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1.
Nature ; 585(7823): 141-145, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32641835

RESUMEN

The transient receptor potential ion channel TRPA1 is expressed by primary afferent nerve fibres, in which it functions as a low-threshold sensor for structurally diverse electrophilic irritants, including small volatile environmental toxicants and endogenous algogenic lipids1. TRPA1 is also a 'receptor-operated' channel whose activation downstream of metabotropic receptors elicits inflammatory pain or itch, making it an attractive target for novel analgesic therapies2. However, the mechanisms by which TRPA1 recognizes and responds to electrophiles or cytoplasmic second messengers remain unknown. Here we use strutural studies and electrophysiology to show that electrophiles act through a two-step process in which modification of a highly reactive cysteine residue (C621) promotes reorientation of a cytoplasmic loop to enhance nucleophilicity and modification of a nearby cysteine (C665), thereby stabilizing the loop in an activating configuration. These actions modulate two restrictions controlling ion permeation, including widening of the selectivity filter to enhance calcium permeability and opening of a canonical gate at the cytoplasmic end of the pore. We propose a model to explain functional coupling between electrophile action and these control points. We also characterize a calcium-binding pocket that is highly conserved across TRP channel subtypes and accounts for all aspects of calcium-dependent TRPA1 regulation, including potentiation, desensitization and activation by metabotropic receptors. These findings provide a structural framework for understanding how a broad-spectrum irritant receptor is controlled by endogenous and exogenous agents that elicit or exacerbate pain and itch.


Asunto(s)
Calcio/metabolismo , Calcio/farmacología , Activación del Canal Iónico/efectos de los fármacos , Canal Catiónico TRPA1/química , Canal Catiónico TRPA1/metabolismo , Secuencia de Aminoácidos , Cisteína/metabolismo , Conductividad Eléctrica , Humanos , Yodoacetamida/farmacología , Modelos Moleculares , Mutación , Oximas/farmacología , Canal Catiónico TRPA1/genética
2.
Proc Natl Acad Sci U S A ; 119(33): e2207200119, 2022 08 16.
Artículo en Inglés | MEDLINE | ID: mdl-35858375

RESUMEN

The ability to produce folded and functional proteins is a necessity for structural biology and many other biological sciences. This task is particularly challenging for numerous biomedically important targets in human cells, including membrane proteins and large macromolecular assemblies, hampering mechanistic studies and drug development efforts. Here we describe a method combining CRISPR-Cas gene editing and fluorescence-activated cell sorting to rapidly tag and purify endogenous proteins in HEK cells for structural characterization. We applied this approach to study the human proteasome from HEK cells and rapidly determined cryogenic electron microscopy structures of major proteasomal complexes, including a high-resolution structure of intact human PA28αß-20S. Our structures reveal that PA28 with a subunit stoichiometry of 3α/4ß engages tightly with the 20S proteasome. Addition of a hydrophilic peptide shows that polypeptides entering through PA28 are held in the antechamber of 20S prior to degradation in the proteolytic chamber. This study provides critical insights into an important proteasome complex and demonstrates key methodologies for the tagging of proteins from endogenous sources.


Asunto(s)
Citometría de Flujo , Edición Génica , Proteínas Musculares , Complejo de la Endopetidasa Proteasomal , Sistemas CRISPR-Cas , Microscopía por Crioelectrón , Citometría de Flujo/métodos , Edición Génica/métodos , Células HEK293 , Humanos , Proteínas Musculares/química , Proteínas Musculares/genética , Proteínas Musculares/aislamiento & purificación , Complejo de la Endopetidasa Proteasomal/química , Complejo de la Endopetidasa Proteasomal/genética , Complejo de la Endopetidasa Proteasomal/aislamiento & purificación , Proteolisis
3.
Proc Natl Acad Sci U S A ; 119(12): e2114583119, 2022 03 22.
Artículo en Inglés | MEDLINE | ID: mdl-35290117

