bluuebunny/crossref_metadata_2025 huggingface dataset:
Bisphenol A Detection Using Molybdenum Disulfide (MoS2) Field‐Effect Transistor Functionalized with DNA Aptamers
Authors: Hossain Mohammad Mosarof , Shabbir Babar , Liu Jingying , Wan Zhichen , Walia Sumeet , Bao Qiaoliang , Alan Tuncay , Mokkapati Sudha
Published: March 2023

Bisphenol A exposure, even at very low concentrations, is associated with an increased risk of high blood pressure, heart disease, diabetes and some cancers. It is important to monitor BPA exposure level for human healthcare. Two‐dimensional materials‐based field‐effect transistors are promising for sensing applications due to their high sensitivity, label‐free detection, and reusability. Among 2D materials MoS2 based semiconductor materials provides higher sensitivity compared to the lack of sensitive existing graphene materials due to bandgap. In this work, a microfluidic device based on MoS2 field‐effect transistor is demonstrated that can be adapted to detect several biomolecules at very low concentrations. MoS2 channel is functionalized by depositing gold nanoparticles and immobilizing single one (or double)‐stranded DNA. It is found that dsDNA functionalized devices exhibit higher sensitivity compared to ssDNA for all BPA concentrations due to p‐doing effect of dsDNA on MoS2 semiconducting surface. Both ss and dsDNA functionalized MoS2 FET devices are able to detect BPA concentration as low as 1 pg mL−1, as observed by a 4.27% and 2.17% change in the current, respectively, and a response time of about ≈4 s. The demonstrated MoS2 FET sensors are very promising to detect lower concentration biomolecules and DNA in biomedical applications.
Tannic Acid Lipid Nanoparticles can Deliver Messenger RNA Payloads and Improve their Endosomal Escape
Authors: Ma Yutian , Fenton Owen S.
Published: March 2023

Even though lipid nanoparticles (LNPs) can deliver messenger RNA (mRNA) payloads into cells, their efficiency is often limited by endosomal trapping which prevents RNA payloads from acting therapeutically. Improving the percentage of RNA LNPs that can escape from endosomes and enter the cytoplasm is therefore an area of active research interest that could lead to improved safety profiles and reduced manufacturing costs of mRNA drugs. Here, tannic acid mRNA LNPs [TA(+) mRNA LNPs] are reported as an effective delivery platform for the delivery of mRNA payloads. The formulation, characterization, and stability of TA(+) mRNA LNPs are described; two different approaches via confocal microscopy are then utilized to quantify the endosomal escape of the TA(+) mRNA LNPs; and lastly, the biodistribution and tolerability of the TA(+) mRNA LNPs are evaluated in mice following intravenous and intramuscular dosing regimens. To isolate the effect that TA imparts on each of these properties, mRNA LNPs that do not contain TA [TA(−) mRNA LNPs] are evaluated side‐by‐side in each of these studies. A collective analysis of these results suggests that TA(+) mRNA LNPs are effective carriers for mRNA payloads and that the incorporation of TA within each formulation improves the endosomal escape of mRNA LNPs.
Comparative evaluation of bioethanol fermentation process parameters using RSM, ANN and ANFIS
Authors: Taiwo Abiola E. , Musonge Paul
Published: March 2023

The drive for renewable energy as an alternative to fossil fuel is on the increase globally. Modeling a renewable energy process is crucial for increasing process monitoring and control of plant efficiency for the ultimate objective of optimal biorefinery operations. This study aims to develop and compare models that best predict the fermentation process parameters of bioethanol production using corn‐steep liquor (CSL) as a media supplement. The response surface method (RSM), artificial neural networks (ANNs) and adaptive neuro‐fuzzy inference system (ANFIS) were tested in the modeling of bioethanol fermentation processes. Box–Behnken design was used to investigate fermentation process parameters considering the effect of CSL (0.5–5.5 w/v), pH (4, 5), time (12–36 h), temperature (25–35°C) and inoculum size (0.5–5.5 v/v). The results from the kinetics study show media formulation with corn steep liquor results in a comparable yield with that substituted with yeast extract. The study shows that, for CSL, a maximum ethanol concentration of 17.40 g L−1 was obtained after 48 h of fermentation while 21.53 g L−1 was attained after 6 h for the media formulation with yeast extract. Based on the model evaluation using statistical error indices, ANN predictability was better at R2 = 0.90; R = 0.95; SEP = 1.73. The ANN models described the process better than ANFIS and RSM. This study shows the intelligent predictive ability of ANN that could be useful for the scale‐up process of ethanol production in industry. © 2023 The Authors. Biofuels, Bioproducts and Biorefining published by Society of Industrial Chemistry and John Wiley & Sons Ltd.
Tuning fluorescence of dapoxetine by blocking of photoinduced electron transfer (PET): Application in real human plasma
Authors: Elsayed Mohamed Ahmed , Abbas Khaled Abdel‐Hakam , Abdelmontaleb Hani Shaaban , Mohamed Abobakr A.
Published: March 2023

Photoinduced electron transfer (PET) is the most common mechanism proposed to account for quenching of fluorophores. Herein, the intrinsic fluorescence of dapoxetine (DPX) hydrochloride is in the “OFF” state, owing to the deactivation effect of PET. When the amine moiety is protonated, the fluorescence is restored. Protonation of the nitrogen atom of the tertiary amine moiety in DPX leads to “ON” state of fluorescence due to hindrance of the deactivating effect of PET by protonation of the amine moiety. This permits specific and sensitive determination of DPX in human plasma [lower limit of quantification (LLOQ) = 30.0 
]. The suggested method adopts protonation of DPX using 0.25 M hydrochloric acid in anionic micelles [6.94 mM sodium dodecyl sulfate (SDS)] leads to a marked enhancement of DPX‐fluorescence, after excitation at 290 nm.
Personality traits and disorders in Alzheimer's disease
Authors: Henriques‐Calado Joana
Published: March 2023

Background

The relationships between axis II personality disorders and the normative personality traits were explored in the context of current and pre‐morbid personality assessment in Alzheimer's disease (AD).

