bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of non‐target toxicity of insecticides on Ganaspis brasiliensis (Ihering) in laboratory and field conditions
Authors: Fellin Lorenzo , Dal Zotto Giovanni , Lisi Fabrizio , Chiesa Serena Giorgia , Saddi Alberto , Fusillo Matteo , Anfora Gianfranco , Biondi Antonio , Mori Nicola , Rossi Stacconi Marco Valerio
Published: July 2024

Background

G1 strain Ganaspis brasiliensis (Ihering) has been recently released in both Europe and America as a biological control agent of the spotted wing drosophila, Drosophila suzukii (Matsumura). In initial phases of classical biological control programs, it becomes imperative to evaluate the susceptibility of parasitoids to insecticides, to identify the best alternatives to adopt in an integrated pest management and organic perspective. In this study, we evaluated lethal and sublethal effects of topical application of five different insecticides classes: neonicotinoids, diamides, pyrethroids, organophosphates and spinosyns. Additionally, we tested residual toxicity in field trials in vineyards and sweet cherry orchards.

Results

Adult wasps' susceptibility to different insecticides' classes were consistent between laboratory and field. Spinosad exhibited the highest toxicity, with a median lethal concentration (LC50) of 0.00372 of the maximum field dose, and the highest knock‐down effect in field trials, causing 92.5 ± 5% of mortality at T0. λ‐cyhalothrin showed sublethal effects on both male and female insects' longevity when applied at LC30. In field trials, deltamethrin showed the highest persistence, causing significant parasitoid mortality up to 14 days after treatment. Conversely, cyantraniliprole was the least toxic active ingredient according to both topical and residual bioassays, even though its residues caused mortality up to 7 days after the treatment in the field.

Conclusion

Our results indicate that spinosad and λ‐cyhalothrin are highly toxic to G. brasiliensis, making them incompatible with classical biological control programs. Cyantraniliprole exhibited lower toxicity, and may be considered a selective pesticide for the integrated management of D. suzukii. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Persistence of widespread moderate Spinosad resistance among wild melon fly (Zeugodacus cucurbitae) and oriental fruit fly (Bactrocera dorsalis) populations on the major Hawaiian islands
Authors: Stockton Dara G. , Kraft Laura , Dombrowski Patricia , Doucette Laura , Bosch Michael , Gutierrez‐Coarite Rosemary , Manandhar Roshan , Uyeda Jensen , Silva Joshua , Hawkins Jennifer , Shikano Ikkei
Published: July 2024

BACKGROUND

Insecticide resistance among invasive tephritid fruit flies poses a great risk to national food security and has the potential to disrupt quarantine and eradication programs, which rely on the efficacy of Spinosad to prevent widespread establishment in North America. During 2022 to 2023 we surveyed the extent of Spinosad resistance of two key species, oriental fruit fly Bactrocera dorsalis, and melon fly Zeugodacus cucurbitae, from 20 sites across five Hawaiian Islands including Kaua'i, O'ahu, Maui, Molokai and the “Big Island” (Hawai'i).

RESULTS

We used topical thoracic applications of eight concentrations of Spinosad ranging from 0.028 to 3.6 mg/mL to evaluate the lethal concentration (LC50 and LC99) required to kill wild‐caught males. Resistance ratios (RR) were calculated by comparing the LC50 of wild flies to laboratory susceptible lines maintained in colony. Our results identified at least two new sites of concern for melon fly resistance on the Big Island, and at least four sites of concern for oriental fruit fly, all of which were located on the Big Island. At these locations RRs were >5. On O'ahu, melon fly RRs were >10.

CONCLUSIONS

The persistence of Spinosad resistance is concerning, yet it is a reduction compared to the values reported previously and before changes to Spinosad use recommendations by local extension agents beginning in 2017. For oriental fruit fly, these RR values are the highest levels that have been detected in wild Hawai'i populations. These data suggest that expanded Spinosad reduction and replacement programs are warranted given the ongoing issues with Spinosad resistance in Hawai'i and expansion in the number of species affected. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.
Repellency, toxicity, and physiological actions of low molecular weight basic amines in mosquitoes
Authors: Yang Liu , Demares Fabien , Norris Edmund J. , Bloomquist Jeffrey R.
Published: July 2024

BACKGROUND

This study investigated the behavioral responses and toxicity of three basic amines: 1‐methylpiperazine, 1‐methylpyrrolidine, and triethylamine (TEA), compounds suggested previously to be anosmic in vapor exposures to caged mosquitoes.

RESULTS

These compounds showed repellency of Aedes aegypti mosquitoes, followed by flightlessness, knockdown, and paralysis, all increasing with exposure time and dosage. Electrophysiological experiments showed a blocking effect on nerve discharge of the Drosophila melanogaster larval central nervous system (CNS) with little evidence of hyperexcitation. Blockage of voltage‐gated (Kv2) potassium channel currents under patch clamp occurred at similar concentrations. Involvement of K+ channels in the action of basic amines was supported by behavior and CNS recordings of a Shaker Kv1 mutant exposed to TEA, where instead of blockage, a hyperexcitation of nerve firing was observed. Experiments on cockroach leg mechanoreceptors demonstrated neuronal excitation and on mosquito antennae strong electroantennogram (EAG) signals with an augmentation of blank air responses after a single puff of basic amine.

