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Hematopoietic stem and progenitor cells (HSPCs) are a heterogeneous group of cells with expansion, differentiation, and repopulation capacities. How HSPCs orchestrate the stemness state with diverse lineage differentiation at steady condition or acute stress remains largely unknown. Here, we show that zebrafish mutants that are deficient in an epigenetic regulator Atf7ip or Setdb1 methyltransferase undergo excessive myeloid differentiation with impaired HSPC expansion, manifesting a decline in T cells and erythroid lineage. We find that Atf7ip regulates hematopoiesis through Setdb1-mediated H3K9me3 modification and chromatin remodeling. During hematopoiesis, the interaction of Atf7ip and Setdb1 triggers H3K9me3 depositions in hematopoietic regulatory genes including cebpß and cdkn1a, preventing HSPCs from loss of expansion and premature differentiation into myeloid lineage. Concomitantly, loss of Atf7ip or Setdb1 derepresses retrotransposons that instigate the viral sensor Mda5/Rig-I like receptor (RLR) signaling, leading to stress-driven myelopoiesis and inflammation. We find that ATF7IP or SETDB1 depletion represses human leukemic cell growth and induces myeloid differentiation with retrotransposon-triggered inflammation. These findings establish that Atf7ip/Setdb1-mediated H3K9me3 deposition constitutes a genome-wide checkpoint that impedes the myeloid potential and maintains HSPC stemness for diverse blood cell production, providing unique insights into potential intervention in hematological malignancy.
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Células-Tronco Hematopoéticas , Histona-Lisina N-Metiltransferase , Peixe-Zebra , Animais , Humanos , Diferenciação Celular , Linhagem da Célula , Hematopoese , Células-Tronco Hematopoéticas/patologia , Histona-Lisina N-Metiltransferase/genética , Inflamação/patologia , Peixe-Zebra/genética , Peixe-Zebra/metabolismoRESUMO
Leveraging its ultrahigh carrier mobility, zero-bandgap linear dispersion, and extremely short response time, graphene exhibits remarkable potential in ultrafast broad-band photodetection. Nonetheless, the inherently low responsivity of graphene photodetectors, due to the low photogenerated carrier density, significantly impedes the development of practical devices. In this study, we present an improved photoresponse within a graphene-hexagonal boron nitride-graphene vertical tunnel junction device, where the crystallographic orientation of the two graphene electrodes is aligned. Through meticulous device structure design and the adjustment of bias and gate voltages, we observe a 2 orders of magnitude increase in tunneling photocurrent, which is attributed to the momentum-conserving resonant electron tunneling. The enhanced external photoresponsivity is evident across a wide temperature and spectral range and achieves 0.7 A/W for visible light excitation. This characteristic, coupled with the device's negative differential conductance, suggests a novel avenue for highly efficient photodetection and high-frequency, logic-based optoelectronics using van der Waals heterostructures.
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Enhancing the antitumor immune response and targeting ability of oncolytic viruses will improve the effect of tumor immunotherapy. Through infecting neural stem cells (NSCs) with a capsid dual-modified oncolytic adenovirus (CRAd), we obtained and characterized the "oncolytic extracellular vesicles" (CRAdEV) with improved targeted infection and tumor killing activity compared with CRAd. Both ex vivo and in vivo studies revealed that CRAdEV activated innate immune cells and importantly enhanced the immunomodulatory effect compared to CRAd. We found that CRAdEV effectively increased the number of DCs and activated CD4+ and CD8+ T cells, significantly increased the number and activation of B cells, and produced higher levels of tumor-specific antibodies, thus eliciting enhanced antitumor activity compared with CRAd in a B16 xenograft immunocompetent mice model. This study provides a novel approach to oncolytic adenovirus modification and demonstrates the potential of "oncolytic extracellular vesicles" in antitumor immunotherapy.
