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1.
Cell ; 187(5): 1255-1277.e27, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38359819

RESUMO

Despite the successes of immunotherapy in cancer treatment over recent decades, less than <10%-20% cancer cases have demonstrated durable responses from immune checkpoint blockade. To enhance the efficacy of immunotherapies, combination therapies suppressing multiple immune evasion mechanisms are increasingly contemplated. To better understand immune cell surveillance and diverse immune evasion responses in tumor tissues, we comprehensively characterized the immune landscape of more than 1,000 tumors across ten different cancers using CPTAC pan-cancer proteogenomic data. We identified seven distinct immune subtypes based on integrative learning of cell type compositions and pathway activities. We then thoroughly categorized unique genomic, epigenetic, transcriptomic, and proteomic changes associated with each subtype. Further leveraging the deep phosphoproteomic data, we studied kinase activities in different immune subtypes, which revealed potential subtype-specific therapeutic targets. Insights from this work will facilitate the development of future immunotherapy strategies and enhance precision targeting with existing agents.


Assuntos
Neoplasias , Proteogenômica , Humanos , Terapia Combinada , Genômica , Neoplasias/genética , Neoplasias/imunologia , Neoplasias/terapia , Proteômica , Evasão Tumoral
2.
Cell ; 182(1): 245-261.e17, 2020 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-32649877

RESUMO

Genomic studies of lung adenocarcinoma (LUAD) have advanced our understanding of the disease's biology and accelerated targeted therapy. However, the proteomic characteristics of LUAD remain poorly understood. We carried out a comprehensive proteomics analysis of 103 cases of LUAD in Chinese patients. Integrative analysis of proteome, phosphoproteome, transcriptome, and whole-exome sequencing data revealed cancer-associated characteristics, such as tumor-associated protein variants, distinct proteomics features, and clinical outcomes in patients at an early stage or with EGFR and TP53 mutations. Proteome-based stratification of LUAD revealed three subtypes (S-I, S-II, and S-III) related to different clinical and molecular features. Further, we nominated potential drug targets and validated the plasma protein level of HSP 90ß as a potential prognostic biomarker for LUAD in an independent cohort. Our integrative proteomics analysis enables a more comprehensive understanding of the molecular landscape of LUAD and offers an opportunity for more precise diagnosis and treatment.


Assuntos
Adenocarcinoma de Pulmão/metabolismo , Neoplasias Pulmonares/metabolismo , Proteômica , Adenocarcinoma de Pulmão/genética , Povo Asiático/genética , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Sistemas de Liberação de Medicamentos , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Pulmonares/genética , Masculino , Pessoa de Meia-Idade , Mutação/genética , Estadiamento de Neoplasias , Fosfoproteínas/metabolismo , Análise de Componente Principal , Prognóstico , Proteoma/metabolismo , Resultado do Tratamento , Proteína Supressora de Tumor p53/genética
3.
Cell ; 183(7): 1962-1985.e31, 2020 12 23.
Artigo em Inglês | MEDLINE | ID: mdl-33242424

RESUMO

We report a comprehensive proteogenomics analysis, including whole-genome sequencing, RNA sequencing, and proteomics and phosphoproteomics profiling, of 218 tumors across 7 histological types of childhood brain cancer: low-grade glioma (n = 93), ependymoma (32), high-grade glioma (25), medulloblastoma (22), ganglioglioma (18), craniopharyngioma (16), and atypical teratoid rhabdoid tumor (12). Proteomics data identify common biological themes that span histological boundaries, suggesting that treatments used for one histological type may be applied effectively to other tumors sharing similar proteomics features. Immune landscape characterization reveals diverse tumor microenvironments across and within diagnoses. Proteomics data further reveal functional effects of somatic mutations and copy number variations (CNVs) not evident in transcriptomics data. Kinase-substrate association and co-expression network analysis identify important biological mechanisms of tumorigenesis. This is the first large-scale proteogenomics analysis across traditional histological boundaries to uncover foundational pediatric brain tumor biology and inform rational treatment selection.