RESUMEN

Communication between interacting organisms via bioactive molecules is widespread in nature and plays key roles in diverse biological processes. Small RNAs (sRNAs) can travel between host plants and filamentous pathogens to trigger transkingdom RNA interference (RNAi) in recipient cells and modulate plant defense and pathogen virulence. However, how fungal pathogens counteract transkingdom antifungal RNAi has rarely been reported. Here we show that a secretory protein VdSSR1 (secretory silencing repressor 1) from Verticillium dahliae, a soil-borne phytopathogenic fungus that causes wilt diseases in a wide range of plant hosts, is required for fungal virulence in plants. VdSSR1 can translocate to plant nucleus and serve as a general suppressor of sRNA nucleocytoplasmic shuttling. We further reveal that VdSSR1 sequesters ALY family proteins, adaptors of the TREX complex, to interfere with nuclear export of the AGO1­microRNA (AGO1­miRNA) complex, leading to a great attenuation in cytoplasmic AGO1 protein and sRNA levels. With this mechanism, V. dahliae can suppress the accumulation of mobile plant miRNAs in fungal cells and succedent transkingdom silencing of virulence genes, thereby increasing its virulence in plants. Our findings reveal a mechanism by which phytopathogenic fungi antagonize antifungal RNAi-dependent plant immunity and expand the understanding on the complex interaction between host and filamentous pathogens.


Asunto(s)
MicroARNs , Verticillium , Transporte Activo de Núcleo Celular , Antifúngicos , MicroARNs/genética , MicroARNs/metabolismo , Enfermedades de las Plantas/microbiología , Plantas/genética , ARN de Planta , Verticillium/metabolismo
4.
Plant Biotechnol J ; 22(6): 1435-1452, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38194521

RESUMEN

Wolfberry is a plant with medicinal and food values. However, its bioactive ingredients and the corresponding genetic bases have not been determined. Here, we de novo generated a chromosome-level genome assembly for wolfberry, yielding a genome sequence of ~1.77 Gb with contig N50 of 50.55 Mb and 39 224 predicted gene models. A variation map, using 307 re-sequenced accessions, was called based on this genome assembly. Furthermore, the fruit metabolome of these accessions was profiled using 563 annotated metabolites, which separated Lycium barbarum L. and non-L. barbarum L. The flavonoids, coumarins, alkaloids and nicotinic acid contents were higher in the former than in the latter. A metabolite-based genome-wide association study mapped 156 164 significant single nucleotide polymorphisms corresponding to 340 metabolites. This included 19 219 unique lead single nucleotide polymorphisms in 1517 significant association loci, of which three metabolites, flavonoids, betaine and spermidine, were highlighted. Two candidate genes, LbUGT (evm.TU.chr07.2692) and LbCHS (evm.TU.chr07.2738), with non-synonymous mutations, were associated with the flavonoids content. LbCHS is a structural gene that interacts with a nearby MYB transcription factor (evm.TU.chr07.2726) both in L. barbarum and L. ruthenicum. Thus, these three genes might be involved in the biosynthesis/metabolism of flavonoids. LbSSADH (evm.TU.chr09.627) was identified as possibly participating in betaine biosynthesis/metabolism. Four lycibarbarspermidines (E-G and O) were identified, and only the lycibarbarspermidines O content was higher in L. barbarum varieties than in non-L. barbarum varieties. The evm.TU.chr07.2680 gene associated with lycibarbarspermidines O was annotated as an acetyl-CoA-benzylalcohol acetyltransferase, suggesting that it is a candidate gene for spermidine biosynthesis. These results provide novel insights into the specific metabolite profile of non-L. barbarum L. and the genetic bases of flavonoids, betaine and spermidine biosynthesis/metabolism.


Asunto(s)
Betaína , Flavonoides , Estudio de Asociación del Genoma Completo , Lycium , Polimorfismo de Nucleótido Simple , Espermidina , Flavonoides/metabolismo , Lycium/genética , Lycium/metabolismo , Espermidina/metabolismo , Betaína/metabolismo , Polimorfismo de Nucleótido Simple/genética , Genoma de Planta/genética , Frutas/genética , Frutas/metabolismo
5.
New Phytol ; 242(2): 558-575, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38396374

