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1.
Cell ; 186(23): 4996-5014.e24, 2023 11 09.
Artículo en Inglés | MEDLINE | ID: mdl-37949056

RESUMEN

A formal demonstration that mammalian pluripotent stem cells possess preimplantation embryonic cell-like (naive) pluripotency is the generation of chimeric animals through early embryo complementation with homologous cells. Whereas such naive pluripotency has been well demonstrated in rodents, poor chimerism has been achieved in other species including non-human primates due to the inability of the donor cells to match the developmental state of the host embryos. Here, we have systematically tested various culture conditions for establishing monkey naive embryonic stem cells and optimized the procedures for chimeric embryo culture. This approach generated an aborted fetus and a live chimeric monkey with high donor cell contribution. A stringent characterization pipeline demonstrated that donor cells efficiently (up to 90%) incorporated into various tissues (including the gonads and placenta) of the chimeric monkeys. Our results have major implications for the study of primate naive pluripotency and genetic engineering of non-human primates.


Asunto(s)
Células Madre Embrionarias , Ingeniería Genética , Haplorrinos , Animales , Femenino , Embarazo , Haplorrinos/genética , Nacimiento Vivo , Mamíferos , Células Madre Pluripotentes , Primates , Ingeniería Genética/métodos
2.
Cell ; 185(10): 1777-1792.e21, 2022 05 12.
Artículo en Inglés | MEDLINE | ID: mdl-35512705

RESUMEN

Spatially resolved transcriptomic technologies are promising tools to study complex biological processes such as mammalian embryogenesis. However, the imbalance between resolution, gene capture, and field of view of current methodologies precludes their systematic application to analyze relatively large and three-dimensional mid- and late-gestation embryos. Here, we combined DNA nanoball (DNB)-patterned arrays and in situ RNA capture to create spatial enhanced resolution omics-sequencing (Stereo-seq). We applied Stereo-seq to generate the mouse organogenesis spatiotemporal transcriptomic atlas (MOSTA), which maps with single-cell resolution and high sensitivity the kinetics and directionality of transcriptional variation during mouse organogenesis. We used this information to gain insight into the molecular basis of spatial cell heterogeneity and cell fate specification in developing tissues such as the dorsal midbrain. Our panoramic atlas will facilitate in-depth investigation of longstanding questions concerning normal and abnormal mammalian development.


Asunto(s)
Organogénesis , Transcriptoma , Animales , ADN/genética , Embrión de Mamíferos , Femenino , Perfilación de la Expresión Génica/métodos , Mamíferos/genética , Ratones , Organogénesis/genética , Embarazo , Análisis de Secuencia de ARN/métodos , Análisis de la Célula Individual/métodos , Transcriptoma/genética
3.
Cell ; 184(2): 404-421.e16, 2021 01 21.
Artículo en Inglés | MEDLINE | ID: mdl-33357445

RESUMEN

Hepatocellular carcinoma (HCC) has high relapse and low 5-year survival rates. Single-cell profiling in relapsed HCC may aid in the design of effective anticancer therapies, including immunotherapies. We profiled the transcriptomes of ∼17,000 cells from 18 primary or early-relapse HCC cases. Early-relapse tumors have reduced levels of regulatory T cells, increased dendritic cells (DCs), and increased infiltrated CD8+ T cells, compared with primary tumors, in two independent cohorts. Remarkably, CD8+ T cells in recurrent tumors overexpressed KLRB1 (CD161) and displayed an innate-like low cytotoxic state, with low clonal expansion, unlike the classical exhausted state observed in primary HCC. The enrichment of these cells was associated with a worse prognosis. Differential gene expression and interaction analyses revealed potential immune evasion mechanisms in recurrent tumor cells that dampen DC antigen presentation and recruit innate-like CD8+ T cells. Our comprehensive picture of the HCC ecosystem provides deeper insights into immune evasion mechanisms associated with tumor relapse.