Assuntos
Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Proteogenômica , Neoplasias Encefálicas/imunologia , Criança , Variações do Número de Cópias de DNA/genética , Regulação Neoplásica da Expressão Gênica , Redes Reguladoras de Genes , Genoma Humano , Glioma/genética , Glioma/patologia , Humanos , Linfócitos do Interstício Tumoral/imunologia , Mutação/genética , Gradação de Tumores , Recidiva Local de Neoplasia/patologia , Fosfoproteínas/metabolismo , Fosforilação , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transcriptoma/genética
4.
Mol Cell ; 83(11): 1887-1902.e8, 2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-37244254

RESUMO

Interleukin-1ß (IL-1ß) is a key protein in inflammation and contributes to tumor progression. However, the role of IL-1ß in cancer is ambiguous or even contradictory. Here, we found that upon IL-1ß stimulation, nicotinamide nucleotide transhydrogenase (NNT) in cancer cells is acetylated at lysine (K) 1042 (NNT K1042ac) and thereby induces the mitochondrial translocation of p300/CBP-associated factor (PCAF). This acetylation enhances NNT activity by increasing the binding affinity of NNT for NADP+ and therefore boosts NADPH production, which subsequently sustains sufficient iron-sulfur cluster maintenance and protects tumor cells from ferroptosis. Abrogating NNT K1042ac dramatically attenuates IL-1ß-promoted tumor immune evasion and synergizes with PD-1 blockade. In addition, NNT K1042ac is associated with IL-1ß expression and the prognosis of human gastric cancer. Our findings demonstrate a mechanism of IL-1ß-promoted tumor immune evasion, implicating the therapeutic potential of disrupting the link between IL-1ß and tumor cells by inhibiting NNT acetylation.


Assuntos
NADP Trans-Hidrogenases , Neoplasias , Humanos , NADP Trans-Hidrogenases/genética , NADP Trans-Hidrogenases/metabolismo , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Acetilação , Processamento de Proteína Pós-Traducional , Imunoterapia , Neoplasias/tratamento farmacológico , Neoplasias/genética
5.
Nature ; 625(7994): 312-320, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38200293

RESUMO

The Holocene (beginning around 12,000 years ago) encompassed some of the most significant changes in human evolution, with far-reaching consequences for the dietary, physical and mental health of present-day populations. Using a dataset of more than 1,600 imputed ancient genomes1, we modelled the selection landscape during the transition from hunting and gathering, to farming and pastoralism across West Eurasia. We identify key selection signals related to metabolism, including that selection at the FADS cluster began earlier than previously reported and that selection near the LCT locus predates the emergence of the lactase persistence allele by thousands of years. We also find strong selection in the HLA region, possibly due to increased exposure to pathogens during the Bronze Age. Using ancient individuals to infer local ancestry tracts in over 400,000 samples from the UK Biobank, we identify widespread differences in the distribution of Mesolithic, Neolithic and Bronze Age ancestries across Eurasia. By calculating ancestry-specific polygenic risk scores, we show that height differences between Northern and Southern Europe are associated with differential Steppe ancestry, rather than selection, and that risk alleles for mood-related phenotypes are enriched for Neolithic farmer ancestry, whereas risk alleles for diabetes and Alzheimer's disease are enriched for Western hunter-gatherer ancestry. Our results indicate that ancient selection and migration were large contributors to the distribution of phenotypic diversity in present-day Europeans.


Assuntos
Asiático , População Europeia , Genoma Humano , Seleção Genética , Humanos , Afeto , Agricultura/história , Alelos , Doença de Alzheimer/genética , Ásia/etnologia , Asiático/genética , Diabetes Mellitus/genética , Europa (Continente)/etnologia , População Europeia/genética , Fazendeiros/história , Loci Gênicos/genética , Predisposição Genética para Doença , Genoma Humano/genética , História Antiga , Migração Humana , Caça/história , Família Multigênica/genética , Fenótipo , Biobanco do Reino Unido , Herança Multifatorial/genética
6.
Nature ; 617(7962): 738-742, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37100919

