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1.
Nature ; 624(7991): 295-302, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38092907

RESUMEN

Connecting different electronic devices is usually straightforward because they have paired, standardized interfaces, in which the shapes and sizes match each other perfectly. Tissue-electronics interfaces, however, cannot be standardized, because tissues are soft1-3 and have arbitrary shapes and sizes4-6. Shape-adaptive wrapping and covering around irregularly sized and shaped objects have been achieved using heat-shrink films because they can contract largely and rapidly when heated7. However, these materials are unsuitable for biological applications because they are usually much harder than tissues and contract at temperatures higher than 90 °C (refs. 8,9). Therefore, it is challenging to prepare stimuli-responsive films with large and rapid contractions for which the stimuli and mechanical properties are compatible with vulnerable tissues and electronic integration processes. Here, inspired by spider silk10-12, we designed water-responsive supercontractile polymer films composed of poly(ethylene oxide) and poly(ethylene glycol)-α-cyclodextrin inclusion complex, which are initially dry, flexible and stable under ambient conditions, contract by more than 50% of their original length within seconds (about 30% per second) after wetting and become soft (about 100 kPa) and stretchable (around 600%) hydrogel thin films thereafter. This supercontraction is attributed to the aligned microporous hierarchical structures of the films, which also facilitate electronic integration. We used this film to fabricate shape-adaptive electrode arrays that simplify the implantation procedure through supercontraction and conformally wrap around nerves, muscles and hearts of different sizes when wetted for in vivo nerve stimulation and electrophysiological signal recording. This study demonstrates that this water-responsive material can play an important part in shaping the next-generation tissue-electronics interfaces as well as broadening the biomedical application of shape-adaptive materials.


Asunto(s)
Electrofisiología , Polímeros , Agua , Animales , alfa-Ciclodextrinas/química , Electrodos , Electrofisiología/instrumentación , Electrofisiología/métodos , Electrofisiología/tendencias , Corazón , Músculos , Polietilenglicoles/química , Polímeros/química , Seda/química , Arañas , Agua/química , Hidrogeles/química , Electrónica/instrumentación , Electrónica/métodos , Electrónica/tendencias
2.
Nature ; 614(7948): 456-462, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36792740

RESUMEN

Stretchable hybrid devices have enabled high-fidelity implantable1-3 and on-skin4-6 monitoring of physiological signals. These devices typically contain soft modules that match the mechanical requirements in humans7,8 and soft robots9,10, rigid modules containing Si-based microelectronics11,12 and protective encapsulation modules13,14. To make such a system mechanically compliant, the interconnects between the modules need to tolerate stress concentration that may limit their stretching and ultimately cause debonding failure15-17. Here, we report a universal interface that can reliably connect soft, rigid and encapsulation modules together to form robust and highly stretchable devices in a plug-and-play manner. The interface, consisting of interpenetrating polymer and metal nanostructures, connects modules by simply pressing without using pastes. Its formation is depicted by a biphasic network growth model. Soft-soft modules joined by this interface achieved 600% and 180% mechanical and electrical stretchability, respectively. Soft and rigid modules can also be electrically connected using the above interface. Encapsulation on soft modules with this interface is strongly adhesive with an interfacial toughness of 0.24 N mm-1. As a proof of concept, we use this interface to assemble stretchable devices for in vivo neuromodulation and on-skin electromyography, with high signal quality and mechanical resistance. We expect such a plug-and-play interface to simplify and accelerate the development of on-skin and implantable stretchable devices.


