bluuebunny/crossref_metadata_2025 huggingface dataset:
Site‐Specific Incorporation of Fluorinated Prolines into Proteins and Their Impact on Neighbouring Residues
Authors: Elena‐Real Carlos A. , Urbanek Annika , Sagar Amin , Mohanty Priyesh , Levy Geraldine , Morató Anna , Fournet Aurélie , Allemand Frédéric , Sibille Nathalie , Mittal Jeetain , Sinnaeve Davy , Bernadó Pau
Published: December 2024

The incorporation of fluorinated amino acids into proteins provides new opportunities to study biomolecular structure‐function relationships in an elegant manner. The available strategies to incorporate the majority of fluorinated amino acids are not site‐specific or imply important structural modifications. Here, we present a chemical biology approach for the site‐specific incorporation of three commercially available Cγ‐modified fluoroprolines that has been validated using a non‐pathogenic version of huntingtin exon‐1 (HttExon‐1). 19F, 1H and 15N NMR chemical shifts measured for multiple variants of HttExon‐1 indicated that the trans/cis ratio was strongly dependent on the fluoroproline variant and the sequence context. By isotopically labelling the rest of the protein, we have shown that the extent of spectroscopic perturbations to the neighbouring residues depends on the number of fluorine atoms and the stereochemistry at Cγ, as well as the isomeric form of the fluoroproline. We have rationalized these observations by means of extensive molecular dynamics simulations, indicating that the observed atomic chemical shift perturbations correlate with the distance to fluorine atoms and that the effect remains very local. These results validate the site‐specific incorporation of fluoroprolines as an excellent strategy to monitor intra‐ and intermolecular interactions in disordered proline‐rich proteins.
Selective Self‐Assembly of Supramolecular Helices and Macrocycles Directed by Halogen Bonding
Authors: Hu Zhi‐Yuan , Du Mengxin , Li Wenhao , Huang Xin , Ma Ruijie , Li Yunhan , Shen Ren‐Zeng , Wang Tao , Liu Chuan‐Zhi , Li Zhan‐Ting
Published: December 2024

In this study, several hydrogen‐bonded arylamide foldamers (compounds 1–5) with the same degree of polymerization were designed and synthesized. The polyfluoroiodobenzene or iodoethynyl polyfluoroiodobenzene segment was modified as a halogen donor at the end of the monomer, and pyridine or pyridine oxynitride served as the corresponding halogen acceptor segment. The crystal structure of compound 1 indicates that the supramolecular double helices were constructed by stacking a P helix and an M helix in an antiparallel manner in the direction of intermolecular I⋅⋅⋅−O−N+ halogen bonding. The zig‐zag‐shaped linear structures of compounds 2 and 3 were generated under the induction of intermolecular I⋅⋅⋅N and I⋅⋅⋅−O−N+ halogen bonds. [1+1] near‐planar bimolecular supramolecular macrocycles in compounds 4 and 5 were formed by multiple groups of effective intramolecular three‐center hydrogen bonding and strong I⋅⋅⋅N and I⋅⋅⋅−O−N+ halogen bonds. Hirshfeld surface analysis and theoretical modelling of the halogen bonding energy were performed. The noncovalent interactions on the surface of the monomers and the halogen bonding energy were investigated in detail.
Establishment and simulation study of equivalent model for thermal contact resistance in electronic devices
Authors: Xiao Weiqiang , Lu Xinbo , Teng Ruyu , Xu Qingyi , Wu Jian , Xu Jian , Han Yufeng , Zhou Guojun , Zhan Wangcheng
Published: December 2024

To accurately determine thermal contact resistance (TCR) for the thermal design of electronic devices, a simplified simulation method is first proposed for calculating thermal contact resistance. First, an equivalent geometric model is established based on actual rough surfaces Then, finite element methods are employed to calculate the thermal contact resistance. The results demonstrate that the proposed equivalent geometric model, containing contact point information, can accurately predict the thermal contact resistance, which has a deviation of 10% with the experimental data. Furthermore, the results revealed that both the contact pressure and the surface roughness of the materials significantly influenced TCR, through adjusting the gap thickness. As the contact pressure increased from 200 to 1400 kPa, the TCR decreased from to . The decrease became more gradual at high contact pressure, indicating a nonlinear relationship between pressure and TCR. On the other hand, the surface roughness affected TCR primarily through the equivalent contact point height, that is, the gap thickness between two samples. Moreover, temperature affected TCR mainly through radiative heat transfer, which was dependent on material intrinsic properties. The developed simplified calculation method can efficiently simulate TCR for electronic devices, which not only enhanced the understanding of TCR behaviour but also provided a practical tool for optimizing thermal designs in electronic devices.
Test of a serial mediated model of green human resource management in the manufacturing industry
Authors: Nosrati Saeid , Talebzadeh Niusha , Maydon Denitsa Hristoforova , Karatepe Osman M.
Published: December 2024

Our paper develops and tests a serial mediated model of green human resource management (GHRM). Data came from entry‐level employees and supervisors in the power manufacturing industry in Bulgaria. The results from PROCESS Macro suggest that egoistic value, altruistic value, and biospheric value completely mediate the link between GHRM and eco‐friendly behavior (ECB). The impact of GHRM on ECB is completely mediated by environmental empathy. More importantly, egoistic value, altruistic value, or biospheric value and environmental empathy completely and serially mediate the link between GHRM and ECB. The abovementioned findings enhance the current knowledge on the mediators that operate in the association between GHRM and ECB. The results will assist policymakers, businesses, and scholars in understanding the significance of GHRM in the international marketplace as well as the underlying associations between GHRM and ECB, serving as a valuable tool for fostering and attaining these behaviors in the manufacturing industry.
River confinement and braiding loss in Canterbury region, Aotearoa New Zealand
Authors: Barlow Victoria , Ashmore Peter
Published: December 2024