RESUMEN

Black wolfberry (Lycium ruthenicum Murr.) contains various bioactive metabolites represented by flavonoids, which are quite different among production regions. However, the underlying regulation mechanism of flavonoid biosynthesis governing the bioactivity of black wolfberry remains unclear. Presently, we compared the bioactivity of black wolfberry from five production regions. Multi-omics were performed to construct the regulation network associated with the fruit bioactivity. The detailed regulation mechanisms were identified using genetic and molecular methods. Typically, Qinghai (QH) fruit exhibited higher antioxidant and anti-inflammatory activities. The higher medicinal activity of QH fruit was closely associated with the accumulation of eight flavonoids, especially Kaempferol-3-O-rutinoside (K3R) and Quercetin-3-O-rutinoside (rutin). Flavonoid biosynthesis was found to be more active in QH fruit, and the upregulation of LrFLS, LrCHS, LrF3H and LrCYP75B1 caused the accumulation of K3R and rutin, leading to high medicinal bioactivities of black wolfberry. Importantly, transcription factor LrMYB94 was found to regulate LrFLS, LrCHS and LrF3H, while LrWRKY32 directly triggered LrCYP75B1 expression. Moreover, LrMYB94 interacted with LrWRKY32 to promote LrWRKY32-regulated LrCYP75B1 expression and rutin synthesis in black wolfberry. Transgenic black wolfberry overexpressing LrMYB94/LrWRKY32 contained higher levels of K3R and rutin, and exhibited high medicinal bioactivities. Importantly, the LrMYB94/LrWRKY32-regulated flavonoid biosynthesis was light-responsive, showing the importance of light intensity for the medicinal quality of black wolfberry. Overall, our results elucidated the regulation mechanisms of K3R and rutin synthesis, providing the basis for the genetic breeding of high-quality black wolfberry.


Asunto(s)
Lycium , Lycium/genética , Fitomejoramiento , Flavonoides , Antioxidantes , Rutina , Frutas/genética
6.
Mol Psychiatry ; 28(11): 4877-4888, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37365243

RESUMEN

We previously reported that prolonged exposure to an enriched environment (EE) enhances hippocampal synaptic plasticity, with one of the significant mechanistic pathways being activation of ß2-adrenergic receptor (ß2-AR) signaling, thereby mitigating the synaptotoxic effects of soluble oligomers of amyloid ß-protein (oAß). However, the detailed mechanism remained elusive. In this work, we recorded field excitatory postsynaptic potentials (fEPSP) in the CA1 region of mouse hippocampal slices treated with or without toxic Aß-species. We found that pharmacological activation of ß2-AR, but not ß1-AR, selectively mimicked the effects of EE in enhancing LTP and preventing oAß-induced synaptic dysfunction. Mechanistic analyses showed that certain histone deacetylase (HDAC) inhibitors mimicked the benefits of EE, but this was not seen in ß2-AR knockout mice, suggesting that activating ß2-AR prevents oAß-mediated synaptic dysfunction via changes in histone acetylation. EE or activation of ß-ARs each decreased HDAC2, whereas Aß oligomers increased HDAC2 levels in the hippocampus. Further, oAß-induced inflammatory effects and neurite degeneration were prevented by either ß2-AR agonists or certain specific HDAC inhibitors. These preclinical results suggest that activation of ß2-AR is a novel potential therapeutic strategy to mitigate oAß-mediated features of AD.


Asunto(s)
Péptidos beta-Amiloides , Hipocampo , Ratones , Animales , Péptidos beta-Amiloides/toxicidad , Péptidos beta-Amiloides/metabolismo , Transducción de Señal , Epigénesis Genética , Ratones Noqueados
7.
Microb Ecol ; 87(1): 43, 2024 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-38363394