Asunto(s)
Electromiografía , Electrónica Médica , Nanoestructuras , Docilidad , Polímeros , Prótesis e Implantes , Dispositivos Electrónicos Vestibles , Humanos , Nanoestructuras/química , Polímeros/química , Piel , Monitoreo Fisiológico , Electrónica Médica/instrumentación , Electrónica Médica/métodos , Electromiografía/instrumentación
3.
Plant J ; 118(6): 2085-2093, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38525917

RESUMEN

With global climate change, the high-temperature environment has severely impacted the community structure and phenotype of marine diatoms. Phaeodactylum tricornutum, a model species of marine diatom, is sensitive to high temperature, which grow slowly under high temperature. However, the regulatory mechanism of P. tricornutum in response to high-temperature is still unclear. In this study, we found that the expression level of the HSP70A in the wild type (WT) increased 28 times when exposed to high temperature (26°C) for 1 h, indicating that HSP70A plays a role in high temperature in P. tricornutum. Furthermore, overexpression and interference of HSP70A have great impact on the exponential growth phase of P. tricornutum under 26°C. Moreover, the results of Co-immunoprecipitation (Co-IP) suggested that HSP70A potentially involved in the correct folding of the photosynthetic system-related proteins (D1/D2), preventing aggregation. The photosynthetic activity results demonstrated that overexpression of HSP70A improves non-photochemical quenching (NPQ) activity under high-temperature stress. These results reveal that HSP70A regulates the photosynthetic activity of P. tricornutum under high temperatures. This study not only helps us to understand the photosynthetic activity of marine diatoms to high temperature but also provides a molecular mechanism for HSP70A in P. tricornutum under high-temperature stress.


Asunto(s)
Diatomeas , Proteínas HSP70 de Choque Térmico , Fotosíntesis , Diatomeas/metabolismo , Diatomeas/fisiología , Diatomeas/genética , Calor , Proteínas HSP70 de Choque Térmico/metabolismo , Proteínas HSP70 de Choque Térmico/genética , Fotosíntesis/fisiología
4.
Plant J ; 117(5): 1558-1573, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38113320

RESUMEN

Stalk lodging is a severe problem that limits maize production worldwide, although little attention has been given to its genetic basis. Here we measured rind penetrometer resistance (RPR), an effective index for stalk lodging, in a multi-parent population of 1948 recombinant inbred lines (RILs) and an association population of 508 inbred lines (AMP508). Linkage and association mapping identified 53 and 29 single quantitative trait loci (QTLs) and 50 and 19 pairs of epistatic interactions for RPR in the multi-parent population and AMP508 population, respectively. Phenotypic variation explained by all identified epistatic QTLs (up to ~5%) was much less than that explained by all single additive QTLs (up to ~33% in the multi-parent population and ~ 60% in the AMP508 population). Among all detected QTLs, only eight single QTLs explained >10% of phenotypic variation in single RIL populations. Alleles that increased RPR were enriched in tropical/subtropical (TST) groups from the AMP508 population. Based on genome-wide association studies in both populations, we identified 137 candidate genes affecting RPR, which were assigned to multiple biological processes, such as the biosynthesis of cell wall components. Sixty-six candidate genes were cross-validated by multiple methods or populations. Most importantly, 23 candidate genes were upregulated or downregulated in high-RPR lines relative to low-RPR lines, supporting the associations between candidate genes and RPR. These findings reveal the complex nature of the genetic basis underlying RPR and provide loci or candidate genes for developing elite varieties that are resistant to stalk lodging via molecular breeding.


Asunto(s)
Estudio de Asociación del Genoma Completo , Zea mays , Mapeo Cromosómico , Zea mays/genética , Fenotipo , Ligamiento Genético
5.
Circulation ; 2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38686562