In relation to the wider concern that rivers in Aotearoa New Zealand have been narrowed by river control and land‐use encroachment, and that iconic braided patterns are being lost, nine braided rivers from the Canterbury region were studied to compare river width, pattern type and braiding intensity between the mid‐1900s and the present based on mapping from aerial images. Channel narrowing occurred along >90% (~490 km) of the length of the rivers studied, 375 km of which were historically braided. In total, the rivers narrowed by an average of 43% (48% for braided reaches). Coinciding with narrowing, braided reaches lost 1.3 channels, on average. Overall, 20% (over 100 km) length of the rivers recorded a change from braided to more simple pattern types including wandering (~18%) and single channel (~1%). The relationship of channel width and pattern change demonstrates the predictability of braiding change based on channel narrowing. As channels narrow, the likelihood of pattern simplification and change increases, although the amount of narrowing required to induce change depends on the initial width and pattern. Narrowing causes a reduction of braiding intensity even when the channel pattern remains braided. Based on these results, a predictor of channel pattern change and reduction of braiding intensity, based only on channel width and width change, can be applied to aid room‐for‐river management plans for conserving or restoring braided river morphologies. Channel width provides a general criterion for the prediction of braiding intensity and channel pattern threshold illustrating the scale‐related effects on channel pattern.
Commentary on “A Pilot Study Investigating the Influence of Dietary Boron Levels on Osteoporosis in Postmenopausal Women”
Authors: Ullah Bahar
Published: December 2024

This letter discusses the potential influence of dietary boron on osteoporosis in postmenopausal women, a demographic significantly affected by this condition. Recent studies suggest that boron plays a critical role in bone health by modulating mineral metabolism and hormonal balance. Despite its potential benefits, boron is often overlooked in dietary recommendations for this group. This correspondence aims to raise awareness and encourage further research into the incorporation of boron‐rich foods to enhance bone density and overall health in postmenopausal women.
Enhancing Stirred Yogurt Quality With Hyaluronic Acid‐Rich Rooster Comb Extract: Effects on Texture and Shelf Life
Authors: Tabari Shahandasht Nastaran , Bolandi Marzieh , Rahmati Majid , Jafarisani Moslem
Published: December 2024

Yogurt is a popular milk‐based product known for its nutritional benefits and effects on the large intestine. However, yogurt production faces challenges like texture, consistency, and syneresis. Hydrocolloids, such as gums and polysaccharides, can enhance yogurt's consistency and rheological properties. This research evaluates rooster comb extract (RCE) as a natural additive to improve stirred yogurt's properties during 21 days of storage at 4°C. Two treatments with 0.8 and 0.9 g of RCE were added to stirred yogurt. Results showed a decrease in pH (from 3.89 to 4.38) and microbial counts (> 107 log CFU/g), along with an increase in titratable acidity (1.03%–1.48%) in RCE‐enriched yogurt (p < 0.05). The 0.8 g RCE treatment showed reduced syneresis, lightness, and setting time compared to the control (p < 0.05). Rheological analysis indicated thixotropic shear‐thinning behavior, accurately described by the Herschel–Bulkley model. All samples displayed solid viscoelastic properties, with the storage modulus exceeding the loss modulus in the linear viscoelastic region. While flavor and overall acceptability declined in enriched samples compared to controls (p < 0.05), no significant differences were found in other characteristics, including texture, color, and aroma (p > 0.05). In conclusion, RCE is a promising natural hydrocolloid for producing functional stirred yogurt, offering potential consumer benefits.
Chenopodium botrys Extract Affects Acute Kidney Injury Caused by Rhabdomyolysis in Rats Through TNF/NF‐κB Signaling Pathway
Authors: Momeni‐Moghaddam Mohammad Amin , Abbasnezhad Abbasali , Ebadi Amir Hossein , Mohebbati Reza
Published: December 2024

Due to the anti‐inflammatory and antioxidant properties of the Chenopodium botrys and the pathological mechanisms of rhabdomyolysis in the kidney, this plant can be used to improve the symptoms of this disease. Then, in this study, we investigated the effects of this herb in improving kidney injury by rhabdomyolysis. Animals were divided into five groups: control, glycerol (received it for rhabdomyolysis induction), extract (received 12 mg/kg C. botrys extract), and treatment groups with dexamethasone (0.03 mg/kg) and extract (12 mg/kg). The extract was analyzed using HNMR. After a week, blood and urine samples were taken to measure protein, urea, and creatinine. Then, the animals were sacrificed, and the kidney tissue was removed to examine the antioxidant, TNF‐α, and histopathological evaluations. Also, NF‐κB gene expression was investigated. The serum creatinine, TNF‐α, and NF‐κB ratio significantly increased and antioxidant capacity decreased in the glycerol group compared with the control. Pathological evaluation also showed severe renal damage based on the related criteria. In the treatment groups with dexamethasone and especially extract, the considered parameters attenuated relatively compared with the glycerol group. Kidney damage and functional impairment associated with rhabdomyolysis, as well as the inflammatory response caused by increased NF‐κB and the proinflammatory cytokine TNF‐α, may be alleviated by C. botrys. Consequently, C. botrys could represent a potential therapeutic approach for patients with rhabdomyolysis‐induced acute kidney injury.
Topological Quantum Numbers in Quasicrystals
Authors: Kellendonk Johannes
Published: December 2024

