Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 3.548
Filter
Add more filters

Publication year range
1.
Nature ; 627(8002): 149-156, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38418876

ABSTRACT

The glymphatic movement of fluid through the brain removes metabolic waste1-4. Noninvasive 40 Hz stimulation promotes 40 Hz neural activity in multiple brain regions and attenuates pathology in mouse models of Alzheimer's disease5-8. Here we show that multisensory gamma stimulation promotes the influx of cerebrospinal fluid and the efflux of interstitial fluid in the cortex of the 5XFAD mouse model of Alzheimer's disease. Influx of cerebrospinal fluid was associated with increased aquaporin-4 polarization along astrocytic endfeet and dilated meningeal lymphatic vessels. Inhibiting glymphatic clearance abolished the removal of amyloid by multisensory 40 Hz stimulation. Using chemogenetic manipulation and a genetically encoded sensor for neuropeptide signalling, we found that vasoactive intestinal peptide interneurons facilitate glymphatic clearance by regulating arterial pulsatility. Our findings establish novel mechanisms that recruit the glymphatic system to remove brain amyloid.


Subject(s)
Alzheimer Disease , Amyloid , Brain , Cerebrospinal Fluid , Extracellular Fluid , Gamma Rhythm , Glymphatic System , Animals , Mice , Alzheimer Disease/metabolism , Alzheimer Disease/pathology , Alzheimer Disease/prevention & control , Amyloid/metabolism , Aquaporin 4/metabolism , Astrocytes/metabolism , Brain/cytology , Brain/metabolism , Brain/pathology , Cerebrospinal Fluid/metabolism , Disease Models, Animal , Extracellular Fluid/metabolism , Glymphatic System/physiology , Interneurons/metabolism , Vasoactive Intestinal Peptide/metabolism , Cerebral Cortex/cytology , Cerebral Cortex/metabolism , Cerebral Cortex/pathology , Electric Stimulation
2.
Genes Dev ; 36(17-18): 1031-1042, 2022 09 01.
Article in English | MEDLINE | ID: mdl-36328355

ABSTRACT

Targeted protein degradation (TPD) has risen as a promising therapeutic modality. Leveraging the catalytic nature of the ubiquitin-proteasome enzymatic machinery, TPD exhibits higher potency to eliminate disease-causing target proteins such as oncogenic transcription factors that may otherwise be difficult to abrogate by conventional inhibitors. However, there are challenges that remain. Currently, nearly all degraders engage CUL4CRBN or CUL2VHL as the E3 ligase for target ubiquitination. While their immediate efficacies are evident, the narrowed E3 ligase options make TPD vulnerable to potential drug resistance. In addition, E3 ligases show differential tissue expression and have intrinsic limitations in accessing varying types of disease-relevant targets. As the success of TPD is closely associated with the ability of E3 ligases to efficiently polyubiquitinate the target of interest, the long-term outlook of TPD drug development will depend on whether E3 ligases such as CUL4CRBN and CUL2VHL are accessible to the targets of interest. To overcome these potential caveats, a broad collection of actionable E3 ligases is required. Here, we designed a macrocyclic degrader engaging CUL3KLHL20 for targeting BET proteins and validated CUL3KLHL20 as an E3 ligase system suitable for TPD. This work thus contributes to the expansion of usable E3 ligases for potential drug development.


Subject(s)
Adaptor Proteins, Signal Transducing , Ubiquitin-Protein Ligases , Ubiquitin-Protein Ligases/metabolism , Proteolysis , Ligands , Adaptor Proteins, Signal Transducing/metabolism , Ubiquitination
3.
Immunity ; 53(6): 1151-1167.e6, 2020 12 15.
Article in English | MEDLINE | ID: mdl-33159853

ABSTRACT

Establishment of B-lineage-specific gene expression requires the binding of transcription factors to inaccessible chromatin of progenitors. The transcription factor EBF1 can bind genomic regions prior to the detection of chromatin accessibility in a manner dependent on EBF1's C-terminal domain (CTD) and independent of cooperating transcription factors. Here, we studied the mechanism whereby the CTD enables this pioneering function. The CTD of EBF1 was dispensable for initial chromatin targeting but stabilized occupancy via recruitment of the chromatin remodeler Brg1. We found that the CTD harbors a prion-like domain (PLD) with an ability of liquid-liquid phase separation, which was enhanced by interaction of EBF1 with the RNA-binding protein FUS. Brg1 also partitioned into phase-separated FUS condensates and coincided with EBF1 and FUS foci in pro-B cells. Heterologous PLDs conferred pioneering function on EBF1ΔCTD. Thus, the phase separation ability of EBF1 facilitates Brg1-mediated chromatin opening and the transition of naive progenitor chromatin to B-lineage-committed chromatin.