RESUMEN

BACKGROUND: Myocardial mitochondrial dysfunction underpins the pathogenesis of heart failure (HF), yet therapeutic options to restore myocardial mitochondrial function are scarce. Epigenetic modifications of mitochondrial DNA (mtDNA), such as methylation, play a pivotal role in modulating mitochondrial homeostasis. However, their involvement in HF remains unclear. METHODS: Experimental HF models were established through continuous angiotensin II and phenylephrine (AngII/PE) infusion or prolonged myocardial ischemia/reperfusion injury. The landscape of N6-methyladenine (6mA) methylation within failing cardiomyocyte mtDNA was characterized using high-resolution mass spectrometry and methylated DNA immunoprecipitation sequencing. A tamoxifen-inducible cardiomyocyte-specific Mettl4 knockout mouse model and adeno-associated virus vectors designed for cardiomyocyte-targeted manipulation of METTL4 (methyltransferase-like protein 4) expression were used to ascertain the role of mtDNA 6mA and its methyltransferase METTL4 in HF. RESULTS: METTL4 was predominantly localized within adult cardiomyocyte mitochondria. 6mA modifications were significantly more abundant in mtDNA than in nuclear DNA. Postnatal cardiomyocyte maturation presented with a reduction in 6mA levels within mtDNA, coinciding with a decrease in METTL4 expression. However, an increase in both mtDNA 6mA level and METTL4 expression was observed in failing adult cardiomyocytes, suggesting a shift toward a neonatal-like state. METTL4 preferentially targeted mtDNA promoter regions, which resulted in interference with transcription initiation complex assembly, mtDNA transcriptional stalling, and ultimately mitochondrial dysfunction. Amplifying cardiomyocyte mtDNA 6mA through METTL4 overexpression led to spontaneous mitochondrial dysfunction and HF phenotypes. The transcription factor p53 was identified as a direct regulator of METTL4 transcription in response to HF-provoking stress, thereby revealing a stress-responsive mechanism that controls METTL4 expression and mtDNA 6mA. Cardiomyocyte-specific deletion of the Mettl4 gene eliminated mtDNA 6mA excess, preserved mitochondrial function, and mitigated the development of HF upon continuous infusion of AngII/PE. In addition, specific silencing of METTL4 in cardiomyocytes restored mitochondrial function and offered therapeutic relief in mice with preexisting HF, irrespective of whether the condition was induced by AngII/PE infusion or myocardial ischemia/reperfusion injury. CONCLUSIONS: Our findings identify a pivotal role of cardiomyocyte mtDNA 6mA and the corresponding methyltransferase, METTL4, in the pathogenesis of mitochondrial dysfunction and HF. Targeted suppression of METTL4 to rectify mtDNA 6mA excess emerges as a promising strategy for developing mitochondria-focused HF interventions.

6.
Bioinformatics ; 40(9)2024 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-39222004

RESUMEN

MOTIVATION: Natural language is poised to become a key medium for human-machine interactions in the era of large language models. In the field of biochemistry, tasks such as property prediction and molecule mining are critically important yet technically challenging. Bridging molecular expressions in natural language and chemical language can significantly enhance the interpretability and ease of these tasks. Moreover, it can integrate chemical knowledge from various sources, leading to a deeper understanding of molecules. RESULTS: Recognizing these advantages, we introduce the concept of conversational molecular design, a novel task that utilizes natural language to describe and edit target molecules. To better accomplish this task, we develop ChatMol, a knowledgeable and versatile generative pretrained model. This model is enhanced by incorporating experimental property information, molecular spatial knowledge, and the associations between natural and chemical languages. Several typical solutions including large language models (e.g. ChatGPT) are evaluated, proving the challenge of conversational molecular design and the effectiveness of our knowledge enhancement approach. Case observations and analysis offer insights and directions for further exploration of natural-language interaction in molecular discovery. AVAILABILITY AND IMPLEMENTATION: Codes and data are provided in https://github.com/Ellenzzn/ChatMol/tree/main.


Asunto(s)
Procesamiento de Lenguaje Natural , Humanos , Programas Informáticos , Biología Computacional/métodos
7.
Cereb Cortex ; 34(2)2024 01 31.
Artículo en Inglés | MEDLINE | ID: mdl-38372291