Asunto(s)
Carcinoma Hepatocelular/patología , Neoplasias Hepáticas/patología , Recurrencia Local de Neoplasia/patología , Análisis de la Célula Individual , Linfocitos T CD8-positivos/inmunología , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/inmunología , Regulación Neoplásica de la Expresión Génica , Humanos , Células Asesinas Naturales/inmunología , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/inmunología , Células Mieloides/metabolismo , Recurrencia Local de Neoplasia/genética , Recurrencia Local de Neoplasia/inmunología , Fenotipo , RNA-Seq , Microambiente Tumoral
4.
Nature ; 605(7909): 315-324, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35314832

RESUMEN

After fertilization, the quiescent zygote experiences a burst of genome activation that initiates a short-lived totipotent state. Understanding the process of totipotency in human cells would have broad applications. However, in contrast to in mice1,2, demonstration of the time of zygotic genome activation or the eight-cell (8C) stage in in vitro cultured human cells has not yet been reported, and the study of embryos is limited by ethical and practical considerations. Here we describe a transgene-free, rapid and controllable method for producing 8C-like cells (8CLCs) from human pluripotent stem cells. Single-cell analysis identified key molecular events and gene networks associated with this conversion. Loss-of-function experiments identified fundamental roles for DPPA3, a master regulator of DNA methylation in oocytes3, and TPRX1, a eutherian totipotent cell homeobox (ETCHbox) family transcription factor that is absent in mice4. DPPA3 induces DNA demethylation throughout the 8CLC conversion process, whereas TPRX1 is a key executor of 8CLC gene networks. We further demonstrate that 8CLCs can produce embryonic and extraembryonic lineages in vitro or in vivo in the form of blastoids5 and complex teratomas. Our approach provides a resource to uncover the molecular process of early human embryogenesis.


Asunto(s)
Embrión de Mamíferos , Desarrollo Embrionario , Células Madre Pluripotentes , Cigoto , Humanos , Proteínas Cromosómicas no Histona/genética , Embrión de Mamíferos/citología , Proteínas de Homeodominio/genética , Células Madre Pluripotentes/citología , Factores de Transcripción/genética , Cigoto/citología
5.
Nature ; 604(7907): 723-731, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35418686

RESUMEN

Studying tissue composition and function in non-human primates (NHPs) is crucial to understand the nature of our own species. Here we present a large-scale cell transcriptomic atlas that encompasses over 1 million cells from 45 tissues of the adult NHP Macaca fascicularis. This dataset provides a vast annotated resource to study a species phylogenetically close to humans. To demonstrate the utility of the atlas, we have reconstructed the cell-cell interaction networks that drive Wnt signalling across the body, mapped the distribution of receptors and co-receptors for viruses causing human infectious diseases, and intersected our data with human genetic disease orthologues to establish potential clinical associations. Our M. fascicularis cell atlas constitutes an essential reference for future studies in humans and NHPs.


Asunto(s)
Macaca fascicularis , Transcriptoma , Animales , Comunicación Celular , Macaca fascicularis/genética , Receptores Virales/genética , Transcriptoma/genética , Vía de Señalización Wnt
6.
EMBO J ; 42(21): e112963, 2023 11 02.
Artículo en Inglés | MEDLINE | ID: mdl-37743772

RESUMEN

The large intestine harbors microorganisms playing unique roles in host physiology. The beneficial or detrimental outcome of host-microbiome coexistence depends largely on the balance between regulators and responder intestinal CD4+ T cells. We found that ulcerative colitis-like changes in the large intestine after infection with the protist Blastocystis ST7 in a mouse model are associated with reduction of anti-inflammatory Treg cells and simultaneous expansion of pro-inflammatory Th17 responders. These alterations in CD4+ T cells depended on the tryptophan metabolite indole-3-acetaldehyde (I3AA) produced by this single-cell eukaryote. I3AA reduced the Treg subset in vivo and iTreg development in vitro by modifying their sensing of TGFß, concomitantly affecting recognition of self-flora antigens by conventional CD4+ T cells. Parasite-derived I3AA also induces over-exuberant TCR signaling, manifested by increased CD69 expression and downregulation of co-inhibitor PD-1. We have thus identified a new mechanism dictating CD4+ fate decisions. The findings thus shine a new light on the ability of the protist microbiome and tryptophan metabolites, derived from them or other sources, to modulate the adaptive immune compartment, particularly in the context of gut inflammatory disorders.


