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1.
Nature ; 609(7927): 616-621, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35917926

RESUMEN

The PIN-FORMED (PIN) protein family of auxin transporters mediates polar auxin transport and has crucial roles in plant growth and development1,2. Here we present cryo-electron microscopy structures of PIN3 from Arabidopsis thaliana in the apo state and in complex with its substrate indole-3-acetic acid and the inhibitor N-1-naphthylphthalamic acid (NPA). A. thaliana PIN3 exists as a homodimer, and its transmembrane helices 1, 2 and 7 in the scaffold domain are involved in dimerization. The dimeric PIN3 forms a large, joint extracellular-facing cavity at the dimer interface while each subunit adopts an inward-facing conformation. The structural and functional analyses, along with computational studies, reveal the structural basis for the recognition of indole-3-acetic acid and NPA and elucidate the molecular mechanism of NPA inhibition on PIN-mediated auxin transport. The PIN3 structures support an elevator-like model for the transport of auxin, whereby the transport domains undergo up-down rigid-body motions and the dimerized scaffold domains remain static.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Ácidos Indolacéticos , Apoproteínas/química , Apoproteínas/metabolismo , Apoproteínas/ultraestructura , Arabidopsis/química , Arabidopsis/metabolismo , Arabidopsis/ultraestructura , Proteínas de Arabidopsis/antagonistas & inhibidores , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/ultraestructura , Transporte Biológico/efectos de los fármacos , Microscopía por Crioelectrón , Ácidos Indolacéticos/química , Ácidos Indolacéticos/metabolismo , Ftalimidas/química , Ftalimidas/farmacología , Dominios Proteicos , Multimerización de Proteína , Subunidades de Proteína/química , Subunidades de Proteína/metabolismo
2.
Mol Cell ; 75(4): 823-834.e5, 2019 08 22.
Artículo en Inglés | MEDLINE | ID: mdl-31302001

RESUMEN

Sirt3, as a major mitochondrial nicotinamide adenine dinucleotide (NAD)-dependent deacetylase, is required for mitochondrial metabolic adaption to various stresses. However, how to regulate Sirt3 activity responding to metabolic stress remains largely unknown. Here, we report Sirt3 as a SUMOylated protein in mitochondria. SUMOylation suppresses Sirt3 catalytic activity. SUMOylation-deficient Sirt3 shows elevated deacetylation on mitochondrial proteins and increased fatty acid oxidation. During fasting, SUMO-specific protease SENP1 is accumulated in mitochondria and quickly de-SUMOylates and activates Sirt3. SENP1 deficiency results in hyper-SUMOylation of Sirt3 and hyper-acetylation of mitochondrial proteins, which reduces mitochondrial metabolic adaption responding to fasting. Furthermore, we find that fasting induces SENP1 translocation into mitochondria to activate Sirt3. The studies on mice show that Sirt3 SUMOylation mutation reduces fat mass and antagonizes high-fat diet (HFD)-induced obesity via increasing oxidative phosphorylation and energy expenditure. Our results reveal that SENP1-Sirt3 signaling modulates Sirt3 activation and mitochondrial metabolism during metabolic stress.


Asunto(s)
Cisteína Endopeptidasas/metabolismo , Mitocondrias/metabolismo , Mutación , Obesidad/metabolismo , Transducción de Señal , Sirtuina 3/metabolismo , Sumoilación , Acetilación , Animales , Cisteína Endopeptidasas/genética , Grasas de la Dieta/efectos adversos , Grasas de la Dieta/farmacología , Células HEK293 , Humanos , Masculino , Ratones , Ratones Mutantes , Mitocondrias/genética , Mitocondrias/patología , Obesidad/inducido químicamente , Obesidad/genética , Obesidad/patología , Sirtuina 3/genética
3.
N Engl J Med ; 389(18): 1649-1659, 2023 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-37913505

