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Spin accumulation in semiconductor structures at room temperature and without magnetic fields is key to enable a broader range of optoelectronic functionality1. Current efforts are limited owing to inherent inefficiencies associated with spin injection across semiconductor interfaces2. Here we demonstrate spin injection across chiral halide perovskite/III-V interfaces achieving spin accumulation in a standard semiconductor III-V (AlxGa1-x)0.5In0.5P multiple quantum well light-emitting diode. The spin accumulation in the multiple quantum well is detected through emission of circularly polarized light with a degree of polarization of up to 15 ± 4%. The chiral perovskite/III-V interface was characterized with X-ray photoelectron spectroscopy, cross-sectional scanning Kelvin probe force microscopy and cross-sectional transmission electron microscopy imaging, showing a clean semiconductor/semiconductor interface at which the Fermi level can equilibrate. These findings demonstrate that chiral perovskite semiconductors can transform well-developed semiconductor platforms into ones that can also control spin.
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Exciton-polariton systems composed of a light-matter quasi-particle with a light effective mass easily realize Bose-Einstein condensation. In this work, we constructed an annular trap in a halide perovskite semiconductor microcavity and observed the spontaneous formation of symmetrical petal-shaped exciton-polariton condensation in the annular trap at room temperature. In our study, we found that the number of petals of the petal-shaped exciton-polariton condensates, which is decided by the orbital angular momentum, is dependent on the light intensity distribution. Therefore, the selective excitation of perovskite microcavity exciton-polariton condensates under all-optical control can be realized by adjusting the light intensity distribution. This could pave the way to room-temperature topological devices, optical cryptographical devices, and new quantum gyroscopes in the exciton-polariton system.
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Maleic anhydride (MAH)-modified polymers are used as tie layers for binding dissimilar polymers in multilayer polymer films. The MAH chemistry which promotes adhesion is well characterized in the bulk; however, only recently has the interfacial chemistry been studied. Sum frequency generation vibrational spectroscopy (SFG) is an interfacial spectroscopy technique which provides detailed information on interfacial chemical reactions, species, and molecular orientations and has been essential for characterizing the MAH chemistry in both nylon and ethyl vinyl alcohol copolymer (EVOH) model systems and coextruded multilayer films. Here, we further characterize the interfacial chemistry between MAH-modified polyethylene tie layers and both EVOH and nylon by investigating the model systems over a range of MAH concentrations. We can detect the interfacial chemical reaction products between MAH and the barrier layer at MAH concentrations of ≥0.022 wt % for nylon and ≥0.077 wt % for EVOH. Additionally, from the concentration-dependent reaction reactant/product SFG peak positions and the product imide or ester/acid CâO group tilt angles extracted from the polarization-dependent SFG spectra, we quantitatively observe concentration-dependent changes to both the interfacial chemistry and interfacial structure. The interfacial chemistry and molecular orientation as a function of MAH concentration are well correlated with the adhesion strength, providing important quantitative information for the future design of MAH-modified tie layers for a variety of important applications.
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This study aimed to investigate the influence of the moisture content of dehulled sesame seeds on the aroma formation and harmful substances in sesame paste (SP). The SP samples were made of dehulled sesame seeds with moisture contents of 5%, 10%, 15%, 20%, and 25% and denoted as T5, T10, T15, T20, and T25, respectively. The results revealed that adjusting the moisture content had a significant impact on aroma compounds, color intensity, and sensory properties. SP pre-adjusted to a moisture content of 10% exhibited the smallest L* value and the highest browning strength. Using gas chromatography-olfactometry-mass spectrometry analysis, the researchers identified 38 aroma-active compounds in the SP, with pyrazines being the most abundant, contributing to roasted sesame and nutty aromas. Additionally, the presence of pyrrole and furan derivatives led to enhanced caramel and almond aromas, positively influencing the overall sensory properties. T10 demonstrated the highest levels of roasted sesame and nutty odors. Furthermore, the regulation of moisture content also affected the formation of harmful compounds, such as heterocyclic amines and polycyclic aromatic hydrocarbons (PAHs). Notably, the sample made of the sesame seeds with 10% and 15% moisture content exhibited the lowest total PAHs content (18.21-28.91 ng/g) and PAH4 content (non-detectable-0.15 ng/g). The carcinogen benzo[a]pyrene was not detected in any of the samples, ensuring a safer product. The pre-adjustment of moisture content in SP appears to be a promising approach to improve both its flavor and safety qualities.