Methods

The study was conducted with four groups who were administered the NEO‐FFI and the PDQ‐4+, in the form of individual interview sessions. Current personality measure: consisting of 44 female participants (AD group) and, the control group, consisting of 80 female participants from the population at large. Pre‐morbid personality measure: AD group informants (n = 40); control group informants (n = 42).

Results

The results are in line with the literature review and provide new research data. By factorial discriminant analysis, the current and pre‐morbid personality variables that differentiate AD from control groups are identified. The personality traits variables are the best discriminators such as low agreeableness, low openness to experience, and high neuroticism, suggesting that the maladaptive personality functioning can be described extending the range of psychopathology to a dimensional approach.

Conclusions

The study of personality variables seems to suggest, in their inclusion, the possibility to increase sensitivity toward an assessment in AD.
Exploration of the Production of Three Thiodiketopiperazines by an Endophytic Fungal Strain of Cophinforma mamane
Authors: Pacheco‐Tapia Romina , Ortíz Sergio , Jargeat Patricia , Amasifuen Carlos , Vansteelandt Marieke , Haddad Mohamed
Published: March 2023

Endophytic fungi possess a versatile metabolism which is related to their ability to live in diverse ecological niches. While culturing under laboratory conditions, their metabolism is mainly influenced by the culture media, time of incubation and other physicochemical factors. In this study, we focused on the production of 3 thiodiketopiperazines (TDKPs) botryosulfuranols A−C produced by an endophytic strain of Cophinforma mamane isolated from the leaves of Bixa orellana L collected in the Peruvian Amazon. We studied the time‐course production of botryosulfuranols A−C during 28 days and evaluated the variations in the production of secondary metabolites, including the TDKPs, produced by C. mamane in response to different culture media, light versus dark conditions and different incubation times. We observed a short time‐frame production of botryosulfuranol C while its production was significantly affected by the light conditions and nutrients of the culture media. Botryosulfuranols A and B showed a similar production pattern and a similar response to culturing conditions. Molecular networking allowed us to detect three compounds related to TDKPs that will be the focus of future experiments.
Synthesis of Ester‐Linked Ursolic Acid‐Based Hybrid Compounds: Potential Antibacterial and Anticancer Agents
Authors: Khwaza Vuyolwethu , Oyedeji Opeoluwa O. , Oselusi Samson O. , Morifi Eric , Nwamadi Mutshinyalo , Tantoh Ndinteh Derek , Ramushu P. , Matsebatlela Thabe , Aderibigbe Blessing A.
Published: March 2023

The molecular hybridization of two or more drugs into a single molecule is an effective drug design approach to reduce pill burden and improve patient treatment adherence. Ursolic acid‐based hybrid compounds were synthesized and characterized followed by molecular docking studies. In vitro studies against various bacterial strains and human cancer cells (MDA‐MB‐231, HeLa, and MCF‐7) were performed. Compounds 14–19, 21, 34, 31, and 30 demonstrated significant antibacterial activities with MIC values of 15.625 μg/ml. Compounds 29 and 34 were more cytotoxic than ursolic acid, with IC50 values of 46.99 and 48.18 μg/ml. Compounds 29 and 34 in the docking studies presented favourable binding interactions and better docking energy against the Epidermal Growth Factor Receptor (EGFR) than the parent compound, ursolic acid. The findings revealed that the ursolic acid scaffold is a promising precursor for the development of molecules with promising anticancer and antimicrobial activities. However, more studies are needed to fully understand their mode of action.
Taking Synthetic Biology to the Seas: From Blue Chassis Organisms to Marine Aquaforming
Authors: Schada von Borzyskowski Lennart
Published: March 2023

Oceans cover 71 % of Earth's surface and are home to hundreds of thousands of species, many of which are microbial. Knowledge about marine microbes has strongly increased in the past decades due to global sampling expeditions, and hundreds of detailed studies on marine microbial ecology, physiology, and biogeochemistry. However, the translation of this knowledge into biotechnological applications or synthetic biology approaches using marine microbes has been limited so far. This review highlights key examples of marine bacteria in synthetic biology and metabolic engineering, and outlines possible future work based on the emerging marine chassis organisms Vibrio natriegens and Halomonas bluephagenesis. Furthermore, the valorization of algal polysaccharides by genetically enhanced microbes is presented as an example of the opportunities and challenges associated with blue biotechnology. Finally, new roles for marine synthetic biology in tackling pressing global challenges, including climate change and marine pollution, are discussed.
Protein Backbone Alteration in Non‐Hairpin β‐Turns: Impacts on Tertiary Folded Structure and Folded Stability
Authors: Harmon Thomas W. , Horne W. Seth
Published: March 2023

