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We have developed a state-of-the-art apparatus for laser-based spin- and angle-resolved photoemission spectroscopy with micrometer spatial resolution (µ-SARPES). This equipment is realized by the combination of a high-resolution photoelectron spectrometer, a 6 eV laser with high photon flux that is focused down to a few micrometers, a high-precision sample stage control system, and a double very-low-energy-electron-diffraction spin detector. The setup achieves an energy resolution of 1.5 (5.5) meV without (with) the spin detection mode, compatible with a spatial resolution better than 10 µm. This enables us to probe both spatially-resolved electronic structures and vector information of spin polarization in three dimensions. The performance of µ-SARPES apparatus is demonstrated by presenting ARPES and SARPES results from topological insulators and Au photolithography patterns on a Si (001) substrate.
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In Ficus septica, the short-term control of isoprene production and, therefore, isoprene emission has been linked to the hormone balance between auxin (IAA) and jasmonic acid (JA). However, the relationship between long-term changes in isoprene emission and that of plant hormones remains unknown. This study tracked isoprene emissions from F. septica leaves, plant hormone concentrations and signalling gene expression, MEP pathway metabolite concentrations, and related enzyme gene expression for 1 year in the field to better understand the role of plant hormones and their long-term control. Seasonality of isoprenes was mainly driven by temperature- and light-dependent variations in substrate availability through the MEP route, as well as transcriptional and post-transcriptional control of isoprene synthase (IspS). Isoprene emissions are seasonally correlated with plant hormone levels. This was especially evident in the cytokinin profiles, which decreased in summer and increased in winter. Only 4-hydroxy-3-methylbut-2-butenyl-4-diphosphate (HMBDP) exhibited a positive connection with cytokinins among the MEP metabolites examined, suggesting that HMBDP and its biosynthetic enzyme, HMBDP synthase (HDS), play a role in channelling of MEP pathway metabolites to cytokinin production. Thus, it is probable that cytokinins have potential feed-forward regulation of isoprene production. Under long-term natural conditions, the hormonal balance of IAA/JA-Ile was not associated with IspS transcripts or isoprene emissions. This study builds on prior work by revealing differences between short- and long-term hormonal modulation of isoprene emissions in the tropical tree F. septica.
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Ficus , Reguladores del Crecimiento de las Plantas , Reguladores del Crecimiento de las Plantas/metabolismo , Estaciones del Año , Ficus/genética , Ficus/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Hemiterpenos/metabolismo , Butadienos/metabolismo , Citocininas/metabolismo , Hormonas/metabolismo , Hojas de la Planta/metabolismo , Pentanos/metabolismoRESUMEN
OBJECTIVES: Extending healthy life expectancy (HALE), defined as the average number of years that a person can expect to live in "full health" by taking into account years lived in less than full health due to disease and/or injury, is a common topic worldwide. This study aims to clarify the relationships between the Mediterranean diet score (MDS) and life expectancy (LE) and HALE globally using publicly available international data. SETTING: Analyses were conducted on 130 countries with populations of 1 million or more for which all data were available. Individual countries were scored from 0 to 9 to indicate adherence to the Mediterranean diet according to the MDS scoring method. The supply of vegetables, legumes, fruits and nuts, cereals, fish, and olive oil per 1,000 kcal per country was calculated based on the Food and Agriculture Organization Corporate Statistical Database, with a score of 1 for above the median and 0 for below. The same method was used to calculate scores of presumed detrimental components (meat and dairy), with consumption below the median given a value of 1, and consumption above the median given a value of 0. For ethanol, a score of 1 was given for 10g to 50 g of consumption. We investigated the cross-sectional associations between the MDS and LE and HALE at birth in 2009, and the longitudinal associations between the MDS in 2009 and LE and HALE between 2009 and 2019, controlling for covariates at baseline using linear mixed models. RESULTS: In the cross-sectional analysis, the MDS was significantly positively associated with LE (ß=0.906 [95% confidence interval, 0.065-1.747], p=0.037) and HALE (ß=0.875 [0.207-1.544], p=0.011) after controlling for all covariates. The longitudinal analysis also revealed significantly positive associations between the MDS and LE (0.621 [0.063-1.178], p=0.030) and HALE (0.694 [0.227-1.161], p=0.004) after controlling for all covariates. CONCLUSION: The present study, based on an analysis using 10 years of international data, showed that countries with a higher MDS showed a positive association with HALE.