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Adenoviridae , Vesículas Extracelulares , Terapia Viral Oncolítica , Vírus Oncolíticos , Animais , Camundongos , Adenoviridae/genética , Terapia Viral Oncolítica/métodos , Humanos , Linhagem Celular Tumoral , Imunoterapia , Células-Tronco Neurais/imunologia , Imunomodulação/efeitos dos fármacos , Melanoma Experimental/imunologia , Melanoma Experimental/terapia , Melanoma Experimental/patologia , Linfócitos T CD8-Positivos/imunologiaRESUMO
While the formation of an inorganic-rich solid electrolyte interphase (SEI) plays a crucial role, the persistent challenge lies in the formation of an organic-rich SEI due to the high solvent ratio in low-concentration electrolytes (LCEs), which hinders the achievement of high-performance lithium metal batteries. Herein, by incorporating di-fluoroethylene carbonate (DFEC) as a non-solvating cosolvent, a solvation structure dominated by anions is introduced in the innovative LCE, leading to the creation of a durable and stable inorganic-rich SEI. Leveraging this electrolyte design, the Li||NCM83 cell demonstrates exceptional cycling stability, maintaining 82.85% of its capacity over 500 cycles at 1 C. Additionally, Li||NCM83 cell with a low N/P ratio (≈2.57) and reduced electrolyte volume (30 µL) retain 87.58% of its capacity after 150 cycles at 0.5 C. Direct molecular information is utilized to reveal a strong correlation between solvation structures and reduction sequences, proving the anion-dominate solvation structure can impedes the preferential reduction of solvents and constructs an inorganic-rich SEI. These findings shed light on the pivotal role of solvation structures in dictating SEI composition and battery performance, offering valuable insights for the design of advanced electrolytes for next-generation lithium metal batteries.
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Assembly of the adenovirus capsid protein hexon depends on the assistance of the molecular chaperone L4-100K. However, the chaperone mechanisms remain unclear. In this study, we found that L4-100K was involved in the hexon translation process and could prevent hexon degradation by the proteasome in cotransfected human cells. Two nonadjacent domains, 84-133 and 656-697, at the N-terminal and C-terminal regions of human adenovirus type 5 L4-100K, respectively, were found to be crucial and cooperatively responsible for hexon trimer expression and assembly. These two chaperone-related domains were conserved in the sequence of L4-100K and in the function of hexon assembly across different adenovirus serotypes. Different degrees of cross-activity of hexon trimerization with different serotypes were detected in subgroups B, C, and D, which were proven to be controlled by the interaction between the C-terminal chaperone-related domain of L4-100K and hypervariable regions (HVR) of hexon. Additionally, HVR-chimeric hexon mutants were successfully assembled with the assistance of the 1-697 mutant. Structural analysis of 656-697 by nuclear magnetic resonance and structural prediction of L4-100K using Robetta showed that the two conserved domains are mainly composed of α-helices and are located on the surface of the highly folded core region. Our research provides a more complete understanding of hexon assembly and guidance for the development of hexon-chimeric adenovirus vectors that will be safer, smarter, and more efficient. IMPORTANCE Adenovirus vectors have been widely used in clinical trials of vaccines and gene therapy, although some deficiencies remain. Chimeric modification of the hexon was expected to improve the potency of preexisting immune evasion and targeting, but in many cases, viral packaging is prevented by the inability of the chimeric hexon to assemble correctly. So far, few studies have examined the mechanisms of hexon trimer assembly. Here, we show how the chaperone protein L4-100K contributes to the assembly of the adenovirus capsid protein hexon, and these data will provide a guide for novel adenovirus vector design and development, as we desired.
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Adenovírus Humanos , Chaperonas Moleculares , Proteínas não Estruturais Virais , Humanos , Adenovírus Humanos/genética , Adenovírus Humanos/metabolismo , Capsídeo/metabolismo , Proteínas do Capsídeo/metabolismo , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismo , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/metabolismoRESUMO
Integration of the human papillomavirus (HPV) genome into the cellular genome is a key event that leads to constitutive expression of viral oncoprotein E6/E7 and drives the progression of cervical cancer. However, HPV integration patterns differ on a case-by-case basis among related malignancies. Next-generation sequencing technologies still face challenges for interrogating HPV integration sites. In this study, utilizing Nanopore long-read sequencing, we identified 452 and 108 potential integration sites from the cervical cancer cell lines (CaSki and HeLa) and five tissue samples, respectively. Based on long Nanopore chimeric reads, we were able to analyze the methylation status of the HPV long control region (LCR), which controls oncogene E6/E7 expression, and to identify transcriptionally-active integrants among the numerous integrants. As a proof of concept, we identified an active HPV integrant in between RUNX2 and CLIC5 on chromosome 6 in the CaSki cell line, which was supported by ATAC-seq, H3K27Ac ChIP-seq, and RNA-seq analysis. Knockout of the active HPV integrant, by the CRISPR/Cas9 system, dramatically crippled cell proliferation and induced cell senescence. In conclusion, identifying transcriptionally-active HPV integrants with Nanopore sequencing can provide viable targets for gene therapy against HPV-associated cancers.