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Sesamum , Compostos Orgânicos Voláteis , Odorantes/análise , Sesamum/química , Compostos Orgânicos Voláteis/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Sementes/químicaRESUMO
Gas chromatography-olfactory-mass spectrometry (GC-O-MS) combined with Aroma Extract Dilution Analysis (AEDA) were employed to characterize the key odor-active compounds in sesame paste (SP) and dehulled sesame paste (DSP). The AEDA results revealed the presence of 32 and 22 odor-active compounds in SP and DSP, respectively. Furthermore, 13 aroma compounds with FD ≥ 2, OAV ≥ 1, and VIP ≥ 1 were identified as key differential aroma compounds between SP and DSP. Specifically, compounds such as 3-methylbutyraldehyde (OAV = 100.70-442.57; fruity), 2-methylbutyraldehyde (OAV = 106.89-170.31; almond), m-xylene (FD = 16; salty pastry), and 2,5-dimethylpyrazine (FD = 8-16; roasted, salty pastry) played an important role in this differentiation. Additionally, the dehulling process led to increased fermented, sweet, green, and nutty aroma notes in DSP compared to the more pronounced burnt and roasted sesame aroma notes in SP. Our findings offer a theoretical foundation for the regulation of sesame paste aroma profiles.
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Manipulação de Alimentos , Cromatografia Gasosa-Espectrometria de Massas , Odorantes , Sesamum , Sesamum/química , Odorantes/análise , Manipulação de Alimentos/métodos , Pirazinas/análise , Xilenos/análise , Aldeídos/análise , Paladar , Aromatizantes/análise , Compostos Orgânicos Voláteis/análiseRESUMO
Understanding the evolution of aroma profiles in stored sesame paste (SP) is essential for maintaining its quality. This study investigated the storage quality of SP and potential aroma markers indicative of sensory degradation. The descriptive sensory analysis demonstrated changes in aroma attributes during storage, transitioning from roasted sesame and nutty aromas to fermented and green aromas. Physicochemical analysis showed deepening color, intensified lipid oxidation, decreased levels of bioactive components, increased particle aggregation, and deteriorated flowability over 63 days at 40 °C. Gas chromatography-olfactometry-mass spectrometry identified 37 aroma-active compounds, with pyrazines, aldehydes, and phenols identified as the major constituents. Partial least squares regression analysis revealed 2-ethyl-3-methyl-pyrazine, 2-methoxy-4-vinylphenol, and benzaldehyde as key aroma-active compounds contributing significantly to the distinctive aromas "roasted nut and roasted sesame" found in SP. Conversely, hexanal and dimethyl disulfide emerged as potential markers of undesirable aromas in SP, including "rancid, green, and fermented". These findings provide insights into SP changes during storage, which is vital for preservation and quality enhancement strategies.
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Armazenamento de Alimentos , Cromatografia Gasosa-Espectrometria de Massas , Odorantes , Sesamum , Paladar , Sesamum/química , Odorantes/análise , Humanos , Compostos Orgânicos Voláteis/química , OlfatometriaRESUMO
There has been much controversy over the effects of music tempo on movement flow. In this study, a single-factor repeated-measurement design was used to explore the effect of music tempo (fast, slow, and no music control) on movement flow by measuring both subjective experiences and objective electroencephalographic (EEG) characteristics during brisk walking. In the experiment, 20 college students walked briskly on a treadmill using EEG equipment. Each participant walked for 10 min on three different days. Their brain waves were recorded during brisk walking on a treadmill. After each walk, the participants completed a form of short flow state scale-2 (S FSS-2), which covered nine major aspects of flow. The results showed that music tempo had a significant effect on subjective experiences and objective physiological characteristics; that is, a higher subjective flow level for fast-tempo music in brisk walking and a significant enhancement of mean power values in the subconscious brain waves of the delta, theta, alpha, and beta bands for fast tempo music were observed. A fast tempo facilitated the movement flow. The findings of this study can be instructive for the use of music in exercises to improve sports training outcomes.
