bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evolutionarily related host and microbial pathways regulate fat desaturation in C. elegans
Authors: Fox Bennett W. , Helf Maximilian J. , Burkhardt Russell N. , Artyukhin Alexander B. , Curtis Brian J. , Palomino Diana Fajardo , Schroeder Allen F. , Chaturbedi Amaresh , Tauffenberger Arnaud , Wrobel Chester J. J. , Zhang Ying K. , Lee Siu Sylvia , Schroeder Frank C. 
Published: February 2024

AbstractFatty acid desaturation is central to metazoan lipid metabolism and provides building blocks of membrane lipids and precursors of diverse signaling molecules. Nutritional conditions and associated microbiota regulate desaturase expression, but the underlying mechanisms have remained unclear. Here, we show that endogenous and microbiota-dependent small molecule signals promote lipid desaturation via the nuclear receptor NHR-49/PPARα in C. elegans. Untargeted metabolomics of a β-oxidation mutant, acdh-11, in which expression of the stearoyl-CoA desaturase FAT-7/SCD1 is constitutively increased, revealed accumulation of a β-cyclopropyl fatty acid, becyp#1, that potently activates fat-7 expression via NHR-49. Biosynthesis of becyp#1 is strictly dependent on expression of cyclopropane synthase by associated bacteria, e.g., E. coli. Screening for structurally related endogenous metabolites revealed a β-methyl fatty acid, bemeth#1, which mimics the activity of microbiota-dependent becyp#1 but is derived from a methyltransferase, fcmt-1, that is conserved across Nematoda and likely originates from bacterial cyclopropane synthase via ancient horizontal gene transfer. Activation of fat-7 expression by these structurally similar metabolites is controlled by distinct mechanisms, as microbiota-dependent becyp#1 is metabolized by a dedicated β-oxidation pathway, while the endogenous bemeth#1 is metabolized via α-oxidation. Collectively, we demonstrate that evolutionarily related biosynthetic pathways in metazoan host and associated microbiota converge on NHR-49/PPARα to regulate fat desaturation.
Highly anisotropic Fe3C microflakes constructed by solid-state phase transformation for efficient microwave absorption
Authors: Zhao Rongzhi , Gao Tong , Li Yixing , Sun Zhuo , Zhang Zhengyu , Ji Lianze , Hu Chenglong , Liu Xiaolian , Zhang Zhenhua , Zhang Xuefeng , Qin Gaowu 
Published: February 2024

AbstractSoft magnetic materials with flake geometry can provide shape anisotropy for breaking the Snoek limit, which is promising for achieving high-frequency ferromagnetic resonances and microwave absorption properties. Here, two-dimensional (2D) Fe3C microflakes with crystal orientation are obtained by solid-state phase transformation assisted by electrochemical dealloying. The shape anisotropy can be further regulated by manipulating the thickness of 2D Fe3C microflakes under different isothermally quenching temperatures. Thus, the resonant frequency is adjusted effectively from 9.47 and 11.56 GHz under isothermal quenching from 700 °C to 550 °C. The imaginary part of the complex permeability can reach 0.9 at 11.56 GHz, and the minimum reflection loss (RLmin) is −52.09 dB (15.85 GHz, 2.90 mm) with an effective absorption bandwidth (EAB≤−10 dB) of 2.55 GHz. This study provides insight into the preparation of high-frequency magnetic loss materials for obtaining high-performance microwave absorbers and achieves the preparation of functional materials from traditional structural materials.
Achieving environmental stability in an atomically thin quantum spin Hall insulator via graphene intercalation
Authors: Schmitt Cedric , Erhardt Jonas , Eck Philipp , Schmitt Matthias , Lee Kyungchan , Keßler Philipp , Wagner Tim , Spring Merit , Liu Bing , Enzner Stefan , Kamp Martin , Jovic Vedran , Jozwiak Chris , Bostwick Aaron , Rotenberg Eli , Kim Timur , Cacho Cephise , Lee Tien-Lin , Sangiovanni Giorgio , Moser Simon , Claessen Ralph 
Published: February 2024