Subject(s)
B-Lymphocytes/metabolism , Chromatin/metabolism , Prions/chemistry , Trans-Activators/metabolism , Amino Acid Sequence , B-Lymphocytes/cytology , DNA Helicases/metabolism , Humans , Nuclear Proteins/metabolism , Phase Transition , Precursor Cells, B-Lymphoid/cytology , Precursor Cells, B-Lymphoid/metabolism , Protein Domains , RNA-Binding Protein FUS/metabolism , RNA-Binding Proteins/metabolism , Trans-Activators/chemistry , Transcription Factors/metabolism
4.
Proc Natl Acad Sci U S A ; 121(23): e2317790121, 2024 Jun 04.
Article in English | MEDLINE | ID: mdl-38814866

ABSTRACT

The transformation of lung adenocarcinoma to small cell lung cancer (SCLC) is a recognized resistance mechanism and a hindrance to therapies using epidermal growth factor receptor tyrosine kinase inhibitors (TKIs). The paucity of pretranslational/posttranslational clinical samples limits the deeper understanding of resistance mechanisms and the exploration of effective therapeutic strategies. Here, we developed preclinical neuroendocrine (NE) transformation models. Next, we identified a transcriptional reprogramming mechanism that drives resistance to erlotinib in NE transformation cell lines and cell-derived xenograft mice. We observed the enhanced expression of genes involved in the EHMT2 and WNT/ß-catenin pathways. In addition, we demonstrated that EHMT2 increases methylation of the SFRP1 promoter region to reduce SFRP1 expression, followed by activation of the WNT/ß-catenin pathway and TKI-mediated NE transformation. Notably, the similar expression alterations of EHMT2 and SFRP1 were observed in transformed SCLC samples obtained from clinical patients. Importantly, suppression of EHMT2 with selective inhibitors restored the sensitivity of NE transformation cell lines to erlotinib and delayed resistance in cell-derived xenograft mice. We identify a transcriptional reprogramming process in NE transformation and provide a potential therapeutic target for overcoming resistance to erlotinib.


Subject(s)
Carcinoma, Non-Small-Cell Lung , Cell Transformation, Neoplastic , Erlotinib Hydrochloride , Lung Neoplasms , Humans , Animals , Lung Neoplasms/genetics , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , Lung Neoplasms/drug therapy , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/metabolism , Carcinoma, Non-Small-Cell Lung/pathology , Carcinoma, Non-Small-Cell Lung/drug therapy , Mice , Erlotinib Hydrochloride/pharmacology , Cell Line, Tumor , Cell Transformation, Neoplastic/genetics , Gene Expression Regulation, Neoplastic , Drug Resistance, Neoplasm/genetics , Wnt Signaling Pathway/genetics , Membrane Proteins/genetics , Membrane Proteins/metabolism , Protein Kinase Inhibitors/pharmacology , Xenograft Model Antitumor Assays , Small Cell Lung Carcinoma/genetics , Small Cell Lung Carcinoma/metabolism , Small Cell Lung Carcinoma/pathology , Transcription, Genetic , Histocompatibility Antigens , Histone-Lysine N-Methyltransferase
5.
J Cell Sci ; 137(8)2024 04 15.
Article in English | MEDLINE | ID: mdl-38587461