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Dieta Mediterránea , Animales , Estudios Transversales , Esperanza de Vida Saludable , Humanos , Esperanza de Vida , Modelos LinealesRESUMEN
Effective treatment approaches for patients with COVID-19 remain limited and are neither curative nor widely applicable. Activated specialized tissue effector extracellular vesicles (ASTEX) derived from genetically-enhanced skin fibroblasts, exert disease-modifying bioactivity in vivo in models of heart and lung injury. Here we report that ASTEX antagonizes SARS-CoV-2 infection and its pathogenic sequelae. In human lung epithelial cells exposed to SARS-CoV-2, ASTEX is cytoprotective and antiviral. Transcriptomic analysis implicated the mammalian target of rapamycin (mTOR) pathway, as infected cells upregulated mTOR signaling and pre-exposure to ASTEX attenuated it. The implication of mTOR signaling was further confirmed using mTOR inhibition and activation, which increased and decreased viral load, respectively. Dissection of ASTEX cargo identifies miRs including miR-16 as potential inhibitors of mTOR signaling. The findings reveal a novel, dual mechanism of action for ASTEX as a therapeutic candidate for COVID-19, with synergistic antiviral and cytoprotective benefits.
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Plant hormone signalling and the circadian clock have been implicated in the transcriptional control of isoprene biosynthesis. To gain more insight into the hormonal control of isoprene biosynthesis, the present study measured plant hormone concentrations in jasmonic acid (JA)-treated leaves of our previous model study, examined their relationship with gene expression of isoprene synthase (IspS) and hormone signalling transcription factors. Of the plant hormones, IAA and JA-Ile and their related transcription factors (MYC2 and SAUR21) were significantly correlated with IspS gene expression. Concentrations of cytokinins, isopentenyladenine (iP), trans-zeatin riboside (tZR) and cis-zeatin riboside (cZR), were similarly significantly correlated with IspS expression. However, there was no significant correlation between their related transcription factor (ARR-B) and IspS expression. The circadian clock-related gene PRR7, but not the transcription factor LHY, was highly correlated with IspS expression. These results suggest that the hormonal balance between JA-Ile and IAA plays a central role in transcriptional regulation of IspS through the transcription factors MYC2 and SAUR21, the early auxin responsive genes. The putative cis-acting elements for SAUR on the IspS promoter (TGTCNN and CATATG), in addition to the G-box for MYC2, support the above proposal. These results provide insightful information on the core components of plant hormone-related regulation of IspS under coordination with the circadian clock genes.
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Ficus , Reguladores del Crecimiento de las Plantas , Butadienos , Ficus/genética , Ficus/metabolismo , Hemiterpenos/metabolismo , Reguladores del Crecimiento de las Plantas/metabolismo , Árboles/fisiologíaRESUMEN
While it is known that the degenerated intervertebral disc (IVD) is one of the primary reasons for low-back pain and subsequent need for medical care, there are currently no established effective methods for direct treatment. Nuclear factor-κB (NF-κB) is a transcription factor that regulates various genes' expression, among which are inflammatory cytokines, in many tissues including the IVD. NF-κB decoy is an oligodeoxynucleotide containing the NF-κB binding site that entraps NF-κB subunits, resulting in suppression of NF-κB activity. In the present preclinical study, NF-κB decoy was injected into degenerated IVDs using the rabbit anular-puncture model. In terms of distribution, NF-κB decoy persisted in the IVDs up to at least 4 weeks after injection. The remaining amount of NF-κB decoy indicated that it fit a double-exponential-decay equation. Investigation of puncture-caused degeneration of IVDs showed that NF-κB decoy injection recovered, dose-dependently, the reduced disc height that was associated with reparative cell cloning and morphological changes, as assessed through histology. Gene expression, by quantitative real-time polymerase chain reaction (qRT-PCR), showed that NF-κB decoy attenuated inflammatory gene expression, such as that of interleukin-1 and tumor necrosis factor-α, in rabbit degenerated IVDs. NF-κB decoy also reduced the pain response as seen using the "pain sensor" nude rat xenograft-radiculopathy model. This is the first report demonstrating that NF-κB decoy suppresses the inflammatory response in degenerated IVDs and restores IVD disc height loss. Therefore, the intradiscal injection of NF-κB decoy may have the potential as an effective therapeutic strategy for discogenic pain associated with degenerated IVDs.