We provide an overview on the theory of topological quantum numbers from the point of view of non‐commutative topology. Topological phases are described by K‐groups of C*‐algebras. The algebras are constructed from the set of positions of the nuclei of the materials we want to study. Topological quantum numbers are Chern numbers of K‐group elements. Maps between K‐groups which are of algebraic topological origin provide the means to obtain relations between different topological quantum numbers as, for instance, in the bulk edge correspondence. We present simple aperiodic examples related to quasicrystals to illustrate the theory.
Prenatal multidisciplinary counseling for fetal congenital anomalies: A narrative review
Authors: Lugli Licia , Rossi Cecilia , Berardi Alberto , Pugliese Marisa , Ceccarelli Pier Luca , Sileo Filomena Giulia , Chiossi Giuseppe , Contu Giannina , Calabrese Olga , La Marca Antonio , Bertucci Emma
Published: December 2024

Introduction

Prenatal multidisciplinary counseling for fetuses with congenital anomalies involves a collaborative approach, integrating expertise from various medical fields.

Aims and Approach

This comprehensive strategy aims to provide expectant parents with accurate information about the diagnosis, potential outcomes, and available interventions. Genetic counselors, obstetricians, neonatologists, and other specialists work together to address medical, psychological, and ethical aspects. The prenatal multidisciplinary counseling approach emphasizes open communication, fostering a supportive environment for the couple to express their concerns and ask questions. In the case of prenatally detected fetal congenital anomalies, several different scenarios can be delineated: (1) detection of surgically correctable congenital anomalies, (2) identification of genetic disease or fetal anomalies likely to result in disabilities, (3) discovery of severe and lethal congenital anomalies, and (4) encountering fetal anomalies that are not well‐defined, leading to an unclear scenario. The process of counseling includes discussing the possibility of pregnancy termination, treatment options, potential challenges, and emotional support, enabling expectant parents to make informed decisions aligned with their values and preferences. Additionally, the counseling process extends beyond the initial diagnosis, providing ongoing support as the pregnancy progresses and helping families to prepare for the difficulties they may face after the birth of the child with congenital anomalies. This collaborative effort not only focuses on the medical aspects but also considers the emotional and ethical dimensions of decision‐making.

Conclusion

The multidisciplinary approach enhances the quality of care and empower parents, facilitating a more informed and compassionate journey throughout the prenatal period.
Co‐creating a conceptual model of Indigenous relational wellbeing in early childhood: Planting seeds of connectedness
Authors: Wesner Chelsea A. , Around Him Deana , Ullrich Jessica Saniguq , Martin Lisa , Denmark Nicole , Russette Helen , Lee KyungSook , Sarche Michelle , Asdigian Nancy L. , Barnes‐Najor Jessica , Whitesell Nancy Rumbaugh ,   the Tribal Early Childhood Research Center Early Relational Wellbeing Community of Learning
Published: December 2024

The purpose of this article is to share our story of conceptualizing Indigenous early relational wellbeing (ERW), specifically reflecting American Indian and Alaska Native worldviews. Our approach is grounded in Indigenous methodologies and guided by a Community of Learning comprised of Indigenous and allied Tribal early childhood community partners, researchers, practitioners, and federal funders. We describe the steps we took to conceptualize caregiver–child relationships from an Indigenous perspective, center Indigenous values of child development, apply an established Indigenous connectedness framework to early childhood, and co‐create a conceptual model of Indigenous ERW to guide future practice and research. This model highlights relational practices as seeds of connectedness and relational wellbeing, and includes the roles of spirituality, culture, and ceremony in nurturing ERW; the manifestations of relational wellbeing across the lifespan; and the interdependence of relational wellbeing within communities and families, across generations, and with the environment. The model also informs the creation of a measure to understand practices that foster relational wellbeing among Indigenous children and families and their relationship to positive development, thus informing research, practice, and policy.
Accuracy of Reaction Coordinate Based Rate Theories for Modelling Chemical Reactions: Insights From the Thermal Isomerization in Retinal
Authors: Ghysbrecht Simon , Donati Luca , Keller Bettina G.
Published: December 2024

Modern potential energy surfaces have shifted attention to molecular simulations of chemical reactions. While various methods can estimate rate constants for conformational transitions in molecular dynamics simulations, their applicability to studying chemical reactions remains uncertain due to the high and sharp energy barriers and complex reaction coordinates involved. This study focuses on the thermal cis‐trans isomerization in retinal, employing molecular simulations and comparing rate constant estimates based on one‐dimensional rate theories with those based on sampling transitions and grid‐based models for low‐dimensional collective variable spaces. Even though each individual method to estimate the rate passes its quality tests, the rate constant estimates exhibit considerable disparities. Rate constant estimates based on one‐dimensional reaction coordinates prove challenging to converge, even if the reaction coordinate is optimized. However, consistent estimates of the rate constant are achieved by sampling transitions and by multi‐dimensional grid‐based models.
A novel magnetic bifunctional hydrochar catalyst derived from palm leaf residue for biodiesel production: kinetic and thermodynamic studies
Authors: Aliyu Muhammad , Rashid Umer , Tsubota Toshiki , Wan Ab Karim Ghani Wan Azlina , Mohd Salleh Mohamad Amran , Khuong Duy Anh , Trinh Kieu Trang , Duc Nguyen Trung , Tashima Daisuke , Ryu Tomi
Published: December 2024