RESUMEN

The ecological validity of bilingual code-switching has garnered increasing attention in recent years. Contrary to traditional studies that have focused on forced language switching, emerging theories posit that voluntary switching may not incur such a cost. To test these claims and understand differences between forced and voluntary switching, the present study conducted a systematic comparison through both behavioral and neural perspectives. Utilizing fMRI alongside picture-naming tasks, our findings diverge from prior work. Voluntary language switching not only demonstrated switching costs at the behavioral level but also significantly activated brain regions associated with inhibitory control. Direct comparisons of voluntary and forced language switching revealed no significant behavioral differences in switching costs, and both shared several common brain regions that were activated. On the other hand, a nuanced difference between the two types of language switching was revealed by whole-brain analysis: voluntary switching engaged fewer language control regions than forced switching. These findings offer a comprehensive view of the neural and behavioral dynamics involved in bilingual language switching, challenging prior claims that voluntary switching imposes no behavioral or neural costs, and thus providing behavioral and neuroimaging evidence for the involvement of inhibitory control in voluntary language switching.


Asunto(s)
Imagen por Resonancia Magnética , Multilingüismo , Humanos , Lenguaje , Cognición , China
8.
J Neurosci ; 43(40): 6760-6778, 2023 10 04.
Artículo en Inglés | MEDLINE | ID: mdl-37607820

RESUMEN

Unconscious acquisition of sequence structure from experienced events can lead to explicit awareness of the pattern through extended practice. Although the implicit-to-explicit transition has been extensively studied in humans using the serial reaction time (SRT) task, the subtle neural activity supporting this transition remains unclear. Here, we investigated whether frequency-specific neural signal transfer contributes to this transition. A total of 208 participants (107 females) learned a sequence pattern through a multisession SRT task, allowing us to observe the transitions. Session-by-session measures of participants' awareness for sequence knowledge were conducted during the SRT task to identify the session when the transition occurred. By analyzing time course RT data using switchpoint modeling, we identified an increase in learning benefit specifically at the transition session. Electroencephalogram (EEG)/magnetoencephalogram (MEG) recordings revealed increased theta power in parietal (precuneus) regions one session before the transition (pretransition) and a prefrontal (superior frontal gyrus; SFG) one at the transition session. Phase transfer entropy (PTE) analysis confirmed that directional theta transfer from precuneus → SFG occurred at the pretransition session and its strength positively predicted learning improvement at the subsequent transition session. Furthermore, repetitive transcranial magnetic stimulation (TMS) modulated precuneus theta power and altered transfer strength from precuneus to SFG, resulting in changes in both transition rate and learning benefit at that specific point of transition. Our brain-stimulation evidence supports a role for parietal → prefrontal theta signal transfer in igniting conscious awareness of implicitly acquired knowledge.SIGNIFICANCE STATEMENT There exists a pervasive phenomenon wherein individuals unconsciously acquire sequence patterns from their environment, gradually becoming aware of the underlying regularities through repeated practice. While previous studies have established the robustness of this implicit-to-explicit transition in humans, the refined neural mechanisms facilitating conscious access to implicit knowledge remain poorly understood. Here, we demonstrate that prefrontal activity, known to be crucial for conscious awareness, is triggered by neural signal transfer originating from the posterior brain region, specifically the precuneus. By employing brain stimulation techniques, we establish a causal link between neural signal transfer and the occurrence of awareness. Our findings unveil a mechanism by which implicit knowledge becomes consciously accessible in human cognition.


Asunto(s)
Concienciación , Aprendizaje , Femenino , Humanos , Concienciación/fisiología , Aprendizaje/fisiología , Corteza Prefrontal/fisiología , Tiempo de Reacción/fisiología , Electroencefalografía
9.
Cancer Sci ; 115(8): 2602-2616, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38816349