The importance of β‐turns to protein folding has motivated extensive efforts to stabilize the motif with non‐canonical backbone connectivity. Prior work has focused almost exclusively on turns between strands in a β‐sheet (i. e., hairpins). Turns in other structural contexts are also common in nature and have distinct conformational preferences; however, design principles for their mimicry remain poorly understood. Here, we report strategies that stabilize non‐hairpin β‐turns through systematic evaluation of the impacts of backbone alteration on the high‐resolution folded structure and folded stability of a helix‐loop‐helix prototype protein. Several well‐established hairpin turn mimetics are shown detrimental to folded stability and/or hydrophobic core packing, while less‐explored modification schemes that reinforce alternate turn types lead to improved stability and more faithful structural mimicry. Collectively, these results have implications in control over protein folding through chemical modification as well as the design of protein mimetics.
Ashwagandha‐induced acute liver injury: A case report
Authors: Tóth Marcell , Benedek Andrea E. , Longerich Thomas , Seitz Helmut‐Karl
Published: March 2023

Drug‐induced liver injury became one of the most important liver disorders and diagnostic challenge for clinicians and pathologists. Here, we report a rare case of ashwagandha‐induced acute liver injury. The patient developed jaundice 2 weeks after starting ashwagandha intake and recovered within 5 months after withdrawal without any specific treatment.
Data Glove with Integrated Polyethylene‐Carbon Composite‐Based Strain Sensor for Virtual Reality Applications
Authors: Lee Kok Tong , Chee Pei Song , Lim Eng Hock , Kam Yu Heng
Published: March 2023

A data glove enables fine motion control in virtual reality (VR). This work presents a cost‐effective data glove made of a commercial nylon‐based glove with integrated polyethylene‐carbon composites (Velostat). The resistance of the Velostat varies when a finger is bent. This piezoresistive behavior was explored by designing the Velostat as the strain sensor. The strain sensor was characterized for its flexure sensing by connecting it to a data acquisition circuit. The circuit is designed to process the output of the joint angles and feed it to the computer. A linear resistance output was measured with a sensitivity/gauge factor of 1.45 % per degree with a response time of 0.0158 seconds when the strain sensor bends from 0° to 30°. To control the 3D virtual hand's movement, the data glove was coupled with two inertial measurement unit sensors at the forearm and upper arm to identify its coordinates. The fabricated data glove successfully performs a proof‐of‐concept by picking‐and‐placing multiple objects in a VR environment.
Flow Field Simulation and Measurement in Packed Beds Based on 4D‐X‐Ray Computed Tomography
Authors: Martinez-Garcia Jorge , Fenk Benjamin , Gwerder Damian , Schiffmann David , Delgado-Diaz William , Stamatiou Anastasia , Fischer Ludger J. , Schuetz Philipp
Published: March 2023

X‐ray computed tomography (XCT) combined with computational fluid dynamics (CFD) simulations have proved to be a powerful and versatile tool to describe fluids flow through packed bed systems. In this contribution, two examples of the application of XCT experiments to track the fluid flow and fluid penetration in packed bed systems are shown. The first one shows how geometrical information extracted from XCT measurements can be coupled to CFD simulations to assess fluid flows reliably. Here the example of a packed bed of three‐dimensional (3D) printed cylindrical‐shaped particles is considered. Finally, a short case study on the monitoring of the progress of the water penetration front in a packed bed composed of glass spheres using four‐dimensional (4D) XCT imaging data is presented.
Leaf temperatures and environmental conditions predict daily stem radial variations in a temperate coniferous forest
Authors: Weygint William A. , Eitel Jan U. H. , Maguire Andrew J. , Vierling Lee A. , Johnson Daniel M. , Campbell Colin S. , Griffin Kevin L.
Published: March 2023

Hourly‐resolved measurements of stem radial variations (SRVs) provide valuable insights into how climate‐induced changes in hydrological regimes affect tree water status and tree stem radial growth. However, while SRVs are easily measured at the individual tree level, currently no methods are available to monitor this phenomenon across broad regions at intra‐annual (daily to weekly) scales. Near‐surface (in situ) thermal remote sensing—with its sensitivity to plant water status—may provide an approach for monitoring intra‐annual SRVs, with the potential for scaling these approaches to the landscape level. Thus, we explored the suitability of in situ thermal remote sensing, in combination with other environmental data, to monitor SRVs in a coniferous forest of the North American Intermountain West. Specifically, we were interested in answering two main questions: Can we use in situ thermal remote sensing by itself and in combination with environmental variables (i.e., photoperiod, photosynthetically active radiation, and soil moisture) to predict (1) daily tree water status and (2) daily tree stem radial growth derived from SRVs? We used data collected by an environmental monitoring network in central Idaho over three growing seasons (2019–2021) to address these questions. Results showed that leaf temperature (TL) in combination with environmental variables explained up to three‐quarters of the SRV‐based variability in daily tree water status (in the form of tree water deficit [TWD]) and approximately one‐half of the variability in daily stem radial growth. The time of day when TL was acquired also appeared to change the strength, shape, and predictive power of the models, with acquisition times in the morning and evening showing stronger relationships with daily SRVs than other times of the day. Overall, these results highlight the promise of utilizing thermal remote sensing data to derive tree hydrological and growth status, and reveal key considerations (e.g., the time of data acquisition) for future observational and modeling efforts. This study also provides a benchmark against which to compare future efforts to test these observed relationships at coarser spatial scales.
Risk‐targeted importance factors for prescriptive seismic design of critical buildings
Authors: Badal Prakash S. , Sinha Ravi
Published: March 2023