BACKGROUND

Novel magnetic bifunctional hydrochar‐based catalysts were produced from activated hydrochar derived from palm leaf residue (PLRAH) via a wet impregnation technique and used to perform one‐step waste cooking oil (WCO) transesterification to produce biodiesel. The magnetic bifunctional hydrochar‐based catalysts were evaluated for their acid–base properties, crystallinity, functional groups, magnetism, textural properties, thermal stability, chemical composition, and morphology.

RESULTS

The PLRAH‐Fe2O3/K2O magnetic catalyst performed well in thermal testing, with a large specific surface area of 111.08 m2 g−1 and its high basicity value of 7.34 mmol g−1, as well as an acidity value of 12.67 mmol g−1, significantly contributed to the WCO transesterification. An optimum biodiesel yield of 98.36% was obtained under the following conditions: catalyst loading of 3 wt%, a methanol‐to‐WCO molar ratio of 12:1, and a reaction temperature of 75 °C for a duration of 4 h and biodiesel yields maintained at >80% after five cycles. The produced biodiesel complied with the physicochemical properties stated in ASTM D6751. The kinetic study also revealed that WCO transesterification using the one‐step approach had a pseudo‐first order and activation energy () of 24.27 kJ mol−1. Furthermore, the thermodynamic variables, including Gibbs free energy (∆Go), enthalpy (∆Ho), and entropy (∆So) of WCO transesterification, were found to be 7.60 kJ mol−1, 24.27 kJ mol−1, and −21.78 J mol−1 K, respectively. This suggests that WCO transesterification was an endothermic and non‐spontaneous process.

CONCLUSION

The synthesized magnetic bifunctional hydrochar‐based catalyst demonstrated outstanding performance for WCO transesterification, highlighting its potential for efficient biodiesel production. © 2024 Society of Chemical Industry (SCI).
Risk stratification and diagnostic evaluation of patients found to have microscopic hematuria by their primary care providers
Authors: An Clemens , Jeong Jake , Chiu Cedrick , Gaston Evan , Kennedy Amanda , Sternberg Kevan
Published: December 2024

Background

Our goal was to identify, and risk stratify primary care patients with microscopic hematuria (MH), describe the diagnostic evaluations they received, and determine whether the evaluations were consistent with the recommendations of the 2020 AUA/SUFU microscopic hematuria guidelines.

Methods

A retrospective review of patients presenting to primary care clinics with a diagnosis of MH was performed. The patient risk category was determined based on the 2020 AUA/SUFU guidelines. Diagnostic strategies were recorded, and guideline concordance was determined. Descriptive statistics were generated to describe outcomes.

Results

A total of 368 patients had a diagnosis of MH; 267/368 (72.6%) patients had all pertinent data available for risk stratification. One‐hundred and fifty‐six (58.4) patients were high‐risk and 55 (35.3%) had a urologic visit. Forty‐one of the 55 (75%) were diagnostically evaluated of which 13 (31.7%) were in‐line with guideline recommendations. Eighty‐two (30.7%) patients were at intermediate risk of which 33 (40.2%) had a urology visit. Of these 33 intermediate‐risk patients, 27 (81.8%) were diagnostically evaluated, five (18.5%) of which were in‐line with guideline recommendations. Twenty‐nine patients were low risk of which 4 (13.8%) had a urology visit. Three of the four patients seen by urology (75%) were evaluated with imaging studies and none received a cystoscopy.

Conclusion

Almost 60% of the patients in our cohort were high‐risk according to the AUA/SUFU 2020 guidelines. Across all strata, the majority of patients lacked a urology visit and diagnostic evaluation consistent with guideline recommendations. Future efforts should ensure appropriate urologic referral and optimize initial diagnostic strategies for patients with MH.
Estimating the Evolving Trade Effect of Foreign Aid in the Context of Aid Competition: Evidence From European Countries
Authors: Xu Hongyi , Sun Zesheng , Chen Hao
Published: December 2024

This paper explores the evolving trade effect of foreign aid using data from European countries from 1962 to 2020 in the context of multidonor competition. Our varying‐coefficient panel shows a significant country‐ and time‐heterogeneous trade effect of European donors' aid; however, aid competition can produce a mix of trade promotion and inhibitory effects. Estimations of aid's evolving trade effect reveal that donors' aid scale and (export) industrial concentration have a positive effect on promoting the trade–aid relationship with aid scale showing a reverse U‐shaped effect; the share of Aid for Trade (AfT) exerts a negative effect, and the donor's trade deficit demonstrates a positive impact on aid–trade effect.
Development of barley proteins into peptides nanomicelles for encapsulation of hydrophobic bioactive ingredient
Authors: Song Hongdong , Duan Longhuan , Ren Shaoxia , Wang Xinyue , Feng Zhongyang , Shen Jianhua , Wang Chengtao , Guan Xiao
Published: December 2024

BACKGROUND

As natural polymer materials, barley proteins have been utilized to fabricate nanocarriers to encapsulate and delivery hydrophobic bioactive ingredients. However, as a result of the high proportion of hydrophobic amino acids and structural rigidity, barley protein‐based nanocarriers tend to aggregate easily and have a low loading capacity, which greatly limits their application. In the present study, barley proteins were enzymolyzed to fabricate nanomicelles and then applied to encapsulate hydrophobic bioactive ingredient.