RESUMEN

Glioma is the most common malignant tumor in the central nervous system, and it is crucial to uncover the factors that influence prognosis. In this study, we utilized Mfuzz to identify a gene set that showed a negative correlation with overall survival in patients with glioma. Gene Ontology (GO) enrichment analyses were then undertaken to gain insights into the functional characteristics and pathways associated with these genes. The expression distribution of Hyaluronan Synthase 2 (HAS2) was explored across multiple datasets, revealing its expression patterns. In vitro and in vivo experiments were carried out through gene knockdown and overexpression to validate the functionality of HAS2. Potential upstream transcription factors of HAS2 were predicted using transcriptional regulatory databases, and these predictions were experimentally validated using ChIP-PCR and dual-luciferase reporter gene assays. The results showed that elevated expression of HAS2 in glioma indicates poor prognosis. HAS2 was found to play a role in activating an antiferroptosis pathway in glioma cells. Inhibiting HAS2 significantly increased cellular sensitivity to ferroptosis-inducing agents. Finally, we determined that the oncogenic effect of HAS2 is mediated by the key receptor of the WNT pathway, FZD7.


Asunto(s)
Neoplasias Encefálicas , Ferroptosis , Receptores Frizzled , Regulación Neoplásica de la Expresión Génica , Glioma , Hialuronano Sintasas , Humanos , Ferroptosis/genética , Glioma/patología , Glioma/genética , Glioma/metabolismo , Línea Celular Tumoral , Receptores Frizzled/metabolismo , Receptores Frizzled/genética , Animales , Hialuronano Sintasas/metabolismo , Hialuronano Sintasas/genética , Ratones , Pronóstico , Neoplasias Encefálicas/patología , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Vía de Señalización Wnt/genética , Ratones Desnudos , Masculino , Femenino
10.
BMC Plant Biol ; 24(1): 862, 2024 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-39271987

RESUMEN

Drought poses a significant ecological threat that limits the production of crops worldwide. The objective of this study to examine the impact of soil applied biochar (BC) and peatmoss (PM) on the morpho-biochemical and quality traits of tobacco plants under drought conditions. In the present experiment work, a pot trial was conducted with two levels of drought severity (~ well-watered 75 ± 5% field capacity) and severe drought stress (~ 35 ± 5% field capacity), two levels of peatmoss (PM) @ 5% [PM+ (with peatmoss) and PM- (without peatmoss)] and three levels of rice straw biochar (BC0 = no biochar; BC1 = 150 mg kg- 1; and BC2 = 300 mg kg- 1 of soil) in tobacco plants. The results indicate that drought conditions significantly impacted the performance of tobacco plants. However, the combined approach of BC and PM significantly improved the growth, biomass, and total chlorophyll content (27.94%) and carotenoids (32.00%) of tobacco. This study further revealed that the drought conditions decreased the production of lipid peroxidation and proline accumulation. But the synergistic approach of BC and PM application increased soluble sugars (17.63 and 12.20%), soluble protein (31.16 and 15.88%), decreased the proline accumulation (13.92 and 9.03%), and MDA content (16.40 and 8.62%) under control and drought stressed conditions, respectively. Furthermore, the combined approach of BC and PM also improved the leaf potassium content (19.02%) by limiting the chloride ions (33.33%) under drought stressed conditions. Altogether, the balanced application of PM and BC has significant potential as an effective approach and sustainable method to increase the tolerance of tobacco plants subjected to drought conditions. This research uniquely highlights the combined potential of PM and BC as an eco-friendly strategy to enhance plant resilience under drought conditions, offering new insights into sustainable agricultural practices.


Asunto(s)
Carbón Orgánico , Nicotiana , Sphagnopsida , Nicotiana/crecimiento & desarrollo , Nicotiana/fisiología , Fotosíntesis , Especies Reactivas de Oxígeno , Metabolismo de los Lípidos , Hojas de la Planta , Análisis de Componente Principal , Sequías , Agua
11.
Small ; : e2404957, 2024 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-39031994