CONCLUSIONS

The neurophysiological effects of basic amines are consistent with K+ channel block, whereas the antennal EAG response was not obviously associated with anosmia. The low‐dose effects of basic amines appear to be repellency and bradykinesia. Overall, the findings provide key insights into the mechanisms underlying the biological activity of basic amines. © 2024 Society of Chemical Industry.
Unveiling the energetic complexity of noncovalent interactions in halogenated dimers
Authors: Liu Fang , Du Likai
Published: July 2024

The understanding of noncovalent interactions is crucial in explaining critical phenomena such as self‐assembly, chemical reactivity, and crystallization. This work examines the energetic diversity of conformations and local minima for several halogenated dimers, represented as R‐X (R = H, F, CH3, CF3; X = Cl, Br, I). Thousands of configurations are randomly generated and refined through geometric optimizations to yield a diverse set of molecular conformers. Frequency calculations were performed for all optimized conformers to confirm that they are local minima. The noncovalent interactions in optimized dimers of halogen‐containing molecules were analyzed with atom in molecules (AIM) method and symmetry‐adapted perturbation theory (SAPT). Additionally, a protocol for generating machine learning models to recover accurate predictions of the physically meaningful SAPT energy components with minor computational cost is presented. These results deepen our understanding of the intricate energy balance and dedicated equilibrium of different noncovalent interactions in halogenated dimers.
Greenhouse gas emissions during decomposition of cover crops and poultry litter with simulated tillage in 90‐day soil incubations
Authors: Salehin Sk Musfiq Us , Rajan Nithya , Mowrer Jake , Casey Kenneth D. , Somenahally Anil C. , Bagavathiannan Muthu
Published: July 2024

Investigating the impact of cover crops and manure on soil greenhouse gas (GHG) emissions is crucial for advancing our understanding of the climate‐smart potential of organic management practices. This soil incubation experiment was conducted to investigate the combined effects of manure and cover crop residue decomposition on soil carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4) emissions under simulated tillage conditions. Undisturbed soil cores, collected from an organic cotton (Gossypium hirsutum L.) field experiment, were incubated for 90 days in a 2 × 4 factorial design for 2 consecutive years. Four combinations of cover crop and poultry litter (PL) residues were the primary treatment factor. The amount of residues added in the incubation study reflected the cover crop biomass produced under field conditions and the amount of PL applied in the field. Residue treatments included PL only at the full application rate (250 kg ha−1), PL with oat (Avena sativa L.), PL with turnip (Brassica rapa subsp. rapa), and half the rate of PL with Austrian winter pea (Pisum sativum) (AWP). The residues were either soil incorporated or surface applied to simulate disking and no‐till field conditions. On average, 3.5% of applied carbon escaped as CO2 during the 90‐day incubation period across treatments. Similarly, on average, 0.75% of applied nitrogen escaped as N2O. The proportion of nitrogen emitted as N2O under simulated no‐till was 81.2% higher in 2020 (P < 0.05) compared to conventional tillage. In 2021, N2O emission was 35.8% higher (P < 0.1). When normalized over the amount of carbon added, total CO2 equivalent GHG emissions were the highest in the legume AWP treatment for both years. However, neither residue types nor simulated tillage affected net soil CH4 uptake (P > 0.1). While no‐till practices may increase soil total carbon and nitrogen stocks during the cover crops and manure decomposition, the impact on GHG emissions depends on residue type and should be considered in estimating the climate‐smart potential of organic management practices.
Sustainable development of local livelihoods in Vietnam: A demand‐driven approach through “One Commune, One Product”
Authors: Trang Nguyen Thuy , W. Kopp Steven , Tu Vo Hong
Published: July 2024

“One Commune One Product” (OCOP) is a national target program intended to develop the rural economy of Vietnam. The goal of the OCOP program is to identify and promote competitive, marketable products that originate from local and indigenous resources. Since its nationwide implementation in 2018, nearly 5000 OCOP products have been evaluated and certified for OCOP status. The present study interviewed 600 Vietnamese consumers and employed the latent class choice model to investigate the consumers' willingness to pay for OCOP attributes, including the ethical attributes of traceability information, local production, and fair trade, along with the government “star rating” for the product and the OCOP certification label. Through a choice experiment, we identified two distinct consumer segments, one of which (about 74% of the sample) expressed preference and willingness to pay price premiums for the product attributes and the other which (about 26%) was unwilling to pay for any of the attributes. We also found that the consumers in the “Optimist” segment were willing to pay a price premium for “private” product attributes compared to “public” attributes. Consumers in the “Opponent” segment were characterized as highly price sensitive; they expressed lower levels of concern for the environment and lower preferences for local products. Based on these results, we propose some policy implications for continued development of the OCOP program and local livelihoods.
Plant‐derived bioactive peptides: A comprehensive review
Authors: Kadam Deepak , Kadam Aayushi , Koksel Filiz , Aluko Rotimi E.
Published: July 2024

Bioactive peptides that are derived through the enzymatic hydrolysis of proteins have garnered significant attention for their diverse health‐promoting properties. This article delves into the technology behind plant‐derived bioactive peptide production by emphasizing the principles of enzyme hydrolysis. Furthermore, the review highlights the refinement techniques, employing membrane ultrafiltration and various forms of column chromatography to isolate and purify these peptides effectively. The bioactive properties of protein hydrolysates encompass a range of health benefits, including antihypertensive, antioxidant, anti‐diabetic, anti‐obesity, and neuroprotective effects. Additionally, bioactive peptides demonstrate promise in inhibiting cancer cell growth, supporting bone health, and modulating immune responses. These properties hold immense potential for revolutionizing approaches to various health conditions. Continued research in this field promises further insights and breakthroughs, propelling bioactive peptides to the forefront of nutrition and healthcare innovation. The convergence of advanced technology and the multifaceted bioactivity of peptides present an exciting avenue for improving human well‐being and addressing a wide array of health challenges.
Fabricating Ion Sieves by 3D Printing for Selective Lithium Adsorption from Brines
Authors: Martínez Omar Jair Licea , Delgado Beatriz Guadalupe Saucedo , Rodríguez Luis Mario González , Sequeda Jair Fernando Rangel , Rivera Gloria Lourdes Dimas , Martínez Ricardo Briones , De Haro Del Río David Alejandro
Published: July 2024