RESULTS

Self‐assembled barley peptides could be obtained by controllable enzymolysis of barley proteins. The obtained barley peptides could self‐assemble into nanomicelles (BPNMs) with a diameter of approximately 90 nm when the concentration was > 2.1 μg mL−1. Hydrophobic interaction, disulfide bonds and hydrogen bonds were involved in maintaining the structure of BPNMs. Six self‐assembled peptides (QQPFPQ, QTPLPQ, QLPQIPE, QPFPQQPQLPH, QPFPQQPPFGL and QPFPQQPPFWQQQ) were identified and they were characterized by alternating arrangement of hydrophobic amino acids and hydrophilic amino acids. Moreover, BPNMs were utilized to encapsulate hydrophobic bioactive ingredient quercetin. When quercetin was encapsulated by BPNMs, its water solubility was significantly increased, being approximately 30‐fold higher than free quercetin. Meanwhile, encapsulation of BPNMs could greatly increase quercetin stability. The interaction between BPNMs and quercetin occurred spontaneously, mainly driven by van der Waals forces and hydrogen bonds.

CONCLUSION

In the present study, BPNMs were successfully developed and could be used as a promising delivery system to improve the water solubility and stability of hydrophobic bioactive ingredients. © 2024 Society of Chemical Industry.
Lie Symmetries With Exact Solution for Time‐Fractional Foam Drainage Equation
Authors: Simon S. Gimnitz , Bira B.
Published: December 2024

In this article, we consider a nonlinear time‐fractional foam drainage equation and investigate the behavior of fluid flow through the foam. First, we apply the symmetry analysis and obtain the infinitesimal group of transformations involving some arbitrary parameters. Further, we classify the one‐dimensional optimal algebra, and using that, we obtain the similarity variables, which consequently reduces the time fractional partial differential equation (FPDE) to fractional‐order ordinary differential equation (FODE). Next, under the invariance condition, we construct exact solution for the given model and presented graphically. Furthermore, we derive the two‐dimensional optimal systems and nonclassical symmetry for the governing equation. Finally, we study the nature of fluid flow through the foam by numerical simulation.
A Wideband High Gain Transmit‐Array Antenna Exploiting Polarization‐Rotated Metasurface Cell
Authors: Zhang Yamei , Xu Feng , Qiang Jingxia , Liu Shui , Xie Qi
Published: December 2024

A novel polarization‐insensitive transmit‐array (TA) antenna using linear polarization‐rotated (PR) metasurface (MS) unit cells has been proposed in this article. Firstly, we design a wideband polarization‐insensitive polarization‐rotated MS unit cell. The MS cell can provide high transmission for incident linear polarized waves with polarization rotation by 90°. Then, we investigate the stability of the MS cell under the oblique incident wave. The proposed MS cell keeps a stable response under oblique incident wave over ± 30°. To verify the excellent performance of the proposed MS. We design a high‐gain TA antenna consisting of a standard feed horn and an aperture with a gradient phase. The gradient phase compensation is provided by varying the geometric dimension of the proposed MS. The obtained TA antenna works in a wide band with high gain. We fabricated the aperture and set up a prototype of TA antenna to verify our work. We measure the TA antenna and the results show a wide operating band from 14.2 to 18 GHz with a pick gain of 23.9 dBi. The favorable performance of the TA antenna is a good candidate in satellite systems and long‐distance satellite system. Furthermore, the angular stability of the MS cell is also verified by realizing the beam scanning performance. An over ± 30° scan range is obtained. Good beam scanning can be used in radar detection and expand signal coverage.
A Rollar‐Type Resonant Photoacoustic Spectroscopy for Trace Gas Detection
Authors: Zhang Yongjia , Wu Guojie , Gong Zhenfeng , Mei Liang
Published: December 2024

This paper presents a miniature Rollar‐type resonant photoacoustic cell (RRPAC), consisting of two cylindrical resonant cavities and a buffer chamber. The finite element analysis of the acoustic field distributions for the RRPAC and T‐type resonant photoacoustic cell (TRPAC) is utilized, demonstrating that RRPAC can produce a greater photoacoustic signal than the conventional TRPAC. A high sensitivity trace C2H2 photoacoustic spectroscopy (PAS) system is successfully developed by combining a cantilever beam‐based acoustic sensor as the acoustic sensing unit and a high‐speed spectrometer as the demodulation unit with the RRPAC. The experimental results indicate that the 2f signal of the RRPAC at the first‐order resonance mode is approximately 1.5 times of the TRPAC with the same C2H2 concentration. The gas detection limit of the RRPAC PAS system for C2H2 is 40.7 ppb at an averaging time of 100 s. In comparison with the conventional TRPAC, the RRPAC exhibits higher sensitivity, thus providing a novel solution for the advancement of the PAS system.
Estimating the CTDIvol with helical acquisitions: Results from a national generalizability study
Authors: Barreto Izabella L. , Gress Dustin A. , Leon Stephanie M. , Schwarz Bryan C. , Kobistek Robert J. , Mahesh M. , Tomlinson James A. , Dillon Chad M.
Published: December 2024

Background

While many clinical computed tomography (CT) protocols use helical scanning, the traditional method for measuring the volume CT Dose Index (CTDIvol) requires modifying the helical protocol to perform a single axial rotation. This modification can present challenges and mismatched settings across various scanner models.