RESUMO

Cities are generally warmer than their adjacent rural land, a phenomenon known as the urban heat island (UHI). Often accompanying the UHI effect is another phenomenon called the urban dry island (UDI), whereby the humidity of urban land is lower than that of the surrounding rural land1-3. The UHI exacerbates heat stress on urban residents4,5, whereas the UDI may instead provide relief because the human body can cope with hot conditions better at lower humidity through perspiration6,7. The relative balance between the UHI and the UDI-as measured by changes in the wet-bulb temperature (Tw)-is a key yet largely unknown determinant of human heat stress in urban climates. Here we show that Tw is reduced in cities in dry and moderately wet climates, where the UDI more than offsets the UHI, but increased in wet climates (summer precipitation of more than 570 millimetres). Our results arise from analysis of urban and rural weather station data across the world and calculations with an urban climate model. In wet climates, the urban daytime Tw is 0.17 ± 0.14 degrees Celsius (mean ± 1 standard deviation) higher than rural Tw in the summer, primarily because of a weaker dynamic mixing in urban air. This Tw increment is small, but because of the high background Tw in wet climates, it is enough to cause two to six extra dangerous heat-stress days per summer for urban residents under current climate conditions. The risk of extreme humid heat is projected to increase in the future, and these urban effects may further amplify the risk.


Assuntos
Cidades , Clima , Transtornos de Estresse por Calor , Temperatura Alta , Umidade , Chuva , Humanos , Cidades/epidemiologia , Temperatura Alta/efeitos adversos , Tempo (Meteorologia) , Umidade/efeitos adversos , Fatores de Risco , Transtornos de Estresse por Calor/epidemiologia , Transtornos de Estresse por Calor/etiologia , Transtornos de Estresse por Calor/prevenção & controle , População Rural , Modelos Climáticos , População Urbana , Estações do Ano
7.
Nature ; 622(7982): 292-300, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37704731

RESUMO

The past decades have witnessed the evolution of electronic and photonic integrated circuits, from application specific to programmable1,2. Although liquid-phase DNA circuitry holds the potential for massive parallelism in the encoding and execution of algorithms3,4, the development of general-purpose DNA integrated circuits (DICs) has yet to be explored. Here we demonstrate a DIC system by integration of multilayer DNA-based programmable gate arrays (DPGAs). We find that the use of generic single-stranded oligonucleotides as a uniform transmission signal can reliably integrate large-scale DICs with minimal leakage and high fidelity for general-purpose computing. Reconfiguration of a single DPGA with 24 addressable dual-rail gates can be programmed with wiring instructions to implement over 100 billion distinct circuits. Furthermore, to control the intrinsically random collision of molecules, we designed DNA origami registers to provide the directionality for asynchronous execution of cascaded DPGAs. We exemplify this by a quadratic equation-solving DIC assembled with three layers of cascade DPGAs comprising 30 logic gates with around 500 DNA strands. We further show that integration of a DPGA with an analog-to-digital converter can classify disease-related microRNAs. The ability to integrate large-scale DPGA networks without apparent signal attenuation marks a key step towards general-purpose DNA computing.


Assuntos
Computadores Moleculares , DNA , Algoritmos , DNA/química , Oligonucleotídeos/química , MicroRNAs/classificação , Doença/genética
8.
Nature ; 617(7960): 417-425, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37138078

RESUMO

The κ-opioid receptor (KOR) represents a highly desirable therapeutic target for treating not only pain but also addiction and affective disorders1. However, the development of KOR analgesics has been hindered by the associated hallucinogenic side effects2. The initiation of KOR signalling requires the Gi/o-family proteins including the conventional (Gi1, Gi2, Gi3, GoA and GoB) and nonconventional (Gz and Gg) subtypes. How hallucinogens exert their actions through KOR and how KOR determines G-protein subtype selectivity are not well understood. Here we determined the active-state structures of KOR in a complex with multiple G-protein heterotrimers-Gi1, GoA, Gz and Gg-using cryo-electron microscopy. The KOR-G-protein complexes are bound to hallucinogenic salvinorins or highly selective KOR agonists. Comparisons of these structures reveal molecular determinants critical for KOR-G-protein interactions as well as key elements governing Gi/o-family subtype selectivity and KOR ligand selectivity. Furthermore, the four G-protein subtypes display an intrinsically different binding affinity and allosteric activity on agonist binding at KOR. These results provide insights into the actions of opioids and G-protein-coupling specificity at KOR and establish a foundation to examine the therapeutic potential of pathway-selective agonists of KOR.


