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Germinal centers (GCs) support high-affinity, long-lived humoral immunity. How memory B cells develop in GCs is not clear. Through the use of a cell-cycle-reporting system, we identified GC-derived memory precursor cells (GC-MP cells) that had quit cycling and reached G0 phase while in the GC, exhibited memory-associated phenotypes with signs of affinity maturation and localized toward the GC border. After being transferred into adoptive hosts, GC-MP cells reconstituted a secondary response like genuine memory B cells. GC-MP cells expressed the interleukin 9 (IL-9) receptor and responded to IL-9. Acute treatment with IL-9 or antibody to IL-9 accelerated or retarded the positioning of GC-MP cells toward the GC edge and exit from the GC, and enhanced or inhibited the development of memory B cells, which required B cell-intrinsic responsiveness to IL-9. Follicular helper T cells (TFH cells) produced IL-9, and deletion of IL-9 from T cells or, more specifically, from GC TFH cells led to impaired memory formation of B cells. Therefore, the GC development of memory B cells is promoted by TFH cell-derived IL-9.
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Subgrupos de Linfocitos B/inmunología , Linfocitos B/inmunología , Centro Germinal/inmunología , Memoria Inmunológica/inmunología , Interleucina-9/inmunología , Linfocitos T Colaboradores-Inductores/inmunología , Animales , Subgrupos de Linfocitos B/efectos de los fármacos , Linfocitos B/efectos de los fármacos , Células Cultivadas , Citometría de Flujo , Técnica del Anticuerpo Fluorescente , Técnicas de Silenciamiento del Gen , Memoria Inmunológica/efectos de los fármacos , Técnicas In Vitro , Interleucina-9/farmacología , Tejido Linfoide , Ratones , Ratones Noqueados , Reacción en Cadena en Tiempo Real de la PolimerasaRESUMEN
The role of B cells in anti-tumour immunity is still debated and, accordingly, immunotherapies have focused on targeting T and natural killer cells to inhibit tumour growth1,2. Here, using high-throughput flow cytometry as well as bulk and single-cell RNA-sequencing and B-cell-receptor-sequencing analysis of B cells temporally during B16F10 melanoma growth, we identified a subset of B cells that expands specifically in the draining lymph node over time in tumour-bearing mice. The expanding B cell subset expresses the cell surface molecule T cell immunoglobulin and mucin domain 1 (TIM-1, encoded by Havcr1) and a unique transcriptional signature, including multiple co-inhibitory molecules such as PD-1, TIM-3, TIGIT and LAG-3. Although conditional deletion of these co-inhibitory molecules on B cells had little or no effect on tumour burden, selective deletion of Havcr1 in B cells both substantially inhibited tumour growth and enhanced effector T cell responses. Loss of TIM-1 enhanced the type 1 interferon response in B cells, which augmented B cell activation and increased antigen presentation and co-stimulation, resulting in increased expansion of tumour-specific effector T cells. Our results demonstrate that manipulation of TIM-1-expressing B cells enables engagement of the second arm of adaptive immunity to promote anti-tumour immunity and inhibit tumour growth.
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Linfocitos B , Melanoma , Animales , Ratones , Linfocitos B/citología , Linfocitos B/inmunología , Linfocitos B/metabolismo , Activación de Linfocitos , Melanoma/inmunología , Melanoma/patología , Melanoma/prevención & control , Linfocitos T/citología , Linfocitos T/inmunología , Citometría de Flujo , Melanoma Experimental/inmunología , Melanoma Experimental/patología , Ganglios Linfáticos/citología , Ganglios Linfáticos/inmunología , Presentación de Antígeno , Receptores de Antígenos de Linfocitos B/genética , Análisis de Expresión Génica de una Sola Célula , Carga Tumoral , Interferón Tipo IRESUMEN
Follicular T helper (Tfh) cells highly express the programmed cell death-1 (PD-1) molecule. Whereas inhibition of T cell receptor (TCR) signaling and CD28 co-stimulation is thought to be the primary mode of PD-1 functions, whether and how PD-1 regulates Tfh cell development and function is unclear. Here we showed that, when engaged by the ensemble of bystander B cells constitutively expressing PD-1 ligand 1 (PD-L1), PD-1 inhibited T cell recruitment into the follicle. This inhibition involved suppression of PI3K activities downstream of the follicle-guidance receptor CXCR5, was independent of co-signaling with the TCR, and necessitated ICOS signaling to overcome. PD-1 further restricted CXCR3 upregulation on Tfh cells, serving to concentrate these cells toward the germinal center territory, where PD-L1-PD-1 interactions between individual Tfh and B cells optimized B cell competition and affinity maturation. Therefore, operating in both costimulation-independent and -dependent manners, PD-1 controls tissue positioning and function of Tfh cells.