RESUMEN

Biological soil crusts (biocrusts) are considered "desert ecosystem engineers" because they play a vital role in the restoration and stability maintenance of deserts, including those cold sandy land ecosystems at high latitudes, which are especially understudied. Microorganisms participate in the formation and succession of biocrusts, contributing to soil properties' improvement and the stability of soil aggregates, and thus vegetation development. Accordingly, understanding the composition and successional characteristics of microorganisms is a prerequisite for analyzing the ecological functions of biocrusts and related applications. Here, the Hulun Buir Sandy Land region in northeastern China-lying at the highest latitude of any sandy land in the country-was selected for study. Through a field investigation and next-generation sequencing (Illumina MiSeq PE300 Platform), our goal was to assess the shifts in diversity and community composition of soil bacteria and fungi across different stages during the succession of biocrusts in this region, and to uncover the main factors involved in shaping their soil microbial community. The results revealed that the nutrient enrichment capacity of biocrusts for available nitrogen, total nitrogen, total phosphorus, total content of water-soluble salt, available potassium, soil organic matter, and available phosphorus was progressively enhanced by the succession of cyanobacterial crusts to lichen crusts and then to moss crusts. In tandem, soil bacterial diversity increased as biocrust succession proceeded but fungal diversity decreased. A total of 32 bacterial phyla and 11 fungal phyla were identified, these also known to occur in other desert ecosystems. Among those taxa, the relative abundance of Proteobacteria and Cyanobacteria significantly increased and decreased, respectively, along the cyanobacterial crust-lichen-moss crust successional gradient. However, for Actinobacteria, Chloroflexi, and Acidobacteria their changed relative abundance was significantly hump-shaped, increasing in the shift from cyanobacterial crust to lichen crust, and then decreasing as lichen crust shifted to moss crust. In this process, the improved soil properties effectively enhanced soil bacterial and fungal community composition. Altogether, these findings broaden our understanding about how soil microbial properties can change during the succession of biocrusts in high-latitude, cold sandy land ecosystems.


Asunto(s)
Cianobacterias , Líquenes , Microbiota , Ecosistema , Suelo , Arena , Microbiología del Suelo , Nitrógeno , Fósforo , China
8.
BMC Psychiatry ; 24(1): 297, 2024 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-38641813

RESUMEN

BACKGROUND: This study aimed to investigate the interplay between anxiety and depressive symptoms in Chinese college freshmen using the causal system perspective (CSP), which differs from the traditional common cause perspective (CCP) by providing an alternative explanation by attributing comorbidity to direct interactions among symptoms. METHODS: A convenience sample of 2,082 Chinese college freshmen (39.51% male, Mage = 18.61) from a normal university completed the Generalized Anxiety Disorder 7-Item Scale (GAD-7) and the Patient Health Questionnaire (PHQ-9). Network analysis was conducted and evaluated as to centrality, stability, node predictability, and bridging features. Moreover, the moderated network model (MNM) was utilized to detect the moderation effects of gender in the comorbidity network. RESULTS: The network of anxiety and depressive symptoms exhibited stability, characterized by the core symptoms of "restlessness", "lack of energy", and "excessive worry about control", as well as the bridging symptoms of "fearfulness", "sad mood", and "irritability". Notably, the nodes representing "uncontrollable worry" and "difficulty in relaxation" demonstrated the highest predictive power. Gender did not exert any moderating effects on the anxiety and depressive symptom network. CONCLUSION: These results reinforce that certain anxiety or depressive symptoms are more central than others, and thus play a more vital role in the comorbid network. These findings highlight underlying potential targeting symptoms to consider in future interventions.


Asunto(s)
Ansiedad , Depresión , Masculino , Humanos , Adolescente , Femenino , Depresión/diagnóstico , Depresión/epidemiología , Universidades , Ansiedad/epidemiología , Ansiedad/diagnóstico , Trastornos de Ansiedad/diagnóstico , Trastornos de Ansiedad/epidemiología , Comorbilidad
9.
Nano Lett ; 23(14): 6497-6503, 2023 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-37450769

RESUMEN

We report an experimental study of proximity induced superconductivity in planar Josephson junction devices made from free-standing InAs nanosheets. The nanosheets are grown by molecular beam epitaxy, and the Josephson junction devices are fabricated by directly contacting the nanosheets with superconductor Al electrodes. The fabricated devices are explored by low-temperature carrier transport measurements. The measurements show that the devices exhibit a gate-tunable supercurrent, multiple Andreev reflections, and a good quality superconductor-semiconductor interface. The superconducting characteristics of the Josephson junctions are investigated at different magnetic fields and temperatures and are analyzed based on the Bardeen-Cooper-Schrieffer (BCS) theory. The measurements of the ac Josephson effect are also conducted under microwave radiations with different radiation powers and frequencies, and integer Shapiro steps are observed. Our work demonstrates that InAs nanosheet based hybrid devices are desired systems for investigating the forefront of physics, such as two-dimensional topological superconductivity.