Asunto(s)
Microbioma Gastrointestinal , Microbiota , Animales , Ratones , Eucariontes/metabolismo , Triptófano/metabolismo , Linfocitos T Reguladores
7.
Hum Mol Genet ; 33(4): 342-354, 2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-37944069

RESUMEN

Peripheral blood mononuclear cells (PBMCs) reflect systemic immune response during cancer progression. However, a comprehensive understanding of the composition and function of PBMCs in cancer patients is lacking, and the potential of these features to assist cancer diagnosis is also unclear. Here, the compositional and status differences between cancer patients and healthy donors in PBMCs were investigated by single-cell RNA sequencing (scRNA-seq), involving 262,025 PBMCs from 68 cancer samples and 14 healthy samples. We observed an enhanced activation and differentiation of most immune subsets in cancer patients, along with reduction of naïve T cells, expansion of macrophages, impairment of NK cells and myeloid cells, as well as tumor promotion and immunosuppression. Based on characteristics including differential cell type abundances and/or hub genes identified from weight gene co-expression network analysis (WGCNA) modules of each major cell type, we applied logistic regression to construct cancer diagnosis models. Furthermore, we found that the above models can distinguish cancer patients and healthy donors with high sensitivity. Our study provided new insights into using the features of PBMCs in non-invasive cancer diagnosis.


Asunto(s)
Leucocitos Mononucleares , Neoplasias , Humanos , Análisis de Expresión Génica de una Sola Célula , Neoplasias/diagnóstico , Neoplasias/genética , Diferenciación Celular , Transformación Celular Neoplásica
8.
Plant Cell ; 35(10): 3697-3711, 2023 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-37378548

RESUMEN

FLOWERING PROMOTING FACTOR1 (FPF1), a small protein without any known domains, promotes flowering in several plants; however, its functional mechanism remains unknown. Here, we characterized 2 FPF1-like proteins, FPL1 and FPL7, which, in contrast, function as flowering repressors in Brachypodium distachyon. FPL1 and FPL7 interact with the components of the florigen activation complex (FAC) and inhibit FAC activity to restrict expression of its critical target, VERNALIZATION1 (VRN1), in leaves, thereby preventing overaccumulation of FLOWERING LOCUS T1 (FT1) at the juvenile stage. Further, VRN1 can directly bind to the FPL1 promoter and repress FPL1 expression; hence, as VRN1 gradually accumulates during the late vegetative stage, FAC is released. This accurate feedback regulation of FPL1 by VRN1 allows proper FT1 expression in leaves and ensures sufficient FAC formation in shoot apical meristems to trigger timely flowering. Overall, we define a sophisticated modulatory loop for flowering initiation in a temperate grass, providing insights toward resolving the molecular basis underlying fine-tuning flowering time in plants.

9.
Cell ; 145(2): 173-4, 2011 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-21496638

RESUMEN

The stability and translation efficiency of many messenger RNAs is regulated by microRNAs (miRNAs), which exert their effects through associated Argonaute proteins. In this issue, Zhu, Zhang, and colleagues reveal that plants also exploit miRNA binding by Argonautes as a sequestering mechanism that prevents miRNAs from fulfilling their normal roles.