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Degeneración del Disco Intervertebral , Disco Intervertebral , Dolor de la Región Lumbar , Radiculopatía , Animales , Modelos Animales de Enfermedad , Xenoinjertos , Degeneración del Disco Intervertebral/genética , FN-kappa B , Oligodesoxirribonucleótidos/farmacología , Punciones , Conejos , RatasRESUMEN
In a combined experimental and theoretical study, we investigated how Fe and Co adlayers on W(110) affect the Dirac-type surface state (DSS). Angle-resolved photoelectron spectroscopy data show an increase in binding energy of 75 meV and 107 meV for Fe and Co, respectively. In order to identify the origin of the energy shift we performed first-principles calculations of the surface electronic structure. The inward surface relaxation of the uncovered W(110) surface is lifted by the adlayers. This structural change is one reason of the energy shift of the DSS. Furthermore, the Fe and Co adlayers change the surface potential, which results in an additional energy shift of the DSS.
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We report the observation of a nontrivial spin texture in Dirac node arcs, i.e., novel topological objects formed when Dirac cones of massless particles extend along an open one-dimensional line in momentum space. We find that such states are present in all the compounds of the tetradymite M_{2}Te_{2}X family (M=Ti, Zr, or Hf and X=P or As) regardless of the weak or strong character of the topological invariant. The Dirac node arcs in tetradymites are thus the simplest possible textbook example of a type-I Dirac system with a single spin-polarized node arc.
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Materials that possess nontrivial topology and magnetism is known to exhibit exotic quantum phenomena such as the quantum anomalous Hall effect. Here, we fabricate a novel magnetic topological heterostructure Mn4Bi2Te7/Bi2Te3 where multiple magnetic layers are inserted into the topmost quintuple layer of the original topological insulator Bi2Te3. A massive Dirac cone (DC) with a gap of 40-75 meV at 16 K is observed. By tracing the temperature evolution, this gap is shown to gradually decrease with increasing temperature and a blunt transition from a massive to a massless DC occurs around 200-250 K. Structural analysis shows that the samples also contain MnBi2Te4/Bi2Te3. Magnetic measurements show that there are two distinct Mn components in the system that corresponds to the two heterostructures; MnBi2Te4/Bi2Te3 is paramagnetic at 6 K while Mn4Bi2Te7/Bi2Te3 is ferromagnetic with a negative hysteresis (critical temperature ~20 K). This novel heterostructure is potentially important for future device applications.
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Modification of the gap at the Dirac point (DP) in axion antiferromagnetic topological insulator [Formula: see text] and its electronic and spin structure have been studied by angle- and spin-resolved photoemission spectroscopy (ARPES) under laser excitation at various temperatures (9-35 K), light polarizations and photon energies. We have distinguished both large (60-70 meV) and reduced ([Formula: see text]) gaps at the DP in the ARPES dispersions, which remain open above the Neél temperature ([Formula: see text]). We propose that the gap above [Formula: see text] remains open due to a short-range magnetic field generated by chiral spin fluctuations. Spin-resolved ARPES, XMCD and circular dichroism ARPES measurements show a surface ferromagnetic ordering for the "large gap" sample and apparently significantly reduced effective magnetic moment for the "reduced gap" sample. These observations can be explained by a shift of the Dirac cone (DC) state localization towards the second Mn layer due to structural disturbance and surface relaxation effects, where DC state is influenced by compensated opposite magnetic moments. As we have shown by means of ab-initio calculations surface structural modification can result in a significant modulation of the DP gap.