This work presents the formation of a stable 3D monolith based on manganese oxide for the adsorption of lithium from brine. The precursor phase was prepared by microwave‐assisted hydrothermal synthesis and a subsequent calcination process to achieve the desired crystalline phase LiMn2O4. The monolith was formed using additive manufacturing, which allowed its size and shape to be controlled. Subsequently, this monolith was washed with a HCl solution to generate adsorption sites for lithium. The prepared materials were characterized by XRD, FTIR, TGA, N2 physisorption, and SEM‐EDS. Analysis confirmed that the 3D monolith retained its crystalline structure throughout the process. The kinetic characteristics of the adsorption process were evaluated using pseudo‐first and pseudo‐second order equations, as well as Freundlich and Langmuir equations, to describe thermodynamic equilibrium. Monoliths were able to capture lithium up to 13.84 mg/g and the Freundlich equation described the equilibrium (R2=0.9751), while the second‐order equation better described the kinetic behavior (R2=0.9130). Results showed that monoliths are selective towards lithium in the presence of competing cations. The stability of the materials was evaluated in adsorption‐desorption cycles, demonstrating a competitive reuse after five cycles. This research presents a promising new approach for developing efficient lithium extraction methods from brine.
Arsenate Stabilization via Dynamic Covalent Chemistry
Authors: Gaspar‐López Federico Javier , Lechuga‐Islas Víctor Daniel , Tlahuext Hugo , Navarrete‐Vazquez Gabriel , Moo‐Puc Rosa E. , Chale‐Dzul Juan B. , Tapia‐Benavides Antonio R. , Tlahuextl Margarita
Published: July 2024

We report the synthesis of arsenic heterocycles derived from saccharides 2–4 and AsCl3. Compounds 5 and 6 are stable in aqueous solutions, DMSO, or methanolic solutions. However, NMR and HPLC studies revealed that intramolecular trans‐esterification processes leads to dynamic equilibria. Theoretical studies revealed that three arsenates and two arsoranes participate in these intramolecular equilibria and account for the experimental spectroscopy and HPLC results. Through the correlation between the experimental and theoretical 13C NMR spectra, we proposed the speciation of arsenic Compounds 5 and 6. Moreover, experimental and theoretical IR spectra demonstrated that arsenates 5 A and 6 A predominate in the solid state. QTAIM studies were performed to explain the chemical shifts in the 13C NMR spectra. Biological studies suggest that the structural flexibility of Compounds 5 and 6 increase the cytotoxic and antiproliferative activities of these compounds.
Design, Synthesis and Evaluation of Thioacetamide‐Tethered Thiadiazole‐1,2,4‐Triazole Hybrids as SHP2 Inhibitors for Cancer Therapy
Authors: Mitra Rangan , Kumar Sandeep , Chaudhuri Aiswarya , Agrawal Ashish Kumar , Ayyannan Senthil Raja
Published: July 2024

Src homology‐2 (SH2) domain‐containing phosphatase‐2 (SHP2), the first protooncogenic phosphatase is a key mediator in the development and progression of various cancers. Several allosteric sites have been identified in SHP2, inhibitors of which are being developed. In the current study, we have designed and synthesized a library of 21 thioacetamide‐tethered thiadiazole‐1,2,4‐triazole hybrids (compounds 16–36) and evaluated their in vitro SHP2 inhibitory potential. Compound 28 (N‐(5‐(benzo[d][1,3]dioxol‐5‐yl)‐1,3,4‐thiadiazol‐2‐yl)‐2‐((5‐(4‐methoxyphenyl)‐4H‐1,2,4‐triazol‐3‐yl)thio)acetamide) emerged as the most potent SHP2 inhibitor (IC50=0.318±0.001 μM) inhibiting the enzyme in a mixed to non‐competitive manner. In silico studies revealed that the lead inhibitor strongly binds to the tunnel allosteric site of SHP2. Further, cytotoxicity studies revealed that compound 28 caused death of SHP2‐driven MCF‐7 (GI50=37.02±0.25 μM) and U87MG cells (GI50=68.69±0.21 μM) in a dose‐dependent manner and inhibited MCF‐7 cell colony formation and migration. Flow cytometric analysis showed that it exerted its antiproliferative effect on U87MG cells by inducing early apoptosis (Q2 phase) and inhibiting cell cycle progression at the G1 and S phase. Compound 28 was shown to increase oxidative stress in the U87 cells by promoting ROS generation and loss of mitochondrial integrity. In summary, the present study produced a potent SHP2 inhibitor (compound 28) with a promising in vitro cytotoxicity profile, thus meriting further investigation.
Facile Condensation of 2‐Aminobenzaldehydes into Azolo[4,5‐b]Quinolones
Authors: Opryshko Victoria E. , Zaitseva Elvira R. , Ivanov Dmitrii S. , Eshtukov‐Shcheglov Artur V. , Tyurin Anton P. , Mikhaylov Andrey A. , Smirnov Alexander Yu. , Baranov Mikhail S.
Published: July 2024