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Antígeno B7-H1/metabolismo , Centro Germinal/citología , Fosfatidilinositol 3-Quinasas/metabolismo , Receptor de Muerte Celular Programada 1/metabolismo , Linfocitos T Colaboradores-Inductores/citología , Animales , Linfocitos B/inmunología , Diferenciación Celular/inmunología , Línea Celular , Movimiento Celular/inmunología , Femenino , Centro Germinal/inmunología , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Receptores CXCR3/genética , Receptores CXCR5/genética , Linfocitos T Colaboradores-Inductores/inmunologíaRESUMEN
Endometriosis is a common benign gynecologic condition. Endometriosis lesions are associated with endometrial cell proliferation, migration, invasion, and neovascularization, while the specific molecular mechanisms are still elusive. Transcriptome sequencing has been used for the identification of diagnostic markers in endometriosis. Here, transcriptome profiling revealed that kallikrein-related peptidase 4 (KLK4) expression was up-regulated in ectopic endometrium (EC) tissues of patients with endometriosis. KLK4 mediates the degradation of extracellular matrix proteins, and its proteolytic activity activates many tumorigenic and metastatic pathways via tumor invasion and migration. Nevertheless, whether KLK4 serves as an important regulatory factor in endometriosis remains unclear. This study confirmed that KLK4 was highly expressed in ectopic endometrial stromal cells (EC-ESCs). KLK4 overexpression promoted proliferation and suppressed apoptosis of EC-ESCs, induced cell migration and invasion, and enhanced angiogenesis in vivo. Mechanistically, KLK4 overexpression mediated the protein cleavage of pro-brain-derived neurotrophic factor in EC-ESCs. Finally, brain-derived neurotrophic factor was a vital downstream substrate of KLK4 maintained the proliferation, metastasis, and pro-angiogenesis abilities and inhibited apoptosis of ESCs through a rescue study. Together, these findings demonstrate the promotive role of KLK4 in endometriosis development. In addition, the study provides a new insight that KLK4 might be a potential therapeutic target and prognostic marker for patients with endometriosis.
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Endometriosis , Femenino , Humanos , Angiogénesis , Factor Neurotrófico Derivado del Encéfalo , Movimiento Celular , Proliferación Celular , Endometriosis/patología , Endometrio/patología , Calicreínas/genética , Calicreínas/metabolismo , Células del Estroma/metabolismoRESUMEN
When catalytic reactions are interfered with by radiation sources, thorium clusters are promising as potential catalysts due to their superior radiation resistance. However, there is currently very little research on the design synthesis and catalytic application of radiation-stable thorium clusters. In this work, we have elaborately engineered and fabricated three high-nuclear thorium cluster catalysts denoted as Th12L3-MA12, Th12L3-MA6-BF6, and Th12L3-Fcc12, which did not undergo any significant alterations in their molecular structures and compositions after irradiation with 690 kGy γ-rays. We systematically investigated the photocatalytic/thermocatalytic properties of these radiation-resistant thorium clusters for the first time and found that γ-rays could not alter their catalytic activities. In addition, it was found that ligand engineering could modulate the catalytic activity of thorium clusters, thus expanding the range of catalytic applications of thorium clusters, including reduction reactions (nitroarene reduction) and some oxidation reactions (N-heterocyclic oxidative dehydrogenation and diphenylmethane oxidation). Meanwhile, all of these organic transformation reactions achieved a >80% conversion and nearly 100% product selectivity. Radiation experiments combined with DFT calculations showed that the synergistic catalysis of thorium-oxo core and ligands led to the generation of specific active species (H+, O2â¢-, or tBuO/tBuOOâ¢) and activation of substrate molecules, thus achieving superior catalytic performance. This work is not only the first to develop radiation-resistant thorium cluster catalysts to perform efficient redox reactions but also provides design ideas for the construction of high-nuclearity thorium clusters under mild conditions.