10.
J Sci Food Agric ; 104(1): 303-314, 2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-37582691

RESUMEN

BACKGROUND: In this study, different proportions of soybean flour and gluten flour were used as partial replacements for wheat flour for the fermentation of Pixian Douban-Meju (PXDB). The aim was to study the effects of soybean flour/gluten flour on the quality improvement of PXDB. RESULTS: In comparison with the control group (CT) (0% substitution of wheat flour), substitution of wheat flower with 12.5% soybean flour (the H2 group), 7.5% gluten flour (G2), and 10% gluten flour (G3) improved the amino acid nitrogen content by 3.8%, 5.6%, and 9.4% respectively. The mixtures of wheat flour and gluten flour (G2 or G3) increased the organic acid and free amino acid content. The results of two-dimensional gas chromatography mass spectrometry (GC × GC-MS) showed that the amount of key aroma substances increased about sixfold in comparison with the CT group (194.61 g.kg-1 ), achieving 1283.67, 1113.883, and 1160.19 g.kg-1 in the H2, G2, and G3 groups, respectively. There were also more aldehydes and pyrazines in all the substitution groups. Quantitative descriptive analysis indicated that the G3 sample presented the best organoleptic quality with a reddish-brown color and a more mellow aroma than the control sample. CONCLUSION: In conclusion, the fermentation of G3 resulted in higher quality PXDB-meju, showing that partial substitution of wheat flour with gluten improved the quality of PXDB. © 2023 Society of Chemical Industry.


Asunto(s)
Harina , Glútenes , Glútenes/química , Harina/análisis , Glycine max , Polvos , Triticum/química , Aminoácidos/química
11.
Yi Chuan ; 46(4): 266-278, 2024 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-38632090

RESUMEN

RNA silencing (or RNA interference, RNAi) is a conserved mechanism for regulating gene expression in eukaryotes, which plays vital roles in plant development and response to biotic and abiotic stresses. The discovery of trans-kingdom RNAi and interspecies RNAi provides a theoretical basis for exploiting RNAi-based crop protection strategies. Here, we summarize the canonical RNAi mechanisms in plants and review representative studies associated with plant-pathogen interactions. Meanwhile, we also elaborate upon the principles of host-induced gene silencing, spray-induced gene silencing and microbe-induced gene silencing, and discuss their applications in crop protection, thereby providing help to establish novel RNAi-based crop protection strategies.


Asunto(s)
Protección de Cultivos , Plantas , Interferencia de ARN , Plantas/genética , Eucariontes/genética , ARN Interferente Pequeño/genética
12.
Cytokine ; 167: 156213, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37121091

RESUMEN

BACKGROUND: Anti-aging protein Klotho has been reported to be associated with atherosclerosis, which was considered as a chronic inflammatory disease. However, the relationship between Klotho and senile inflammation remained unclear. The present study aims to ascertain the correlation of Klotho with inflammation in middle-aged and elderly coronary atherosclerotic disease (CAD). METHODS: A total of 302 patients with CAD were included in this study. Coronary atherosclerosis was confirmed and quantified for all patients by coronary angiography. Serum Klotho was detected by enzyme linked immunosorbent assay. Serum concentrations of IL-6 and IL-8 were quantified by chemiluminescence assay. T-lymphocyte subsets were measured using flow cytometry. RESULTS: Multivariate linear regression analysis showed that serum Klotho was an independent predictor for circulating monocytes (standard ß = -0.321, P < 0.001) and CD4+/CD8+ ratio (standard ß = -0.522, P < 0.001). After adjustment, serum Klotho was still independently associated with IL-6 (standard ß = -0.395, P < 0.001) and IL-8 (standard ß = -0.296, P < 0.001). Moreover, circulating monocytes, CD4+ and CD8+ lymphocytes were correlated with increased serum concentrations of IL-6 and IL-8, independent of CRP (P < 0.05). In receiver operating characteristic curve analysis, CD4+/CD8+ ratio (AUC = 0.863, P < 0.001), IL-6 (AUC = 0.893, P < 0.001) and IL-8 (AUC = 0.884, P < 0.001) presented the excellent predictive performance for significant CAD. CONCLUSIONS: Decreased concentrations in serum Klotho reflect senile inflammation, which is related to the severity of CAD in middle-aged and elderly patients.