An operationally simple approach to azolo[4,5‐b]quinolines based on the condensation of 2‐aminobenzaldehydes with various azolones is developed. A series of 22 compounds was synthesized typically in good yields (40–92 %).
Oxime Derivatives: A Valid Pharmacophore in Medicinal Chemistry
Authors: Chandran Namitha , Bose Kuntal , Thekkantavida Amrutha Chandran , Thomas Riya Rachel , Anirudhan Karthika , Bindra Sandeep , Sura Sooraj , Hasan Haydara Ammar , Kumar Sunil , Rangarajan T. M. , Al‐Sehemi Abdullah G. , Gahtori Prashant , Kim Hoon , Mathew Bijo
Published: July 2024

Oximes, belonging to imines with the general formula of RR'C=NOH, are produced by the nucleophilic addition reaction between hydroxylamine with ketones or aldehydes, yielding corresponding aldoxime and ketoxime. The presence of hydrogen bond acceptor and donor is the classical feature of oxime‐containing structural framework. This review presents a summary of the role of oximes and its structure activity relationships including antimicrobial, anticancer, anti‐inflammatory, antihyperglycemic, insecticidal agents, along with their involvement in the treatment of organophosphorus poisoning. The review also focused on the pharmacological profile of lead molecules of several classes of oxime‐containing compounds.
R‐BINOL‐Chiral Phosphoric Acid Catalyzed Regioselective Synthesis of 7‐Oxo‐Pyrazolo[1,2‐a]Pyrazoles via [3+2] Cycloaddition Reaction of Morita Baylis Hillman Adducts with N, N’‐Cyclic Azomethine Imines
Authors: Karthikeyan S. , Choppella Sairathna , Murali Anna Chandrasekar , Subimol K. R. , Monica J. Helen Ratna , Ravva Mahesh Kumar , Kumar Ayyanoth Karthik Krishna
Published: July 2024

We report an efficient [3+2] cycloaddition protocol for the synthesis of pyrazolo[1,2‐a]pyrazolones from Morita‐Baylis‐Hillman adducts and N,N’‐cyclic azomethine imines. The R‐BINOL chiral phosphoric acid was identified as the suitable catalyst for the reported cycloaddition protocol. Almost all MBH adducts regioselectively delivered 7‐oxo‐pyrazolo[1,2‐a]pyrazoles at an efficient yield of 69–91 %. With exception, the MBH adducts derived from acrylonitrile deliver 5‐oxo‐pyrazolo[1,2‐a]pyrazoles comparatively at a higher yield than the 7‐oxo‐pyrazolo[1,2‐a]pyrazoles. The density functional theory (DFT) studies demonstrate that the reaction is thermodynamically more feasible in the presence of R‐BINOL chiral phosphoric acid.
Novel Coumarin‐Pyrazole‐Thiazoles Hybrids: Synthesis, Anticancer Activity, Molecular Docking and In Silico ADMET prediction Studies
Authors: Alsolimani Ayat K. , Ali Tarik E. , Assiri Mohammed A. , Shati Ali A. , Alfaifi Mohammad Y. , Elbehairi Serag E. I.
Published: July 2024

A novel series of coumarin‐pyrazole‐thiazoles hybrids was designed. The methodology depended on a simple condensation reaction of 3‐(2‐oxo‐2H‐chromen‐3‐yl)‐1‐phenyl‐1H‐pyrazole‐4‐carboxaldehyde with a variety of thiazole compounds having amino or active methylene groups. In addition, another series of 1‐(thiazol‐2‐yl)‐3‐(2‐oxo‐2H‐chromen‐3‐yl)‐1H‐pyrazole‐4‐carboxaldehydes was also achieved by applying Vilsmeier‐Haack formylation on 3‐[1‐(2‐(thiazol‐2‐yl)hydrazineylidene]ethyl)‐2H‐chromen‐2‐ones. The obtained products were verified by spectral techniques such as IR, NMR, and mass spectra. To screen their abilities to inhibit cancer cell growth, these compounds were investigated against three tumor cell lines (MCF‐7, HepG2, and HCT116) using a standard method called SRB. The products 3 e, 7 b, 12 c and 14 a have considerable cytotoxic effects comparable to Doxorubicin. These products caused significant cell death by late apoptosis in all tumor cell lines. Furthermore, they preferentially induced G2 cell cycle arrest in MCF‐7 and HepG2 cells, while causing G1 cell cycle arrest in HCT116 cells. The molecular docking of these bioactive products showed good binding affinities with Cyclin‐dependent kinase 8 (CDK‐8). The ADMET‐predicted drug‐likeness properties of these bioactive compounds enable them to can used as promising anticancer agents.
Size‐Dependent Optical Properties and Exciton Self‐Trapping Emission in Carbon Quantum Dots
Authors: Van Duong Pham , Anh Thi Le , Duc Toan Le , Hong Minh Pham , Thanh Binh Nguyen , Hoang Tung Do , Dinh Lam Nguyen , Minh Hoa Nguyen
Published: July 2024