ABSTRACT

Mitochondrial fission is a tightly regulated process involving multiple proteins and cell signaling. Despite extensive studies on mitochondrial fission factors, our understanding of the regulatory mechanisms remains limited. This study shows the critical role of a mitochondrial GTPase, GTPBP8, in orchestrating mitochondrial fission in mammalian cells. Depletion of GTPBP8 resulted in drastic elongation and interconnectedness of mitochondria. Conversely, overexpression of GTPBP8 shifted mitochondrial morphology from tubular to fragmented. Notably, the induced mitochondrial fragmentation from GTPBP8 overexpression was inhibited in cells either depleted of the mitochondrial fission protein Drp1 (also known as DNM1L) or carrying mutated forms of Drp1. Importantly, downregulation of GTPBP8 caused an increase in oxidative stress, modulating cell signaling involved in the increased phosphorylation of Drp1 at Ser637. This phosphorylation hindered the recruitment of Drp1 to mitochondria, leading to mitochondrial fission defects. By contrast, GTPBP8 overexpression triggered enhanced recruitment and assembly of Drp1 at mitochondria. In summary, our study illuminates the cellular function of GTPBP8 as a pivotal modulator of the mitochondrial division apparatus, inherently reliant on its influence on Drp1.


Subject(s)
Dynamins , Microtubule-Associated Proteins , Mitochondria , Mitochondrial Dynamics , Monomeric GTP-Binding Proteins , Humans , Dynamins/metabolism , Dynamins/genetics , GTP Phosphohydrolases/metabolism , GTP Phosphohydrolases/genetics , GTP-Binding Proteins/metabolism , GTP-Binding Proteins/genetics , Microtubule-Associated Proteins/metabolism , Microtubule-Associated Proteins/genetics , Mitochondria/metabolism , Mitochondrial Dynamics/genetics , Mitochondrial Proteins/metabolism , Mitochondrial Proteins/genetics , Oxidative Stress , Phosphorylation , Monomeric GTP-Binding Proteins/genetics , Monomeric GTP-Binding Proteins/metabolism
6.
Brief Bioinform ; 25(2)2024 Jan 22.
Article in English | MEDLINE | ID: mdl-38426327

ABSTRACT

Cluster assignment is vital to analyzing single-cell RNA sequencing (scRNA-seq) data to understand high-level biological processes. Deep learning-based clustering methods have recently been widely used in scRNA-seq data analysis. However, existing deep models often overlook the interconnections and interactions among network layers, leading to the loss of structural information within the network layers. Herein, we develop a new self-supervised clustering method based on an adaptive multi-scale autoencoder, called scAMAC. The self-supervised clustering network utilizes the Multi-Scale Attention mechanism to fuse the feature information from the encoder, hidden and decoder layers of the multi-scale autoencoder, which enables the exploration of cellular correlations within the same scale and captures deep features across different scales. The self-supervised clustering network calculates the membership matrix using the fused latent features and optimizes the clustering network based on the membership matrix. scAMAC employs an adaptive feedback mechanism to supervise the parameter updates of the multi-scale autoencoder, obtaining a more effective representation of cell features. scAMAC not only enables cell clustering but also performs data reconstruction through the decoding layer. Through extensive experiments, we demonstrate that scAMAC is superior to several advanced clustering and imputation methods in both data clustering and reconstruction. In addition, scAMAC is beneficial for downstream analysis, such as cell trajectory inference. Our scAMAC model codes are freely available at https://github.com/yancy2024/scAMAC.


Subject(s)
Data Analysis , Single-Cell Gene Expression Analysis , Cluster Analysis , Sequence Analysis, RNA , Gene Expression Profiling , Algorithms
7.
PLoS Pathog ; 20(3): e1012113, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38547316

ABSTRACT

Chronic viral infections cause T cell dysfunction in both animal models and human clinical settings, thereby affecting the ability of the host immune system to clear viral pathogens and develop proper virus-specific immune memory. However, the impact of chronic viral infections on the host's immune memory to other pathogens has not been well described. In this study, we immunized mice with recombinant Listeria monocytogenes expressing OVA (Lm-OVA) to generate immunity to Lm and allow analysis of OVA-specific memory T (Tm) cells. We then infected these mice with lymphocytic choriomeningitis virus (LCMV) strain Cl-13 which establishes a chronic infection. We found that chronically infected mice were unable to protect against Listeria re-challenge. OVA-specific Tm cells showed a progressive loss in total numbers and in their ability to produce effector cytokines in the context of chronic LCMV infection. Unlike virus-specific T cells, OVA-specific Tm cells from chronically infected mice did not up-regulate the expression of inhibitory receptors, a hallmark feature of exhaustion in virus-specific T cells. Finally, OVA-specific Tm cells failed to mount a robust recall response after bacteria re-challenge both in the chronically infected and adoptively transferred naïve hosts. These results show that previously established bacteria-specific Tm cells become functionally impaired in the setting of an unrelated bystander chronic viral infection, which may contribute to poor immunity against other pathogens in the host with chronic viral infection.