RESUMEN

BACKGROUND: Recurrent bleeding from the small intestine accounts for 5 to 10% of cases of gastrointestinal bleeding and remains a therapeutic challenge. Thalidomide has been evaluated for the treatment of recurrent bleeding due to small-intestinal angiodysplasia (SIA), but confirmatory trials are lacking. METHODS: We conducted a multicenter, double-blind, randomized, placebo-controlled trial to investigate the efficacy and safety of thalidomide for the treatment of recurrent bleeding due to SIA. Eligible patients with recurrent bleeding (at least four episodes of bleeding during the previous year) due to SIA were randomly assigned to receive thalidomide at an oral daily dose of 100 mg or 50 mg or placebo for 4 months. Patients were followed for at least 1 year after the end of the 4-month treatment period. The primary end point was effective response, which was defined as a reduction of at least 50% in the number of bleeding episodes that occurred during the year after the end of thalidomide treatment as compared with the number that occurred during the year before treatment. Key secondary end points were cessation of bleeding without rebleeding, blood transfusion, hospitalization because of bleeding, duration of bleeding, and hemoglobin levels. RESULTS: Overall, 150 patients underwent randomization: 51 to the 100-mg thalidomide group, 49 to the 50-mg thalidomide group, and 50 to the placebo group. The percentages of patients with an effective response in the 100-mg thalidomide group, 50-mg thalidomide group, and placebo group were 68.6%, 51.0%, and 16.0%, respectively (P<0.001 for simultaneous comparison across the three groups). The results of the analyses of the secondary end points supported those of the primary end point. Adverse events were more common in the thalidomide groups than in the placebo group overall; specific events included constipation, somnolence, limb numbness, peripheral edema, dizziness, and elevated liver-enzyme levels. CONCLUSIONS: In this placebo-controlled trial, treatment with thalidomide resulted in a reduction in bleeding in patients with recurrent bleeding due to SIA. (Funded by the National Natural Science Foundation of China and the Shanghai Municipal Education Commission, Gaofeng Clinical Medicine; ClinicalTrials.gov number, NCT02707484.).


Asunto(s)
Angiodisplasia , Hemorragia Gastrointestinal , Fármacos Hematológicos , Enfermedades Intestinales , Intestino Delgado , Talidomida , Humanos , Angiodisplasia/complicaciones , Angiodisplasia/tratamiento farmacológico , China , Método Doble Ciego , Hemorragia Gastrointestinal/tratamiento farmacológico , Hemorragia Gastrointestinal/etiología , Talidomida/administración & dosificación , Talidomida/efectos adversos , Talidomida/uso terapéutico , Resultado del Tratamiento , Enfermedades Intestinales/complicaciones , Enfermedades Intestinales/tratamiento farmacológico , Recurrencia , Intestino Delgado/irrigación sanguínea , Administración Oral , Fármacos Hematológicos/administración & dosificación , Fármacos Hematológicos/efectos adversos , Fármacos Hematológicos/uso terapéutico
4.
Mol Biol Evol ; 41(7)2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38885310

RESUMEN

Large-scale genomic projects and ancient DNA innovations have ushered in a new paradigm for exploring human evolutionary history. However, the genetic legacy of spatiotemporally diverse ancient Eurasians within Chinese paternal lineages remains unresolved. Here, we report an integrated Y-chromosome genomic database encompassing 15,563 individuals from both modern and ancient Eurasians, including 919 newly reported individuals, to investigate the Chinese paternal genomic diversity. The high-resolution, time-stamped phylogeny reveals multiple diversification events and extensive expansions in the early and middle Neolithic. We identify four major ancient population movements, each associated with technological innovations that have shaped the Chinese paternal landscape. First, the expansion of early East Asians and millet farmers from the Yellow River Basin predominantly carrying O2/D subclades significantly influenced the formation of the Sino-Tibetan people and facilitated the permanent settlement of the Tibetan Plateau. Second, the dispersal of rice farmers from the Yangtze River Valley carrying O1 and certain O2 sublineages reshapes the genetic makeup of southern Han Chinese, as well as the Tai-Kadai, Austronesian, Hmong-Mien, and Austroasiatic people. Third, the Neolithic Siberian Q/C paternal lineages originated and proliferated among hunter-gatherers on the Mongolian Plateau and the Amur River Basin, leaving a significant imprint on the gene pools of northern China. Fourth, the J/G/R paternal lineages derived from western Eurasia, which were initially spread by Yamnaya-related steppe pastoralists, maintain their presence primarily in northwestern China. Overall, our research provides comprehensive genetic evidence elucidating the significant impact of interactions with culturally distinct ancient Eurasians on the patterns of paternal diversity in modern Chinese populations.