Purpose

This study investigates the generalizability of a helical methodology for estimating CTDIvol across a diverse range of participants, CT scanner models, and protocol parameters.

Methods

A web‐based platform collected axial and helical CTDIvol measurements from 24 medical physicists who submitted 569 data sets obtained using four CT protocols on scanners from seven CT manufacturers. Various parameters were tested for tube voltage (70–140 kVp), rotation time (0.25–1.50 s), beam width (8–80 mm), and pitch (0.29–3.0) settings. Measurements from the two methodologies were assessed for reproducibility using three repeated exposures and then compared to each other and to the scanner‐displayed CTDIvol. Agreement between the methodologies was assessed using Bland–Altman analysis, linear regression, paired t‐tests, and a paired two one‐sided tests (TOST) procedure with equivalence margins of 5% of the mean protocol CTDIvol. The impact of beam width and pitch on measurement accuracy was assessed using linear regression analysis and an independent t‐test.

Results

This study demonstrated better measurement reproducibility with the helical method (p < 0.05) and excellent concordance between helical and axial measurements (CCC > 0.99), with an average difference of ‐0.61 mGy (limits of agreement: ‐4.54 and 3.32). The TOST analysis confirmed that the measurement methods were statistically equivalent within the defined equivalence margins. The number of measurements that differed from the displayed CTDIvol by more than ± 20% was 10 for the axial method and 22 for the helical method. We did not identify a linear correlation between measurement accuracy and beam width or pitch (R2 < 0.06). However, differences between axial and helical methods were significant for protocols with beam widths up to 40 mm versus those greater than 40 mm, as well as for protocols with pitch factors up to 1.0 compared to those greater than 1.0 (p < 0.001).

Conclusion

Utilizing the same equipment currently used for measuring CTDIvol and a simple measurement setup, the helical method offers an alternative measurement methodology that can be seamlessly implemented by medical physicists and adopted by regulatory and accrediting bodies for routine quality control of CT scanners.
On the Observation of Glucose–Insulin Models
Authors: Röbenack Klaus , Gerbet Daniel
Published: December 2024

The glucose–insulin subsystem has been modeled in different ways as a low‐dimensional dynamical system. These models consist of various parameters, which are fitted such that the model coincides with specific experiments. For individuals with the Diabetes Mellitus syndrome model‐based controllers for insulin injection have been proposed. These controllers, however, require the knowledge of the model parameters as well as the full systems state, which must be estimated as well. In addition, the system is disturbed by, in general, unknown carbohydrate intake. From a control‐theoretic point of view, the state estimation using only the measurable glucose concentration is an observer problem. Due to the nonlinearity of the system, its observability is more difficult to test. There may also be some points in the state space, where the system is not locally observable for some parameters tuples. Those issues are important for a robust observer design. In this contribution, several observers are discussed for the widely used Bergman minimal model. These include unknown‐input observers that make use of the special systems structure as well as observers based on the observability canonical form with different embedding dimensions. The canonical form is computed by algebraic methods.
Process parameters optimization of double‐vacuum‐bag technology for carbon fiber/resin composites
Authors: Ren Liangliang , Zhang Deyuan
Published: December 2024

Double‐vacuum‐bag (DVB) process, as an effective out‐of‐autoclave (OoA) technology, can manufacture composite materials with low void content and high mechanical properties. Therefore, this paper aimed to achieve low void content, the effects of pressure difference between inner and outer bags, dwelling temperature, and dwelling time on the void of composite laminates were studied based on orthogonal experimental method. The void content and morphology of laminates were statistically analyzed, by observing the microscopic images of the samples on cross‐section. The results show that the pressure difference between the inner and outer bags has a significant impact on the void content and morphology, while the dwelling temperature and dwelling time have little effect. In addition, with the variance analysis and extreme difference analysis, the optimal process parameters were determined as follows: pressure difference between inner and outer bags was 0 MPa, dwelling temperature was 110°C, and dwelling time was 15 min. The void content of composite laminates manufactured under these parameters is 0.07%, less than 1% requirement for aerospace components, and interlaminar shear strength (ILSS) is 110 MPa, which is 54.93% higher than the single‐vacuum‐bag (SVB) process. Generally, the void content and ILSS reached the level of hot press process with 0.6 MPa.

Highlights

Influence of different DVB process parameters on void were studied.

Void content manufactured with the optimal DVB process parameters was less than 1%.

ILSS of laminate with the optimal DVB process parameters was equal as hot press process.
Bio‐based epoxidized natural rubber nanocomposites for high‐performance tire tread applications
Authors: Zhao Luan , Liu Ling , Li Hanyu , Zhang Yuxi , Zhang Liqun
Published: December 2024

In this work, epoxidized natural rubber (ENR) with low epoxide degrees is synthesized through in situ epoxidation and then blended with TESPT‐modified silica to obtain the corresponding nanocomposites (ENR‐x/silica). It is found the filler‐rubber interaction is significantly enhanced by the ring‐opening reaction between silanol groups on silica and epoxy groups of ENR macromolecular chain. Therefore, wet‐skid resistance, fuel efficiency, abrasion resistance, and moduli of the ENR‐x/silica nanocomposites are superior to those of NR/silica nanocomposites. ENR‐15/silica demonstrates a balanced “magic triangle” performance, with wet‐skid resistance increasing by 74%, abrasion resistance improving by 17%, and rolling resistance decreasing by 29%, in relative to NR/silica.