Subject(s)
Lymphocytic Choriomeningitis , Virus Diseases , Humans , Animals , Mice , CD8-Positive T-Lymphocytes , Immunologic Memory , Lymphocytic choriomeningitis virus , Cytokines , Mice, Inbred C57BL
8.
J Virol ; 98(9): e0102824, 2024 Sep 17.
Article in English | MEDLINE | ID: mdl-39194247

ABSTRACT

Grass carp reovirus (GCRV) is the most virulent pathogen in the genus Aquareovirus, belonging to the family Spinareoviridae. Members of the Spinareoviridae family are known to replicate and assemble in cytoplasmic inclusion bodies termed viroplasms; however, the detailed mechanism underlying GCRV viroplasm formation and its specific roles in virus infection remains largely unknown. Here, we demonstrate that GCRV viroplasms form through liquid-liquid phase separation (LLPS) of the nonstructural protein NS80 and elucidate the specific role of LLPS during reovirus infection and immune evasion. We observe that viroplasms coalesce within the cytoplasm of GCRV-infected cells. Immunofluorescence and transmission electron microscopy indicate that GCRV viroplasms are membraneless structures. Live-cell imaging and fluorescence recovery after photobleaching assay reveal that GCRV viroplasms exhibit liquid-like properties and are highly dynamic structures undergoing fusion and fission. Furthermore, by using a reagent to inhibit the LLPS process and constructing an NS80 mutant defective in LLPS, we confirm that the liquid-like properties of viroplasms are essential for recruiting viral dsRNA, viral RdRp, and viral proteins to participate in viral genome replication and virion assembly, as well as for sequestering host antiviral factors for immune evasion. Collectively, our findings provide detailed insights into reovirus viroplasm formation and reveal the specific functions of LLPS during virus infection and immune evasion, identifying potential targets for the prevention and control of this virus. IMPORTANCE: Grass carp reovirus (GCRV) poses a significant threat to the aquaculture industry, particularly in China, where grass carp is a vital commercial fish species. However, detailed information regarding how GCRV viroplasms form and their specific roles in GCRV infection remains largely unknown. We discovered that GCRV viroplasms exhibit liquid-like properties and are formed through a physico-chemical biological phenomenon known as liquid-liquid phase separation (LLPS), primarily driven by the nonstructural protein NS80. Furthermore, we confirmed that the liquid-like properties of viroplasms are essential for virus replication, assembly, and immune evasion. Our study not only contributes to a deeper understanding of GCRV infection but also sheds light on broader aspects of viroplasm biology. Given that viroplasms are a universal feature of reovirus infection, inhibiting LLPS and then blocking viroplasms formation may serve as a potential pan-reovirus inhibition strategy.


Subject(s)
Carps , Immune Evasion , Reoviridae Infections , Reoviridae , Viral Nonstructural Proteins , Virus Replication , Reoviridae/genetics , Reoviridae/physiology , Animals , Viral Nonstructural Proteins/metabolism , Viral Nonstructural Proteins/genetics , Carps/virology , Reoviridae Infections/virology , Inclusion Bodies, Viral/metabolism , Fish Diseases/virology , Fish Diseases/immunology , Cytoplasm/virology , Cytoplasm/metabolism , Genome, Viral , Cell Line , RNA, Viral/genetics , Phase Separation
9.
Brief Bioinform ; 24(1)2023 01 19.
Article in English | MEDLINE | ID: mdl-36458451