10.
Plant J ; 118(6): 1955-1971, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38491864

RESUMEN

Photoperiod employs complicated networks to regulate various developmental processes in plants, including flowering transition. However, the specific mechanisms by which photoperiod affects epigenetic modifications and gene expression variations in plants remain elusive. In this study, we conducted a comprehensive analysis of DNA methylation, small RNA (sRNA) accumulation, and gene expressions under different daylengths in facultative long-day (LD) grass Brachypodium distachyon and short-day (SD) grass rice. Our results showed that while overall DNA methylation levels were minimally affected by different photoperiods, CHH methylation levels were repressed under their favorable light conditions, particularly in rice. We identified numerous differentially methylated regions (DMRs) that were influenced by photoperiod in both plant species. Apart from differential sRNA clusters, we observed alterations in the expression of key components of the RNA-directed DNA methylation pathway, DNA methyltransferases, and demethylases, which may contribute to the identified photoperiod-influenced CHH DMRs. Furthermore, we identified many differentially expressed genes in response to different daylengths, some of which were associated with the DMRs. Notably, we discovered a photoperiod-responsive gene MYB11 in the transcriptome of B. distachyon, and further demonstrated its role as a flowering inhibitor by repressing FT1 transcription. Together, our comparative and functional analysis sheds light on the effects of daylength on DNA methylation, sRNA accumulation, and gene expression variations in LD and SD plants, thereby facilitating better designing breeding programs aimed at developing high-yield crops that can adapt to local growing seasons.


Asunto(s)
Metilación de ADN , Regulación de la Expresión Génica de las Plantas , Oryza , Fotoperiodo , ARN de Planta , Oryza/genética , Oryza/metabolismo , Oryza/fisiología , ARN de Planta/genética , ARN de Planta/metabolismo , Brachypodium/genética , Brachypodium/metabolismo , Brachypodium/fisiología , Epigénesis Genética , Flores/genética , Flores/fisiología , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
11.
Stem Cells ; 42(8): 752-762, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-38829368

RESUMEN

Bone marrow mesenchymal stem cells (BMSCs) possess the potential to differentiate into cartilage cells. Long noncoding RNA (lncRNAs) urothelial carcinoma associated 1 (UCA1) has been confirmed to improve the chondrogenic differentiation of marrow mesenchymal stem cells (MSCs). Herein, we further investigated the effects and underlying mechanisms of these processes. The expression of UCA1 was positively associated with chondrogenic differentiation and the knockdown of UCA1 has been shown to attenuate the expression of chondrogenic markers. RNA pull-down assay and RNA immunoprecipitation showed that UCA1 could directly bind to PARP1 protein. UCA1 could improve PARP1 protein via facilitating USP9X-mediated PARP1 deubiquitination. Then these processes stimulated the NF-κB signaling pathway. In addition, PARP1 was declined in UCA1 knockdown cells, and silencing of PARP1 could diminish the increasing effects of UCA1 on the chondrogenic differentiation from MSCs and signaling pathway activation. Collectively, these outcomes suggest that UCA1 could act as a mediator of PARP1 protein ubiquitination and develop the chondrogenic differentiation of MSCs.


Asunto(s)
Diferenciación Celular , Condrogénesis , Células Madre Mesenquimatosas , Poli(ADP-Ribosa) Polimerasa-1 , ARN Largo no Codificante , Ubiquitinación , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Células Madre Mesenquimatosas/metabolismo , Células Madre Mesenquimatosas/citología , Humanos , Diferenciación Celular/genética , Condrogénesis/genética , Poli(ADP-Ribosa) Polimerasa-1/metabolismo , Poli(ADP-Ribosa) Polimerasa-1/genética , Transducción de Señal , Células de la Médula Ósea/metabolismo , Células de la Médula Ósea/citología , FN-kappa B/metabolismo
12.
EMBO Rep ; 24(1): e54969, 2023 01 09.
Artículo en Inglés | MEDLINE | ID: mdl-36327141

RESUMEN

T cell activation and effector functions are determined by the affinity of the interaction between T cell receptor (TCR) and its antigenic peptide MHC (pMHC) ligand. A better understanding of the quantitative aspects of TCR-pMHC affinity-dependent T cell activation is critical for the development of new immunotherapeutic strategies. However, the role of TCR-pMHC affinity in regulating the kinetics of CD8+ T cell commitment to proliferation and differentiation is unknown. Here, we show that the stronger the TCR-pMHC affinity, the shorter the time of T cell-APC co-culture required to commit CD8+ T cells to proliferation. The time threshold for T cell cytokine production is much lower than that for cell proliferation. There is a strong correlation between affinity-dependent differences in AKT phosphorylation and T cell proliferation. The cytokine IL-15 increases the poor proliferation of T cells stimulated with low affinity pMHC, suggesting that pro-inflammatory cytokines can override the affinity-dependent features of T cell proliferation.