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The construction of isotypic high-nuclearity inorganic cages with identical pristine parent structure and increasing nuclearity is highly important for molecular growth and structure-property relationship study, yet it still remains a great challenge. Here, we provide an in situ growth approach for successfully synthesizing a series of new giant hollow polymolybdate dodecahedral cages, Mo250, Mo260-I, and Mo260-E, whose structures are growth based on giant polymolybdate cage Mo240. Remarkably, they show two pathways of nuclear growth based on Mo240, that is, the growth of 10 and 20 Mo centers on the inner and outer surfaces to afford Mo250 and Mo260-I, respectively, and the growth of 10 Mo centers both on the inner and outer surfaces to give Mo260-E. To the best of our knowledge, this is the first study to display the internal and external nuclear growth of a giant hollow polyoxometalate cage. More importantly, regular variations in structure and nuclearity confer these polymolybdate cages with different optical properties, oxidative activities, and hydrogen atom transfer effect, thus allowing them to exhibit moderate to excellent photocatalytic performance in oxidative cross-coupling reactions between different unactivated alkanes and N-heteroarenes. In particular, Mo240 and Mo260-E with better comprehensive abilities can offer the desired coupling product with yield up to 92% within 1 h.
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BACKGROUND: Adenomyosis is a benign uterine disease and affected patients present with symptoms such as menorrhagia, chronic pelvic pain, abnormal uterine bleeding, and infertility. However, the specific mechanisms by which adenomyosis occurs need to be further studied. OBJECTIVE: Dataset of adenomyosis from our hospital and a public database were analyzed using bioinformatics. Corresponding differentially expressed genes (DEGs) and gene enrichment were detected to explore potential genetic adenomyosis targets. METHODS: Clinical data on adenomyosis were accessed based on the pathological specimens of patients with adenomyosis obtained from the Shengjing Hospital. R software was used to screen for DEGs, and volcano and cluster maps were drawn. Adenomyosis datasets (GSE74373) were downloaded from the GEO database. GEO2R online tool was used to screen for DEGs between adenomyosis and normal controls. Genes with P < 0.01 and |logFC| >1 were selected as DEGs. DAVID software was used for functional and pathway enrichment analyses. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed on common DEGs to obtain descriptions of the genes. The online database STRING was used for interaction gene retrieval. Moreover, Cytoscape software was used to construct a protein-protein interaction (PPI) network map for common DEGs to visualize potential gene interactions and screen the hub genes. RESULTS: A total of 845 DEGs were identified in the dataset obtained from Shengjing Hospital. A total of 175 genes were downregulated, and 670 genes were upregulated. In the GSE74373 database, 1679 genes were differentially expressed, 916 genes were downregulated, and 763 genes were upregulated. A total of 40 downregulated and 148 upregulated common DEGs showed potential gene interactions. The top ten upregulated hub genes were CDH1, EPCAM, CLDN7, ESRP1, RAB25, SPINT1, PKP3, TJP3, GRHL2, and CDKN2A. CONCLUSION: Genes involved in tight junction may be key in the development of adenomyosis and may provide a potential treatment strategy for adenomyosis.