ABSTRACT

In epistasis analysis, single-nucleotide polymorphism-single-nucleotide polymorphism interactions (SSIs) among genes may, alongside other environmental factors, influence the risk of multifactorial diseases. To identify SSI between cases and controls (i.e. binary traits), the score for model quality is affected by different objective functions (i.e. measurements) because of potential disease model preferences and disease complexities. Our previous study proposed a multiobjective approach-based multifactor dimensionality reduction (MOMDR), with the results indicating that two objective functions could enhance SSI identification with weak marginal effects. However, SSI identification using MOMDR remains a challenge because the optimal measure combination of objective functions has yet to be investigated. This study extended MOMDR to the many-objective version (i.e. many-objective MDR, MaODR) by integrating various disease probability measures based on a two-way contingency table to improve the identification of SSI between cases and controls. We introduced an objective function selection approach to determine the optimal measure combination in MaODR among 10 well-known measures. In total, 6 disease models with and 40 disease models without marginal effects were used to evaluate the general algorithms, namely those based on multifactor dimensionality reduction, MOMDR and MaODR. Our results revealed that the MaODR-based three objective function model, correct classification rate, likelihood ratio and normalized mutual information (MaODR-CLN) exhibited the higher 6.47% detection success rates (Accuracy) than MOMDR and higher 17.23% detection success rates than MDR through the application of an objective function selection approach. In a Wellcome Trust Case Control Consortium, MaODR-CLN successfully identified the significant SSIs (P < 0.001) associated with coronary artery disease. We performed a systematic analysis to identify the optimal measure combination in MaODR among 10 objective functions. Our combination detected SSIs-based binary traits with weak marginal effects and thus reduced spurious variables in the score model. MOAI is freely available at https://sites.google.com/view/maodr/home.


Subject(s)
Epistasis, Genetic , Models, Genetic , Algorithms , Phenotype , Multifactor Dimensionality Reduction/methods , Polymorphism, Single Nucleotide
10.
Bioinformatics ; 40(9)2024 Sep 02.
Article in English | MEDLINE | ID: mdl-39213324

ABSTRACT

SUMMARY: The burgeoning high-throughput technologies have led to a significant surge in the scale of pharmacotranscriptomic datasets, especially for oncology. Signature search methods (SSMs), utilizing oncogenic signatures formed by differentially expressed genes through sequencing, have been instrumental in anti-cancer drug screening and identifying mechanisms of action without relying on prior knowledge. However, various studies have found that different SSMs exhibit varying performance across pharmacotranscriptomic datasets. In addition, the size of the oncogenic signature can also significantly impact the result of drug repurposing. Therefore, finding the optimal SSMs and customized oncogenic signature for a specific disease remains a challenge. To address this, we introduce Signature Search Polestar (SSP), a webserver integrating the largest pharmacotranscriptomic datasets of anti-cancer drugs from LINCS L1000 with five state-of-the-art SSMs (XSum, CMap, GSEA, ZhangScore, XCos). SSP provides three main modules: Benchmark, Robustness, and Application. Benchmark uses two indices, Area Under the Curve and Enrichment Score, based on drug annotations to evaluate SSMs at different oncogenic signature sizes. Robustness, applicable when drug annotations are insufficient, uses a performance score based on drug self-retrieval for evaluation. Application provides three screening strategies, single method, SS_all, and SS_cross, allowing users to freely utilize optimal SSMs with tailored oncogenic signature for drug repurposing. AVAILABILITY AND IMPLEMENTATION: SSP is free at https://web.biotcm.net/SSP/. The current version of SSP is archived in https://doi.org/10.6084/m9.figshare.26524741.v1, allowing users to directly use or customize their own SSP webserver.


Subject(s)
Antineoplastic Agents , Drug Repositioning , Software , Drug Repositioning/methods , Humans , Antineoplastic Agents/pharmacology , Neoplasms/drug therapy , Neoplasms/genetics , Computational Biology/methods
11.
Bioinformatics ; 40(9)2024 Sep 02.
Article in English | MEDLINE | ID: mdl-39222004

ABSTRACT

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.


Subject(s)
Natural Language Processing , Humans , Software , Computational Biology/methods
12.
Plant Physiol ; 195(1): 395-409, 2024 Apr 30.
Article in English | MEDLINE | ID: mdl-38198215