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As a new vector insect of pine wood nematodes in China, the Monochamus saltuarius (Coleoptera: Cerambycidae) vectors pine wilt nematodes into healthy pine trees through feeding and oviposition, resulting in huge economic losses to forestry. A promising control strategy is to develop safe and efficient attractants. This study aims to screen for the key active volatiles of Pinus koraiensis (Pinales: Pinaceae), Pinus tabuliformis (Pinales: Pinaceae), and Picea asperata (Pinales: Pinaceae) that can attract M. saltuarius, and to study the synergistic attraction of the main attractant plant volatiles with ethanol and insect aggregation pheromones. The preference of M. saltuarius for three hosts is P. koraiensis > P. tabuliformis > Picea asperata. We detected 18 organic volatiles from three host plants. Through EAG assays and indoor Y-tube behavioral experiments, 3-carene, (-)-camphor, ß-pinene, α-phellandrene, terpinolene, α-pinene, D-limonene, and myrcene were screened to have attractive effects on M. saltuarius. We found that 3-carene, ß-pinene, and α-pinene are the most attractive kairomones in field experiments, which may play a crucial role in the host localization of M. saltuarius. Ethanol has a synergistic effect on the attractant activity of 3-carene and ß-pinene, and the synergistic effect on ß-pinene is the best. The mixture of ethanol, 2-undecyloxy-1-ethanol, and ipsdienol can significantly enhance the attraction effect of ß-pinene on M. saltuarius. These new findings provide a theoretical basis for the development of attractants for adult M. saltuarius and contribute to the green control of M. saltuarius.
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In this study, the influence of pre-regulation of the water content (5-25 %) on the harmful substances and aroma compounds of sesame paste (SP) was investigated. The results indicated that pre-regulation of the water content reduced the generation of harmful substances in SP. Notably, the total heterocyclic amine content in SP-15 was significantly lower than in other samples. SP-10 had the lowest total polycyclic aromatic hydrocarbon content, while SP-5 exhibited the lowest PAH4 content. Using solvent-assisted aroma evaporation and GC-O-MS, 50 aroma compounds were identified in SP. Pre-regulation of water content in SP led to an elevated concentration of heterocyclic compounds thereby imparting a diverse aromatic profile. It enhanced the perceived intensity of roasted sesame and salty pastry aromas while reducing the perceived intensity of fermentation and burnt aromas. The findings suggested the pre-regulation of the water content played a crucial role in aroma modulation and harmful substances control in SP.
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The high intensity of diverse human activities in urban-rural areas leads to complex soil Pb accumulation processes and high spatiotemporal heterogeneity, making it difficult to reveal the spatiotemporal characteristics of soil Pb accumulation in these areas. This study used a typical urban-rural area in a large city in Central China as the study area, constructed a soil Pb accumulation model, and established a spatiotemporal simulation method for soil Pb accumulation processes combining this model and land use classification and simulation results. Using this method, we simulated the soil Pb content in the study area from 2013 to 2040 and elucidated the future spatiotemporal variation characteristics of soil Pb content. The results showed that the average soil Pb content in the study area in 2013 was approximately 1.77 times the background value of the Pb content in the surface soil of the province where the city is located, indicating significant soil Pb pollution. The soil Pb content was predicted to continue increasing from 2013 to 2040, with relatively low increases (0.53-2.25 mg·kg-1) in the western, northern, and southern parts of the study area, accounting for 25.46 % of the total area, and relatively high increases (3.98-5.70 mg·kg-1) in the eastern part, accounting for 17.14 % of the total area. The increase in the area of forest land and the decrease in the area of water bodies and grassland in the eastern part of the study area led to a substantial rise in soil Pb content in this region; in addition, the spatial distribution of soil Pb content was highly correlated with the distribution of important factories and transportation facilities. This study overcomes the limitations of previous research that treated land use as unchanging and to a certain extent reflects the impact of regional land use changes on the heavy metal accumulation process. It provides a method for simulating the soil Pb accumulation process in urban-rural areas and a basis for controlling soil Pb pollution in the city's urban-rural areas.
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Gelatinizing high-amylose maize starch (HAMSt) requires high temperatures to allow complexation with lipids, making it a challenging process. An octenylsuccinylation method was examined as a part of a strategy to decrease the gelatinization temperature of HAMSt, thereby promoting the complexation between HAMSt and myristic acid (MAc). Octenyl succinic anhydride (OSA) modification of HAMSt reduces the onset gelatinization temperature of HAMSt from 71.63 °C to 66.97 °C. Moreover, as the OSA concentration increased from 2 % to 11 %, the degree of substitution and molecular weights of the esterified HAMSt gradually increased from 0.0069 to 0.0184 and from 0.97 × 106 to 1.17 × 106 g/mol, respectively. Fourier transform infrared analysis indicated that the octenyl-succinate groups were grafted onto the HAMSt chains. The formation of HAMSt-MAc complexes improved the thermal stability of OSA-treated HAMSt (peak temperature increased by 0.11 °C-13.95 °C). Moreover, the diffraction intensity of the V-type peak of the 11 % sample was greater than that of other samples. Finally, the anti-retrogradation ability was in the order of OSA-HAMSt-MAc complexes > HAMSt-MAc complexes > HAMSt. Overall, our results indicate that octenylsuccinylation can be an effective strategy to promote the formation of OSA-HAMSt-MAc complexes and delay starch retrogradation.