AbstractAtomic monolayers on semiconductor surfaces represent an emerging class of functional quantum materials in the two-dimensional limit — ranging from superconductors and Mott insulators to ferroelectrics and quantum spin Hall insulators. Indenene, a triangular monolayer of indium with a gap of ~ 120 meV is a quantum spin Hall insulator whose micron-scale epitaxial growth on SiC(0001) makes it technologically relevant. However, its suitability for room-temperature spintronics is challenged by the instability of its topological character in air. It is imperative to develop a strategy to protect the topological nature of indenene during ex situ processing and device fabrication. Here we show that intercalation of indenene into epitaxial graphene provides effective protection from the oxidising environment, while preserving an intact topological character. Our approach opens a rich realm of ex situ experimental opportunities, priming monolayer quantum spin Hall insulators for realistic device fabrication and access to topologically protected edge channels.
Cooperative Cu/azodiformate system-catalyzed allylic C–H amination of unactivated internal alkenes directed by aminoquinoline
Authors: Wang Le , Wang Cheng-Long , Li Zi-Hao , Lian Peng-Fei , Kang Jun-Chen , Zhou Jia , Hao Yu , Liu Ru-Xin , Bai He-Yuan , Zhang Shu-Yu 
Published: February 2024

AbstractAliphatic allylic amines are common in natural products and pharmaceuticals. The oxidative intermolecular amination of C(sp3)-H bonds represents one of the most straightforward strategies to construct these motifs. However, the utilization of widely internal alkenes with amines in this transformation remains a synthetic challenge due to the inefficient coordination of metals to internal alkenes and excessive coordination with aliphatic and aromatic amines, resulting in decreasing the reactivity of the catalyst. Here, we present a regioselective Cu-catalyzed oxidative allylic C(sp3)-H amination of internal olefins with azodiformates to these problems. A removable bidentate directing group is used to control the regiochemistry and stabilize the π-allyl-metal intermediate. Noteworthy is the dual role of azodiformates as both a nitrogen source and an electrophilic oxidant for the allylic C-H activation. This protocol features simple conditions, remarkable scope and functional group tolerance as evidenced by >40 examples and exhibits high regioselectivity and excellent E/Z selectivity.
Spatial patterns of Holocene temperature changes over mid-latitude Eurasia
Authors: Jiang Jiawei , Meng Bowen , Wang Huanye , Liu Hu , Song Mu , He Yuxin , Zhao Cheng , Cheng Jun , Chu Guoqiang , Krivonogov Sergey , Liu Weiguo , Liu Zhonghui 
Published: February 2024

AbstractThe Holocene temperature conundrum, the discrepancy between proxy-based Holocene global cooling and simulated global annual warming trends, remains controversial. Meanwhile, reconstructions and simulations show inconsistent spatial patterns of terrestrial temperature changes. Here we report Holocene alkenone records to address spatial patterns over mid-latitude Eurasia. In contrast with long-term cooling trends in warm season temperatures in northeastern China, records from southwestern Siberia are characterized by colder conditions before ~6,000 years ago, thus long-term warming trends. Together with existing records from surrounding regions, we infer that colder airmass might have prevailed in the interior of mid-latitude Eurasian continent during the early to mid-Holocene, perhaps associated with atmospheric response to remnant ice sheets. Our results challenge the proposed seasonality bias in proxies and modeled spatial patterns in study region, highlighting that spatial patterns of Holocene temperature changes should be re-considered in record integrations and model simulations, with important implications for terrestrial hydroclimate changes.
A high-current hydrogel generator with engineered mechanoionic asymmetry
Authors: Liu Hongzhen , Ji Xianglin , Guo Zihao , Wei Xi , Fan Jinchen , Shi Peng , Pu Xiong , Gong Feng , Xu Lizhi 
Published: February 2024