Assuntos
Microscopia Crioeletrônica , Proteínas Heterotriméricas de Ligação ao GTP , Ligantes , Receptores Opioides kappa , Analgésicos Opioides/metabolismo , Analgésicos Opioides/farmacologia , Receptores Opioides kappa/química , Receptores Opioides kappa/metabolismo , Receptores Opioides kappa/ultraestrutura , Transdução de Sinais , Proteínas Heterotriméricas de Ligação ao GTP/química , Proteínas Heterotriméricas de Ligação ao GTP/metabolismo , Proteínas Heterotriméricas de Ligação ao GTP/ultraestrutura , Especificidade por Substrato , Regulação Alostérica/efeitos dos fármacos , Alucinógenos/metabolismo , Alucinógenos/farmacologia
9.
Plant Cell ; 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38917246

RESUMO

Although the strigolactone (SL) signaling pathway and SL-mediated anthocyanin biosynthesis have been reported, the molecular association between SL signaling and anthocyanin biosynthesis remains unclear. In this study, we identified the SL signal transduction pathway associated with anthocyanin biosynthesis and the crosstalk between gibberellin (GA) and SL signaling in apple (Malus × domestica). ELONGATED HYPOCOTYL5 (HY5) acts as a key node integrating SL signaling and anthocyanin biosynthesis, and the SL response factor AGAMOUS-LIKE MADS-BOX9 (AGL9) promotes anthocyanin biosynthesis by activating HY5 transcription. The SL signaling repressor SUPPRESSOR OF MAX2 1-LIKE8 (SMXL8) interacts with AGL9 to form a complex that inhibits anthocyanin biosynthesis by downregulating HY5 expression. Moreover, the E3 ubiquitin ligase PROTEOLYSIS1 (PRT1) mediates the ubiquitination-mediated degradation of SMXL8, which is a key part of the SL signal transduction pathway associated with anthocyanin biosynthesis. In addition, the GA signaling repressor REPRESSOR-of-ga1-3-LIKE2a (RGL2a) mediates the crosstalk between GA and SL by disrupting the SMXL8-AGL9 interaction that represses HY5 transcription. Taken together, our study reveals the regulatory mechanism of SL-mediated anthocyanin biosynthesis and uncovers the role of SL-GA crosstalk in regulating anthocyanin biosynthesis in apple.

10.
Proc Natl Acad Sci U S A ; 120(8): e2218405120, 2023 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-36787368

RESUMO

Most metals adopt simple structures such as body-centered cubic (BCC), face-centered cubic (FCC), and hexagonal close-packed (HCP) structures in specific groupings across the periodic table, and many undergo transitions to surprisingly complex structures on compression, not expected from conventional free-electron-based theories of metals. First-principles calculations have been able to reproduce many observed structures and transitions, but a unified, predictive theory that underlies this behavior is not yet in hand. Discovered by analyzing the electronic properties of metals in various lattices over a broad range of sizes and geometries, a remarkably simple theory shows that the stability of metal structures is governed by electrons occupying local interstitial orbitals and their strong chemical interactions. The theory provides a basis for understanding and predicting structures in solid compounds and alloys over a broad range of conditions.