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Adenomiosis , Perfilación de la Expresión Génica , Femenino , Humanos , Mapeo de Interacción de Proteínas , Biomarcadores de Tumor/genética , Adenomiosis/genética , Regulación Neoplásica de la Expresión Génica , Endometrio/metabolismo , Biología Computacional , Proteínas de Unión al GTP rab/genética , Proteínas de Unión al GTP rab/metabolismo , Proteínas de la Zonula Occludens/genética , Proteínas de la Zonula Occludens/metabolismoRESUMEN
BACKGROUND: The options for first-line treatment of advanced oesophageal squamous cell carcinoma are scarce, and the outcomes remain poor. The anti-PD-1 antibody, tislelizumab, has shown antitumour activity in previously treated patients with advanced oesophageal squamous cell carcinoma. We report interim analysis results from the RATIONALE-306 study, which aimed to assess tislelizumab plus chemotherapy versus placebo plus chemotherapy as first-line treatment for advanced or metastatic oesophageal squamous cell carcinoma. METHODS: This global, randomised, double-blind, parallel-arm, placebo-controlled, phase 3 study was conducted at 162 medical centres across Asia, Europe, Oceania, and North America. Patients (aged ≥18 years) with unresectable, locally advanced, recurrent or metastatic oesophageal squamous cell carcinoma (regardless of PD-L1 expression), Eastern Cooperative Oncology Group performance status of 0-1, and measurable or evaluable disease per Response Evaluation Criteria in Solid Tumours (version 1.1) were recruited. Patients were randomly assigned (1:1), using permuted block randomisation (block size of four) and stratified by investigator-chosen chemotherapy, region, and previous definitive therapy, to tislelizumab 200 mg or placebo intravenously every 3 weeks on day 1, together with an investigator-chosen chemotherapy doublet, comprising a platinum agent (cisplatin 60-80 mg/m2 intravenously on day 1 or oxaliplatin 130 mg/m2 intravenously on day 1) plus a fluoropyrimidine (fluorouracil [750-800 mg/m2 intravenously on days 1-5] or capecitabine [1000 mg/m2 orally twice daily on days 1-14]) or paclitaxel (175 mg/m2 intravenously on day 1). Treatment was continued until disease progression or unacceptable toxicity. Investigators, patients, and sponsor staff or designees were masked to treatment. The primary endpoint was overall survival. The efficacy analysis was done in the intention-to-treat population (ie, all randomly assigned patients) and safety was assessed in all patients who received at least one dose of study treatment. The trial is registered with ClinicalTrials.gov, NCT03783442. FINDINGS: Between Dec 12, 2018, and Nov 24, 2020, 869 patients were screened, of whom 649 were randomly assigned to tislelizumab plus chemotherapy (n=326) or placebo plus chemotherapy (n=323). Median age was 64·0 years (IQR 59·0-69·0), 563 (87%) of 649 participants were male, 86 (13%) were female, 486 (75%) were Asian, and 155 (24%) were White. 324 (99%) of 326 patients in the tislelizumab group and 321 (99%) of 323 in the placebo group received at least one dose of the study drug. As of data cutoff (Feb 28, 2022), median follow-up was 16·3 months (IQR 8·6-21·8) in the tislelizumab group and 9·8 months (IQR 5·8-19·0) in the placebo group, and 196 (60%) of 326 patients in the tislelizumab group versus 226 (70%) of 323 in the placebo group had died. Median overall survival in the tislelizumab group was 17·2 months (95% CI 15·8-20·1) and in the placebo group was 10·6 months (9·3-12·1; stratified hazard ratio 0·66 [95% CI 0·54-0·80]; one-sided p<0·0001). 313 (97%) of 324 patients in the tislelizumab group and 309 (96%) of 321 in the placebo group had treatment-related treatment-emergent adverse events. The most common grade 3 or 4 treatment-related treatment-emergent adverse events were decreased neutrophil count (99 [31%] in the tislelizumab group vs 105 [33%] in the placebo group), decreased white blood cell count (35 [11%] vs 50 [16%]), and anaemia (47 [15%] vs 41 [13%]). Six deaths in the tislelizumab group (gastrointestinal and upper gastrointestinal haemorrhage [n=2], myocarditis [n=1], pulmonary tuberculosis [n=1], electrolyte imbalance [n=1], and respiratory failure [n=1]) and four deaths in the placebo group (pneumonia [n=1], septic shock [n=1], and unspecified death [n=2]) were determined to be treatment-related. INTERPRETATION: Tislelizumab plus chemotherapy as a first-line treatment for advanced or metastatic oesophageal squamous cell carcinoma provided superior overall survival with a manageable safety profile versus placebo plus chemotherapy. Given that the interim analysis met its superiority boundary for the primary endpoint, as confirmed by the independent data monitoring committee, this Article represents the primary study analysis. FUNDING: BeiGene.