Asunto(s)
Linfocitos T CD8-positivos , Citocinas , Receptores de Antígenos de Linfocitos T/metabolismo , Antígenos de Histocompatibilidad/metabolismo , Activación de Linfocitos , Unión Proteica , Proliferación Celular
13.
Exp Cell Res ; 441(1): 114167, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-39004202

RESUMEN

This research aims to explore the mechanism by which microRNAs may regulate the biological behavior of tumor cells in ALDH1+ fibrosarcoma. We identified differentially expressed miRNAs in ALDH + NMFH-1 cells, screened genes related to sarcoma metastasis in the TCGA database, and finally obtained key genes regulated by miRNAs that are involved in metastasis. The function and mechanism of these key genes were then validated at the cellular level. Using the ULCAN database, a significant correlation was found between hsa-mir-206 and mortality in sarcoma patients. WGCNA analysis identified 352 genes related to tumor metastasis. Through Venn diagrams, we obtained 15 metastasis-related genes regulated by hsa-mir-206. Survival analysis showed that SYNPO2 expression is significantly correlated with survival rate and is significantly underexpressed in multiple tumors. SYNPO2 showed a negative correlation with macrophages and a positive correlation with CD8+ T cells. After inhibiting the expression of hsa-mir-206 with siRNA plasmids, the mRNA expression of SYNPO2 was significantly upregulated. The results of CCK8 assay, scratch assay, and transwell assay showed that the proliferation and migration ability of NFMH-1 cells were promoted after SYNPO2 was inhibited. ALDH1+ tumor stem cells promote the proliferation and invasion of malignant fibrous histiocytoma cells by inhibiting SYNPO2 through hsa-mir-206.


Asunto(s)
Familia de Aldehído Deshidrogenasa 1 , Movimiento Celular , Proliferación Celular , Regulación Neoplásica de la Expresión Génica , MicroARNs , Células Madre Neoplásicas , Retinal-Deshidrogenasa , MicroARNs/genética , MicroARNs/metabolismo , Humanos , Células Madre Neoplásicas/metabolismo , Células Madre Neoplásicas/patología , Familia de Aldehído Deshidrogenasa 1/genética , Familia de Aldehído Deshidrogenasa 1/metabolismo , Proliferación Celular/genética , Retinal-Deshidrogenasa/genética , Retinal-Deshidrogenasa/metabolismo , Movimiento Celular/genética , Línea Celular Tumoral , Fibrosarcoma/patología , Fibrosarcoma/genética , Fibrosarcoma/metabolismo , Progresión de la Enfermedad , Ratones , Animales
14.
Nucleic Acids Res ; 51(19): 10238-10260, 2023 10 27.
Artículo en Inglés | MEDLINE | ID: mdl-37650633

RESUMEN

Plant pathogens are challenged by host-derived iron starvation or excess during infection, but the mechanism through which pathogens counteract iron stress is unclear. Here, we found that Fusarium graminearum encounters iron excess during the colonization of wheat heads. Deletion of heme activator protein X (FgHapX), siderophore transcription factor A (FgSreA) or both attenuated virulence. Further, we found that FgHapX activates iron storage under iron excess by promoting histone H2B deubiquitination (H2B deub1) at the promoter of the responsible gene. Meanwhile, FgSreA is shown to inhibit genes mediating iron acquisition during iron excess by facilitating the deposition of histone variant H2A.Z and histone 3 lysine 27 trimethylation (H3K27 me3) at the first nucleosome after the transcription start site. In addition, the monothiol glutaredoxin FgGrx4 is responsible for iron sensing and control of the transcriptional activity of FgHapX and FgSreA via modulation of their enrichment at target genes and recruitment of epigenetic regulators, respectively. Taken together, our findings elucidated the molecular mechanisms for adaptation to iron excess mediated by FgHapX and FgSreA during infection in F. graminearum and provide novel insights into regulation of iron homeostasis at the chromatin level in eukaryotes.