11.
Proc Natl Acad Sci U S A ; 120(9): e2215192120, 2023 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-36802440

RESUMO

Numerous studies have investigated the impacts of common types of chronic pain (CP) on patients' cognitive function and observed that CP was associated with later dementia. More recently, there is a growing recognition that CP conditions frequently coexist at multiple body sites and may bring more burdens on patients' overall health. However, whether and how multisite CP (MCP) contributes to an increased risk of dementia, compared to single-site CP (SCP) and pain-free (PF), is largely unclear. In the current study, utilizing the UK Biobank cohort, we first investigated dementia risk in individuals (n = 354,943) with different numbers of coexisting CP sites using Cox proportional hazards regression models. We then applied generalized additive models to investigate whether MCP leads to excessive deterioration of participants' (n = 19,116) cognition and brain structure. We found that individuals with MCP were associated with significantly higher dementia risk, broader and faster cognitive impairment, and greater hippocampal atrophy than both PF individuals and those with SCP. Moreover, the detrimental effects of MCP on dementia risk and hippocampal volume aggravated along with the number of coexisting CP sites. Mediation analyses further revealed that the decline of fluid intelligence in MCP individuals was partially mediated by hippocampal atrophy. Our results suggested that cognitive decline and hippocampal atrophy interact biologically and may underlie the increased risk of dementia associated with MCP.


Assuntos
Dor Crônica , Disfunção Cognitiva , Demência , Doenças Neurodegenerativas , Humanos , Dor Crônica/patologia , Imageamento por Ressonância Magnética , Disfunção Cognitiva/patologia , Doenças Neurodegenerativas/patologia , Hipocampo/patologia , Demência/epidemiologia , Demência/etiologia , Demência/patologia , Atrofia/patologia
12.
FASEB J ; 38(1): e23354, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38085162

RESUMO

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common malignancy worldwide, and the development of novel therapeutic strategies for HNSCC requires a profound understanding of tumor cells and the tumor microenvironment (TME). Additionally, HNSCC has a poor prognosis, necessitating the use of genetic markers for predicting clinical outcomes in HNSCC. In this study, we performed single-cell sequencing analysis on tumor tissues from seven HNSCC patients, along with one adjacent normal tissue. Firstly, the analysis of epithelial cell clusters revealed two clusters of malignant epithelial cells, characterized by unique gene expression patterns and dysregulated signaling pathways compared to normal epithelial cells. Secondly, the examination of the TME unveiled extensive crosstalk between fibroblasts and malignant epithelial cells, potentially mediated through ligand-receptor interactions such as COL1A1-SDC1, COL1A1-CD44, and COL1A2-SDC1. Furthermore, transcriptional heterogeneity was observed in immune cells present in the TME, including macrophages and dendritic cells. Finally, leveraging the gene expression profiles of malignant epithelial cells, we developed a prognostic model comprising six genes, which we validated using two independent datasets. These findings shed light on the heterogeneity within HNSCC tumors and the intricate interplay between malignant cells and the TME. Importantly, the developed prognostic model demonstrates high efficacy in predicting the survival outcomes of HNSCC patients.


Assuntos
Carcinoma , Neoplasias de Cabeça e Pescoço , Humanos , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Prognóstico , Neoplasias de Cabeça e Pescoço/genética , Células Epiteliais , Microambiente Tumoral/genética
13.
J Immunol ; 211(10): 1516-1525, 2023 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-37819772

RESUMO

Notopterol, an active component isolated from the traditional Chinese medicine Notopterygium incisum Ting ex H.T. Chang, exerts anti-inflammatory activity in rheumatoid arthritis. However, its roles in suppression of inflammatory insults and halting progression of tissue destruction in periodontitis remain elusive. In this study, we reveal that notopterol can inhibit osteoclastogenesis, thereby limiting alveolar bone loss in vivo. In vitro results demonstrated that notopterol administration inhibited synthesis of inflammatory mediators such as IL-1ß, IL-32, and IL-8 in LPS-stimulated human gingival fibroblasts. Mechanistically, notopterol inhibits activation of the NF-κB signaling pathway, which is considered a prototypical proinflammatory signaling pathway. RNA sequencing data revealed that notopterol activates the PI3K/protein kinase B (Akt)/NF-E2-related factor 2 (Nrf2) signaling pathway in LPS-stimulated human gingival fibroblasts, a phenomenon validated via Western blot assay. Additionally, notopterol treatment suppressed reactive oxygen species levels by upregulating the expression of antioxidant genes, including heme oxygenase 1 (HO-1), NAD(P)H quinone oxidoreductase 1 (NQO1), catalase (CAT), and glutathione reductase (GSR), indicating that notopterol confers protection against oxidative stress. Notably, inhibition of Akt activity by the potent inhibitor, MK-2206, partially attenuated both anti-inflammatory and antioxidant effects of notopterol. Collectively, these results raise the possibility that notopterol relieves periodontal inflammation by suppressing and activating the NF-κB and PI3K/AKT/Nrf2 signaling pathways in periodontal tissue, respectively, suggesting its potential as an efficacious treatment therapy for periodontitis.