Asunto(s)
Pueblo Asiatico , Cromosomas Humanos Y , Migración Humana , Humanos , China , Pueblo Asiatico/genética , Masculino , Cromosomas Humanos Y/genética , ADN Antiguo/análisis , Herencia Paterna , Filogenia , Pueblos del Este de Asia
5.
Hum Genomics ; 18(1): 104, 2024 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-39289776

RESUMEN

BACKGROUND: High-quality genomic datasets from under-representative populations are essential for population genetic analysis and medical relevance. Although the Tujia are the most populous ethnic minority in southwestern China, previous genetic studies have been fragmented and only partially reveal their genetic diversity landscape. The understanding of their fine-scale genetic structure and potentially differentiated biological adaptive features remains nascent. OBJECTIVES: This study aims to explore the demographic history and genetic architecture related to the natural selection of the Tujia people, focusing on a meta-Tujia population from the central regions of the Yangtze River Basin. RESULTS: Population genetic analyses conducted on the meta-Tujia people indicate that they occupy an intermediate position in the East Asian North-South genetic cline. A close genetic affinity was identified between the Tujia people and neighboring Sinitic-speaking populations. Admixture models suggest that the Tujia can be modeled as a mixture of northern and southern ancestries. Estimates of f3/f4 statistics confirmed the presence of ancestral links to ancient Yellow River Basin millet farmers and the BaBanQinCen-related groups. Furthermore, population-specific natural selection signatures were explored, revealing highly differentiated functional variants between the Tujia and southern indigenous populations, including genes associated with hair morphology (e.g., EDAR) and skin pigmentation (e.g., SLC24A5). Additionally, both shared and unique selection signatures were identified among ethnically diverse but geographically adjacent populations, highlighting their extensive admixture and the biological adaptations introduced by this admixture. CONCLUSIONS: The study unveils significant population movements and genetic admixture among the Tujia and other ethno-linguistically diverse East Asian groups, elucidating the differentiated adaptation processes across geographically diverse populations from the current genetic landscape.


Asunto(s)
Alelos , Genética de Población , Selección Genética , Humanos , Adaptación Biológica/genética , China , Pueblos del Este de Asia/genética , Etnicidad/genética , Variación Genética , Haplotipos , Polimorfismo de Nucleótido Simple
6.
J Med Genet ; 61(8): 741-749, 2024 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-38621993

RESUMEN

BACKGROUND: As one of the most common congenital abnormalities in male births, cryptorchidism has been found to have a polygenic aetiology according to previous studies of common variants. However, little is known about genetic predisposition of rare variants for cryptorchidism, since rare variants have larger effective size on diseases than common variants. METHODS: In this study, a cohort of 115 Chinese probands with cryptorchidism was analysed using whole-genome sequencing, alongside 19 parental controls and 2136 unaffected men. Additionally, CRISPR-Cas9 editing of a conserved variant was performed in a mouse model, with MRI screening used to observe the phenotype. RESULTS: In 30 of 115 patients (26.1%), we identified four novel genes (ARSH, DMD, MAGEA4 and SHROOM2) affecting at least five unrelated patients and four known genes (USP9Y, UBA1, BCORL1 and KDM6A) with the candidate rare pathogenic variants affecting at least two cases. Burden tests of rare variants revealed the genome-wide significances for newly identified genes (p<2.5×10-6) under the Bonferroni correction. Surprisingly, novel and known genes were mainly found on X chromosome (seven on X and one on Y) and all rare X-chromosomal segregating variants exhibited a maternal inheritance rather than de novo origin. CRISPR-Cas9 mouse modelling of a splice donor loss variant in DMD (NC_000023.11:g.32454661C>G), which resides in a conserved site across vertebrates, replicated bilateral cryptorchidism phenotypes, confirmed by MRI at 4 and 10 weeks. The movement tests further revealed symptoms of Duchenne muscular dystrophy (DMD) in transgenic mice. CONCLUSION: Our results revealed the role of the DMD gene mutation in causing cryptorchidism. The results also suggest that maternal-X inheritance of pathogenic defects could have a predominant role in the development of cryptorchidism.