RESUMEN

Transition metal sulfides are investigation hotspots of anode material for sodium-ion batteries (SIBs) due to their structural diversity and high storage capacity. However, they are still plagued by inevitable volume expansion during sodiation/desodiation and an unclear energy storage mechanism. Herein, a one-step sulfidation-carbonization strategy is proposed for in situ confined growth of Cu1.96S nanoparticles in nitrogen-doped carbon (Cu1.96S@NC) using octahedral metal-organic framework (Cu-BTC) as a precursor and investigate the driving effect of Cu current collector on its sodium storage. The generation of S─C bonds in Cu1.96S@NC avoids the volume change and structural collapse of Cu1.96S nanoparticles during the cycling process and improves the adsorption and transport capacity of the material for Na+. More exciting, the Cu species in the Cu current collector are self-induced forming Cu2S quantum dots to enter the original anode material during the initial few charging and discharging cycles, which unique small-size effect and abundant edge-active sites enhance the energy storage capacity of Cu1.96S. Thus, the Cu1.96S@NC exhibits a superior first discharge capacity of 608.56 mAh g-1 at 0.2 A g-1 with an initial Coulomb efficiency (ICE) of 75.4%, as well as provides excellent rate performance and long cycle durability up to 2000 cycles.

12.
Small ; 20(25): e2309724, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38239083

RESUMEN

The commercialization of silicon anode for lithium-ion batteries has been hindered by severe structure fracture and continuous interfacial reaction against liquid electrolytes, which can be mitigated by solid-state electrolytes. However, rigid ceramic electrolyte suffers from large electrolyte/electrode interfacial resistance, and polymer electrolyte undergoes poor ionic conductivity, both of which are worsened by volume expansion of silicon. Herein, by dispersing Li1.3Al0.3Ti1.7(PO4)3 (LATP) into poly(vinylidene fluoride)-hexafluoropropylene (PVDF-HFP) and poly(ethylene oxide) (PEO) matrix, the PVDF-HFP/PEO/LATP (PHP-L) solid-state electrolyte with high ionic conductivity (1.40 × 10-3 S cm-1), high tensile strength and flexibility is designed, achieving brilliant compatibility with silicon nanosheets. The chemical interactions between PVDF-HFP and PEO, LATP increase amorphous degree of polymer, accelerating Li+ transfer. Good flexibility of the PHP-L contributes to adaptive structure variation of electrolyte with silicon expansion/shrinkage, ensuring swift interfacial ions transfer. Moreover, the solid membrane with high tensile limits electrode structural degradation and eliminates continuous interfacial growth to form stable 2D solid electrolyte interface (SEI) film, achieving superior cyclic performance to liquid electrolytes. The Si//PHP-L15//LiFePO4 solid-state full-cell exhibits stable lithium storage with 81% capacity retention after 100 cycles. This work demonstrates the effectiveness of composite solid electrolyte in addressing fundamental interfacial and performance challenges of silicon anodes.

13.
Chembiochem ; : e202400363, 2024 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-39166897

RESUMEN

Mapping the endocytic vesicular acidification process is of prior importance to better understand the health and pathological processes of cells. Herein, by integrating a pH-sensitive i-motif and a pair of fluorescence resonance energy transfer (FRET) into a tetrahedral DNA framework (TDF), we develop a pH-responsive DNA nanomachine, allowing for efficient sensing of pH from 7.0 to 5.5 via the pH-triggered spatial proximity modulation of FRET. The inheriting endo-lysosome-targeting ability of TDF enables spatiotemporal tracking of endocytic vesicle acidification during the endosomal maturation process. Analysis of pH-dependent FRET response at single fluorescent spot level reveals the significant difference of endocytic vesicular acidification between normal and cancer cells. The performance of pH-responsive DNA nanomachine underlines its potential for studies on vesicle acidification-related pathologies as a universal platform.