Assuntos
NF-kappa B , Periodontite , Humanos , NF-kappa B/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Lipopolissacarídeos/farmacologia , Anti-Inflamatórios/farmacologia , Antioxidantes , Heme Oxigenase-1/metabolismo
14.
Mol Cell Proteomics ; 22(9): 100621, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37478973

RESUMO

Targeted mass spectrometry (MS)-based proteomic assays, such as multiplexed multiple reaction monitoring (MRM)-MS assays, enable sensitive and specific quantification of proteotypic peptides as stoichiometric surrogates for proteins. Efforts are underway to expand the use of MRM-MS assays in clinical environments, which requires a reliable strategy to monitor proteolytic digestion efficiency within individual samples. Towards this goal, extended stable isotope-labeled standard (SIS) peptides (hE), which incorporate native proteolytic cleavage sites, can be spiked into protein lysates prior to proteolytic (trypsin) digestion, and release of the tryptic SIS peptide (hT) can be monitored. However, hT measurements alone cannot monitor the extent of digestion and may be confounded by matrix effects specific to individual patient samples; therefore, they are not sufficient to monitor sample-to-sample digestion variability. We hypothesized that measuring undigested hE, along with its paired hT, would improve detection of digestion issues compared to only measuring hT. We tested the ratio of the SIS pair measurements, or hE/hT, as a quality control (QC) metric of trypsin digestion for two MRM assays: a direct-MRM (398 targets) and an immuno-MRM (126 targets requiring immunoaffinity peptide enrichment) assay, with extended SIS peptides observable for 54% (216) and 62% (78) of the targets, respectively. We evaluated the quantitative bias for each target in a series of experiments that adversely affected proteolytic digestion (e.g., variable digestion times, pH, and temperature). We identified a subset of SIS pairs (36 for the direct-MRM, 7 for the immuno-MRM assay) for which the hE/hT ratio reliably detected inefficient digestion that resulted in decreased assay sensitivity and unreliable endogenous quantification. The hE/hT ratio was more responsive to a decrease in digestion efficiency than a metric based on hT measurements alone. For clinical-grade MRM-MS assays, this study describes a ready-to-use QC panel and also provides a road map for designing custom QC panels.


Assuntos
Peptídeos , Proteômica , Humanos , Proteômica/métodos , Tripsina/química , Peptídeos/análise , Espectrometria de Massas/métodos , Controle de Qualidade , Digestão
15.
Proc Natl Acad Sci U S A ; 119(40): e2200835119, 2022 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-36161936

RESUMO

Ice cores from alpine glaciers are unique archives of past global and regional climate conditions. However, recovering climate records from these ice cores is often hindered by the lack of a reliable chronology, especially in the age range of 100 to 500 anni (a) for which radiometric dating has not been available so far. We report on radiometric 39Ar dating of an ice core from the Tibetan Plateau and the construction of a chronology covering the past 1,300 a using the obtained 39Ar ages. This is made possible by advances in the analysis of 39Ar using the laser-based detection method atom trap trace analysis, resulting in a twofold increase in the upper age limit of 39Ar dating. By measuring the anthropogenic 85Kr along with 39Ar we quantify and correct modern air contamination, thus removing a major systematic uncertainty of 39Ar dating. Moreover, the 85Kr data for the top part of the ice core provide information on firn processes, including the age difference between the ice and its enclosed gas. This first application of 39Ar and 85Kr to an ice core facilitates further ice cores from nonpolar glaciers to be used for recovering climate records of the Common Era, a period including pronounced anomalies such as the Little Ice Age and the Medieval Warm Period.