Asunto(s)
Criptorquidismo , Distrofia Muscular de Duchenne , Mutación , Animales , Humanos , Masculino , Ratones , Sistemas CRISPR-Cas/genética , Criptorquidismo/genética , Predisposición Genética a la Enfermedad , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/patología , Fenotipo , Sitios de Empalme de ARN/genética , Secuenciación Completa del Genoma
7.
Proc Natl Acad Sci U S A ; 119(50): e2214096119, 2022 12 13.
Artículo en Inglés | MEDLINE | ID: mdl-36469771

RESUMEN

Mycovirus-infected fungi can suffer from poor growth, attenuated pigmentation, and virulence. However, the molecular mechanisms of how mycoviruses confer these symptoms remain poorly understood. Here, we report a mycovirus Stemphylium lycopersici alternavirus 1 (SlAV1) isolated from a necrotrophic plant pathogen Stemphylium lycopersici that causes altered colony pigmentation and hypovirulence by specifically interfering host biosynthesis of Altersolanol A, a polyketide phytotoxin. SlAV1 significantly down-regulates a fungal polyketide synthase (PKS1), the core enzyme of Altersolanol A biosynthesis. PKS1 deletion mutants do not accumulate Altersolanol A and lose pathogenicity to tomato and lettuce. Transgenic expression of SlAV1 open-reading frame 3 (ORF3) in S. lycopersici inhibits fungal PKS1 expression and Altersolanol A accumulation, leading to symptoms like SlAV1-infected fungal strains. Multiple plant species sprayed with mycelial suspension of S. lycopersici or S. vesicarium strains integrating and expressing ORF3 display enhanced resistance against virulent strains, converting the pathogenic fungi into biocontrol agents. Hence, our study not only proves inhibiting a key enzyme of host phytotoxin biosynthesis as a molecular mechanism underlying SlAV1-mediated hypovirulence of Stemphylium spp., but also demonstrates the potential of mycovirus-gene integrated fungi as a potential biocontrol agent to protect plants from fungal diseases.


Asunto(s)
Ascomicetos , Virus Fúngicos , Enfermedades de las Plantas/microbiología , Virus Fúngicos/genética , Plantas
8.
Nano Lett ; 24(5): 1579-1586, 2024 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-38284987

RESUMEN

Engineering room-temperature strong coupling of few-exciton in transition-metal dichalcogenides (TMDCs) with plasmons promises to construct compact and high-performance quantum optical devices. But it remains unimplemented due to their in-plane excitons. Here, we demonstrate the strong coupling of few-exciton within 10 in monolayer WS2 with the plasmonic mode with a large tangential component of the electric field tightly trapped around the sharp corners of an Au@Ag nanocuboid, the fewest number of excitons observed in the TMDC family so far. Furthermore, we for the first time report a significant deviation with a relative difference of up to 100.6% between the spectrum and eigenlevel splitting dispersions, which increases with decreasing coupling strength. It is also shown that the coupling strength obtained by the conventional concept of both being equal to the measured spectrum splitting is markedly overestimated. Our work enriches the understanding of strong light-matter interactions at room temperature.

9.
BMC Genomics ; 25(1): 611, 2024 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-38890579

RESUMEN

BACKGROUND: Ancient northern East Asians (ANEA) from the Yellow River region, who pioneered millet cultivation, play a crucial role in understanding the origins of ethnolinguistically diverse populations in modern China and the entire landscape of deep genetic structure and variation discovery in modern East Asians. However, the direct links between ANEA and geographically proximate modern populations, as well as the biological adaptive processes involved, remain poorly understood. RESULTS: Here, we generated genome-wide SNP data for 264 individuals from geographically different Han populations in Shandong. An integrated genomic resource encompassing both modern and ancient East Asians was compiled to examine fine-scale population admixture scenarios and adaptive traits. The reconstruction of demographic history and hierarchical clustering patterns revealed that individuals from the Shandong Peninsula share a close genetic affinity with ANEA, indicating long-term genetic continuity and mobility in the lower Yellow River basin since the early Neolithic period. Biological adaptive signatures, including those related to immune and metabolic pathways, were identified through analyses of haplotype homozygosity and allele frequency spectra. These signatures are linked to complex traits such as height and body mass index, which may be associated with adaptations to cold environments, dietary practices, and pathogen exposure. Additionally, allele frequency trajectories over time and a haplotype network of two highly differentiated genes, ABCC11 and SLC10A1, were delineated. These genes, which are associated with axillary odor and bilirubin metabolism, respectively, illustrate how local adaptations can influence the diversification of traits in East Asians. CONCLUSIONS: Our findings provide a comprehensive genomic dataset that elucidates the fine-scale genetic history and evolutionary trajectory of natural selection signals and disease susceptibility in Han Chinese populations. This study serves as a paradigm for integrating spatiotemporally diverse ancient genomes in the era of population genomic medicine.