Carbon quantum dots (CQDs), synthesized through controlled microplasma treatment of orange juice, exhibit unique luminescent characteristics. The impact of synthesis time on particle size was investigated. Deconvoluted emission spectra displayed broad bands, peaking at an excitation wavelength of 350 nm for CQD sizes of 2.06, 2.4, and 3.09 nm, indicating multiple fluorescence peaks. This suggests a mixture of CQDs with different excitation energies on their surfaces. Luminescence kinetics unveiled three exponential decay components with time constants of 2.73, 4.61, and 3.27 ns, indicating multiple luminescent centers. Emission behavior affected by excitation wavelengths ranging from 350 to 490 nm suggests that quantum transition probabilities are influenced by impurities or defects. These findings emphasize the size‐dependent optical properties and exciton self‐trapping (EST) emission of CQDs. The calculation of the Huang‐Rhys factor S values underscores the profound influence of carrier‐phonon coupling and the Huang‐Rhys factor on the emergence of ESTs within CQDs. Understanding these interactions is crucial for fully utilizing the capabilities of CQDs in applications spanning optoelectronics, sensors, bioimaging, and various technological fields.
Thermal Sight: A Position‐Sensitive Detector for a Pinpoint Heat Spot
Authors: Peng Jun , Zhao Pai , Venugopal Rakshith , Deneke Kristian , Haugg Stefanie , Blick Robert , Zierold Robert
Published: July 2024

Precise positioning is a never‐ending goal in both fundamental science and technology. Recent decades of advancements in high‐precision position detection have predominantly relied on photoelectric effects for light detection in semiconductors. Herein, a different approach is proposed: The thermoelectric‐based position‐sensitive detector (T‐PSD) concept is designed to detect single heat spots arising from various energy sources, including electromagnetic radiation, electrons, and macroscopic mechanical heat. The T‐PSD concept is initially derived mathematically from the fundamental principles of heat conduction and the Seebeck effect. Subsequently, it is proved by finite element simulation in both 1D and 2D configurations. Following this theoretical groundwork, T‐PSD prototypes are fabricated and subjected to positional detection using various stimuli such as CO2 laser beam, hot soldering tip, and electron beam. In the prototypes, structured aluminum‐doped zinc oxide thermoelectric thin films, prepared via atomic layer deposition, are outfitted with voltage probes, enabling the measurement of thermoelectric voltages as a function of position and the intensity or temperature of the heat spot. Furthermore, practical decoding strategies are introduced to infer the position from the measured signals. The T‐PSD in this article showcases considerable promise in high‐precision position detection such as (quasi‐)particle tracking and precision machinery, offering an alternative concept in PSD design.
ICP–MS Assisted EDX Tomography: A Robust Method for Studying Electrolyte Penetration Phenomena in Gas Diffusion Electrodes Applied to CO2 Electrolysis
Authors: Rieder Alain , Lorenzetti Julia , Zelocualtecatl Montiel Iván , Dutta Abhijit , Iarchuk Anna , Mirolo Marta , Drnec Jakub , Lorenzutti Francesca , Haussener Sophia , Kovács Noémi , Vesztergom Soma , Broekmann Peter
Published: July 2024

A carbon paper‐based gas diffusion electrode (GDE) is used with a bismuth(III) subcarbonate active catalyst phase for the electrochemical reduction of CO2 in a gas/electrolyte flow‐by configuration electrolyser at high current density. It is demonstrated that in this configuration, the gas and catholyte phases recombine to form K2CO3/KHCO3 precipitates to an extent that after electrolyses, vast amount of K+ ions is found by EDX mapping in the entire GDE structure. The fact that the entirety of the GDE gets wetted during electrolysis should, however, not be interpreted as a sign of flooding of the catalyst layer, since electrolyte perspiring through the GDE can largely be removed with the outflow gas, and the efficiency of electrolysis (toward the selective production of formate) can thus be maintained high for several hours. For a full spatial scale quantitative monitoring of electrolyte penetration into the GDE, (relying on K+ ions as tracer) the method of inductively coupled plasma–mass spectrometry (ICP–MS) assisted energy dispersive X‐ray (EDX) tomography is introduced. This new, cheap and robust tomography of non‐uniform aspect ratio has a large planar span that comprises the entire GDE surface area and a submicrometer depth resolution, hence it can provide quantitative information about the amount and distribution of K+ remnants inside the GDE structure, in three dimensions.
Exploiting Mechanism of Enhanced Charge Transfer in Ternary Organic Solar Cells at Low Energy Loss
Authors: Dahiya Hemraj , Suthar Rakesh , Singh Manish Kumar , Karak Supravat , Sharma Ganesh D.
Published: July 2024

The structural disorder and aggregation of the third acceptor with the host active layer are critical in the light absorption, film morphology, and charge‐carrier mechanism of their photovoltaic blends to achieve highly efficient organic solar cells (OSCs). However, an effective third component needs to be introduced in the host binary blend as a combination of ternary blend, which can improve the absorption profile, film morphology, and charge dynamics. In this work, non‐fullerene acceptor DRCTF is incorporated as a third component in host PM6:Y6 binary blend. Compared to host blend, the ternary blend improves charge‐transfer processes, as evidenced by steady‐state photoluminescence and time‐resolved photoluminescence measurements. It is found that the addition of 20% DRCTF into host binary blend results in improved charge dissociation and transport with reduced recombination, and voltage losses. All these characteristics contribute to an improved power conversion efficiency of 14.45% in the PM6:Y6:DRCTF ternary OSCs (T‐OSCs), compared to PM6:Y6 (12.46%) in open‐air fabrication conditions. Consequently, in this study, the impact of third components on the charge‐transfer mechanism in T‐OSCs is elucidated. These findings suggested that T‐OSCs with a perfectly chosen third component in the host binary blend achieve a comprehensive absorption profile, smooth film morphology, efficient charge dynamics, and reduced voltage loss.
Sequential Deposition of Diluted Aqueous SnO2 Dispersion for Perovskite Solar Cells
Authors: Pylnev Mikhail , Nishikubo Ryosuke , Ishiwari Fumitaka , Wakamiya Atsushi , Saeki Akinori
Published: July 2024