14.
Plant Biotechnol J ; 2024 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-39095952

RESUMEN

Structural variations (SVs) are major genetic variants that can be involved in the origin, adaptation and domestication of species. However, the identification and characterization of SVs in Spinacia species are rare due to the lack of a pan-genome. Here, we report eight chromosome-scale assemblies of cultivated spinach and its two wild species. After integration with five existing assemblies, we constructed a comprehensive Spinacia pan-genome and identified 193 661 pan-SVs, which were genotyped in 452 Spinacia accessions. Our pan-SVs enabled genome-wide association study identified signals associated with sex and clarified the evolutionary direction of spinach. Most sex-linked SVs (86%) were biased to occur on the Y chromosome during the evolution of the sex-linked region, resulting in reduced Y-linked gene expression. The frequency of pan-SVs among Spinacia accessions further illustrated the contribution of these SVs to domestication, such as bolting time and seed dormancy. Furthermore, compared with SNPs, pan-SVs act as efficient variants in genomic selection (GS) because of their ability to capture missing heritability information and higher prediction accuracy. Overall, this study provides a valuable resource for spinach genomics and highlights the potential utility of pan-SV in crop improvement and breeding programmes.

15.
New Phytol ; 243(1): 477-494, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38715078

RESUMEN

Cultivated spinach (Spinacia oleracea) is a dioecious species. We report high-quality genome sequences for its two closest wild relatives, Spinacia turkestanica and Spinacia tetrandra, which are also dioecious, and are used to study the genetics of spinach domestication. Using a combination of genomic approaches, we assembled genomes of both these species and analyzed them in comparison with the previously assembled S. oleracea genome. These species diverged c. 6.3 million years ago (Ma), while cultivated spinach split from S. turkestanica 0.8 Ma. In all three species, all six chromosomes include very large gene-poor, repeat-rich regions, which, in S. oleracea, are pericentromeric regions with very low recombination rates in both male and female genetic maps. We describe population genomic evidence that the similar regions in the wild species also recombine rarely. We characterized 282 structural variants (SVs) that have been selected during domestication. These regions include genes associated with leaf margin type and flowering time. We also describe evidence that the downy mildew resistance loci of cultivated spinach are derived from introgression from both wild spinach species. Collectively, this study reveals the genome architecture of spinach assemblies and highlights the importance of SVs during the domestication of cultivated spinach.


Asunto(s)
Domesticación , Genoma de Planta , Spinacia oleracea , Spinacia oleracea/genética , Cromosomas de las Plantas/genética , Filogenia , Recombinación Genética/genética
16.
Plant Physiol ; 193(2): 1263-1280, 2023 09 22.
Artículo en Inglés | MEDLINE | ID: mdl-37403642

RESUMEN

Sex chromosomes have evolved independently in many different plant lineages. Here, we describe reference genomes for spinach (Spinacia oleracea) X and Y haplotypes by sequencing homozygous XX females and YY males. The long arm of 185-Mb chromosome 4 carries a 13-Mb X-linked region (XLR) and 24.1-Mb Y-linked region (YLR), of which 10 Mb is Y specific. We describe evidence that this reflects insertions of autosomal sequences creating a "Y duplication region" or "YDR" whose presence probably directly reduces genetic recombination in the immediately flanking regions, although both the X and Y sex-linked regions are within a large pericentromeric region of chromosome 4 that recombines rarely in meiosis of both sexes. Sequence divergence estimates using synonymous sites indicate that YDR genes started diverging from their likely autosomal progenitors about 3 MYA, around the time when the flanking YLR stopped recombining with the XLR. These flanking regions have a higher density of repetitive sequences in the YY than the XX assembly and include slightly more pseudogenes compared with the XLR, and the YLR has lost about 11% of the ancestral genes, suggesting some degeneration. Insertion of a male-determining factor would have caused Y linkage across the entire pericentromeric region, creating physically small, highly recombining, terminal pseudoautosomal regions. These findings provide a broader understanding of the origin of sex chromosomes in spinach.


Asunto(s)
Secuencias Repetitivas de Ácidos Nucleicos , Spinacia oleracea , Spinacia oleracea/genética , Secuencias Repetitivas de Ácidos Nucleicos/genética , Cromosomas Sexuales/genética , Evolución Molecular
17.
Opt Lett ; 49(18): 5059-5062, 2024 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-39270227

RESUMEN

Sequentially timed all-optical mapping photography (STAMP) is considered a powerful tool to observe highly dynamic events; however, its application is significantly hindered by its incapability to acquire quantitative phase images. In this work, by integrating diffraction phase microscopy (DPM) and STAMP, we achieve ultrafast single-shot quantitative phase imaging with a frame rate of up to 3.3 trillion fps. The performance of the system is evaluated using a homemade phase module. Experimental results show that the system can accurately record the propagation of laser filamentation in air. We believe our method will greatly enhance the capability of STAMP to measure highly transparent targets.