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Terapia Genética , Sequenciamento por Nanoporos , Infecções por Papillomavirus , Neoplasias do Colo do Útero , Integração Viral , Humanos , Neoplasias do Colo do Útero/virologia , Feminino , Sequenciamento por Nanoporos/métodos , Integração Viral/genética , Terapia Genética/métodos , Infecções por Papillomavirus/virologia , Linhagem Celular Tumoral , Células HeLa , Proteínas Oncogênicas Virais/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Papillomaviridae/genética , Papillomavirus HumanoRESUMO
Reconstructing high-quality images at a low measurement rate is a pivotal objective of Single-Pixel Imaging (SPI). Currently, deep learning methods achieve this by optimizing the loss between the target image and the original image, thereby constraining the potential of low measurement values. We employ conditional probability to ameliorate this, introducing the classifier-free guidance model (CFG) for enhanced reconstruction. We propose a self-supervised conditional masked classifier-free guidance (SCM-CFG) for single-pixel reconstruction. At a 10% measurement rate, SCM-CFG efficiently completed the training task, achieving an average peak signal-to-noise ratio (PSNR) of 26.17â dB on the MNIST dataset. This surpasses other methods of photon imaging and computational ghost imaging. It demonstrates remarkable generalization performance. Moreover, thanks to the outstanding design of the conditional mask in this paper, it can significantly enhance the accuracy of reconstructed images through overlay. SCM-CFG achieved a notable improvement of an average of 7.3â dB in overlay processing, in contrast to only a 1â dB improvement in computational ghost imaging. Subsequent physical experiments validated the effectiveness of SCM-CFG.
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BACKGROUND: Our previous study has demonstrated a decreased colonic CD8+CD39+ T cells, enrichment of granzyme A (GZMA), was found in pediatric-onset colitis and inflammatory bowel disease (IBD) characterized by impaired intestinal barrier function. However, the influence of GZMA on intestinal barrier function remains unknown. METHODS: Western blotting(WB), real-time PCR (qPCR), immunofluorescence (IF) and in vitro permeability assay combined with intestinal organoid culture were used to detect the effect of GZMA on intestinal epithelial barrier function in vivo and in vitro. Luciferase, immunoprecipitation (IP) and subcellular fractionation isolation were performed to identify the mechanism through which GZMA modulated intestinal epithelial barrier function. RESULTS: Herein, we, for the first time, demonstrated that CD8+CD39+ T cells promoted intestinal epithelial barrier function through GZMA, leading to induce Occludin(OCLN) and Zonula Occludens-1(ZO-1) expression, which was attributed to enhanced CDX2-mediated cell differentiation caused by increased glutathione peroxidase 4(GPX4)-induced ferroptosis inhibition in vivo and in vitro. Mechanically, GZMA inhibited intestinal epithelial cellular PDE4B activation to trigger cAMP/PKA/CREB cascade signaling to increase CREB nuclear translocation, initiating GPX4 transactivity. In addition, endogenous PKA interacted with CREB, and this interaction was enhanced in response to GZMA. Most importantly, administration of GZMA could alleviate DSS-induced colitis in vivo. CONCLUSION: These findings extended the novel insight of GZMA contributed to intestinal epithelial cell differentiation to improve barrier function, and enhacement of GZMA could be a promising strategy to patients with IBD.