The widespread use of tin dioxide (SnO2) thin films as electron transport layer (ETL) of perovskite solar cells (PSCs) has been facilitated by commercial SnO2 nanocolloid dispersion. Nevertheless, challenges such as nanoparticle agglomeration have emerged, impacting film quality and interface properties critical for PSC performance. Herein, the efficacy of sequential, multistep spin‐coating of repeatedly diluted SnO2 aqueous suspension as a simple and effective approach to enhance ETL properties is explored. Through systematic experiments using dynamic light scattering, cyclic voltammetry, optical spectroscopy, and photoconductivity, it is demonstrated that the sequential deposition significantly improves the flatness and coverage of SnO2, leading to improved electron transport and transfer from a perovskite layer. Such a synergetic effect enables to fabricate lead iodide PSC (FAPbI3, FA: formamidinium) with a power conversion eﬃciency of 22.99% compared to 20.48% for the conventional 1‐step SnO2 layer. The findings underscore the potential of sequential SnO2 deposition as a promising technique for robust SnO2 films of photoelectric conversion devices.
Direct Quantitation of Poloxamer 188 in Adeno‐Associated Virus Products Using Reversed‐Phase Chromatography With Charged Aerosol Detection
Authors: Nguyen Tai , Sosic Zoran , Xu Chong‐Feng
Published: July 2024

Poloxamer 188 is a commonly used excipient in formulations to protect products against mechanical stress and adsorption loss. In this work, an analytical method was developed to directly and accurately quantitate the amount of Poloxamer 188 in the drug substance of three different adeno‐associated virus (AAV) serotypes. The method is based on reversed‐phase liquid chromatography separation of virus particles from Poloxamer 188 using a charged aerosol detector and provides linearity from 5 to 200 ppm. A good assay precision and analyte recovery allows its adaptability to potentially various applications from process development support to AAV drug product release testing.
Promoting teachers' advocacy and agency for equity in STEM education through research and reflection
Authors: Holincheck Nancy M. , Galanti Terrie M. , Butler Tiffany N.
Published: July 2024

Systemic equity challenges in K‐12 STEM education place students from minoritized groups on an uneven footing, restricting access and opportunity for the diverse students who make up the majority population in US public schools. Teachers play a key role in advocating for equity and justice in STEM education. In positioning themselves as agents of change, they have the power to impact their classrooms, schools, and communities. Using a collaborative coding process informed by dominant and critical framings of equity in STEM education, we analyzed equity research presentations and final written reflections from a graduate course for practicing teachers (n = 23) focused on STEM integration. Teacher participants demonstrated one of four advocacy orientations: (a) equity in classroom teaching, (b) STEM education, (c) equity in STEM education, or (d) neither equity nor STEM. Our analysis of teachers' final course reflections led us to develop a rubric using principles of grammar to evaluate the levels of agency evident in teachers' statements. Most teachers were at least minimally agentic for STEM, but fewer teachers were agentic for equity. Only four of 23 teachers were highly agentic for equity in STEM education. We identify a need for more purposeful scaffolding in professional learning to build teacher advocacy and agency for equity in STEM education. Future research should explore the high‐leverage practices in STEM teacher education that foster advocacy and agency.
Shear strength equation of soils in a wide suction range under various initial void ratios
Authors: Song Zhaoyang , Zhang Zhihong
Published: July 2024

Shear strength equation is a basic theory for solving many geotechnical engineering problems. Although the shear strength equation has received widespread attention, shear strength of clay under wide suction range and different initial void ratio conditions cannot be well predicted. This study aims to establish a new strength equation applicable to soils within a wide suction range. Considering the capillary and adsorptive parts of soil–water interactions, a cohesion expression related to the degree of adsorbed water saturation Sra and the effective stress related to the degree of capillary water saturation Src are proposed. After that, based on the Mohr–Coulomb theory, a shear strength equation of unsaturated soils in a wide range of suction under various is proposed. Five parameters are included in the equation. It is easy to calibrate them through shear tests on saturated and the fully dried soils. It is verified that not only the sandy clay till and clayed silt but also the expansive soil's shear strength in wide ranges of suction under various can be well predicted.
Onset of a conceptual outline map to get a hold on the jungle of cluster analysis
Authors: Van Mechelen Iven , Hennig Christian , Kiers Henk A. L.
Published: July 2024

The domain of cluster analysis is a meeting point for a very rich multidisciplinary encounter, with cluster‐analytic methods being studied and developed in discrete mathematics, numerical analysis, statistics, data analysis, data science, and computer science (including machine learning, data mining, and knowledge discovery), to name but a few. The other side of the coin, however, is that the domain suffers from a major accessibility problem as well as from the fact that it is rife with division across many pretty isolated islands. As a way out, the present paper offers a thorough and in‐depth review of the clustering domain as a whole under the form of an outline map based on an overarching conceptual framework and a common language. With this framework we wish to contribute to structuring the clustering domain, to characterizing methods that have often been developed and studied in quite different contexts, to identifying links between methods, and to introducing a frame of reference for optimally setting up cluster analyses in data‐analytic practice.