Highlights

ENR with low epoxide degrees is synthesized by in situ epoxidation.

Epoxy groups enhance the silica dispersion and filler–rubber interaction.

ENR‐15/silica shows the lowest rolling resistance.

Wet‐skid and abrasion resistance increase with increasing epoxide degree.

ENR/silica with TESPT composites show excellent performance as tire tread.
Outdoor Air Pollution and Its Effects on Lung Health
Authors: Gappa Monika
Published: December 2024

This paper summarizes key factors regarding outdoor pollution and its effects on paediatric respiratory health.
Effects of allosteric effectors on oxygen binding to crystals of hemoglobin in the R‐quaternary structure
Authors: Shibayama Naoya
Published: December 2024

Much is known about how allosteric effectors influence the equilibrium between the relaxed (R) and tense (T) states of hemoglobin (Hb), but little is known about how and to what extent the effectors lower the intrinsic O2 affinity of each allosteric state, especially the R‐state. Here, we provide a thorough characterization of the O2 equilibria of effector‐bound and unbound R‐quaternary form crystals of horse Hb without a quaternary structural switching. In the absence of effectors, R crystals of horse Hb were shown to bind O2 noncooperatively with a very high affinity virtually identical to that of R crystals of human Hb. We found that the effector bezafibrate (BZF) and its derivative L35 lower the overall O2 affinity of R crystals by approximately a factor of 3 and 2, respectively, while both maintaining noncooperative oxygenation. These effects are observed regardless of whether the effectors are co‐crystallized or soaked into the effector‐free protein crystals with a different lattice, confirming that the observed affinity reduction is induced by the BZF derivatives and not by crystal packing forces. Our findings, combined with available co‐crystal structural data, suggest that the BZF derivatives lower the O2 affinity of the R‐quaternary structure of Hb through structural constraints imposed by a quaternary shift slightly toward T. Additionally, since no co‐crystal of R‐state Hb with the effector inositol hexakisphosphate (IHP) is available, we only present an IHP‐soaking experiment showing little change in O2 affinity, and poor IHP binding to the R crystal structure of horse Hb is suggested.
Flexible Spline Models for Blinded Sample Size Reestimation in Event‐Driven Clinical Trials
Authors: Mori Tim , Komukai Sho , Hattori Satoshi , Friede Tim
Published: December 2024

In event‐driven trials, the target power under a certain treatment effect is maintained as long as the required number of events is obtained. The misspecification of the survival function in the planning phase does not result in a loss of power. However, the trial might take longer than planned if the event rate is lower than assumed. Blinded sample size reestimation (BSSR) uses non‐comparative interim data to adjust the sample size if some planning assumptions are wrong. In the setting of an event‐driven trial, the sample size may be adjusted to maintain the chances to obtain the required number of events within the planned time frame. For the purpose of BSSR, the survival function is estimated based on the interim data and often needs to be extrapolated. The current practice is to fit standard parametric models, which may however not always be suitable. Here we propose a flexible spline‐based BSSR method. Specifically, we propose to carry out the extrapolation based on the Royston–Parmar spline model. To compare the proposed procedure with parametric approaches, we carried out a simulation study. Although parametric approaches might seriously over‐ or underestimate the expected number of events, the proposed flexible approach avoided such undesirable behavior. This is also observed in an application to a secondary progressive multiple sclerosis trial. Overall, if planning assumptions are wrong this more robust flexible BSSR method could help event‐driven designs to more accurately adjust recruitment numbers and to finish on time.
Optimal distributions of growing‐type initial perturbations for ensemble forecasts: Theory and application in the Lorenz‐96 model
Authors: Ji Chaopeng , Qin Bo , Mu Mu , Ma Junjie , Fang Xianghui , Feng Jie , Wang Qiang
Published: December 2024

Ensemble forecasts are frequently utilized to assess the uncertainties of prediction systems. There is a consensus that generating initial perturbations with specific structures is more conducive to characterizing the growth dynamics of analysis errors, demonstrating higher forecast skills. However, the widely used methods, such as linear singular vectors (SVs) and orthogonal conditional nonlinear optimal perturbations (O‐CNOPs) exhibit strong linear‐assumption dependence and the overestimation of growing properties for analysis errors, respectively, severely limiting the ability to capture analysis errors and forecast skills. To tackle these challenges, a theoretical framework is established to solve the optimal distribution of the nonlinear growing‐type initial perturbations by variational inference (VI) incorporated with the concept of CNOPs, marked as VI‐CNOPs. As the distribution is obtained, diverse initial perturbations for ensemble forecasts can be easily sampled in it. To evaluate the reliability of VI‐CNOPs, a series of ensemble forecast experiments are then conducted using the Lorenz‐96 model. We compare the deterministic and probabilistic forecast skills of VI‐CNOPs, O‐CNOPs, and SVs under various optimization durations. The results reveal that, as the optimization durations extend, the forecast skills of VI‐CNOPs progressively improve, consistently outperforming O‐CNOPs and SVs. This trend remains consistent across various forecast lead times. Further analysis reveals that VI‐CNOPs more effectively capture the covariance matrix of analysis errors, aligning with the fundamental concept of perturbation generation methods for ensemble forecasts. Moreover, unlike O‐CNOPs and SVs, VI‐CNOPs do not require the utilization of adjoint and tangent linear models, largely expanding its application. These results indicate the novelty and efficacy of VI‐CNOPs for ensemble forecasts.
Simulation of a Three‐Nucleons System Transition on Quantum Circuits
Authors: Nigro Luca , Barbieri Carlo , Prati Enrico
Published: December 2024