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Neoplasias Esofágicas , Carcinoma de Células Escamosas de Esófago , Humanos , Masculino , Femenino , Adolescente , Adulto , Persona de Mediana Edad , Anticuerpos Monoclonales Humanizados , Paclitaxel , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Método Doble CiegoRESUMEN
The selective photoisomerization or photocyclization of stilbene to achieve value upgrade is of great significance in industry applications, yet it remains a challenge to accomplish both of them through a one-pot photocatalysis strategy under mild conditions. Here, a sevenfold interpenetrating 3D covalent organic framework (TPDT-COF) has been synthesized through covalent coupling between N,N,N,N-tetrakis(4-aminophenyl)-1,4-benzenediamine (light absorption and free radical generation) and 5,5'-(2,1,3-benzothiadiazole-4,7-diyl)bis[2-thiophenecarboxaldehyde] (catalytic center). The thus-obtained sevenfold interpenetrating structure presents a functional pore channel with a tunable photocatalytic ability and specific pore confinement effect that can be applied for selective stilbene photoisomerization and photocyclization. Noteworthily, it enables photogeneration of cis-stilbene or phenanthrene with >99% selectivity by simply changing the gas atmosphere under mild conditions (Ar, SeleCis. > 99%, SelePhen. < 1% and O2, SeleCis. < 1%, and SelePhen. > 99%). Theoretical calculations prove that different gas atmospheres possess varying influences on the energy barriers of reaction intermediates, and the pore confinement effect plays a synergistically catalytic role, thus inducing different product generation. This study might facilitate the exploration of porous crystalline materials in selective photoisomerization and photocyclization.
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While the difference in catalytic reactivity between mono- and multimetallic sites is often attributed to more than just the number of active sites, still few catalyst model systems have been developed to explore more underlying causal factors. In this work, we have elaborately designed and constructed three stable calix[4]arene (C4A)-functionalized titanium-oxo compounds, Ti-C4A, Ti4-C4A, and Ti16-C4A, with well-defined crystal structures, increasing nuclearity, and tunable light absorption capacity and energy levels. Among them, Ti-C4A and Ti16-C4A can be taken as model catalysts to compare the differences in reactivity between mono- and multimetallic sites. Taking CO2 photoreduction as the basic catalytic reaction, both compounds can achieve CO2-to-HCOO- conversion with high selectivity (close to 100%). Moreover, the catalytic activity of multimetallic Ti16-C4A is up to 2265.5 µmol g-1 h-1, which is at least 12 times higher than that of monometallic Ti-C4A (180.0 µmol g-1 h-1), and is the best-performing crystalline cluster-based photocatalyst known to date. Catalytic characterization combined with density functional theory calculations shows that in addition to the advantage of having more metal active sites (for adsorption and activation of more CO2 molecules), Ti16-C4A can effectively reduce the activation energy required for the CO2 reduction reaction by completing the multiple electron-proton transfer process rapidly with synergistic metal-ligand catalysis, thus exhibiting superior catalytic performance to that of monometallic Ti-C4A. This work provides a crystalline catalyst model system to explore the potential factors underlying the difference in catalytic reactivity between mono- and multimetallic sites.
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Rational design of crystalline catalysts with superior light absorption and charge transfer for efficient photoelectrocatalytic (PEC) reaction coupled with energy recovery remains a great challenge. In this work, we elaborately construct three stable titanium-oxo clusters (TOCs, Ti10Ac6, Ti10Fc8, and Ti12Fc2Ac4) modified with a monofunctionalized ligand (9-anthracenecarboxylic acid (Ac) or ferrocenecarboxylic acid (Fc)) and bifunctionalized ligands (Ac and Fc). They have tunable light-harvesting and charge transfer capacities and thus can serve as outstanding crystalline catalysts to achieve efficient PEC overall reaction, that is, the integration of anodic organic pollutant 4-chlorophenol (4-CP) degradation and cathodic wastewater-to-H2 conversion. These TOCs can all exhibit very high PEC activity and degradation efficiency of 4-CP. Especially, Ti12Fc2Ac4 decorated with bifunctionalized ligands exhibits better PEC degradation efficiency (over 99%) and H2 generation than Ti10Ac6 and Ti10Fc8 modified with a monofunctionalized ligand. The study of the 4-CP degradation pathway and mechanism revealed that such better PEC performance of Ti12Fc2Ac4 is probably due to its stronger interactions with the 4-CP molecule and better â¢OH radical production. This work not only presents the effective combination of organic pollutant degradation and simultaneously H2 evolution reaction using crystalline coordination clusters as both anodic and cathodic catalyst but also develops a new PEC application for crystalline coordination compounds.