Asunto(s)
Genética de Población , Haplotipos , Polimorfismo de Nucleótido Simple , Humanos , China , Genómica , Evolución Molecular , Frecuencia de los Genes , Pueblo Asiatico/genética , Genoma Humano
10.
Genome Res ; 31(1): 40-50, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33334733

RESUMEN

Mutations are the source of both genetic diversity and mutational load. However, the effects of increasing environmental temperature on plant mutation rates and relative impact on specific mutational classes (e.g., insertion/deletion [indel] vs. single nucleotide variant [SNV]) are unknown. This topic is important because of the poorly defined effects of anthropogenic global temperature rise on biological systems. Here, we show the impact of temperature increase on Arabidopsis thaliana mutation, studying whole genome profiles of mutation accumulation (MA) lineages grown for 11 successive generations at 29°C. Whereas growth of A. thaliana at standard temperature (ST; 23°C) is associated with a mutation rate of 7 × 10-9 base substitutions per site per generation, growth at stressful high temperature (HT; 29°C) is highly mutagenic, increasing the mutation rate to 12 × 10-9 SNV frequency is approximately two- to threefold higher at HT than at ST, and HT-growth causes an ∼19- to 23-fold increase in indel frequency, resulting in a disproportionate increase in indels (vs. SNVs). Most HT-induced indels are 1-2 bp in size and particularly affect homopolymeric or dinucleotide A or T stretch regions of the genome. HT-induced indels occur disproportionately in nucleosome-free regions, suggesting that much HT-induced mutational damage occurs during cell-cycle phases when genomic DNA is packaged into nucleosomes. We conclude that stressful experimental temperature increases accelerate plant mutation rates and particularly accelerate the rate of indel mutation. Increasing environmental temperatures are thus likely to have significant mutagenic consequences for plants growing in the wild and may, in particular, add detrimentally to mutational load.


Asunto(s)
Arabidopsis , Arabidopsis/genética , Biodiversidad , Mutación , Tasa de Mutación , Temperatura
11.
Small ; : e2406070, 2024 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-39128138

RESUMEN

This work reports a strategy that integrates the carbon nanotube (CNT) supporting, ultrathin carbon coating and oxygen defect generation to fabricate the RuO2 based catalysts toward the pH-universal hydrogen evolution reaction (HER) with high efficiencies. Specifically, the CNT supported RuO2 nanoparticles with ultrathin carbon loricae and rich oxygen vacancies at the surface (C@OV-RuO2/CNTs-325) have been synthesized. The C@OV-RuO2/CNTs-325 shows superior activities and excellent durability for the HER. It only requires overpotentials of 36.1, 18.0, and 19.3 mV to deliver -10 mA cm-2 in the acidic, neutral, and alkaline media, respectively. Its HER activities are comparable to that of the Pt/C in the acidic media but higher than those of the Pt/C in the neutral and alkaline media. The C@OV-RuO2/CNTs-325 shows excellent HER durability with no activity losses for > 500 h in the acidic, neutral or alkaline media at -250 mA cm-2. The density-functional-theory calculations indicate that the CNT supporting, the carbon coating, and the OVs can modulate the d-band centers of Ru, increasing the HER activities of C@OV-RuO2/CNTs-325, and stabilize the Ru atoms in the catalyst, increasing the durability of the C@OV-RuO2/CNTs-325. More interestingly, the C@OV-RuO2/CNTs-325 shows great potential for practical applications toward overall seawater splitting.

12.
Small ; : e2402652, 2024 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-38838056

RESUMEN

The optimization of metal-support interactions is used to fabricate noble metal-based nanoclusters with high activity for hydrogen evolution reaction (HER) in acid media. Specifically, the oxygen-defective Mn3O4 nanosheets supported Pt nanoclusters of ≈1.71 nm in diameter (Pt/V·-Mn3O4 NSs) are synthesized through the controlled solvothermal reaction. The Pt/V·-Mn3O4 NSs show a superior activity and excellent stability for the HER in the acidic media. They only require an overpotential of 19 mV to drive -10 mA cm-2 and show negligible activity loss at -10 and -250 mA cm-2 for >200 and >60 h, respectively. Their Pt mass activity is 12.4 times higher than that of the Pt/C and even higher than those of many single-atom based Pt catalysts. DFT calculations show that their high HER activity arises mainly from the strong metal-support interaction between Pt and Mn3O4. It can facilitate the charge transfer from Mn3O4 to Pt, optimizing the H adsorption on the catalyst surface and promoting the evolution of H2 through the Volmer-Tafel mechanism. The oxygen vacancies in the V·-Mn3O4 NSs are found to be inconducive to the high activity of the Pt/V·-Mn3O4 NSs, highlighting the great importance to reduce the vacancy levels in V·-Mn3O4 NSs.