Quantum computers have proven to be effective in simulating many quantum systems. Simulating nuclear processes and state preparation poses significant challenges, even for traditional supercomputers. This study demonstrates the feasibility of a complete simulation of a nuclear transition, including the preparation of both ground and first excited states. To tackle the complexity of strong interactions between two and three nucleons, the states are modeled on the tritium nucleus. Both the initial and final states are represented using quantum circuits with variational quantum algorithms and inductive biases. Describing the spin‐isospin states requires four qubits, and a parameterized quantum circuit that exploits a total of 16 parameters is initialized. The estimated energy has a relative error of 2% for the ground state and 10% for the first excited state of the system. The simulation estimates the transition probability between the two states as a function of the dipole polarization angle. This work marks a first step toward leveraging digital quantum computers to simulate nuclear physics.
Spin Pumping in Epitaxial Ge1‐xSnx Alloys
Authors: Longo Emanuele , Concepción Omar , Mantovan Roberto , Fanciulli Marco , Myronov Maksym , Bonera Emiliano , Pedrini Jacopo , Buca Dan , Pezzoli Fabio
Published: December 2024

The use of Ge1‐xSnx semiconductor alloys is generating significant interest in the scientific community due to their precisely tunable Sn content. This tunability makes them particularly attractive for applications in photonics, electronics, and, more recently, spintronics. Room‐temperature emission and detection of spin currents are observed in Ge1‐xSnx/Co hybrids through spin‐pumping ferromagnetic resonance. Experiments conducted over a wide range of compositions and strains show that spin current injection is enhanced in Ge1‐xSnx solid solutions compared to elemental Ge. The magnetization dynamics reveal an intriguing scenario where the Gilbert damping constant and the spin mixing conductance display a non‐monotonic behavior. The maximum spin‐pumping efficiency occurs at a Sn molar fraction of ≈10 at.% and remains unaffected by the elastic strain built up in Ge1‐xSnx films through epitaxial growth on Ge‐buffered Si substrates. These findings highlight the non‐trivial dependence of alloy scattering in defining spin accumulation and relaxation mechanisms, providing insightful information on phenomena at the forefront of spintronics and quantum technology research.
Ultrastable Seawater Oxidation at Ampere‐level Current Densities with Corrosion‐resistant CoCO3/CoFe Layered Double Hydroxide Electrocatalyst
Authors: Yao Yongchao , Zou Chang , Sun Shengjun , Guo Yaxin , Hong Shaohuan , Cai Zhangping , Yang Chengli , Zhuang Weihua , Luo Fengming , Hamdy Mohamed S. , Ibrahim Fatma A. , Gong Feng , Li Yanan , Sun Xuping , Hu Wenchuang (Walter)
Published: December 2024

Hydrogen is an essential energy resource, playing a pivotal role in advancing a sustainable future. Electrolysis of seawater shows great potential for large‐scale hydrogen production but encounters challenges such as electrode corrosion caused by chlorine evolution. Herein, a durable CoCO3/CoFe layered double hydroxide (LDH) electrocatalyst is presented for alkaline seawater oxidation, showcasing resistance to corrosion and stable operation exceeding 1,000 h at a high current density of 1 A cm−2. The results indicate that CoCO3 within the electrocatalyst undergoes conversion into CoOOH and releases CO32− during electrolysis. The incorporation of CO32− within its layers and the anchoring of the electrocatalyst's surface prevent the adverse adsorption of chloride ions, enhancing resistance to chloride ion corrosion, thereby protecting the active sites of the electrocatalyst effectively.
Economic policy uncertainty and the Kimchi premium in the cryptocurrency market
Authors: Cho Dooyeon , Lee Kyung‐woo
Published: December 2024

We construct a new daily measure of uncertainty about economic policy for Korea. The economic policy uncertainty (EPU) index is extracted from the reporting about economic policy in major Korean newspapers. We then investigate how daily EPU affects the Kimchi premium, which is the ratio of the Bitcoin price in Korea to that in the United States, adjusted for the exchange rate. Our findings indicate that an increase in Korea's EPU makes Bitcoin more expensive in Korea, while the U.S. dollar strengthens against the Korean won. The stronger appreciation of the U.S. dollar outweighs the increase in Bitcoin prices, thereby lowering the Kimchi premium. Similarly, an increase in U.S. EPU has comparable but weaker effects. The appreciation of the U.S. dollar almost entirely offsets the higher relative price of Bitcoin in Korea, resulting in no significant impact on the Kimchi premium from changes in U.S. EPU. In addition, the results suggest that the Kimchi premium tends to rise with increased trading volume in Korea but decreases as trading volume increases in the United States. We also document that while the Kimchi premium is positively associated with Bitcoin price volatility in Korea, it is not significantly related to that in the United States.