This article is categorized under:

Technologies > Structure Discovery and Clustering
NHS dentistry in Britain: A long overdue check‐up
Authors: Lunt Neil , Exworthy Mark
Published: July 2024

There has been longstanding international fascination with the British National Health Service since it was established in 1948. The British population itself has offered enduring support for the principles and institutions of public provision. However, coverage of the NHS has typically been uneven in academic and policy debates. There is limited understanding of some darker corners of NHS provision resulting in a partial picture of public service provision. Public dentistry has been a Cinderella service in broader debates about the NHS and a check‐up is overdue. We offer a long‐term view of dentistry that assesses the current state of dental health policy, including its gradual decay. We examine the purpose of dentistry and the challenge of injecting fundamental National Health Service values (weighted capitation and a focus on need) into services and which necessitates redistribution and tackling shibboleths of NHS provision. Alongside political values and public attitudes, we examine the interests of professional stakeholders and how the combination of values, attitudes, and interests does not currently cohere into a sustainable policy. We explore how dentistry might recover purpose and respond to need. Discussion is prescient considering an acknowledged crisis in British dental care, including widespread public and media coverage, and with 2024 being a general election year with NHS provision a familiar battleground.
Reactivity of Phosphaalkyne tBuCP Toward a Ga‐Functionalized Germylene
Authors: Sun Xiaofei , Roesky Peter W.
Published: July 2024

Phosphaalkynes are the heavier congener of nitriles which feature a polarized Cδ−≡Pδ+ triple bond. Since the isolation of the first phosphaalkyne in 1981, these compounds have become important ligands for transition metals and valuable building blocks in synthetic chemistry. The reported reactivity with germylenes is rare, to expand this chemistry, we studied the reactivity of the recently developed gallium‐substituted germylene 1 ([LPhGe−Ga(Cl)LBDI] (LPh=PhC(NtBu)2; LBDI=[{2,6‐iPr2C6H3NCMe}2CH]) with tBuC≡P. Already at room temperature, insertion of the phosphaalkyne into the Ga−Ge bond occurred, resulting a metal‐functionalized (Z)‐phosphaalkenyl complex [LPhGe{C(tBu)=P}−Ga(Cl)LBDI] (2). Complex 2 was characterized by single crystal X‐ray diffraction analysis and spectroscopic methods (1H, 13C{1H}, 31P{1H} NMR and IR).
Asymptotic analysis of MHD chemically reacting boundary layer flow of Jeffrey hybrid nanofluid
Authors: Kathuroju Santhosh Kumar , Prashar Preeti , Ojjela Odelu
Published: July 2024

Fluids with enhanced heat transport characteristics are essential for efficient convection heat transportation. Hybrid nanofluids have demonstrated their effectiveness as viable substitutes for conventional heat transport fluids. This study explores the heat and mass exchange occurring within a chemically reactive, unsteady boundary layer flow of a copper oxide‐multi‐walled carbon nanotubes (CuO‐MWCNTs)/ethylene glycol Jeffrey hybrid nanofluid. Additionally, the influence of heat source/sink effects in a hydromagnetic environment is carefully added. The study employs a non‐Newtonian flow model and incorporates the Arrhenius activation energy for analysis. The hybrid nanofluid consists of a base fluid, ethylene glycol, enriched with copper oxide nanoparticles and multi‐walled carbon nanotubes. The governing coupled non‐linear partial differential equations are transformed into ordinary differential equations using similarity transformations, considering appropriate free stream, and wall boundary conditions; then, the Shooting method is employed to solve the resulting ordinary differential equations (ODEs) in MATLAB. The graphical and numerical outcomes are studied for various parameter combinations. The graphs illustrate the numerical results for the CuO‐MWCNTs/ethylene glycol hybrid nanofluid. These results are comprehensively discussed to analyze the influence of different thermo‐fluidic parameters on the Jeffrey hybrid nanofluid's heat, mass, and flow characteristics. The skin friction, Nusselt number, and Sherwood number are provided in a numerical table that displays the alterations of these parameters across various parameter values. As the Jeffrey fluid parameter rises, the Nusselt number and skin friction escalate, while the Sherwood number diminishes. Conversely, as the Deborah number rises, the Nusselt number and skin friction decline, but the Sherwood number increases. A comparative analysis with published results confirms the consistency of the present results.
Nearly critical superfluid: effective field theory and holography
Authors: Bu Yanyan , Gao Hongfei , Gao Xin , Li Zhiwei
Published: July 2024

Abstract

We study a nearly critical superfluid system from two complementary approaches. Within the first approach, we formulate a Schwinger-Keldysh effective field theory (EFT) for the system when it is located slightly above the critical temperature. The dynamical variables in the EFT construction are two scalars: a neutral scalar associated with the conserved U(1) charge, and a complex scalar describing the order parameter. The set of symmetries, particularly the dynamical Kubo-Martin-Schwinger (KMS) symmetry and chemical shift symmetry, strictly constrains the form of EFT action. Within the second approach, using the holographic Schwinger-Keldysh technique, we derive the effective action for a “microscopic” holographic superfluid, confirming the EFT construction. A systematic inclusion of non-Gaussianity is one highlight of present study.
Topological defects in K3 sigma models
Authors: Angius Roberta , Giaccari Stefano , Volpato Roberto
Published: July 2024

Abstract

We consider the topological defect lines commuting with the spectral flow and the $$ \mathcal{N} $$
N
= (4, 4) superconformal symmetry in two dimensional non-linear sigma models on K3. By studying their fusion with boundary states, we derive a number of general results for the category of such defects. We argue that while for certain K3 models infinitely many simple defects, and even a continuum, can occur, at generic points in the moduli space the category is actually trivial, i.e. it is generated by the identity defect. Furthermore, we show that if a K3 model is at the attractor point for some BPS configuration of D-branes, then all topological defects have integral quantum dimension. We also conjecture that a continuum of topological defects arises if and only if the K3 model is a (possibly generalized) orbifold of a torus model. Finally, we test our general results in a couple of examples, where we provide a partial classification of the topological defects.
Strong Cosmic Censorship in Kerr-Newman-de Sitter
Authors: Davey Alex , Dias Óscar J. C. , Sola Gil David
Published: July 2024