13.
Bioconjug Chem ; 35(5): 703-714, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38708860

RESUMEN

Manganese(II)-based contrast agents (MBCAs) are potential candidates for gadolinium-free enhanced magnetic resonance imaging (MRI). In this work, a rigid binuclear MBCA (Mn2-PhDTA2) with a zero-length linker was developed via facile synthetic routes, while the other dimer (Mn2-TPA-PhDTA2) with a longer rigid linker was also synthesized via more complex steps. Although the molecular weight of Mn2-PhDTA2 is lower than that of Mn2-TPA-PhDTA2, their T1 relaxivities are similar, being increased by over 71% compared to the mononuclear Mn-PhDTA. In the presence of serum albumin, the relaxivity of Mn2-PhDTA2 was slightly lower than that of Mn2-TPA-PhDTA2, possibly due to the lower affinity constant. The transmetalation reaction with copper(II) ions confirmed that Mn2-PhDTA2 has an ideal kinetic inertness with a dissociation half-life of approximately 10.4 h under physiological conditions. In the variable-temperature 17O NMR study, both Mn-PhDTA and Mn2-PhDTA2 demonstrated a similar estimated q close to 1, indicating the formation of monohydrated complexes with each manganese(II) ion. In addition, Mn2-PhDTA2 demonstrated a superior contrast enhancement to Mn-PhDTA in in vivo vascular and hepatic MRI and can be rapidly cleared through a dual hepatic and renal excretion pattern. The hepatic uptake mechanism of Mn2-PhDTA2 mediated by SLC39A14 was validated in cellular uptake studies.


Asunto(s)
Medios de Contraste , Hígado , Imagen por Resonancia Magnética , Manganeso , Manganeso/química , Hígado/diagnóstico por imagen , Hígado/metabolismo , Imagen por Resonancia Magnética/métodos , Animales , Medios de Contraste/química , Medios de Contraste/síntesis química , Humanos , Proteínas de Transporte de Catión/metabolismo , Proteínas de Transporte de Catión/química , Ratones , Complejos de Coordinación/química , Complejos de Coordinación/síntesis química
14.
Opt Express ; 32(7): 11934-11951, 2024 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-38571030

RESUMEN

Optical coherence tomography (OCT) can resolve biological three-dimensional tissue structures, but it is inevitably plagued by speckle noise that degrades image quality and obscures biological structure. Recently unsupervised deep learning methods are becoming more popular in OCT despeckling but they still have to use unpaired noisy-clean images or paired noisy-noisy images. To address the above problem, we propose what we believe to be a novel unsupervised deep learning method for OCT despeckling, termed Double-free Net, which eliminates the need for ground truth data and repeated scanning by sub-sampling noisy images and synthesizing noisier images. In comparison to existing unsupervised methods, Double-free Net obtains superior denoising performance when trained on datasets comprising retinal and human tissue images without clean images. The efficacy of Double-free Net in denoising holds significant promise for diagnostic applications in retinal pathologies and enhances the accuracy of retinal layer segmentation. Results demonstrate that Double-free Net outperforms state-of-the-art methods and exhibits strong convenience and adaptability across different OCT images.


Asunto(s)
Algoritmos , Tomografía de Coherencia Óptica , Humanos , Tomografía de Coherencia Óptica/métodos , Retina/diagnóstico por imagen , Cintigrafía , Procesamiento de Imagen Asistido por Computador/métodos
15.
Chem Rec ; 24(1): e202300206, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37736673

RESUMEN

The development of sodium-ion battery (SIB) anodes is still hindered by their rapid capacity decay and poor rate capabilities. Although there have been some new materials that can be used to fabricate stable anodes, SIBs are still far from wide applications. Strategies like nanostructure construction and material modification have been used to prepare more robust SIB anodes. Among all the design strategies, the hollow structure design is a promising method in the development of advanced anode materials. In the past decade, research efforts have been devoted to modifying the synthetic route, the type of templates, and the interior structure of hollow structures with high capacity and stability. A brief introduction is made to the main material systems and classifications of hollow structural materials first. Then different morphologies of hollow structural materials for SIB anodes from the latest reports are discussed, including nanoboxes, nanospheres, yolk shells, nanotubes, and other more complex shapes. The most used templates for the synthesis of hollow structrual materials are covered and the perspectives are highlighted at the end. This review offers a comprehensive discussion of the synthesis of hollow structural materials for SIB anodes, which could be potentially of use to research areas involving hollow materials design for batteries.