The post‐earthquake recovery of a community depends on the ability of important buildings to perform their functions. Lifeline and other critical buildings that meet a predictable enhanced seismic performance increase the community's disaster risk management capacity. In prescriptive force‐based design standards, the seismic design force for these buildings is typically enhanced using an importance factor depending on the risk category. The present paper proposes an innovative framework based on performance‐based seismic design (PBSD) principles using risk‐targeted importance factors suitable for use with prescriptive standards. The framework decouples probabilistic assessments of building typologies to experts, while the structural designers can continue the conventional design approach. The framework explicitly considers probabilistic seismic demand, uncertainty in the performance of the building, and the inter‐building variation within a particular building typology in seismic performance. Six special reinforced concrete (RC) frame buildings conforming to Indian standards are selected to illustrate the framework. Sensitivity studies on parameter selection are used to establish the framework's robustness. An expression for the importance factors is also proposed. The use of the proposed importance factor expression is shown to meet a wide range of risk targets corresponding to different performance levels. The paper also proposes design factors for enhanced performance objectives suitable for the risk‐targeted prescriptive design. Further, the framework is implemented to estimate the seismic risk associated with existing building typology conforming to prevalent design standards. The assembly‐ and critical‐category RC buildings are found to require higher importance factors for achieving enhanced performance objectives than currently prescribed.
(Dis)connectivity in hydro‐geomorphic systems – emerging concepts and their applications
Authors: Poeppl Ronald E. , Polvi Lina E. , Turnbull Laura
Published: March 2023

In geomorphology, connectivity has emerged as a framework for understanding the transfer of water and sediment through landscapes. Over the past decade, sessions on (dis)connectivity at the General Assembly of the European Geosciences Union (EGU), and more recently, three mini‐conferences in 2020 and 2021 called ‘Connectivity Conversations’, organized by the International Association of Geomorphologists (IAG) working group on ‘Connectivity in Geomorphology’, have created a space for the exchange of ideas relating to (dis)connectivity in geomorphology and related disciplines. The result of these initiatives has been a collection of research articles related to a special issue (SI) entitled ‘(Dis)connectivity in hydro‐geomorphic systems – emerging concepts and their applications’. In this article, we provide a synthesis that embraces the SI contributions related to the application of the connectivity concept in different environments and geomorphic process domains, spatial and temporal scales, types and spatial dimensions of connectivity and the role of human impacts and associated river and catchment management aspects.
Rehydration modeling and characterization of dehydrated sweet corn
Authors: Nayi Pratik , Kumar Navneet , Kachchadiya Sagar , Chen Ho‐Hsien , Singh Punit , Shrestha Pratiksha , Pandiselvam Ravi
Published: March 2023

The increasing demand of rehydrated foods is due to its better storage stability at ambient conditions and not requiring refrigeration. Prior to drying at 55, 60, 65, and 70°C in a hot air tray dryer, hot water blanching (HB), steam blanching (SB), and microwave blanching (MB) were employed as pretreatments. Rehydration of dried pretreated sweet corn kernel was performed in boiling water. The pretreatments and drying temperatures were independent factors that affected the dependent factors such as rehydration ratio, total sugar, ascorbic acid, geometric mean diameter, color, sensory evaluation, water absorption, mass, and geometric mean diameter. Peleg, Weibull, and newly proposed models were considered to describe the change in moisture content during rehydration. The proposed model performed better than other models and indicated the rise in equilibrium moisture content of rehydrated sweet corn with an increase in dehydration temperature of sweet corn due to higher R2 (0.994), and lower chi‐square (0.005) and RMSE (0.064). The rehydrated sweet corn obtained from samples processed with microwave blanching and dehydration at 70°C showed higher retention of total sugar, ascorbic acid, geometric mean diameter, and color.
Deep time spatio‐temporal data analysis using pyGPlates with PlateTectonicTools and GPlately
Authors: Mather Ben R. , Müller R. Dietmar , Zahirovic Sabin , Cannon John , Chin Michael , Ilano Lauren , Wright Nicky M. , Alfonso Christopher , Williams Simon , Tetley Michael , Merdith Andrew
Published: March 2023

PyGPlates is an open‐source Python library to visualize and edit plate tectonic reconstructions created using GPlates. The Python API affords a greater level of flexibility than GPlates to interrogate plate reconstructions and integrate with other Python workflows. GPlately was created to accelerate spatio‐temporal data analysis leveraging pyGPlates and PlateTectonicTools within a simplified Python interface. This object‐oriented package enables the reconstruction of data through deep geologic time (points, lines, polygons and rasters), the interrogation of plate kinematic information (plate velocities, rates of subduction and seafloor spreading), the rapid comparison between multiple plate motion models, and the plotting of reconstructed output data on maps. All tools are designed to be parallel‐safe to accelerate spatio‐temporal analysis over multiple CPU processors.
Analysis of performance and emission patterns of novel biofuel feedstock neat coconut fatty acid distillate (CFAD) fuelled single‐cylinder diesel engine
Authors: Rajesh K. , Sathiyamoorthi R. , Senthil S. , Murugapoopathi S. , Damodharan D.
Published: March 2023