Abstract

Christodoulou’s formulation of Strong Cosmic Censorship (SCC) holds true for Kerr-de Sitter black holes. On the other hand, Reissner-Nordström-de Sitter black holes violate SCC. We do a detailed scan of the parameter space of Kerr-Newman-de Sitter black holes between these two limiting families, to identify the boundary that marks the transition between solutions that respect and violate SCC. We focus our attention on linear scalar field perturbations. SCC is violated inside a (roughly) ‘spherical’ shell of the parameter space of Kerr-Newman-de Sitter, centred at the corner that describes arbitrarily small extremal Reissner-Nordström-de Sitter solutions. Outside of this region, including the Kerr-de Sitter limit, we identify perturbation modes that decay slow enough to enforce SCC. Additionally, we do a necessary study of the quasinormal mode spectra of Kerr-Newman-de Sitter in some detail. As established in the literature, in the Kerr-de Sitter and Reissner-Nordström-de Sitter limits, we find three families of modes: de Sitter, photon sphere and near-horizon modes. These interact non-trivially away from the Reissner-Nordström-de Sitter limit and display eigenvalue repulsions like in Kerr-Newman black holes.
Collider sensitivity to SMEFT heavy-quark operators at one-loop in top-quark processes
Authors: Degrande C. , Rosenfeld R. , Vasquez A.
Published: July 2024

Abstract

We study the effects of four-heavy-quark operators in the production of top quarks in the framework of the Standard Model Effective Field Theory (SMEFT) at the LHC. In particular, we compute for the first time the total contribution of the four-top-quark operator which enters only at the one-loop level in the top-quark pair production process. Analytical results at one-loop are presented for the gluon- and quark-initiated sub-processes, which allowed a first complete validation of the SMEFT@NLO in MadGraph5_aMC@NLO. The 95% CL bounds on four-heavy-quark operators from the available top-quark pair and four-top-quark production data are provided, which are complementary to other bounds found in the literature. We focus on the comparison of the sensitivities of the top-quark pair and the four-top-quark production processes, where in the latter case the four-top-quark operator contributes at tree-level. We conclude that the sensitivities of the two processes to four-heavy-quark operators are comparable. The projected sensitivities of both processes at HL-LHC are also presented.
Deconstructing flavor anomalously
Authors: Fuentes-Martín Javier , Lizana Javier M.
Published: July 2024

Abstract

Flavor deconstruction refers to ultraviolet completions of the Standard Model where the gauge group is split into multiple factors under which fermions transform non-universally. We propose a mechanism for charging same-family fermions into different factors of a deconstructed gauge theory in a way that gauge anomalies are avoided. The mechanism relies in the inclusion of a strongly-coupled sector, responsible of both anomaly cancellation and the breaking of the non-universal gauge symmetry. As an application, we propose different flavor deconstructions of the Standard Model that, instead of complete families, uniquely identify specific third-family fermions. All these deconstructions allow for a new physics scale that can be as low as few TeV and provide an excellent starting point for the explanation of the Standard Model flavor hierarchies.
On Lieb–Robinson Bounds for a Class of Continuum Fermions
Authors: Hinrichs Benjamin , Lemm Marius , Siebert Oliver
Published: July 2024

We consider the quantum dynamics of a many-fermion system in

$${{\mathbb {R}}}^d$$

R

d

with an ultraviolet regularized pair interaction as previously studied in Gebert et al. (Ann Henri Poincaré 21(11):3609–3637, 2020). We provide a Lieb–Robinson bound under substantially relaxed assumptions on the potentials. We also improve the associated one-body Lieb–Robinson bound on

$$L^2$$

L
2

-overlaps to an almost ballistic one (i.e., an almost linear light cone) under the same relaxed assumptions. Applications include the existence of the infinite-volume dynamics and clustering of ground states in the presence of a spectral gap. We also develop a fermionic continuum notion of conditional expectation and use it to approximate time-evolved fermionic observables by local ones, which opens the door to other applications of the Lieb–Robinson bounds.
Implications of stress concentrators and work hardening in flat tensile samples subjected to milling and abrasive water jet machining
Authors: Buglioni Luciano , Krahmer Daniel Martínez , Sánchez Egea Antonio , Simoncelli Alejandro
Published: July 2024

The milling process is the standard method for producing flat tensile test specimens from sheet metal. However, alternative methods employed in the industry for cutting sheet metal include abrasive water jet cutting, laser cutting, punching, and, to a lesser extent, electrical discharge machining. Among these, abrasive water jet cutting stands out for its superior material integrity, versatility, precision, and efficiency, making it a preferred choice. Previous studies consistently show that specimens cut by abrasive water jetting exhibit lower ultimate tensile strength and higher percent elongation than those obtained by milling in standardized tensile tests. This study investigates this behavior across different types of steel and alloys. Both steel types were subjected to milling and water jetting processes, followed by an analysis of their experimental and simulated mechanical behavior to identify discrepancies between the two methods. The findings suggest that milling, influenced by factors such as feed per tooth and cutter diameter, introduces geometric stress concentrators. This relative increase in ultimate tensile strength and decrease in percent elongation are observed consistently in milled tensile specimens compared to those cut by water jet, regardless of material type or thickness. Additionally, the effects of perimeter hardening resulting from superficial plastic deformation caused by the cutting edge, likely due to its small thickness, do not influence the observed trends significantly.