Assuntos
Camada de Gelo , Datação Radiométrica , Clima , Mudança Climática , Datação Radiométrica/métodos , Tibet
16.
Nano Lett ; 24(13): 3843-3850, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38437628

RESUMO

Nanostructured metals with conventional grain boundaries or interfaces exhibit high strength yet usually poor ductility. Here we report an interface engineering strategy that breaks the strength-ductility dilemma via externally incorporating graphene oxide at lamella boundaries of aluminum (Al) nanolaminates. By forming the binary intergranular films where graphene oxide was sandwiched between two amorphous alumina layers, the Al-based composite nanolaminates achieved ultrahigh compressive strength (over 1 GPa) while retaining excellent plastic deformability. Complementing experimental results with molecular dynamics simulation efforts, the ultrahigh strength was interpreted by the strong blocking effect of the binary intergranular films on dislocation nucleation and propagation, and the excellent plasticity was found to originate from the stress/strain-induced crystalline-to-amorphous transition of graphene oxide and the synergistic deformation between Al nanolamellas and the binary intergranular films.

17.
Nano Lett ; 24(13): 3961-3970, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38526195

RESUMO

Developing a high-performance membrane electrode assembly (MEA) poses a formidable challenge for fuel cells, which lies in achieving both high metal loading and efficient catalytic activity concurrently for MEA catalysts. Here, we introduce a porous Co@NC carrier to synthesize sub-4 nm PtCo intermetallic nanocrystals, achieving an impressive Pt loading of 27 wt %. The PtCo-CoNC catalyst demonstrates exceptional catalytic activity and remarkable stability for the oxygen reduction reaction. Advanced characterization techniques and theoretical calculations emphasize the synergistic effect between PtCo alloys and single Co atoms, which enhances the desorption of the OH* intermediate. Furthermore, the PtCo-CoNC-based cathode delivers a high power density of 1.22 W cm-2 in the MEA test owing to the enhanced mass transport, which is verified by the simulation results of the O2 distributions and current density inside the catalyst layer. This study lays the groundwork for the design of efficient catalysts with practical applications in fuel cells.

18.
Nano Lett ; 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38920089

RESUMO

Two-dimensional (2D) lead halide perovskites are excellent candidates for X-ray detection due to their high resistivity, high ion migration barrier, and large X-ray absorption coefficients. However, the high toxicity and long interlamellar distance of the 2D perovskites limit their wide application in high sensitivity X-ray detection. Herein, we demonstrate stable and toxicity-reduced 2D perovskite single crystals (SCs) realized by interlamellar-spacing engineering via a distortion self-balancing strategy. The engineered low-toxicity 2D SC detectors achieve high stability, large mobility-lifetime product, and therefore high-performance X-ray detection. Specifically, the detectors exhibit a record high sensitivity of 13488 µC Gy1- cm-2, a low detection limit of 8.23 nGy s-1, as well as a high spatial resolution of 8.56 lp mm-1 in X-ray imaging, all of which are far better than those of the high-toxicity 2D lead-based perovskite detectors. These advances provide a new technical solution for the low-cost fabrication of low-toxicity, scalable X-ray detectors.

19.
Proteomics ; : e2300350, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38491406

RESUMO

Lysine acylation has been extensively investigated due to its regulatory role in a diverse range of biological functions across prokaryotic and eukaryotic species. In-depth acylomic profiles have the potential to enhance comprehension of the biological implications of organisms. However, the extent of research on global acylation profiles in microorganisms is limited. Here, four lysine acylomes were conducted in Bacillus thuringiensis by using the LC-MS/MS based proteomics combined with antibody-enrichment strategies, and a total of 3438 acetylated sites, 5797 propionylated sites, 1705 succinylated sites, and 925 malonylated sites were identified. The motif analysis of these modified proteins revealed a high conservation of glutamate in acetylation and propionylation, whereas such conservation was not observed in succinylation and malonylation modifications. Besides, conservation analysis showed that homologous acylated proteins in Bacillus subtilis and Escherichia coli were connected with ribosome and aminoacyl-tRNA biosynthesis. Further biological experiments showed that lysine acylation lowered the RNA binding ability of CodY and impaired the in vivo protein activity of MetK. In conclusion, our study expanded the current understanding of the global acylation in Bacillus, and the comparative analysis demonstrated that shared acylation proteins could play important roles in regulating both metabolism and RNA transcription progression.

