3 hybrid solar–biogas system was found to adequately power the house. Financially, the total initial investment cost of the system was $5777.20 with a net present value of $6566.78, net profit of $4443.6, a payback period of 14 years and 8 months, and a levelized cost of energy of $0.21/kWh; these include a 60% initial investment and maintenance costs subsidy. Energy performance contracting and energy-as-a-service were recommended to effectively run and operate the system. The study successfully revealed the design, specifications and upscaling mechanism of the proposed hybrid solar–biogas system. More research is required to unveil the efficacy of the system, the performance gap and the perception of the technology by the beneficiaries.
Exploring commercial water electrolyser systems: a data-based analysis of product characteristics
Authors: Jin Xin , You Shi , Petersen Marianne , Riofrio Jonathan , Thakur Soumya , Træholt Chresten , Feng Zhijian 
Published: January 2024

Abstract
The urgency for energy transition is evident through the increasing demand for new technologies such as water electrolysers (WEs), which have the potential to generate green hydrogen using renewable electricity. This paper aims to provide a comprehensive overview of the technical capabilities of commercially available WE system products. The analysis is based on publicly accessible data gathered from 28 WE manufacturers worldwide with a total of 186 products, focusing on technology types and various technical characteristics of each WE system, including capacity, footprint, hydrogen output pressure, hydrogen purity and conversion rate. The analysis reveals that the current WE system solutions in the market exhibit diverse and varied characteristics. Further, there is a lack of standardized product specifications adopted by manufacturers. This underscores the urgent need for the development of frameworks and standards. Implementing such standards is crucial for enhancing clarity and understanding, facilitating efficient comparisons and selection processes, and supporting the future advancement of WE technologies and WE-enabled Power-to-X applications on a global scale.
Triphosgene crosslinked lignin-based loose nanofiltration membrane with high dye/salt separation performance, anti-fouling, and bactericidal property
Authors: He Zhenyu , Zhang Na , Zhao Li , Li Qiang , Baqiah Hussein , Cui Wanling , Deng Huining 
Published: January 2024

Abstract
A high-performance lignin-based loose nanofiltration membrane is fabricated using quaternized lignin as a novel raw material and triphosgene as a crosslinker. It has high pure water permeance (33.8 L m−2 h−1 bar−1), dye rejections, and low salt rejections during the separation of dye/salt mixtures. The quaternary ammonium functional groups endow the membrane with excellent antibacterial properties. It also has satisfactory dye-fouling resistance and separation-performance stability. Triphosgene plays an important role in optimizing the membrane structure and enhancing permeability.
Enhancement of photochromic molecule decolorization by coating a thin Ti(O) layer over gold nanoparticles
Authors: Higashida Suguru , Toku Ryota , Nakano Genta , Mizutsu Ryo , Asato Ryosuke , Louis Marine , Akiyama Tsuyoshi , Kawai Tsuyoshi 
Published: January 2024

Abstract
Photochemical decolorization reaction of terarylenes with a hydroxy or a methoxy group is studied on the surface of gold nanoparticles (AuNPs)/TiO2 thin hybrid film. AuNPs were deposited on TiO2 film after UV irradiation with HAuCl4. The colored form of terarylenes could not be decolorized at the bare AuNPs on TiO2 under irradiation of green light (530 nm in wavelength). On the other hand, effective decolorization activity of terarylene, having a hydroxy group, was observed at the surface of AuNPs/TiO2 hybrid film with an optimized number of Ti(O) insulator layers on AuNPs. The mechanism for the enhanced decoloration is proposed based on the difference in the substituent of the terarylenes.
Assessment of the applicability of the LFC/3D-RISM-SCF scheme for pKa prediction in methanol solutions
Authors: Fujiki Ryo , Matsui Toru , Shigeta Yasuteru , Yoshida Norio , Nakano Haruyuki 
Published: January 2024

Abstract
The applicability of the linear fitting correction with the three-dimensional reference interaction-site model self-consistent field (LFC/3D-RISM-SCF) scheme, a pKa prediction scheme, for methanol solutions was investigated. The correlation between experimental and predicted pKa values of dissociative molecules with phenol, amine, and carboxyl derivatives was examined. The pKa values of the LFC/3D-RISM-SCF results showed a good linear correlation with the experimental pKa. This result demonstrates that the LFC/3D-RISM-SCF method can be applied to a variety of solvents other than water.
Determination of Fe2+ in tin oxide-containing glass through valence-selective solvent extraction and colorimetric analysis following glass decomposition
Authors: Kanno Naoki , Murata Makiko , Saijo Yoshitaka , Nakase Masahiko 
Published: January 2024

Abstract
This study explores the determination of ferrous (Fe2+) and ferric (Fe3+) ion concentrations in tin (Sn)-containing glass within a standard chemical laboratory setting, aiming to evaluate their applicability in mass-production sites. A novel method is presented for determining Fe2+ concentration in Sn-containing glass by adjusting the acid concentration during glass decomposition and solvent extraction using bis(2-ethylhexyl) hydrogen phosphate dissolved in n-dodecane. The results for Fe2+ and total Fe agreed with the certified values for Sn-containing glass.
Synthesis and structural characterization of benzene-1,3-disulfonamide-containing 11- to 13-membered heterocycles via double Mitsunobu annulation
Authors: Kaneda Kyosuke , Koideya Takato , Toshima Ryuji , Konno Yoshiki , Yamagishi Takehiro 
Published: January 2024

Abstract
The synthesis and 3D-conformation of several novel benzene-1,3-disulfonamides-containing 11- to 13-membered heterocycles have been achieved. Double Mitsunobu annulation was effective for the construction of medium to large ring systems in moderate chemical yields. In addition, the flexibility of sulfonamide moieties in these rings was determined by X-ray crystal structural analysis.
Synthesis of 1,1,4,4-tetra-aryl-1,3-butadienes possessing sulfur substituents at 2,3-positions via dithiol intermediates and their characteristic electrochromic behaviors
Authors: Eguchi Hiroshi , Hifumi Ryoyu , Nishiyama Hiroki , Inagi Shinsuke , Tomita Ikuyoshi 
Published: January 2024

Abstract
Synthesis and reactions of 2,3-dimercapto-1,1,4,4-tetra-aryl-1,3-butadienes as versatile intermediates for sulfur-containing 1,1,4,4-tetra-aryl-1,3-butadiene derivatives are described. The dithiols were prepared from cyclic polysulfides and their structures were characterized by single-crystal X-ray diffraction analyses. Both cyclic dithioacetals and acyclic S,S′-dimethyl derivatives were prepared by facile reactions of the corresponding dithiols. The acyclic sulfur-substituted dienes exhibited electrochromic behavior in which the solution turned from colorless to dark purple under an external electric field above a potential of 0.3 V vs Fc/Fc+.
Solvent dependence on the thermal cycloreversion reaction of photochromic diarylbenzene derivatives
Authors: Morimoto Yusuke , Kitagawa Daichi , Hamatani Shota , Kobatake Seiya 
Published: January 2024

Abstract
In this study, we investigated the solvent dependence on the thermal cycloreversion reaction of photochromic diarylbenzene derivatives. Interestingly, only in the case of a diarylbenzene derivative with methoxy groups, the thermal cycloreversion reaction was accelerated when protic solvents such as ethanol and methanol were used. Moreover, it was found that the thermal cycloreversion reaction was drastically accelerated by acid addition.