AbstractMechanoelectrical energy conversion is a potential solution for the power supply of miniaturized wearable and implantable systems; yet it remains challenging due to limited current output when exploiting low-frequency motions with soft devices. We report a design of a hydrogel generator with mechanoionic current generation amplified by orders of magnitudes with engineered structural and chemical asymmetry. Under compressive loading, relief structures in the hydrogel intensify net ion fluxes induced by deformation gradient, which synergize with asymmetric ion adsorption characteristics of the electrodes and distinct diffusivity of cations and anions in the hydrogel matrix. This engineered mechanoionic process can yield 4 mA (5.5 A m−2) of peak current under cyclic compression of 80 kPa applied at 0.1 Hz, with the transferred charge reaching up to 916 mC m−2 per cycle. The high current output of this miniaturized hydrogel generator is beneficial for the powering of wearable devices, as exemplified by a controlled drug-releasing system for wound healing. The demonstrated mechanisms for amplifying mechanoionic effect will enable further designs for a variety of self-powered biomedical systems.
Transition from positive to negative indirect CO2 effects on the vegetation carbon uptake
Authors: Chen Zefeng , Wang Weiguang , Forzieri Giovanni , Cescatti Alessandro 
Published: February 2024

AbstractAlthough elevated atmospheric CO2 concentration (eCO2) has substantial indirect effects on vegetation carbon uptake via associated climate change, their dynamics remain unclear. Here we investigate how the impacts of eCO2-driven climate change on growing-season gross primary production have changed globally during 1982–2014, using satellite observations and Earth system models, and evaluate their evolution until the year 2100. We show that the initial positive effect of eCO2-induced climate change on vegetation carbon uptake has declined recently, shifting to negative in the early 21st century. Such emerging pattern appears prominent in high latitudes and occurs in combination with a decrease of direct CO2 physiological effect, ultimately resulting in a sharp reduction of the current growth benefits induced by climate warming and CO2 fertilization. Such weakening of the indirect CO2 effect can be partially attributed to the widespread land drying, and it is expected to be further exacerbated under global warming.
Physics guided heat source for quantitative prediction of IN718 laser additive manufacturing processes
Authors: Amin Abdullah Al , Li Yangfan , Lu Ye , Xie Xiaoyu , Gan Zhengtao , Mojumder Satyajit , Wagner Gregory J. , Liu Wing Kam 
Published: February 2024

AbstractChallenge 3 of the 2022 NIST additive manufacturing benchmark (AM Bench) experiments asked modelers to submit predictions for solid cooling rate, liquid cooling rate, time above melt, and melt pool geometry for single and multiple track laser powder bed fusion process using moving lasers. An in-house developed Additive Manufacturing Computational Fluid Dynamics code (AM-CFD) combined with a cylindrical heat source is implemented to accurately predict these experiments. Heuristic heat source calibration is proposed relating volumetric energy density (ψ) based on experiments available in the literature. The parameters of the heat source of the computational model are initially calibrated based on a Higher Order Proper Generalized Decomposition- (HOPGD) based surrogate model. The prediction using the calibrated heat source agrees quantitatively with NIST measurements for different process conditions (laser spot diameter, laser power, and scan speed). A scaling law based on keyhole formation is also utilized in calibrating the parameters of the cylindrical heat source and predicting the challenge experiments. In addition, an improvement on the heat source model is proposed to relate the Volumetric Energy Density (VEDσ) to the melt pool aspect ratio. The model shows further improvement in the prediction of the experimental measurements for the melt pool, including cases at higher VEDσ. Overall, it is concluded that the appropriate selection of laser heat source parameterization scheme along with the heat source model is crucial in the accurate prediction of melt pool geometry and thermal measurements while bypassing the expensive computational simulations that consider increased physics equations.
Cosmic dust fertilization of glacial prebiotic chemistry on early Earth
Authors: Walton Craig R. , Rigley Jessica K. , Lipp Alexander , Law Robert , Suttle Martin D. , Schönbächler Maria , Wyatt Mark , Shorttle Oliver 
Published: February 2024

AbstractEarth’s surface is deficient in available forms of many elements considered limiting for prebiotic chemistry. In contrast, many extraterrestrial rocky objects are rich in these same elements. Limiting prebiotic ingredients may, therefore, have been delivered by exogenous material; however, the mechanisms by which exogeneous material may be reliably and non-destructively supplied to a planetary surface remains unclear. Today, the flux of extraterrestrial matter to Earth is dominated by fine-grained cosmic dust. Although this material is rarely discussed in a prebiotic context due to its delivery over a large surface area, concentrated cosmic dust deposits are known to form on Earth today due to the action of sedimentary processes. Here we combine empirical constraints on dust sedimentation with dynamical simulations of dust formation and planetary accretion to show that localized sedimentary deposits of cosmic dust could have accumulated in arid environments on early Earth, in particular glacial settings that today produce cryoconite sediments. Our results challenge the widely held assumption that cosmic dust is incapable of fertilizing prebiotic chemistry. Cosmic dust deposits may have plausibly formed on early Earth and acted to fertilize prebiotic chemistry.
Ecological niche conservatism spurs diversification in response to climate change
Authors: Qiao Huijie , Peterson A. Townsend , Myers Corinne E. , Yang Qinmin , Saupe Erin E. 
Published: February 2024