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BACKGROUND: Multiparametric magnetic resonance imaging (MP-MRI) has high sensitivity for diagnosing breast cancers but cannot always be used as a routine diagnostic tool. The present study aimed to evaluate whether the diagnostic performance of perfluorobutane (PFB) contrast-enhanced ultrasound (CEUS) is similar to that of MP-MRI in breast cancer and whether combining the two methods would enhance diagnostic efficiency. PATIENTS AND METHODS: This was a head-to-head, prospective, multicenter study. Patients with breast lesions diagnosed by US as Breast Imaging Reporting and Data System (BI-RADS) categories 3, 4, and 5 underwent both PFB-CEUS and MP-MRI scans. On-site operators and three reviewers categorized the BI-RADS of all lesions on two images. Logistic-bootstrap 1000-sample analysis and cross-validation were used to construct PFB-CEUS, MP-MRI, and hybrid (PFB-CEUS + MP-MRI) models to distinguish breast lesions. RESULTS: In total, 179 women with 186 breast lesions were evaluated from 17 centers in China. The area under the receiver operating characteristic curve (AUC) for the PFB-CEUS model to diagnose breast cancer (0.89; 95% confidence interval [CI] 0.74, 0.97) was similar to that of the MP-MRI model (0.89; 95% CI 0.73, 0.97) (P = 0.85). The AUC of the hybrid model (0.92, 95% CI 0.77, 0.98) did not show a statistical advantage over the PFB-CEUS and MP-MRI models (P = 0.29 and 0.40, respectively). However, 90.3% false-positive and 66.7% false-negative results of PFB-CEUS radiologists and 90.5% false-positive and 42.8% false-negative results of MP-MRI radiologists could be corrected by the hybrid model. Three dynamic nomograms of PFB-CEUS, MP-MRI and hybrid models to diagnose breast cancer are freely available online. CONCLUSIONS: PFB-CEUS can be used in the differential diagnosis of breast cancer with comparable performance to MP-MRI and with less time consumption. Using PFB-CEUS and MP-MRI as joint diagnostics could further strengthen the diagnostic ability. Trial registration Clinicaltrials.gov; NCT04657328. Registered 26 September 2020. IRB number 2020-300 was approved in Chinese PLA General Hospital. Every patient signed a written informed consent form in each center.
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Neoplasias de la Mama , Imágenes de Resonancia Magnética Multiparamétrica , Humanos , Femenino , Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/patología , Medios de Contraste , Sensibilidad y Especificidad , Estudios Prospectivos , Ultrasonografía Mamaria/métodos , Imagen por Resonancia Magnética/métodosRESUMEN
Bone loss occurs in astronauts during long-term space flight, but the mechanisms are still unclear. We previously showed that advanced glycation end products (AGEs) were involved in microgravity-induced osteoporosis. Here, we investigated the improvement effects of blocking AGEs formation on microgravity-induced bone loss by using the AGEs formation inhibitor, irbesartan. To achieve this objective, we used a tail-suspended (TS) rat model to simulate microgravity and treated the TS rats with 50 mg/kg/day irbesartan, as well as the fluorochrome biomarkers injected into rats to label dynamic bone formation. To assess the accumulation of AGEs, pentosidine (PEN), non-enzymatic cross-links (NE-xLR), and fluorescent AGEs (fAGEs) were identified in the bone; 8-hydroxydeoxyguanosine (8-OHdG) was analyzed for the reactive oxygen species (ROS) level in the bone. Meanwhile, bone mechanical properties, bone microstructure, and dynamic bone histomorphometry were tested for bone quality assessment, and Osterix and TRAP were immunofluorescences stained for the activities of osteoblastic and osteoclastic cells. Results showed AGEs increased significantly and 8-OHdG expression in bone showed an upward trend in TS rat hindlimbs. The bone quality (bone microstructure and mechanical properties) and bone formation process (dynamic bone formation and osteoblastic cells activities) were inhibited after tail-suspension, and showed a correlation with AGEs, suggesting the elevated AGEs contributed to the disused bone loss. After being treated with irbesartan, the increased AGEs and 8-OHdG expression were significantly inhibited, suggesting irbesartan may reduce ROS to inhibit dicarbonyl compounds, thus suppressing AGEs production after tail-suspension. The inhibition of AGEs can partially alter the bone remodeling process and improve bone quality. Both AGEs accumulation and bone alterations almost occurred in trabecular bone but not in cortical bone, suggesting AGEs effects on bone remodeling under microgravity are dependent on the biological milieu.