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Spin-orbit interaction and structure inversion asymmetry in combination with magnetic ordering is a promising route to novel materials with highly mobile spin-polarized carriers at the surface. Spin-resolved measurements of the photoemission current from the Si-terminated surface of the antiferromagnet TbRh_{2}Si_{2} and their analysis within an ab initio one-step theory unveil an unusual triple winding of the electron spin along the fourfold-symmetric constant energy contours of the surface states. A two-band k·p model is presented that yields the triple winding as a cubic Rashba effect. The curious in-plane spin-momentum locking is remarkably robust and remains intact across a paramagnetic-antiferromagnetic transition in spite of spin-orbit interaction on Rh atoms being considerably weaker than the out-of-plane exchange field due to the Tb 4f moments.
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Topologically nontrivial materials host protected edge states associated with the bulk band inversion through the bulk-edge correspondence. Manipulating such edge states is highly desired for developing new functions and devices practically using their dissipation-less nature and spin-momentum locking. Here we introduce a transition-metal dichalcogenide VTe2, that hosts a charge density wave (CDW) coupled with the band inversion involving V3d and Te5p orbitals. Spin- and angle-resolved photoemission spectroscopy with first-principles calculations reveal the huge anisotropic modification of the bulk electronic structure by the CDW formation, accompanying the selective disappearance of Dirac-type spin-polarized topological surface states that exist in the normal state. Thorough three dimensional investigation of bulk states indicates that the corresponding band inversion at the Brillouin zone boundary dissolves upon the CDW formation, by transforming into anomalous flat bands. Our finding provides a new insight to the topological manipulation of matters by utilizing CDWs' flexible characters to external stimuli.
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The chiral crystal is characterized by a lack of mirror symmetry and inversion center, resulting in the inequivalent right- and left-handed structures. In the noncentrosymmetric crystal structure, the spin and momentum of electrons are expected to be locked in the reciprocal space with the help of the spin-orbit interaction. To reveal the spin textures of chiral crystals, we investigate the spin and electronic structure in a p-type semiconductor, elemental tellurium, with the simplest chiral structure by using spin- and angle-resolved photoemission spectroscopy. Our data demonstrate that the highest valence band crossing the Fermi level has a spin component parallel to the electron momentum around the Brillouin zone corners. Significantly, we have also confirmed that the spin polarization is reversed in the crystal with the opposite chirality. The results indicate that the spin textures of the right- and left-handed chiral crystals are hedgehoglike, leading to unconventional magnetoelectric effects and nonreciprocal phenomena.
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OBJECTIVES: We created a Traditional Japanese Diet Score (TJDS), and to clarify the relationship between TJDS and obesity, ischemic heart disease (IHD), and healthy life expectancy (HALE). DESIGN: Ecological study. SETTING: Food (g/day/capita) and energy (kcal/day/capita) supply was determined using the Food and Agriculture Organization of the United Nations Statistics Division database. The sum of characteristic traditional Japanese foods (beneficial food components in the Japanese diet: rice, fish, soybeans, vegetables, eggs, and seaweeds; food components rarely used in the Japanese diet: wheat, milk, and red meat) was divided as tertiles (beneficial food components: -1, 0, 1; rarely used food components: 1, 0, -1). Obesity rate was determined using the World Health Organization database. Incidence of IHD, HALE and smoking rate were determined using the Global Burden of Diseases, Injuries, and Risk Factors Study 2015 database. Gross domestic product per capita, percentage of population > 65 years old, and health expenditure were determined using the World Bank database. Education years were obtained from the United Nations Educational, Scientific and Cultural Organization Institute for Statistics. Associations between TJDS and obesity, IHD and HALE were examined in 132 countries with a population of 1 million or greater using a general linear model controlled for co-variables. RESULTS: TJDS was distributed from -6 to 7. TJDS was inversely correlated to obesity (ß±SE; -0.70±0.19, p<0.001), IHD (-19.4±4.3, p<0.001), and positively correlated to HALE (0.40±0.14, p<0.01). CONCLUSIONS: TJDS is a good indicator of a healthy diet, and applies to preventing obesity, IHD and extending HALE.