Asunto(s)
Aterosclerosis , Enfermedad de la Arteria Coronaria , Anciano , Humanos , Persona de Mediana Edad , Envejecimiento , Angiografía Coronaria , Inflamación , Interleucina-6 , Interleucina-8
13.
Plant Cell ; 32(10): 3256-3272, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32769133

RESUMEN

Flowering plants and mammals contain imprinted genes that are primarily expressed in the endosperm and placenta in a parent-of-origin manner. In this study, we show that early activation of the geminivirus genes C2 and C3 in Arabidopsis (Arabidopsis thaliana) plants, encoding a viral suppressor of RNA interference and a replication enhancer protein, respectively, is correlated with the transient vegetative expression of VARIANT IN METHYLATION5 (VIM5), an endosperm imprinted gene that is conserved in diverse plant species. VIM5 is a ubiquitin E3 ligase that directly targets the DNA methyltransferases MET1 and CMT3 for degradation by the ubiquitin-26S proteasome proteolytic pathway. Infection with Beet severe curly top virus induced VIM5 expression in rosette leaf tissues, possibly via the expression of the viral replication initiator protein, leading to the early activation of C2 and C3 coupled with reduced symmetric methylation in the C2-3 promoter and the onset of disease symptoms. These findings demonstrate how this small DNA virus recruits a host imprinted gene for the epigenetic activation of viral gene transcription. Our findings reveal a distinct strategy used by plant pathogens to exploit the host machinery in order to inhibit methylation-mediated defense responses when establishing infection.


Asunto(s)
Arabidopsis/genética , Arabidopsis/virología , Geminiviridae/patogenicidad , Enfermedades de las Plantas/virología , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , ADN (Citosina-5-)-Metiltransferasas/genética , ADN (Citosina-5-)-Metiltransferasas/metabolismo , Metilación de ADN , ADN-Citosina Metilasas/genética , ADN-Citosina Metilasas/metabolismo , Epigénesis Genética , Regulación de la Expresión Génica de las Plantas , Impresión Genómica , Interacciones Huésped-Patógeno/genética , Enfermedades de las Plantas/genética , Hojas de la Planta/genética , Hojas de la Planta/virología , Plantas Modificadas Genéticamente , Regiones Promotoras Genéticas , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/metabolismo , Proteínas Virales/genética
14.
Theor Appl Genet ; 136(12): 246, 2023 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-37973669

RESUMEN

KEY MESSAGE: qSB12YSB, a major quantitative sheath blight resistance gene originated from rice variety YSBR1 with good breeding potential, was mapped to a 289-Kb region on chromosome 12. Sheath blight (ShB), caused by Rhizoctonia solani kühn, is one of the most serious global rice diseases. Rice resistance to ShB is a typical of quantitative trait controlled by multiple quantitative trait loci (QTLs). Many QTLs for ShB resistance have been reported while only few of them were fine-mapped. In this study, we identified a QTL on chromosome 12, in which the qSB12YSB resistant allele shows significant ShB resistance, by using 150 BC4 backcross inbred lines employing the resistant rice variety YSBR1 as the donor and the susceptible variety Lemont (LE) as the recurrent parent. We further fine-mapped qSB12YSB to a 289-kb region by generating 34 chromosomal segment substitution lines and identified a total of 18 annotated genes as the most likely candidates for qSB12YSB after analyzing resequencing and transcriptomic data. KEGG analysis suggested that qSB12YSB might activate secondary metabolites biosynthesis and ROS scavenging system to improve ShB resistance. qSB12YSB conferred significantly stable resistance in three commercial rice cultivars (NJ9108, NJ5055 and NJ44) in field trials when introduced through marker assisted selection. Under severe ShB disease conditions, qSB12YSB significantly reduced yield losses by up to 13.5% in the LE background, indicating its great breeding potential. Our results will accelerate the isolation of qSB12YSB and its utilization in rice breeding programs against ShB.