This study examined the potential of using coconut fatty acid distillate (CFAD), a by‐product of the processing of edible oils, as a diesel engine fuel. The major novelty of this study is to assess the CFAD as a viable feedstock of biodiesel to address global energy demands. CFAD has not been specifically researched as a feedstock for producing biodiesel or as a fuel for diesel engines, despite the fact that numerous studies on the production and performance of biodiesel have already been conducted. Fourier transform infrared (FTIR) spectroscopy, gas chromatography (GC), and FTIR were used to analyze the fuel. According to the results of the GC test, CFAD oil contains 91.53% saturated fatty acids, compared with only 8.47% unsaturated fatty acids. High saturation values can be seen in myristic acid (16.92%) and lactic acid (45.33%). Longer hydrocarbon chain lengths indicate higher energy density and boiling point, which also indicate lesser volatility. At a frequency of 1708.54 cm−1, C─H stretching vibrations have been identified through FTIR investigation. The vibrations of C─C stretching at 1465.47 cm−1 indicate the presence of alkenes/fingerprint phase. The blends used for this investigation include 90% diesel with 10% CFAD (CFAD10), 80% diesel with 20% CFAD (CFAD20), 70% diesel with 30% CFAD (CFAD30), and 100% CFAD. The CFAD 10%, 20%, and 30% blends as well as the CFAD100 had brake thermal efficiency values of 27.24%, 26.23%, 24.88%, and 21.52%, correspondingly, at full load. The average increment in brake‐specific energy consumption for CFAD10, CFAD20, CFAD30, and CFAD100 over diesel fuel was 8.23%, 10.88%, 13.77%, and 25.90%, respectively. The behavior of CFAD exhibits reduced cylinder pressure because of the large content of moderate saturated fatty acids in this substance. The net heat release rate (NHRR) and cylinder pressure have a similar relationship in that the NHRR increases with increasing diesel volume. In comparison to diesel, the CO emissions from the CFAD20, CFAD30, and CFAD100 blends increased by 10.79%, 16.66%, and 35.89% at maximum load, respectively. It has been reported that NOx is reduced more significantly the more CFAD is present in the mixture. The blend CFAD10 had the least amount of smoke. The high viscosity of the CFAD and its blends influences the fuel droplets range and the development of spray in the cylinder, which results in delayed combustion and higher unburned hydrocarbon emissions.
A reinforcement learning approach for hotel revenue management with evidence from field experiments
Authors: Chen Ji , Xu Yifan , Yu Peiwen , Zhang Jun
Published: March 2023

We consider a budget hotel chain's revenue management problem of deciding how to dynamically allocate capacity to multiple segments of customers. Our work solves an industrial‐sized problem faced by practitioners, with the reality of implementation motivating us to develop a tailored reinforcement learning approach. Our approach proceeds in two steps. First, a recommended average discount is computed with a reinforcement learning algorithm. Then, the recommended average discount is turned into a capacity allocation through a linear program. This approach overcomes the challenges of characterizing demand and estimating cancellations, and it facilitates hotel managers' acceptance of the revenue management system. We implement this approach in the hotel chain in a pilot study and assess its effectiveness using synthetic control methods. Our approach improves the key operational performance measure—revenue per available room—by 11.80%. There is heterogeneity in how the pilot hotels improve their revenue per available room. Some mainly increase their occupancy rate, some mainly increase the average daily room rate, while others experience significant increases in both. Further analysis shows that our approach uncovers the individual sources of suboptimal performance in pilot hotels and correspondingly improves decision‐making. Our work demonstrates that a reinforcement learning approach for hotel revenue management is promising.
Plastic spectral interference in the biological characterization by Raman or SERS spectroscopy
Authors: Wang Ping‐Shi , Ma Hao , Xi Xiao‐Han , Yue Xiaxia , Pan Si‐Qi , Cao Maofeng , Liu Guo‐Kun , Wang Xiang , Ren Bin
Published: March 2023

Raman spectroscopy and surface‐enhanced Raman spectroscopy (SERS) have been widely applied for characterizing biological samples. Nowadays, it is routine to use plastic products for biological sample preparation and analysis during spectral acquisition. However, plastic containers produce undesirable signals severely interfering with the spectra of biological samples, which is neglectable and misleading. Herein, we unveiled the physical and chemical interference of plastic products in the process of Raman spectroscopy characterization. Firstly, we revisited a representative case of interference from polystyrene plastics on normal Raman and SERS spectra of cysteine and demonstrated its physical interference due to misfocusing. Furthermore, we testified SERS spectra of aqueous solution stored in several plastic materials commonly used in biological experiments. The spectra indicate strong spectral interference from the leaching chemicals. To address these problems, we proposed a series of strategies to avoid interference from plastic products in the Raman and SERS characterization of biological samples.
Separation and determination of triadimefon and its metabolites triadimenol enantiomers in fruit puree by supercritical fluid chromatography
Authors: Zhang Wen‐hua , Xu Dun‐ming , Hou Jian‐bo , He Jian‐min , Zhao Fei , Shi Ying‐zhu , Qian Yan
Published: March 2023