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Dieta Saludable/métodos , Estado de Salud , Esperanza de Vida/tendencias , Isquemia Miocárdica/etiología , Obesidad/etiología , Anciano , Animales , Femenino , Humanos , Incidencia , Japón , Masculino , Factores de RiesgoRESUMEN
BACKGROUND: De novo complement-binding donor-specific anti-human leukocyte antigen antibodies (DSAs) are reportedly associated with an increased risk of kidney graft failure, but there is little information on preformed complement-binding DSAs. This study investigated the correlation between preformed C1q-binding DSAs and medium-term outcomes in kidney transplantation (KT). METHODS: We retrospectively studied 44 pretransplant DSA-positive patients, including 36 patients who underwent KT between April 2010 and October 2016. There were 17 patients with C1q-binding DSAs and 27 patients without C1q-binding DSAs. Clinical variables were examined in the 2 groups. RESULTS: Patients with C1q-binding DSAs had significantly higher blood transfusion history (53.0% vs 18.6%; P = .0174), complement-dependent cytotoxicity crossmatch (CDC-XM)-positivity (29.4% vs 0%; P = .0012), and DSA median fluorescence intensity (MFI) (10,974 vs 2764; P = .0009). Among patients who were not excluded for CDC-XM-positivity and underwent KT, there was no significant difference in cumulative biopsy-proven acute rejection rate (32.5% vs 33.5%; P = .8354), cumulative graft survival, and 3-month and 12-month protocol biopsy results between patients with and without C1q-binding DSAs. Although patients with C1q-binding DSAs showed a higher incidence of delayed graft function (54.6% vs 20.0%; P = .0419), multivariate logistic regression showed that DSA MFI (P = .0124), but not C1q-binding DSAs (P = .2377), was an independent risk factor for delayed graft function. CONCLUSIONS: In patients with CDC-XM-negativity, preformed C1q-binding DSAs were not associated with incidence of antibody-mediated rejection and medium-term graft survival after KT. C1q-binding DSAs were highly correlated with DSA MFI and CDC-XM-positivity.
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Complemento C1q/inmunología , Rechazo de Injerto/inmunología , Antígenos HLA/inmunología , Isoanticuerpos/sangre , Trasplante de Riñón/efectos adversos , Adulto , Funcionamiento Retardado del Injerto/inmunología , Femenino , Rechazo de Injerto/sangre , Rechazo de Injerto/epidemiología , Supervivencia de Injerto/inmunología , Humanos , Incidencia , Isoanticuerpos/inmunología , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Donantes de TejidosRESUMEN
We demonstrate, for the first time, the direct generation of a bottle beam with a well-isolated three-dimensional zero-intensity dark core (high potential barrier) from a compact intracavity frequency-doubled Nd:YVO4 laser with a nearly hemispherical cavity. We also numerically calculate the physical properties of the generated bottle beam using a coherent superposition of a series of frequency-locked Laguerre-Gaussian modes.
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The C2v surface symmetry of W(110) strongly influences a spin-orbit-induced Dirac-cone-like surface state and its characterization by spin- and angle-resolved photoelectron spectroscopy. In particular, using circular polarized light, a distinctive k-dependent spin texture is observed along the [Formula: see text] direction of the surface Brillouin zone. For all spin components Px, Py, and Pz, non-zero values are detected, while the initial-state spin polarization has only a Py component due to mirror symmetry. The observed complex spin texture of the surface state is controlled by transition matrix element effects, which include orbital symmetries of the involved electron states as well as the geometry of the experimental set-up.
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This corrects the article DOI: 10.1038/bcj.2015.86.
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Molecular oxygen serves as a useful oxidant for the glycol scission of 1,2-diols and the Hofmann rearrangement of primary amides using pentamethyliodobenzene as a catalyst. The use of isobutyraldehyde and Lewis basic nitriles under O2 enabled the iodine(i)/(iii) catalytic cycle, where in situ-generated peracid acts as a terminal oxidant.
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We theoretically show that a single free electron in circular motion radiates an electromagnetic wave possessing helical phase structure, which is closely related to orbital angular momentum carried by it. We experimentally demonstrate it by interference and double-slit diffraction experiments on radiation from relativistic electrons in spiral motion. Our results indicate that photons carrying orbital angular momentum should be created naturally by cyclotron/synchrotron radiations or Compton scatterings in various situations in cosmic space. We propose promising laboratory vortex photon sources in various wavelengths ranging from radio wave to gamma-rays.