20.
J Cell Mol Med ; 28(12): e18373, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38894657

RESUMO

Gastric cancer (GC) remains a prominent malignancy that poses a significant threat to human well-being worldwide. Despite advancements in chemotherapy and immunotherapy, which have effectively augmented patient survival rates, the mortality rate associated with GC remains distressingly high. This can be attributed to the elevated proliferation and invasive nature exhibited by GC. Our current understanding of the drivers behind GC cell proliferation remains limited. Hence, in order to reveal the molecular biological mechanism behind the swift advancement of GC, we employed single-cell RNA-sequencing (scRNA-seq) to characterize the tumour microenvironment in this study. The scRNA-seq data of 27 patients were acquired from the Gene Expression Omnibus database. Differential gene analysis, Gene Ontology, Kyoto Encyclopedia of Genes and Genomes and Gene Set Enrichment Analysis were employed to investigate 38 samples. The copy number variation level exhibited by GC cells was determined using InferCNV. The CytoTRACE, Monocle and Slingshot analysis were used to discern the cellular stemness and developmental trajectory of GC cells. The CellChat package was utilized for the analysis of intercellular communication crosstalk. Moreover, the findings of the data analysis were validated through cellular functional tests conducted on the AGS cell line and SGC-7901 cell line. Finally, this study constructed a risk scoring model to evaluate the differences of different risk scores in clinical characteristics, immune infiltration, immune checkpoints, functional enrichment, tumour mutation burden and drug sensitivity. Within the microenvironment of GC, we identified the presence of 8 cell subsets, encompassing NK_T cells, B_Plasma cells, epithelial cells, myeloid cells, endothelial cells, mast cells, fibroblasts, pericytes. By delving deeper into the characterization of GC cells, we identified 6 specific tumour cell subtypes: C0 PSCA+ tumour cells, C1 CLDN7+ tumour cells, C2 UBE2C+ tumour cells, C3 MUC6+ tumour cells, C4 CHGA+ tumour cells and C5 MUC2+ tumour cells. Notably, the C2 UBE2C+ tumour cells demonstrated a close association with cell mitosis and the cell cycle, exhibiting robust proliferative capabilities. Our findings were fortified through enrichment analysis, pseudotime analysis and cell communication analysis. Meanwhile, knockdown of the transcription factor CREB3, which is highly active in UBE2C+ tumour cells, significantly impedes the proliferation, migration and invasion of GC cells. And the prognostic score model constructed with CREB3-related genes showcased commendable clinical predictive capacity, thus providing valuable guidance for patients' prognosis and clinical treatment decisions. We have identified a highly proliferative cellular subgroup C2 UBE2C+ tumour cells in GC for the first time. The employment of a risk score model, which is based on genes associated with UBE2C expression, exhibits remarkable proficiency in predicting the prognosis of GC patients. In our investigation, we observed that the knockdown of the transcription factor CREB3 led to a marked reduction in cellular proliferation, migration and invasion in GC cell line models. Implementing a stratified treatment approach guided by this model represents a judicious and promising methodology.


Assuntos
Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Análise de Célula Única , Neoplasias Gástricas , Microambiente Tumoral , Humanos , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Neoplasias Gástricas/metabolismo , Microambiente Tumoral/genética , Proliferação de Células/genética , Análise de Célula Única/métodos , Linhagem Celular Tumoral , Perfilação da Expressão Gênica , Variações do Número de Cópias de DNA/genética , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Comunicação Celular/genética
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