Asunto(s)
Oryza , Oryza/genética , Fitomejoramiento , Sitios de Carácter Cuantitativo , Fenotipo , Estudios de Asociación Genética
15.
Nanotechnology ; 34(22)2023 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-36827703

RESUMEN

InAs nanowires show important potential applications in novel nanoelectronic devices, infrared optoelectronic devices and quantum devices, and all these applications require controllable growth of the InAs nanowires. However, the growth direction of metal-assisted InAs nanowires on Si substrates is often random. Here, we develop a new approach to grow vertically aligned InAs nanowires on Si (111) substrates by molecular-beam epitaxy using Ag as catalysts. The vertically aligned one-dimensional InAs nanowires are grown on the parasitic two-dimensional InAs film on the Si substrates by using the Ag nanoparticles segregated from Ag-In alloy catalysts. The diameters of the vertically aligned InAs nanowires obtained by this method are mainly distributed between 20 and 50 nm. Detailed transmission electron microscope data show that the nanowires with thinner diameters tend to have less stacking faults and twin defects and high crystal quality pure wurtzite nanowires can be obtained. Using these vertically aligned InAs nanowires as the channel material of field effect transistors, we have obtained a field-effect mobility of ∼2800 cm2V-1s-1and anIon/Ioffratio of ∼104at room temperature. Our work provides a new method for the controlled growth of high-quality vertically aligned InAs nanowires on Si substrates.

16.
Nanotechnology ; 35(6)2023 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-37944189

RESUMEN

In-plane InAs nanowires and nanowire networks show great potential to be used as building blocks for electronic, optoelectronic and topological quantum devices, and all these applications are keen to grow the InAs materials directly on Si substrates since it may enable nanowire electronic and quantum devices with seamless integration with Si platform. However, almost all the in-plane InAs nanowires and nanowire networks have been realized on substrates of III-V semiconductors. Here, we demonstrate the selective area epitaxial growth of in-plane InAs nanowires and nanowire networks on Si substrates. We find that the selectivity of InAs growth on Si substrates is mainly dependent on the growth temperature, while the morphology of InAs nanowires is closely related to the V/III flux ratio. We examine the cross-sectional shapes and facets of the InAs nanowires grown along the 〈110〉, 〈100〉 and 〈112〉 orientations. Thanks to the non-polar characteristics of Si substrates, the InAs nanowires and nanowire networks exhibit superior symmetry compared to that grown on III-V substrates. The InAs nanowires and nanowire networks are zinc-blende (ZB) crystals, but there are many defects in the nanowires, such as stacking faults, twins and grain boundaries. The crystal quality of InAs nanowires and nanowire networks can be improved by increasing the growth temperature within the growth temperature window. Our work demonstrates the feasibility of selective area epitaxial growth of in-plane InAs nanowires and nanowire networks on Si substrates.

17.
Nature ; 552(7685): 426-429, 2017 12 21.
Artículo en Inglés | MEDLINE | ID: mdl-29236684

RESUMEN

Calcium-activated chloride channels (CaCCs) encoded by TMEM16A control neuronal signalling, smooth muscle contraction, airway and exocrine gland secretion, and rhythmic movements of the gastrointestinal system. To understand how CaCCs mediate and control anion permeation to fulfil these physiological functions, knowledge of the mammalian TMEM16A structure and identification of its pore-lining residues are essential. TMEM16A forms a dimer with two pores. Previous CaCC structural analyses have relied on homology modelling of a homologue (nhTMEM16) from the fungus Nectria haematococca that functions primarily as a lipid scramblase, as well as subnanometre-resolution electron cryo-microscopy. Here we present de novo atomic structures of the transmembrane domains of mouse TMEM16A in nanodiscs and in lauryl maltose neopentyl glycol as determined by single-particle electron cryo-microscopy. These structures reveal the ion permeation pore and represent different functional states. The structure in lauryl maltose neopentyl glycol has one Ca2+ ion resolved within each monomer with a constricted pore; this is likely to correspond to a closed state, because a CaCC with a single Ca2+ occupancy requires membrane depolarization in order to open (C.J.P. et al., manuscript submitted). The structure in nanodiscs has two Ca2+ ions per monomer and its pore is in a closed conformation; this probably reflects channel rundown, which is the gradual loss of channel activity that follows prolonged CaCC activation in 1 mM Ca2+. Our mutagenesis and electrophysiological studies, prompted by analyses of the structures, identified ten residues distributed along the pore that interact with permeant anions and affect anion selectivity, as well as seven pore-lining residues that cluster near pore constrictions and regulate channel gating. Together, these results clarify the basis of CaCC anion conduction.