16.
Arch Virol ; 169(9): 188, 2024 Aug 26.
Artículo en Inglés | MEDLINE | ID: mdl-39187668

RESUMEN

Here, we identified a new mycovirus infecting the phytopathogenic fungus Nigrospora oryzae, which we have designated "Nigrospora oryzae partitivirus 2" (NoPV2). The genome of NoPV2 consists of two dsRNA segments (dsRNA 1 and dsRNA 2), measuring 1771 and 1440 bp in length, respectively. dsRNA 1 and dsRNA 2 each contain a single open reading frame (ORF) that encodes the RNA-dependent RNA polymerase (RdRp) and capsid protein (CP), respectively. A BLASTp search showed that the RdRp of NoPV2 had significant sequence similarity to the RdRps of other partitiviruses, including Nigrospora sphaerica partitivirus 1 (75.61% identity) and Magnaporthe oryzae partitivirus 1 (67.53% identity). Phylogenetic analysis revealed that NoPV2 is a new member of the genus Gammapartitivirus in the family Partitiviridae. This study provides important information for understanding the diversity of mycoviruses in N. oryzae.


Asunto(s)
Ascomicetos , Virus Fúngicos , Genoma Viral , Sistemas de Lectura Abierta , Filogenia , ARN Viral , ARN Polimerasa Dependiente del ARN , Virus Fúngicos/clasificación , Virus Fúngicos/genética , Virus Fúngicos/aislamiento & purificación , Ascomicetos/virología , ARN Polimerasa Dependiente del ARN/genética , ARN Viral/genética , Proteínas de la Cápside/genética , ARN Bicatenario/genética , Virus ARN/genética , Virus ARN/aislamiento & purificación , Virus ARN/clasificación , Virus ARN Bicatenario/genética , Virus ARN Bicatenario/aislamiento & purificación , Virus ARN Bicatenario/clasificación , Enfermedades de las Plantas/microbiología , Proteínas Virales/genética
17.
Food Microbiol ; 124: 104613, 2024 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-39244365

RESUMEN

Anthracnose caused by Colletotrichum scovillei is a significant disease of pepper, including in postharvest stage. Bacillus species represent a potential microbial resource for controlling postharvest plant diseases. Here, a strain HG-8-2 was obtained and identified as Bacillus velezensis through morphological, biochemical, physiological, and molecular analyses. The culture filtrate showed highly antifungal activity against C. scovillei both in vitro and on pepper fruit. Crude lipopeptide extracts, which had excellent stability, could effectively inhibit mycelial growth of C. scovillei with an EC50 value of 28.48 ± 1.45 µg mL-1 and inhibited conidial germination. Pretreatment with the extracts reduced the incidence and lesion size of postharvest anthracnose on pepper fruit. Analysis using propidium iodide staining, malondialdehyde content detection and scanning electron microscope observation suggested that the crude lipopeptide extracts harbored antifungal activity by damaging cell membranes and mycelial structures. The RNA-seq analysis conducted on C. scovillei samples treated with the extracts, as compared to untreated samples, revealed significant alterations in the expression of multiple genes involved in protein biosynthesis. Overall, these results demonstrated that B. velezensis HG-8-2 and its crude lipopeptide extracts exhibit highly antagonistic ability against C. scovillei, thereby offering an effective biological agent for the control of anthracnose in pepper fruit.


Asunto(s)
Bacillus , Capsicum , Colletotrichum , Frutas , Enfermedades de las Plantas , Colletotrichum/efectos de los fármacos , Colletotrichum/crecimiento & desarrollo , Capsicum/microbiología , Bacillus/genética , Bacillus/metabolismo , Bacillus/fisiología , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/prevención & control , Frutas/microbiología , Antifúngicos/farmacología , Antifúngicos/metabolismo , Esporas Fúngicas/efectos de los fármacos , Esporas Fúngicas/crecimiento & desarrollo , Lipopéptidos/farmacología , Lipopéptidos/metabolismo , Micelio/crecimiento & desarrollo , Micelio/efectos de los fármacos , Agentes de Control Biológico/farmacología
18.
Psychopathology ; 57(3): 182-191, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38228121