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Productos Finales de Glicación Avanzada , Osteoporosis , Ratas , Animales , Irbesartán , Productos Finales de Glicación Avanzada/metabolismo , Especies Reactivas de Oxígeno , Huesos/metabolismoRESUMEN
Water resources are vital to the development of human society, and mastering the law of runoff changes is the basis for achieving sustainable use of water resources. To study the impact of reservoir construction on the changes of downstream river runoff, this paper decomposes the runoff before and after reservoir construction using the CEEMDAN method based on the runoff data from the Huayuankou hydrological station. The fluctuation characteristics of each decomposition series of runoff before and after reservoir construction and the intra-annual variation pattern of runoff are also analyzed by combining multi-time information entropy and coefficient of variation. The results show that after the operation of the Xiaolangdi Reservoir, the annual runoff variation cycle tends to be flat, and the monthly runoff cycle is significantly reduced. After reservoir construction, the entropy values of each IMF and Res of runoff become larger, the complexity and randomness of runoff changes increase, and predictability decreases. Before and after the operation of the Xiaolangdi Reservoir, the coefficient of variation of runoff were 0.28-1 and 0.38-0.83, the distribution of runoff was more uniform, and the percentage of runoff in the flood season was reduced from 51.51 to 39.89%.
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Inundaciones , Hidrología , Humanos , Entropía , Ríos , Estaciones del AñoRESUMEN
Temperature is an important indicator of climate change. With the gradual increase of global warming, a well-chosen model can improve the accuracy of temperature prediction. It is of great significance and value for future disaster prevention and mitigation and economic development. Monthly temperature is influenced by solar activity, monsoon, and other factors, with significant uncertainty, ambiguity, and randomness. A coupled CEEMD-BiLSTM temperature model is constructed based on the good decomposition-reconstruction characteristics of CEEMD for uncertain time series and the advantages of BiLSTM for solving stochastic prediction, and it is applied to the prediction of monthly temperature in Zhengzhou City. The results show that the minimum relative error of the coupled CEEMD-BiLSTM model is 0.01%, the maximum relative error is 0.99%, and the average relative error is 0.22%, and the prediction accuracy of this coupled model for monthly temperature in Zhengzhou is higher than that of the CEEMD-LSTM model, EEMD-BiLSTM model, and BP neural network model, with better stability and adaptability.
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Desastres , Monitoreo del Ambiente , Temperatura , Redes Neurales de la Computación , Cambio Climático , PredicciónRESUMEN
The full reaction photosynthesis of H2 O2 that can combine water-oxidation and oxygen-reduction without sacrificial agents is highly demanded to maximize the light-utilization and overcome the complex reaction-process of anthraquinone-oxidation. Here, a kind of oxidation-reduction molecular junction covalent-organic-framework (TTF-BT-COF) has been synthesized through the covalent-coupling of tetrathiafulvalene (photo-oxidation site) and benzothiazole (photo-reduction site), which presents visible-light-adsorption region, effective electron-hole separation-efficiency and photo-redox sites that enables full reaction generation of H2 O2 . Specifically, a record-high yield (TTF-BT-COF, ≈276 000â µM h-1 g-1 ) for H2 O2 photosynthesis without sacrificial agents has been achieved among porous crystalline photocatalysts. This is the first work that can design oxidation-reduction molecular junction COFs for full reaction photosynthesis of H2 O2 , which might extend the scope of COFs in H2 O2 production.