A method was established for the separation and determination of triadimefon and its metabolite triadimenol enantiomer residues in major complementary fruit puree for infants and young children (banana puree, pineapple puree, and grape puree) by supercritical fluid chromatography. After the samples were extracted with acetonitrile and purified with a solid phase extraction cartridge, Acquity Trefoil CEL2 chiral chromatographic column was adopted for separation, and gradient elution was conducted at the flow rate of 1.0 ml/min under the mobile phase of supercritical carbon dioxide ‐ 0.5% ammonia methanol, the detection wavelength was 220 nm and quantification was conducted with the external standard method. The limits of quantitation of triadimefon and triadimenol enantiomers were both 0.05 mg/kg, the linear ranges were 0.5–50 mg/L, and the linear correlation coefficients were greater than 0.9993. The recoveries in the spiked samples at 0.05, 0.2, and 3.0 mg/kg were from 80.1 to 106%, and the relative standard deviation reached 3.3–7.6%. The method is efficient, rapid, reproducible, and environmentally friendly, enabling accurate analysis of pesticide enantiomers, which can detect the enantiomer residues of triadimefon and its metabolite triadimenol in major complementary fruit puree for infants and young children.
Highly sensitive liquid chromatographic method combined with online ion suppression to remove interfering anions and mass spectrometry for impurity profiling of paromomycin sulfate
Authors: Chen Zhouzhou , Zhu Xiaoyue , Geng Yue , Huang Zhenyu , Adams Erwin , Chen Daijie , Tang Sheng , Yin Yu , Yuan Yaozuo
Published: March 2023

A previously developed high‐performance liquid chromatography method combined with pulsed amperometric detection allowed to separate many impurities of paromomycin. However, due to the presence of ion pairing agents and sodium hydroxide in the mobile phase, direct coupling to mass spectrometry for the identification of the chemical structures of the impurities was not an option. Indeed, ion suppression was encountered by trifluoroacetic acid and pentafluoroproponic acid in the mobile phase. A cation self‐regenerating suppressor, which was originally designed for increasing analyte conductivity of ammonia and amines analysis in ion chromatography, was coupled between the liquid chromatography and ion trap‐time of flight‐mass spectrometry and almost all trifluoroacetic acid and pentafluoroproponic acid in the mobile phase was removed. The limit of detection of paromomycin in this integrated system improved significantly to 20 ng/ml (0.4 ng). The chemical structures of 19 impurities were elucidated and seven impurities were reported for the first time.
A reconfigurable phase gradient metasurface antenna for beam steering
Authors: Yuan Yi , Ding Jun , Guo Chenjiang , Huang Chao
Published: March 2023

In this article, a reconfigurable phase gradient metasurface (PGM) antenna for beam steering is presented. The antenna consists of a three‐layer transmitarray metasurface and a broadband patch antenna. The PIN diode is loaded onto the split ring resonator (SRR). The phase gradient principle is used to regulate the electromagnetic waves to achieve the function of the gain enhancement and beam tilt. By clever design, the antenna is quickly switched in beam tilt in the 8.9–9.9 GHz range and gain enhancement in the 7.9–9.4 GHz range without the need for additional circuits. The proposed PGM antenna can achieve beam tilt in a certain bandwidth range and gain enhancement simultaneously. Compared with the previous beam steering antenna, it has broader bandwidth and smaller volume. The experimental results are in good agreement with the simulated ones.
A priori error estimates for a semi‐Lagrangian unified finite element method for coupled Darcy‐transport problems
Authors: Salhi Loubna , El‐Amrani Mofdi , Seaid Mohammed
Published: March 2023

A semi‐Lagrangian unified finite element method is investigated for solving time‐dependent coupled Darcy‐transport problems. In this method, the modified method of characteristics is combined with a Galerkin finite element discretization allowing the same finite element space to be used for all solutions of the problem including the pressure, velocity and concentration. Convergence and stability of the method are also analyzed in this study and error estimates in the ‐norm are established for the numerical solutions. For the time integration we consider a second‐order implicit method and discrete error estimates are provided. Due to the Lagrangian treatment of convection terms in the considered problems, the conventional Courant‐Friedrichs‐Lewy condition is relaxed and the time truncation errors are reduced in the diffusion‐reaction part. Numerical results are presented for several test examples to demonstrate the reliability and efficiency of the proposed method. The computed results support our expectations for an accurate and highly efficient semi‐Lagrangian unified finite element method for time‐dependent coupled Darcy‐transport problems.
Experimental investigation on mechanical behaviors of composite sandwich panels with a hybrid facesheet
Authors: Zhu Shuhua , Wang Yuequan , Zhou Long , Yi Wentao , Hu Li , Liu Jian , Kang Xinran , Li Hongshuang
Published: March 2023

A multi‐functional composite sandwich panel was developed with a hybrid facesheet, which was composed of a quartz fiber reinforced plastic (QFRP) laminate and two copper layers. The other facesheet was made of QFRP laminate. The Nomex® honeycomb was used as the core material. The aim of this paper is to investigate the effects of the hybrid facesheet on the mechanical characterizations of the sandwich panel. Four mechanical performances of both composite sandwich panel with and without copper layers were considered, including the flatwise tensile strength test, the edgewise compressive strength test, the three‐point bending test and the tensile plate shear test. The experimental results show that all the four mechanical performances of the sandwich panel with copper layers were lower than the sandwich panel without copper layers. The flatwise tensile strength decreased by 26.1%. The edgewise compressive strength decreased by 9.5%. The shear strength obtained from the three‐point bending test decreased by 14.9%. The shear strength obtained from tensile plate shear test decreased by 13.7%.
Modification of Nafion's nanostructure for the water management of PEM fuel cells
Authors: Li Yuanchao , Linnell Schwab Natalie , Briber Robert M. , Dura Joseph A. , Nguyen Trung Van
Published: March 2023