ABSTRACT

Dwarfism is an important agronomic trait in fruit breeding programs. However, the germplasm resources required to generate dwarf pear (Pyrus spp.) varieties are limited. Moreover, the mechanisms underlying dwarfism remain unclear. In this study, "Yunnan" quince (Cydonia oblonga Mill.) had a dwarfing effect on "Zaosu" pear. Additionally, the dwarfism-related NAC transcription factor gene PbNAC71 was isolated from pear trees comprising "Zaosu" (scion) grafted onto "Yunnan" quince (rootstock). Transgenic Nicotiana benthamiana and pear OHF-333 (Pyrus communis) plants overexpressing PbNAC71 exhibited dwarfism, with a substantially smaller xylem and vessel area relative to the wild-type controls. Yeast one-hybrid, dual-luciferase, chromatin immunoprecipitation-qPCR, and electrophoretic mobility shift assays indicated that PbNAC71 downregulates PbWalls are thin 1 expression by binding to NAC-binding elements in its promoter. Yeast two-hybrid assays showed that PbNAC71 interacts with the E3 ubiquitin ligase PbRING finger protein 217 (PbRNF217). Furthermore, PbRNF217 promotes the ubiquitin-mediated degradation of PbNAC71 by the 26S proteasome, thereby regulating plant height as well as xylem and vessel development. Our findings reveal a mechanism underlying pear dwarfism and expand our understanding of the molecular basis of dwarfism in woody plants.


Subject(s)
Gene Expression Regulation, Plant , Plant Proteins , Plants, Genetically Modified , Pyrus , Transcription Factors , Xylem , Xylem/metabolism , Xylem/genetics , Pyrus/genetics , Pyrus/metabolism , Pyrus/growth & development , Transcription Factors/metabolism , Transcription Factors/genetics , Plant Proteins/genetics , Plant Proteins/metabolism , Nicotiana/genetics , Nicotiana/metabolism , Nicotiana/growth & development , Promoter Regions, Genetic/genetics , Proteasome Endopeptidase Complex/metabolism , Proteasome Endopeptidase Complex/genetics
13.
J Pathol ; 262(2): 240-253, 2024 02.
Article in English | MEDLINE | ID: mdl-38018407

ABSTRACT

Preterm labor/birth is the leading cause of perinatal mortality and morbidity worldwide. Previous studies demonstrated that T cells were crucial for maintaining maternal-fetal immune tolerance during the first trimester of pregnancy; however, their phenotypes and functions in labor and delivery remain largely unknown. We recruited three cohorts of women at delivery for T-cell immunophenotyping in the placentas, fetal membranes, umbilical cord blood, and maternal peripheral blood. Our data showed a differential enrichment of T cells during the third trimester of human pregnancy, with CD4+ T cells being more observable within the umbilical cord blood, whereas CD8+ T cells became relatively more abundant in fetal membranes. CD4+ and CD8+ T cells derived from fetal membranes were dominated by effector memory T cells and exhibited extensive expression of activation markers but decreased expression of homing receptor. In comparison with term births, fetal membrane CD8+ T cells, especially the central memory subset, were significantly increased in frequency and showed more profound activation in spontaneous preterm birth patients. Finally, using an allogeneic mouse model, we found that T-cell-activation-induced preterm birth could be alleviated by the depletion of CD8+ T but not CD4+ T cells in vivo. Collectively, we showed that CD8+ T cells in fetal membranes displayed a unique phenotype, and their activation was involved in the pathophysiology of spontaneous preterm birth, which provides novel insights into the immune mechanisms of preterm birth and potential targets for the prevention of this syndrome. © 2023 The Pathological Society of Great Britain and Ireland.


Subject(s)
Obstetric Labor, Premature , Premature Birth , Pregnancy , Animals , Mice , Humans , Female , Infant, Newborn , Premature Birth/chemically induced , Premature Birth/prevention & control , CD8-Positive T-Lymphocytes , Extraembryonic Membranes , Phenotype
14.
Proc Natl Acad Sci U S A ; 119(52): e2207543119, 2022 Dec 27.
Article in English | MEDLINE | ID: mdl-36538481

ABSTRACT

Phonon lasers, as the counterpart of photonic lasers, have been intensively studied in a large variety of systems; however, (all) most of them are based on the directly coherent pumping. Intuitively, dissipation is unfavorable for lasing. Here, we experimentally demonstrate a mechanism of generating phonon lasing from the dissipative coupling in a multimode optomechanical system. By precisely engineering the dissipations of two membranes and tuning the intensity modulation of the cavity light, the two-membrane-in-the-middle system exhibits non-Hermitian characteristics and the cavity-mediated interaction between two nanomechanical resonators becomes purely dissipative. The level attraction and damping repulsion are clearly exhibited as the signature of dissipative coupling. After the exceptional point, a non-Hermitian phase transition, where eigenvalues and the corresponding eigenmodes coalesce, two phonon modes are simultaneously excited into the self-sustained oscillation regime by increasing the interaction strength over a critical value (threshold). In distinct contrast to conventional phonon lasers, the measurement of the second-order phonon correlation reveals the oscillatory and biexponential phases in the nonlasing regime as well as the coherence phase in the lasing regime. Our study provides a method to study phonon lasers in a non-Hermitian open system and could be applied to a wide range of disciplines, including optics, acoustics, and quantum many-body physics.