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Amilose , Ácido Mirístico , Amido , Succinatos , Zea mays , Zea mays/química , Amilose/química , Amido/química , Amido/análogos & derivados , Succinatos/química , Ácido Mirístico/química , Temperatura , Anidridos Succínicos/químicaRESUMO
The mitochondriaassociated endoplasmic reticulum (ER) membrane (MAM), serving as a vital link between the mitochondria and ER, holds a pivotal role in maintaining the physiological function of these two organelles. Its specific functions encompass the participation in the biosynthesis and functional regulation of the mitochondria, calcium ion transport, lipid metabolism, oxidative stress and autophagy among numerous other facets. Scientific exploration has revealed that MAMs hold potential as effective therapeutic targets influencing the mitochondria and ER within the context of cancer therapy. The present review focused on elucidating the related pathways of mitochondrial autophagy and ER stress and their practical application in ovarian cancer, aiming to identify commonalities existing between MAMs and these pathways, thereby extending to related applications of MAMs in ovarian cancer treatment. This endeavor aimed at exploring new potential for MAMs in clinically managing ovarian cancer.
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Autofagia , Estresse do Retículo Endoplasmático , Retículo Endoplasmático , Mitocôndrias , Neoplasias Ovarianas , Humanos , Neoplasias Ovarianas/patologia , Neoplasias Ovarianas/metabolismo , Feminino , Retículo Endoplasmático/metabolismo , Mitocôndrias/metabolismo , Estresse OxidativoRESUMO
A gold-catalyzed, nucleophile-controlled cascade reaction of N-(2-azidophenyl-ynyl)methanesulfonamides with nitriles and water is described that provides structurally diverse 5H-pyrimido[5,4-b]indoles and 2-benzylidene-3-indolinones in good to excellent yields. Mechanistic studies indicate that the ß-sulfonamido-α-imino gold carbene is the key intermediate which is generated through the gold-catalyzed cyclization of N-(2-azidophenyl-ynyl)methanesulfonamides and undergoes formal [4 + 2] cascade annulation with nitriles and intramolecular SN2' type reaction with water, respectively.
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Reactive oxygen species (ROS) are crucial signaling molecules in plants that play multifarious roles in prompt response to environmental stimuli. Despite the classical thoughts that ROS are toxic when accumulate in excess, recent advances in plant ROS signaling biology reveal that ROS participate in biotic and abiotic stress perception, signal integration, and stress-response network activation, hence contributing to plant defense and stress tolerance. ROS production, scavenging and transport are fine-tuned by plant hormones and stress-response signaling pathways. Crucially, the emerging plant hormone melatonin attenuates excessive ROS accumulation under stress, whereas ROS signaling mediates melatonin-induced plant developmental response and stress tolerance. In particular, RESPIRATORY BURST OXIDASE HOMOLOG (RBOH) proteins responsible for apoplastic ROS generation act downstream of melatonin to mediate stress response. In this review, we discuss promising developments in plant ROS signaling and how ROS might mediate melatonin-induced plant resilience to environmental stress.
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Melatonina , Espécies Reativas de Oxigênio/metabolismo , Melatonina/farmacologia , Plantas/metabolismo , Estresse Fisiológico , Desenvolvimento Vegetal , Reguladores de Crescimento de Plantas/metabolismoRESUMO
In this paper, we demonstrate that exciton/exciton annihilation in the 2D perovskite (PEA)2PbI4 (PEPI)âa major loss mechanism in solar cells and light-emitting diodes, can be controlled through coupling of excitons with cavity polaritons. We study the excited state dynamics using time-resolved transient absorption spectroscopy and show that the system can be tuned through a strong coupling regime by varying the cavity width through the PEPI layer thickness. Remarkably, strong coupling occurs even when the cavity quality factor remains poor, providing easy optical access. We demonstrate that the observed derivative-like transient absorption spectra can be modeled using a time-dependent Rabi splitting that occurs because of transient bleaching of the excitonic states. When PEPI is strongly coupled to the cavity, the exciton/exciton annihilation rate is suppressed by 1 order of magnitude. A model that relies on the partly photonic character of polaritons explains the results as a function of detuning.
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In this paper, the changes in oil body emulsion (OBE) during heptanoic acid demulsification (HD) were investigated from the macro and microscopic points of view. Specifically, the OBE particle size increased from 3.04 to 8.41 µm, while the zeta potential absolute decreased to 2.89 mV. The interfacial tension and apparent viscosity of OBE were reduced significantly. Heptanoic acid could contribute to oil droplets aggregation. The findings indicated that high-molecular proteins, including lipoxygenase (97.58 kDa) and arachin (70.28 kDa), detached from the OBs' interface. HD caused alterations in the secondary structure of protein and the environment around proteins changed. The HD mechanism was speculated that the addition of heptanoic acid resulted in the reduction in pH and changes of environment surrounding OBE, which triggered polymerization and the phase transformation of the oil droplets. Overall, this study is vital for solving the problem of demulsification during aqueous enzymatic extraction (AEE).