Asunto(s)
Fusarium , Histonas , Hierro , Cromatina , Histonas/genética , Histonas/metabolismo , Hierro/metabolismo , Nucleosomas , Sideróforos/genética , Fusarium/metabolismo
15.
Proc Natl Acad Sci U S A ; 119(31): e2203167119, 2022 08 02.
Artículo en Inglés | MEDLINE | ID: mdl-35881786

RESUMEN

Heparan sulfate proteoglycans (HSPGs) mediate essential interactions throughout the extracellular matrix (ECM), providing signals that regulate cellular growth and development. Altered HSPG composition during tumorigenesis strongly aids cancer progression. Heparanase (HPSE) is the principal enzyme responsible for extracellular heparan sulfate catabolism and is markedly up-regulated in aggressive cancers. HPSE overactivity degrades HSPGs within the ECM, facilitating metastatic dissemination and releasing mitogens that drive cellular proliferation. Reducing extracellular HPSE activity reduces cancer growth, but few effective inhibitors are known, and none are clinically approved. Inspired by the natural glycosidase inhibitor cyclophellitol, we developed nanomolar mechanism-based, irreversible HPSE inhibitors that are effective within physiological environments. Application of cyclophellitol-derived HPSE inhibitors reduces cancer aggression in cellulo and significantly ameliorates murine metastasis. Mechanism-based irreversible HPSE inhibition is an unexplored anticancer strategy. We demonstrate the feasibility of such compounds to control pathological HPSE-driven malignancies.


Asunto(s)
Glucuronidasa , Inhibidores de Glicósido Hidrolasas , Metástasis de la Neoplasia , Animales , Proliferación Celular/efectos de los fármacos , Glucuronidasa/antagonistas & inhibidores , Inhibidores de Glicósido Hidrolasas/farmacología , Inhibidores de Glicósido Hidrolasas/uso terapéutico , Proteoglicanos de Heparán Sulfato/metabolismo , Heparitina Sulfato/metabolismo , Humanos , Ratones , Metástasis de la Neoplasia/tratamiento farmacológico
16.
Nano Lett ; 24(3): 914-919, 2024 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-38190329

RESUMEN

Magnetic topological insulators are a fertile platform for studying the interplay between magnetism and topology. The unique electronic band structure can induce exotic transport and optical properties. However, a comprehensive optical study at both near-infrared and terahertz frequencies has been lacking. Here, we report magneto-optical effects from a heterostructure of a Cr-incorporated topological insulator, CBST. By measuring the magneto-optical Kerr effect, we observe a high temperature ferromagnetic transition (160 K) in the CBST film. We also use time-domain terahertz polarimetry to reveal a terahertz Faraday rotation of 1.5 mrad and a terahertz Kerr rotation of 3.6 mrad at 2 K. The calculated terahertz Hall conductance is 0.42 e2/h. Our work shows the optical responses of an artificially layered magnetic topological insulator, paving the way toward a high-temperature quantum anomalous Hall effect via heterostructure engineering.

17.
Nano Lett ; 2024 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-39177647

RESUMEN

In this work, a self-healable, high-stability anode material for rechargeable magnesium batteries (RMBs) has been developed by introducing a core-shell structure of Ga confined by reduced graphene oxide (Ga@rGO). Via this Ga@rGO anode, a specific capacity of 150 mAh g-1 at a current of 0.5 A g-1 stable up to 1200 cycles at room temperature and a specific capacity of 100 mAh g-1 under an ultrahigh current of 1 A g-1 stable up to 700 cycles at a slightly elevated temperature of 40 °C have been achieved. Additionally, the ultrahigh rate, high-cycling stability, and long-cycle life of the anode are attributed to the stabilized structure; such a low-cost, simple, and environmentally friendly direct drop coating (DDC) method is developed to maximize the original state of the active materials. Remarkably, the self-healing ability of anodes is still presented under the ultrahigh charging current. This anode is promising for the development of high rate and high stability RMBs.