15.
Proc Natl Acad Sci U S A ; 119(31): e2201607119, 2022 08 02.
Article in English | MEDLINE | ID: mdl-35878043

ABSTRACT

Nonradical Fenton-like catalysis offers opportunities to overcome the low efficiency and secondary pollution limitations of existing advanced oxidation decontamination technologies, but realizing this on transition metal spinel oxide catalysts remains challenging due to insufficient understanding of their catalytic mechanisms. Here, we explore the origins of catalytic selectivity of Fe-Mn spinel oxide and identify electron delocalization of the surface metal active site as the key driver of its nonradical catalysis. Through fine-tuning the crystal geometry to trigger Fe-Mn superexchange interaction at the spinel octahedra, ZnFeMnO4 with high-degree electron delocalization of the Mn-O unit was created to enable near 100% nonradical activation of peroxymonosulfate (PMS) at unprecedented utilization efficiency. The resulting surface-bound PMS* complex can efficiently oxidize electron-rich pollutants with extraordinary degradation activity, selectivity, and good environmental robustness to favor water decontamination applications. Our work provides a molecule-level understanding of the catalytic selectivity and bimetallic interactions of Fe-Mn spinel oxides, which may guide the design of low-cost spinel oxides for more selective and efficient decontamination applications.


Subject(s)
Electrons , Oxides , Catalysis , Magnesium Oxide/chemistry , Oxides/chemistry , Peroxides/chemistry
16.
Nano Lett ; 24(22): 6568-6575, 2024 Jun 05.
Article in English | MEDLINE | ID: mdl-38787693

ABSTRACT

Zero-dimensional metal halides have received wide attention due to their structural diversity, strong quantum confinement, and associated excellent photoluminescence properties. A reversible and tunable luminescence would be desirable for applications such as anti-counterfeiting, information encryption, and artificial intelligence. Yet, these materials are underexplored, with little known about their luminescence tuning mechanisms. Here we report a pyramidal coplanar dimer, (TBA)Sb2Cl7 (TBA = tetrabutylammonium), showing broadband emission wavelength tuning (585-650 nm) by simple thermal treatment. We attribute the broad color change to structural disorder induced by varying the heat treatment temperatures. Increasing the heating temperature transitions the material from long-range ordered crystalline phase to highly disordered glassy phase. The latter exhibits stronger electron-phonon coupling, enhancing the self-trapped exciton emission efficiency. The work provides a new material platform for manifold optical anti-counterfeiting applications and sheds light on the emission color tuning mechanisms for further design of stimuli-responsive materials.

17.
Nano Lett ; 24(19): 5904-5912, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38700588

ABSTRACT

Stretchable electroluminescent devices represent an emerging optoelectronic technology for future wearables. However, their typical construction on sub-millimeter-thick elastomers has limited moisture permeability, leading to discomfort during long-term skin attachment. Although breathable textile displays may partially address this issue, they often have distinct visual appearances with discrete emissions from fibers or fiber junctions. This study introduces a convenient procedure to create stretchable, permeable displays with continuous luminous patterns. The design utilizes ultrathin nanocomposite devices embedded in a porous elastomeric microfoam to achieve high moisture permeability. These displays also exhibit excellent deformability, low-voltage operation, and excellent durability. Additionally, the device is decorated with fluorinated silica nanoparticles to achieve self-cleaning and washable capabilities. The practical implementation of these nanocomposite devices is demonstrated by creating an epidermal counter display that allows intimate integration with the human body. These developments provide an effective design of stretchable and breathable displays for comfortable wearing.