AbstractLengthy debate has surrounded the theoretical and empirical science of whether climatic niche evolution is related to increased or decreased rates of biological diversification. Because species can persist for thousands to millions of years, these questions cross broad scales of time and space. Thus, short-term experiments may not provide comprehensive understanding of the system, leading to the emergence of contrasting opinions: niche evolution may increase diversity by allowing species to explore and colonize new geographic areas across which they could speciate; or, niche conservatism might augment biodiversity by supporting isolation of populations that may then undergo allopatric speciation. Here, we use a simulation approach to test how biological diversification responds to different rates and modes of niche evolution. We find that niche conservatism promotes biological diversification, whereas labile niches—whether adapting to the conditions available or changing randomly—generally led to slower diversification rates. These novel results provide a framework for understanding how Earth–life interactions produced such a diverse biota.
High-concentration silver alloying and steep back-contact gallium grading enabling copper indium gallium selenide solar cell with 23.6% efficiency
Authors: Keller Jan , Kiselman Klara , Donzel-Gargand Olivier , Martin Natalia M. , Babucci Melike , Lundberg Olle , Wallin Erik , Stolt Lars , Edoff Marika 
Published: February 2024

AbstractChalcopyrite-based solar cells have reached an efficiency of 23.35%, yet further improvements have been challenging. Here we present a 23.64% certified efficiency for a (Ag,Cu)(In,Ga)Se2solar cell, achieved through the implementation of a series of strategies. We introduce a relatively high amount of silver ([Ag]/([Ag] + [Cu]) = 0.19) into the absorber and implement a ‘hockey stick’-like gallium profile with a high concentration of Ga close to the molybdenum back contact and a lower, constant concentration in the region closer to the CdS buffer layer. This kind of elemental profile minimizes lateral and in-depth bandgap fluctuations, reducing losses in open-circuit voltage. In addition, the resulting bandgap energy is close to the local optimum of 1.15 eV. We apply a RbF post-deposition treatment that leads to the formation of a Rb–In–Se phase, probably RbInSe2, passivating the absorber surface. Finally, we discuss future research directions to reach 25% efficiency.
Consumption responses to an unconditional child allowance in the United States
Authors: Parolin Zachary , Giupponi Giulia , Lee Emma K. , Collyer Sophie 
Published: February 2024

AbstractThe COVID-19 pandemic put families in the United States under financial stress. The federal government’s largest response in 2021 was the American Rescue Plan Act, which temporarily expanded the Child Tax Credit (CTC) into a large, unconditional child allowance providing monthly payments to families with children. This study investigates consumption responses to the CTC expansion using anonymized mobile-location data and debit/credit card data that track visits and spending at 1.3 million establishments across US counties. For identification, we exploit variation in the size of households’ income gains due to the CTC across counties in a difference-in-differences framework spanning January 2021 to May 2022. Counties benefiting most from the CTC expansion experienced larger increases in visits to childcare centres and health- and personal-care establishments, and increased visits to and spending per transaction at grocery and general stores. These findings suggest that the CTC expansion increased household consumption and spending on children.
Bonding performance and surface characterization of cold-bonded acetylated beech (Fagus sylvatica L.) laminated veneer lumber
Authors: Slabohm Maik , Militz Holger 
Published: February 2024