A PEM fuel cell with the Nafion ionomer phase of the cathode catalyst layer (CL) that was exposed to hot dry gas during the hot‐pressing process showed improved performance over the whole current density range and ~ 220% peak power increase with humidified air at 80°C. This enhanced performance is attributed to the modified structure of the perfluorosulfonic acid (PFSA) ionomer layer in the CL during the MEA's hot‐pressing process. The dry gas exposure above the glass transition temperature (Tg) results in the aggregation of the ionic groups to retain the residue water molecules. This process separates the ionomer into ionic‐group‐rich domains and ionic‐group‐sparse domains. The ionic‐group‐sparse domains create hydrophobic interface and reactant transport channels with lower water content and thus higher oxygen solubility in the ionomer. Accordingly, the water‐unsaturated ionomer and its surface hydrophobicity enhance the kinetic‐controlled and concentration‐polarized regions of the fuel cell polarization curve, respectively. The surface hydrophobicity of the ionomer layer is analyzed by the contact angle measurement and XPS. The durability of the hydrophobic effect below Tg is demonstrated by boiling the treated material. Re‐treating the hydrophobic sample with humidified gas exposure above Tg eventually exhibits hydrophilic features, further proving the manipulability of the ionic group distribution.
The effect of citrate plasticizers on the properties of nitrocellulose granules
Authors: Gańczyk‐Specjalska Katarzyna , Cieślak Katarzyna , Jakubczak Marcin , Drożdżewska‐Szymańska Katarzyna , Tomaszewski Waldemar , Prasuła Piotr
Published: March 2023

Nitrocellulose granules containing the proposed new eco‐friendly inert plasticizers, substitutes for phthalate derivatives, such as acetyl triethyl nitrate (ATEC) and tributyl citrate (TBC) were obtained. The single‐base propellants were obtained using safe granulation process (water method). Diethylene glycol dinitrate (DEGDN) was used as an energetic modifier in obtained propellants. It was found that the addition of citrate plasticizers reduced the heat of combustion and dynamic vivacity of powders. At the same time DEGDN increased the heat of combustion of tested materials. Citrate derivatives did not affect the density and thermal decomposition of granules. It was concluded based on pyrostatic analysis that the TBC plasticizer influenced the kinetics of nitrocellulose gelatinization by DEGDN. The kinetic model [nth order with autocatalysis (CnB) reaction] was adjusted based on the process of thermal decomposition. The presence of DEGDN in granules reduces the activation energy and increases the constant heat cumulative rate. The prepared propellants are characterized by excellent thermal stability in accordance with the STANAG 4582 standard. The obtained propellants can be potentially used in small calibre ammunition.
Influence of combination of coaxial cylindrical explosives on fragmentation and shock waves of a shelled composite charge
Authors: Li Jun‐bao , Li Wei‐bing , Wang Xiao‐ming , Zou Bin
Published: March 2023

This paper investigates fragmentation and shock waves generated by a novel coaxial cylindrical composite charge composed of an inner explosive, an intermediate inert material and an outer explosive widely used in tunable ammunition. Charges containing two types of explosive combinations were designed, and explosion experiments were conducted in two initiation modes: detonating only an inner explosive and detonating inner and outer explosives simultaneously. Results suggest the composite charge with higher inner‐detonation velocity and lower outer‐detonation velocity achieves more differentiated power output under different initiations. The differences in the average fragment mass and peak overpressure are as high as 34.5 % and 39.9 %, respectively, which are larger than 4.4 % and 8.4 % under the contrary explosive combination. On the basis of this observation, corresponding 2‐D and 3‐D models were simulated using AUTODYN code to investigate the evolution of the detonation waveform and detonation energy release. The numerically simulated initial shell expansion and later shock wave propagation of the composite charge agreed well with the experimental data. The errors in expansion radius and shock wave parameters (peak overpressure and specific impulse) are less than 6.6 % and 16.9 %, respectively, between the simulations and experiments. It was found that the particle velocity profile in the charge with lower outer‐detonation velocity lagged behind that of the charge with higher inner‐detonation velocity under inner initiation, while a wave front collision zone close to the outer charge appeared in the non‐detonation layer under simultaneous initiation.
Science education with multilingual learners: Equity as access and equity as transformation
Authors: Grapin Scott E. , Pierson Ashlyn , González‐Howard María , Ryu Minjung , Fine Caitlin , Vogel Sara
Published: March 2023