18.
Opt Lett ; 49(16): 4533-4536, 2024 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-39146096

RESUMEN

The reactive ion etching (RIE) process is needed to fabricate deep ultraviolet (DUV) light-emitting diodes (LEDs). However, the n-contact performance deteriorates when the high-Al n-AlGaN surface undergoes RIE, leading to decreased LED performance. In this study, we employed an atomic layer etching (ALE) technology to eliminate surface damage generated during the mesa etching process, thus enhancing the n-Al0.65Ga0.35N ohmic contact. The improved contact performance reduced LED operation voltage and mitigated device heat generation. It was observed that DUV LEDs treated with 200 cycles of ALE showed a reduction in operating voltage from 8.3 to 5.2 V at 10 mA, with a knee voltage of 4.95 V. The peak wall plug efficiency (WPE) was approximately 1.74 times that of reference devices. The x-ray photoelectron spectroscopy (XPS) analysis revealed that ALE removed the surface damage layer induced by plasma etching, eliminating surface nitrogen vacancies and increasing surface electron concentration. Consequently, it facilitated better ohmic contact formation on n-Al0.65Ga0.35N. This study demonstrates that the ALE technology achieves etching with minor surface damage and is suitable for use in III-nitride materials and devices to remove surface defects and contaminations, leading to improved device performance.

19.
Chemistry ; : e202402032, 2024 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-39149833

RESUMEN

Lithium-sulfur (Li-S) batteries are considered as a most promising rechargeable lithium metal batteries because of their high energy density and low cost. However, the Li-S batteries mainly suffer the capacity decay issue caused by the shutting effect of lithium polysulfides and the safety issues arising from the Li dendrites formation. This review outlines the current issues of Li-S batteries. Furthermore, we comprehensively summarized the challenges encountered by Li anode in Li-S batteries, such as the heterogeneous deposition of the Li anode, the unstable solid electrolyte interface (SEI) layer, and volume expansion. Moreover, research progresses in the stabilization strategies of Li anodes (physical approaches, optimization of electrolyte, surface protection layer, and design of current collector) is discussed in detail. Lastly, the remaining challenges and future research directions of Li metal anode stabilization in Li-S batteries are also present.

20.
Anal Biochem ; 693: 115593, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-38885872

RESUMEN

MicroRNA (miRNA) is a pivotal biomarker in the diagnosis of various cancers, including bladder cancer (BCa). Despite their significance, the low abundance of miRNA presents a substantial challenge for sensitive and reliable detection. We introduce an innovative, highly sensitive assay for miRNA expression quantification that is both enzyme-free and portable. This method leverages the synergy of target recycling and entropy-driven assembly (EDA) for enhanced sensitivity and specificity. The proposed method possesses several advantages, including i) dual signal amplification through target recycling and EDA, which significantly boosts sensitivity with a lower limit of detection of 2.54 fM; ii) elimination of enzyme requirements, resulting in a cost-effective and stable signal amplification process; and iii) utilization of a personal glucose meter (PGM) for signal recording, rendering the method portable and adaptable to diverse settings. In summary, this PGM-based approach holds promising potential for clinical molecular diagnostics, offering a practical and efficient solution for miRNA analysis in cancer detection.


Asunto(s)
Entropía , MicroARNs , MicroARNs/análisis , MicroARNs/genética , Humanos , Neoplasias de la Vejiga Urinaria/diagnóstico , Neoplasias de la Vejiga Urinaria/genética , Límite de Detección , Técnicas Biosensibles/métodos , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/análisis
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