18.
Nano Lett ; 24(35): 11036-11042, 2024 Sep 04.
Article in English | MEDLINE | ID: mdl-39185718

ABSTRACT

The phase-shifting structured light illumination technique is widely used in imaging but often relies on mechanical translation stages or spatial light modulators, leading to system instability, low displacement accuracy, and limited integration feasibility. In response to these challenges, we propose and demonstrate an approach for generating far-field phase-shifting structured light using a polarization multiplexing metasurface. By controlling the polarization states of incident and transmitted light, the metasurface creates a three-step displacement of structured light, eliminating the need to move samples or illumination sources. As a proof of concept, we experimentally demonstrate microscopic imaging using structured light illumination generated by metasurfaces, extracting high-frequency information from objects, and surpassing the diffraction limit. The proposed metasurface platform offers a promising approach for developing compact and robust phase-shifting imaging systems, with broad prospects in quantitative detection, machine vision, and beyond.

19.
Nano Lett ; 24(6): 2094-2101, 2024 Feb 14.
Article in English | MEDLINE | ID: mdl-38315573

ABSTRACT

Prelithiation plays a crucial role in advancing the development of high-energy-density batteries, and ultrathin lithium (UTL) has been proven to be a promising anode prelithiation reagent. However, there remains a need to explore an adjustable, efficient, and cost-effective method for manufacturing UTL. In this study, we introduce a method for producing UTL with adjustable thicknesses ranging from 1.5 to 10 µm through blade coating of molten lithium on poly(vinylidene fluoride)-modified copper current collectors. By employing the transfer-printing method, prelithiated graphite and Si-C composite electrodes are prepared, which exhibit significantly improved initial Coulombic efficiencies of 99.60% and 99.32% in half-cells, respectively. Moreover, the energy densities of Li(NiCoMn)1/3O2 and LiFePO4 full cells assembled with the prelithiated graphite electrodes increase by 13.1% and 23.6%, respectively.

20.
Neuroimage ; 299: 120810, 2024 Oct 01.
Article in English | MEDLINE | ID: mdl-39181193

ABSTRACT

OBJECTIVE: We aim to investigate the interplay between mentalization, brain microstructure, and psychological resilience as potential protective factors against mental illness. METHOD: Four hundred and twenty-six participants (mean age 40.12±16.95; 202 males, 224 females), without psychiatric or neurological history, completed assessments: Dissociative Process Scale (DPS), Peace of Mind (PoM), Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), Resilience Scale for Adults (RSA), and Magnetic Resonance Imaging (MRI) structures with selected regions of interest, and Diffusion Tensor Imaging (DTI) maps from various tracts in the right hemisphere and connection to the frontal areas, including anterior thalamic radiation (ATR), Cingulum (hippocampus) (CH), Corticospinal tract (CST), Superior longitudinal fasciculus (SLF), Inferior fronto-occipital fasciculus (IFOF), and Uncinate fasciculus (UF) were analyzed. RESULTS: Two clusters, representing hypomentalization (HypoM) and hypermentalization (HyperM), were identified based on DPS, CPSS, and RFQ responses. One-way ANOVA showed no significant age or gender differences between clusters. The HypoM group exhibited lower PoM scores, higher BDI and BAI scores, and lower RSA scores (ps< 0.05). Structural brain metric comparison showed significant differences in GMV in the right caudal middle frontal gyrus (rcMFG), right superior frontal gyrus (rsFG), and right frontal pole (rFP) between groups. In addition, the HyperM individuals with a higher risk of depression and a higher ratio of intrapersonal to interpersonal factors of resilience were found with reduced GMV on the rcMFG. Additionally, analyses of DTI metrics revealed significant differences between two groups in rATR and rSLF in terms of fractional anisotropy (FA) values; rATR, rCST, rUF, rSLF, rCH and rIFOF in terms of mean diffusivity (MD) values, and radial diffusivity (RD) (corrected p = 0.05). Moreover, the positive correlation between different domains of resilience and white matter (WM) integrity implied further enhancement of intrapersonal or interpersonal resilience factors that are different for people with different mentalization. CONCLUSIONS: The findings underscore the importance of considering both intrapersonal and interpersonal factors in understanding the interactions between psychological resilience and mental health conditions relevant to brain mechanisms.


Subject(s)
Diffusion Tensor Imaging , Resilience, Psychological , Humans , Male , Female , Adult , Middle Aged , Young Adult , Brain/diagnostic imaging , Magnetic Resonance Imaging , White Matter/diagnostic imaging , Mental Disorders/diagnostic imaging , Mental Disorders/psychology
SELECTION OF CITATIONS
SEARCH DETAIL