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Methylammonium lead tribromide (MAPbBr3) stands out as the most easily grown wide-band-gap metal halide perovskite. It is a promising semiconductor for room-temperature gamma-ray (γ-ray) spectroscopic detectors, but no operational devices are realized. This can be largely attributed to a lack of understanding of point defects and their influence on detector performance. Here, through a combination of crystal growth design and defect characterization, including positron annihilation and impedance spectroscopy, the presence of specific point defects are identified and correlated to detector performance. Methylammonium (MA) vacancies, MA interstitials, and Pb vacancies are identified as the dominant charge-trapping defects in MAPbBr3 crystals, while Br vacancies caused doping. The addition of excess MABr reduces the MA and Br defects and so enables the detection of energy-resolved γ-ray spectra using a MAPbBr3 single-crystal device. Interestingly, the addition of formamidinium (FA) cations, which converted to methylformamidinium (MFA) cations by reaction with MA+ during crystal growth further reduced MA defects. This enabled an energy resolution of 3.9% for the 662 keV 137Cs line using a low bias of 100 V. The work provides direction toward enabling further improvements in wide-bandgap perovskite-based device performance by reducing detrimental defects.
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Fusarium head blight (FHB) is a devastating wheat disease. Fhb1, the most widely applied genetic locus for FHB resistance, is conferred by TaHRC of an unknown mode of action. Here, we show that TaHRC alleles distinctly drive liquid-liquid phase separation (LLPS) within a proteinaceous complex, determining FHB susceptibility or resistance. TaHRC-S (susceptible) exhibits stronger LLPS ability than TaHRC-R (resistant), and this distinction is further intensified by fungal mycotoxin deoxynivalenol, leading to opposing FHB symptoms. TaHRC recruits a protein class with intrinsic LLPS potentials, referred to as an "HRC-containing hub." TaHRC-S drives condensation of hub components, while TaHRC-R comparatively suppresses hub condensate formation. The function of TaSR45a splicing factor, a hub member, depends on TaHRC-driven condensate state, which in turn differentially directs alternative splicing, switching between susceptibility and resistance to wheat FHB. These findings reveal a mechanism for FHB spread within a spike and shed light on the roles of complex condensates in controlling plant disease.
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Resistência à Doença , Fusarium , Doenças das Plantas , Proteínas de Plantas , Triticum , Triticum/microbiologia , Triticum/genética , Triticum/metabolismo , Fusarium/genética , Doenças das Plantas/microbiologia , Resistência à Doença/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Tricotecenos/metabolismo , Alelos , Processamento AlternativoRESUMO
OBJECTIVE: This study aimed to investigate the impact of microbubble degradation and flow velocity on Sub-Harmonic Aided Pressure Estimation (SHAPE), and to explore the correlation between subharmonic amplitude and pressure as a single factor. METHODS: We develop an open-loop vascular phantom platform system and utilize a commercial ultrasound machine and microbubbles for subharmonic imaging. Subharmonic amplitude was measured continuously at constant pressure and flow velocity to assess the impact of microbubble degradation. Flow velocity was varied within a range of 4-14 cm/s at constant pressure to investigate its relationship to subharmonic amplitude. Furthermore, pressure was varied within a range of 10-110 mm Hg at constant flow velocity to assess its isolated effect on subharmonic amplitude. RESULTS: Under constant pressure and flow velocity, subharmonic amplitude exhibited a continuous decrease at an average rate of 0.221 dB/min, signifying ongoing microbubble degradation during the experimental procedures. Subharmonic amplitude demonstrated a positive correlation with flow velocity, with a variation ratio of 0.423 dB/(cm/s). Under controlled conditions of microbubble degradation and flow velocity, a strong negative linear correlation was observed between pressure and subharmonic amplitude across different Mechanical Index (MI) settings (all R2 > 0.90). The sensitivity of SHAPE was determined to be 0.025 dB/mmHg at an MI of 0.04. CONCLUSION: The assessment of SHAPE sensitivity is affected by microbubble degradation and flow velocity. Excluding the aforementioned influencing factors, a strong linear negative correlation between pressure and subharmonic amplitude was still evident, albeit with a sensitivity coefficient lower than previously reported values.