AbstractAcetylation of wood with acetic anhydride reduces the wood–moisture interaction, improves the dimensional stability and resistance against biodegradation. However, the adhesive bonding is affected by the modification, which is crucial to manufacture engineered wood products, such as laminated veneer lumber (LVL). In this study we report the bonding of 8-layered acetylated beech (Fagus sylvatica L.) LVL boards to 2-layered LVL beams. The beams were glued together at room temperature adding three common load-bearing construction adhesives: melamine–urea–formaldehyde (MUF), phenol–resorcinol–formaldehyde (PRF), and one-component polyurethane (PUR). The bonding performance was tested by assessing its dry and wet tensile shear strength (TSS) and wood failure percentage (WF). Also evaluated were the material's density and moisture content (MC). The surface was characterized prior to bonding by its pH, roughness, and contact angle (CA). The adhesive penetration was observed by fluorescence microscopy. Aside from MUF, applying PRF and PUR adhesives achieved good bonding performance on acetylated LVL and references. Acetylated LVL displayed a more hydrophobic behaviour, a higher pH, a somewhat smoother surface, and an increased density.
The metrics of reading speed: understanding developmental dyslexia
Authors: Conforti Sara , Marinelli Chiara Valeria , Zoccolotti Pierluigi , Martelli Marialuisa 
Published: February 2024

AbstractWe compared reading words and pseudo-words presented in single displays (as typical of psycholinguistic research) with stimuli presented in multiple displays (as typical of real-life conditions and clinical testing) under controlled conditions. Italian sixth-grade children with and without a reading deficit showed an advantage in reading times for multiple over single displays. This finding was partly ascribed to the capacity to overlap the non-decisional component of the response, an effect present in control readers as well as children with dyslexia. Furthermore, there were several indications in the data that the requirement to read sequentially taxes performance by augmenting the relative impact of the experimental manipulations used. This effect was present in both groups of children, but proportionally stronger in children with dyslexia. The study contributes to filling the gap between single and multiple displays, a condition more like real-life situations.
Grain iron and zinc content is independent of anthocyanin accumulation in pigmented rice genotypes of Northeast region of India
Authors: Gogoi Smrita , Singh Sanjay , Swamy B. P. Mallikarjuna , Das Priyanka , Sarma Debojit , Sarma Ramendra Nath , Acharjee Sumita , Deka Sharmila Dutta 
Published: February 2024

AbstractThe traditional rice genotypes of Assam are considered to have biological value due to the presence of several bioactive compounds like flavonoids, polyphenols, and anthocyanins, which have antioxidant, anti-cancer, anti-diabetic, and anti-aging properties. The pigmented genotypes are considered to have high iron (Fe) content. However, the effect of Fe and Zinc (Zn) accumulation on anthocyanin content is yet to be studied in pigmented rice of Assam. We studied the Fe, Zn, and anthocyanin content in grains of 204 traditional rice of Assam, which are traditionally preferred for their nutraceutical properties. We performed phenotypic and biochemical compositional analyses of 204 genotypes to identify those having high Fe, Zn, and anthocyanin. We also carried out the differential expression of a few selected Fe and Zn transporter genes along with the expression of anthocyanin biosynthesis genes. Interestingly, all pigmented rice genotypes contained a higher amount of phenolic compound than the non-pigmented form of rice. We found the highest (32.73 g) seed yield per plant for genotype Jengoni followed by Kajoli chokuwa and Khau Pakhi 1. We also listed 30 genotypes having high levels of Fe and Zn content. The genotype Jengoni accumulated the highest (186.9 μg g−1) Fe, while the highest Zn (119.9 μg g−1) content was measured in genotype Bora (Nagaon), The levels of Ferritin 2 gene expression were found to be significantly higher in Bora (Nagaon) (> 2-fold). For Zn accumulation, the genotype DRR Dhan-45, which was released as a high Zn content variety, showed significant up-regulation of the ZIP4 gene at booting (> 7-fold), post-anthesis (7.8-fold) and grain filling (> 5-fold) stages followed by Bora (Nagaon) (> 3-fold) at post-anthesis. Anthocyanidin synthase gene, Flavanone 3-dioxygenase 1-like (FDO1), and Chalcone-flavanone isomerase-like genes were up-regulated in highly pigmented genotype Bora (Nagaon) followed by Jengoni. Based on our data there was no significant correlation between iron and zinc content on the accumulation of anthocyanin. This challenges the present perception of the higher nutritive value in terms of the micronutrient content of the colored rice of Assam. This is the first report on the detailed characterization of traditional rice genotypes inclusive of phenotypic, biochemical, nutritional, and molecular attributes, which would be useful for designing the breeding program to improve Fe, Zn, or anthocyanin content in rice.