RESUMEN

INTRODUCTION: This study investigated the structure of the borderline personality features (BPFs) network and the most central BPF in adolescence. METHODS: Cross-sectional self-report data from 4,866 Chinese adolescents (M = 13.96, SD = 1.64; 61.3% girls) were included in the network analysis models. BPFs were assessed with the McLean Screening Instrument for Borderline Personality Disorder. RESULTS: Identity disturbance and affective instability emerged as the most central BPF in the current adolescent sample. In addition, chronic emptiness was also found with high centrality. The general networks of BPF were very similar between adolescent boys and girls, although some differences were detected. DISCUSSION: This study further supports the necessity of BPD assessment and diagnosis in adolescence and identifies the distinctive importance of identity and affective dysregulation in the early development of BPD. The findings provide empirical insights into the interconnections of BPF, which resonate with therapeutic mechanisms of evidence-based treatments for BPD. However, the research was limited in its use of a screening measurement rather than a diagnostic tool. Future studies can further explore BPD psychopathology in adolescence with longitudinal data and clinical interviews.


Asunto(s)
Trastorno de Personalidad Limítrofe , Humanos , Trastorno de Personalidad Limítrofe/diagnóstico , Adolescente , Femenino , Masculino , Estudios Transversales , China , Autoinforme , Pueblos del Este de Asia
19.
Chaos ; 34(4)2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38572949

RESUMEN

This paper examines fixed-time synchronization (FxTS) for two-dimensional coupled reaction-diffusion complex networks (CRDCNs) with impulses and delay. Utilizing the Lyapunov method, a FxTS criterion is established for impulsive delayed CRDCNs. Herein, impulses encompass both synchronizing and desynchronizing variants. Subsequently, by employing a Lyapunov-Krasovskii functional, two FxTS boundary controllers are formulated for CRDCNs with Neumann and mixed boundary condition, respectively. It is observed that vanishing Dirichlet boundary contributes to the synchronization of the CRDCNs. Furthermore, this study calculates the optimal constant for the Poincaré inequality in the square domain, which is instrumental in analyzing FxTS conditions for boundary controllers. Conclusive numerical examples underscore the efficacy of the proposed theoretical findings.

20.
Pestic Biochem Physiol ; 202: 105956, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38879338

RESUMEN

Pepper southern blight, caused by Sclerotium rolfsii, is a devastating soil-borne disease resulting in significant loss to pepper, Capsicum annuum L. production. Here, we isolated an antagonistic bacterial strain XQ-29 with antifungal activity against S. rolfsii from rhizospheric soil of pepper. Combining the morphological and biochemical characteristics with the 16S rDNA sequencing, XQ-29 was identified as Streptomyces griseoaurantiacus. It exhibited an inhibition of 96.83% against S. rolfsii and displayed significant inhibitory effects on Botrytis cinerea, Phytophthora capsica and Rhizoctonia solani. Furthermore, XQ-29 significantly reduced the pepper southern blight by 100% and 70.42% during seedling and growth stages, respectively. The antifungal mechanism involved altering the mycelial morphology, disrupting cell wall and membrane integrity, accompanied by accumulation of reactive oxygen species and lipid peroxidation in S. rolfsii mycelia. Furthermore, XQ-29 promoted growth and stimulated resistance of pepper plants by increasing defense-related enzyme activities and upregulating defense-related genes. Correspondingly, XQ-29 harbors numerous functional biosynthesis gene clusters in its genome, including those for siderophores and melanin production. The metabolic constituents present in the ethyl acetate extracts, which exhibited an EC50 value of 85.48 ± 1.62 µg/mL, were identified using LC-MS. Overall, XQ-29 demonstrates significant potential as a biocontrol agent against southern blight disease.


Asunto(s)
Botrytis , Capsicum , Enfermedades de las Plantas , Rhizoctonia , Streptomyces , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/prevención & control , Capsicum/microbiología , Streptomyces/genética , Streptomyces/fisiología , Botrytis/efectos de los fármacos , Botrytis/fisiología , Rhizoctonia/fisiología , Rhizoctonia/efectos de los fármacos , Basidiomycota/fisiología , Phytophthora/fisiología , Phytophthora/efectos de los fármacos , Agentes de Control Biológico/farmacología , Antifúngicos/farmacología
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