Research in science education with multilingual learners (MLs) has expanded rapidly. This rapid expansion can be situated within a larger dialogue about what it means to provide minoritized students with an equitable education. Whereas some conceptions of equity focus on ensuring all students have access to the knowledge, practices, and language normatively valued in K‐12 schools (equity as access), increasingly prominent conceptions focus on transforming those knowledge, practices, and language in ways that center minoritized students and their communities (equity as transformation). In this article, we argue that conceptions of equity provide a useful lens for understanding emerging research in science education with MLs and for charting a research agenda. We begin by tracing how conceptions of equity have evolved in parallel across STEM and multilingual education. Then, we provide an overview of recent developments from demographic, theoretical, and policy perspectives. In the context of these developments, we provide a conceptual synthesis of emerging research by our team of early‐career scholars in three areas: (a) learning, (b) assessment, and (c) teacher education. Within each area, we unpack the research efforts in terms of how they attend to equity as access while pushing toward equity as transformation. Finally, we propose a research agenda for science education with MLs that builds on and extends these efforts. We close by offering recommendations for making this research agenda coherent and impactful: (a) being explicit about our conceptions of equity, (b) paying attention to the interplay of structure and agency, and (c) promoting interdisciplinary collaboration.
Single‐Atom Gd Nanoprobes for Self‐Confirmative MRI with Robust Stability
Authors: Luo Qing , Liu Junhan , Ma Qian , Xu Suying , Wang Leyu
Published: March 2023

Gadolinium (Gd)‐based complexes are extensively utilized as contrast agents (CAs) in magnetic resonance imaging (MRI), yet, suffer from potential safety concerns and poor tumor targeting. Herein, as a mimic of Gd complex, single‐atom Gd nanoprobes with r1 and r2 values of 34.2 and 80.1 mM−1 s−1 (far higher than that of commercial Gd CAs) at 3 T are constructed, which possessed T1/T2 dual‐mode MRI with excellent stability and good tumor targeting ability. Specifically, single‐atom Gd is anchored on nitrogen‐doped carbon matrix (Gd‐NxC) through spatial‐confinement method, which is further subjected to controllable chemical etching to afford fully etched bowl‐shape Gd‐NxC (feGd‐NxC) with hydrophilic properties and defined coordination structure, similar to commercial Gd complex. Such nanostructures not only maximized the Gd3+ site exposure, but also are suitable for self‐confirmative diagnosis through one probe with dual‐mode MRI. Moreover, the strong electron localization and interaction between Gd and N atoms afforded feGd‐NxC excellent kinetic inertness and thermal stability (no significant Gd3+ leaching is observed even incubated with Cu2+ and Zn2+ for two months), providing a creative design protocol for MRI CAs.
Bio‐Inspired Electro‐Thermal‐Hygro Responsive Rewritable Systems with Temporal/Spatial Control for Environment‐Interactive Information Display
Authors: Wu Shuangshuang , Shi Huihui , Wei Shuxin , Shang Hui , Xie Weiping , Chen Xipao , Lu Wei , Chen Tao
Published: March 2023

Utilization of rewritable luminescent materials for secure information storage and delivery has long been envisaged to reduce the cost and environmental wastes. However, it remains challenging to realize a temporally/spatially controlled display of the written information, which is crucial for secure information encryption. Here, inspired by bioelectricity‐triggered skin pattern switching in cephalopods, an ideal rewritable system consisting of conductive graphene film and carbon dots (CDs) gel with blue‐to‐red fluorescence‐color changes via water‐triggered CDs aggregation and re‐dispersion is presented. Its rewritability is guaranteed by using water ink to write on the CDs‐gel and employing Joule heat of graphene film to evaporate water. Due to the highly controlled electrical stimulus, temporally/spatially controlled display is achieved, enabling on‐demand delivery and duration time regulation of the written information. Furthermore, new‐concept environment‐interactive rewritable system is obtained by integrating sensitive acoustic/optical sensors and multichannel electronic time‐delay devices. This work opens unprecedented avenues of rewritable systems and expands potential uses for information encryption/delivery.
Enhanced Sonodynamic Cancer Therapy through Iron‐Doping and Oxygen‐Vacancy Engineering of Piezoelectric Bismuth Tungstate Nanosheets
Authors: Ding Yiming , Zhao Yunchao , Yao Shuncheng , Wang Shaobo , Wan Xingyi , Hu Quanhong , Li Linlin
Published: March 2023

Sonodynamic therapy (SDT) is regarded as a new‐rising strategy for cancer treatment with low invasiveness and high tissue penetration, but the scarcity of high‐efficiency sonosensitizers has seriously hindered its application. Herein, the iron‐doped and oxygen‐deficient bismuth tungstate nanosheets (BWO‐Fe NSs) with piezotronic effect are synthesized for enhanced SDT. Due to the existence of oxygen defects introduced through Fe doping, the bandgap of BWO‐Fe is significantly narrowed so that BWO‐Fe can be more easily activated by exogenous ultrasound (US). The oxygen defects acting as the electron traps inhibit the recombination of US‐induced electrons and holes. More importantly, the dynamically renewed piezoelectric potential facilitates the migration of electrons and holes to opposite side and causes energy band bending, which further promotes the production of reactive oxygen species. Furthermore, Fe doping endows BWO‐Fe with Fenton reactivity, which converts hydrogen peroxide (H2O2) in tumor microenvironment into hydroxyl radicals (•OH), thereby amplifying the cellular oxidative damage and enhancing SDT. Both in vitro and in vivo experiments illustrate their high cytotoxicity and tumor suppression rate against refractory breast cancer in mice. This work may provide an alternative strategy to develop oxygen‐deficient piezoelectric sonosensitizers for enhanced SDT via doping metal ions.