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H2 O2 photosynthesis coupled with biomass valorization can not only maximize the energy utilization but also realize the production of value-added products. Here, a series of COFs (i.e. Cu3 -BT-COF, Cu3 -pT-COF and TFP-BT-COF) with regulated redox molecular junctions have been prepared to study H2 O2 photosynthesis coupled with furfuryl alcohol (FFA) photo-oxidation to furoic acid (FA). The FA generation efficiency of Cu3 -BT-COF was found to be 575â mM g-1 (conversion ≈100 % and selectivity >99 %) and the H2 O2 production rate can reach up to 187 000â µM g-1 , which is much higher than Cu3 -pT-COF, TFP-BT-COF and its monomers. As shown by theoretical calculations, the covalent coupling of the Cu cluster and the thiazole group can promote charge transfer, substrate activation and FFA dehydrogenation, thus boosting both the kinetics of H2 O2 production and FFA photo-oxidation to increase the efficiency. This is the first report about COFs for H2 O2 photosynthesis coupled with biomass valorization, which might facilitate the exploration of porous-crystalline catalysts in this field.
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Structural exploration and functional application of thorium clusters are still very rare on account of their difficult synthesis caused by the susceptible hydrolysis of thorium element. In this work, we elaborately designed and constructed four stable thorium clusters modified with different functionalized capping ligands, Th6-MA, Th6-BEN, Th6-C8A, and Th6-Fcc, which possessed nearly the same hexanuclear thorium-oxo core but different capabilities in light absorption and charge separation. Consequently, for the first time, these new thorium clusters were treated as model catalysts to systematically investigate the light-induced oxidative coupling reaction of benzylamine and thermodriven oxidation of aniline, achieving >90% product selectivity and approximately 100% conversion, respectively. Concurrently, we found that thorium clusters modified by switchable functional ligands can effectively modulate the selectivity and conversion of catalytic reaction products. Moreover, catalytic characterization and density functional theory calculations consistently indicated that these thorium clusters can activate O2/H2O2 to generate active intermediates O2·-/HOO· and then improved the conversion of amines efficiently. Significantly, this work represents the first report of stable thorium clusters applied to photo/thermotriggered catalytic reactions and puts forward a new design avenue for the construction of more efficient thorium cluster catalysts.
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Metal-oxo clusters have emerged as advanced proton conductors with well-defined and tunable structures. Nevertheless, the exploitation of metal-oxo clusters with high and stable proton conductivity over a relatively wide temperature range still remains a great challenge. Herein, three sulfate groups decorated zirconium-oxo clusters (Zr6 , Zr18 , and Zr70 ) as proton conductors are reported, which exhibit ultrahigh bulk proton conductivities of 1.71 × 10-1 , 2.01 × 10-2 , and 3.73 × 10-2 S cm-1 under 70 °C and 98% relative humidity (RH), respectively. Remarkably, Zr6 and Zr70 with multiple sulfate groups as proton hopping sites show ultralow activation energies of 0.22 and 0.18 eV, respectively, and stable bulk conductivities of >10-2 S cm-1 between 30 and 70 °C at 98% RH. Moreover, a time-dependent proton conductivity test reveals that the best performing Zr6 can maintain high proton conductivity up to 15 h with negligible loss at 70 °C and 98% RH, representing one of the best crystalline cluster-based proton conducting materials.
RESUMEN
Hybrid CO2 electroreduction (HCER) is recognized as an important strategy to improve the total value of redox products and energy conversion efficiency. In this work, a coordination catalyst model system (Ni8 -TET with active oxidation sites, Ni-TPP with active reduction sites and PCN-601 with redox-active sites) for HCER was established for the first time. Especially, PCN-601 can complete both anodic methanol oxidation and cathodic CO2 reduction with FEHCOOH and FECO over 90 %. The performance can be further improved with light irradiation (FE nearly 100 %). DFT calculations reveal that the transfer of electrons from NiII 8 clusters to metalloporphyrins under electric fields results in the raised oxidizability of Ni8 clusters and the raised reducibility of metalloporphyrin, which then improves the electrocatalytic performance. This work serves as a well-defined model system and puts forward a new design idea for establishing efficient catalysts for hybrid CO2 electroreduction.