Asunto(s)
Anoctamina-1/química , Anoctamina-1/ultraestructura , Calcio/química , Calcio/farmacología , Microscopía por Crioelectrón , Activación del Canal Iónico/efectos de los fármacos , Animales , Aniones/química , Aniones/metabolismo , Anoctamina-1/metabolismo , Calcio/metabolismo , Glucósidos/química , Células HEK293 , Humanos , Transporte Iónico/efectos de los fármacos , Ratones , Modelos Moleculares , Nanoestructuras/química , Nanoestructuras/ultraestructura , Conformación Proteica/efectos de los fármacos
18.
BMC Med Educ ; 23(1): 124, 2023 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-36810009

RESUMEN

OBJECTIVE: To explore the role of narrative medicine-based education in standardized empathy training for residents. METHODS: Among the 2018-2020 residents at the First Affiliated Hospital of Xinxiang Medical University, 230 receiving neurology training were enrolled in this study and randomly divided into study and control groups. The study group received narrative medicine-based education and standardized routine resident training. The Jefferson Scale of Empathy-Medical Student version (JSE-MS) was used to evaluate empathy in the study group, and the neurological professional knowledge test scores of the two groups were also compared. RESULTS: In the study group, the empathy score was higher than the preteaching score (P < 0.01). The neurological professional knowledge examination score was higher in the study group than in the control group, albeit not significantly. CONCLUSION: The addition of narrative medicine-based education in standardized training improved empathy and may have improved the professional knowledge of neurology residents.


Asunto(s)
Medicina Narrativa , Neurología , Estudiantes de Medicina , Humanos , Empatía , Conocimiento
19.
Nano Lett ; 22(22): 9190-9197, 2022 Nov 23.
Artículo en Inglés | MEDLINE | ID: mdl-36263969

RESUMEN

The metal-insulator transition (MIT) is normally assisted by certain external power input, such as temperature, pressure, strain, or doping. However, these may increase the disorder of the crystal or cause other effects, which makes device fabrication complicated and/or hinders large-scale application. Here, we adopt a new approach to obtain robust modulation of physical properties in magnetic semiconductor (Ga,Mn)As by surface molecular modification. We have probed both sides of the MIT with n- and p-type molecular doping. Density functional theory calculations are carried out to determine the stable absorption configuration and charge transfer mechanism of electron acceptor and donor molecules on the semiconductor surface. Both experimental and theoretical results confirm a remarkable modulation in carrier concentrations without introducing impurities or defects. This work points out the possibility of effectively tuning physical properties of solid-state materials by functional molecules, which is clean, flexible, nondestructive, and easily achieved.

20.
Int J Mol Sci ; 24(14)2023 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-37511211

RESUMEN

Plant height is one of the most crucial components of plant structure. However, due to its complexity, the genetic architecture of rice plant height has not been fully elucidated. In this study, we performed a genome-wide association study (GWAS) to determine rice plant height using 178 commercial rice varieties and identified 37 loci associated with rice plant height (LAPH). Among these loci, in LAPH2, we identified a polygalacturonase gene, OsPG3, which was genetically and functionally associated with rice plant height. The rice plant exhibits a super dwarf phenotype when the knockout of the OsPG3 gene occurs via CRISPR-Cas9 gene-editing technology. RNA-Seq analysis indicated that OsPG3 modulates the expression of genes involved in phytohormone metabolism and cell-wall-biosynthesis pathways. Our findings suggest that OsPG3 plays a vital role in controlling rice plant height by regulating cell wall biosynthesis. Given that rice architecture is one of the most critical phenotypes in rice breeding, OsPG3 has potential in rice's molecular design breeding toward an ideal plant height.


Asunto(s)
Estudio de Asociación del Genoma Completo , Oryza , Oryza/genética , Fitomejoramiento , Genes de Plantas , Fenotipo
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