18.
Nano Lett ; 24(4): 1231-1237, 2024 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-38251914

RESUMEN

Ferroelectricity, especially the Si-compatible type recently observed in hafnia-based materials, is technologically useful for modern memory and logic applications, but it is challenging to differentiate intrinsic ferroelectric polarization from the polar phase and oxygen vacancy. Here, we report electrically controllable ferroelectricity in a Hf0.5Zr0.5O2-based heterostructure with Sr-doped LaMnO3, a mixed ionic-electronic conductor, as an electrode. Electrically reversible extraction and insertion of an oxygen vacancy into Hf0.5Zr0.5O2 are macroscopically characterized and atomically imaged in situ. Utilizing this reversible process, we achieved multilevel polarization states modulated by the electric field. Our study demonstrates the usefulness of the mixed conductor to repair, create, manipulate, and utilize advanced ferroelectric functionality. Furthermore, the programmed ferroelectric heterostructures with Si-compatible doped hafnia are desirable for the development of future ferroelectric electronics.

19.
J Infect Dis ; 2024 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-38412342

RESUMEN

BACKGROUND: Coinfection of human immunodeficiency virus type 1 (HIV-1) is the most significant risk factor for tuberculosis (TB). The immune responses of the lung are essential to restrict the growth of Mycobacterium tuberculosis and avoid the emergence of the disease. Nevertheless, there is still limited knowledge about the local immune response in people with HIV-1-TB coinfection. METHODS: We employed single-cell RNA sequencing (scRNA-seq) on bronchoalveolar lavage fluid from 9 individuals with HIV-1-TB coinfection and 10 with pulmonary TB. RESULTS: A total of 19 058 cells were grouped into 4 major cell types: myeloid cells, T/natural killer (NK) cells, B cells, and epithelial cells. The myeloid cells and T/NK cells were further divided into 10 and 11 subsets, respectively. The proportions of dendritic cell subsets, CD4+ T cells, and NK cells were lower in the HIV-1-TB coinfection group compared to the TB group, while the frequency of CD8+ T cells was higher. Additionally, we identified numerous differentially expressed genes between the CD4+ and CD8+ T-cell subsets between the 2 groups. CONCLUSIONS: HIV-1 infection not only affects the abundance of immune cells in the lungs but also alters their functions in patients with pulmonary TB.

20.
J Am Chem Soc ; 146(32): 22590-22599, 2024 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-39082835

RESUMEN

Anion exchange membrane fuel cells promise a sustainable and ecofriendly energy conversion pathway yet suffer from insufficient performance and durability. Drawing inspiration from mussel foot adhesion proteins for the first time, we herein demonstrate catechol-modified ionomers that synergistically reinforce the membrane electrode assembly interface and triple-phase boundary inside catalyst layers. The resulting ionomers present exceptional alkaline stability with only slight ionic conductivity declines after treatment in 2 M NaOH aqueous solution at 80 °C for 2500 h. Adopting catechol-modified ionomer as both anion exchange membrane and binder achieves a single-cell performance increase of 34%, and more importantly, endows fuel cell operation at a current density of 0.4 A cm-2 for over 300 h with negligible performance degradation (with a cell voltage decay rate of 0.03 mV h-1). Combining theoretical and experimental investigations, we reveal the molecular adhesion mechanism between the catechol-modified ionomer and Pt catalyst and illuminate the effect on the catalyst layer microstructure. Of fundamental interest, this bioadhesive-inspired strategy is critical to enabling knowledge-driven ionomer design and is promising for diverse membrane electrode assembly configurational applications.

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