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Ferroptose , Doenças Inflamatórias Intestinais , Mucosa Intestinal , Fosfolipídeo Hidroperóxido Glutationa Peroxidase , Mucosa Intestinal/metabolismo , Doenças Inflamatórias Intestinais/metabolismo , Doenças Inflamatórias Intestinais/patologia , Doenças Inflamatórias Intestinais/genética , Animais , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/metabolismo , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/genética , Camundongos , Humanos , Camundongos Endogâmicos C57BL , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Função da Barreira IntestinalRESUMO
We report the synthesis and structural characterization of a 2D metal-organic framework with AB-packing layers, [Co2(pybz)2(CH3COO)2]·DMF (Co2, pybz= 4-(4-pyridyl)benzoate), containing a stable (4,4)-grid network fabricated by paddle-wheel nodes, ditopic pybz, and acetate ligands. After removal of the guest, the layer structure is retained but reorganized into an ABCD packing mode in the activated phase (Co2a). Consequently, the intralayer square windows (7.2 × 5.0 Å2) close, while the interlayer separation is decreased slightly from 3.69 to 3.45 Å, leaving a narrow gap. Importantly, the dangling methyl group of the acetate with H-bonds to the adjacent layers and also the well-distributed π-π interactions between the aromatic rings of neighboring layers facilitate the structural stability. These weak supramolecular interactions further allow for favorable dynamic exfoliation of the layers, which promotes efficient adsorption of C2H2 (41.6 cm3 g-1) over CO2 with an adsorption ratio of 6.3 (0.5 bar, 298 K). The effective separation performance of equimolar C2H2/CO2 was verified by cycling breakthrough experiments and was even tolerable to moisture (R.H = 52%). DFT calculations, in situ PXRD, and PDF characterization reveal that the favorable retention of C2H2 rather than that of CO2 is due to its H-bond formation with the paddle-wheel oxygen atoms that triggers the increase in interlayer separation during C2H2 adsorption.
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Organophosphate esters (OPEs) are commonly used chemicals and are also regarded as emerging environmental pollutants. Recently, it has been proved that metabolites of OPEs (mOPEs) could also cause health concerns. However, analytical methods for the concurrent measurement of OPEs and mOPEs in human matrices are still complicated. In this study, a convenient and efficient analytical method combining a cold-induced strategy and HPLC-MS/MS was developed to simultaneously determine 18 OPEs and 10 mOPEs in human serum, urine, and human milk. In brief, after the sample was extracted with acetonitrile, a "one-step" treatment combining purification and enrichment was accomplished by cold-induced liquid-liquid extraction (CI-LLE), and analytes were then quantified by HPLC-ESI-MS/MS. The ratio of acetonitrile/water, and the temperature and time set in the CI-LLE procedure were optimized for achieving the highest enrichment factors. Under the best conditions, linearity, limits of detection (LODs), recovery, precision, and matrix effects of OPEs/mOPEs were verified. LODs of OPEs/mOPEs in serum, urine, and human milk were 0.1-113 pg/mL, 0.1-22 pg/mL, and 0.2-22 pg/mL, respectively. Average recoveries ranged from 80 to 123%, with relative standard deviations lower than 15% for most analytes. The matrix effect test showed slight signal enhancement or inhibition, and the use of isotopically labeled internal standards (ISs) could compensate for the effects. In real sample analysis, both OPEs and mOPEs showed high detecting frequency, which indicated their ubiquity in humans.
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The study of active systems, especially in the presence of a chemical background field, is garnering significant attention. Traditionally, the self-propelled velocity of active colloids was assumed to be constant, independent of the local density of colloids. In this work, we introduce a chemotactic active system that features quorum sensing (QS), wherein particles act as chemorepellents. Interestingly, these particles lose their activity in regions of high local particle density. Our findings reveal that QS leads to a transition from an oscillatory colloidal wave to a Turing-like pattern, with the observation of an intermediate state. With the variation of the sensing threshold, both the mean oscillation frequency of the system and the number of clusters exhibit non-monotonic dependence. Furthermore, the QS-induced pattern differs markedly from systems without QS, primarily due to the competitive interplay between diffusion and chemotaxis. The dynamics of this phenomenon are explained using a coarse-grained mean field model.
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In this work, CuM/CeO2 (M = Mn, Fe, Co, Ni, and Zr) catalysts with a low Cu content of 1 wt% were purposely designed and prepared using the co-impregnation method. The samples were characterized using various techniques (TG-DTA, XRD, N2-adsorption/desorption measurements, H2-TPR, XPS and Raman spectroscopy) and CO preferential oxidation (CO-Prox) under H2/CO2-rich conditions was performed. The results have shown that enhanced catalytic performance was achieved upon the introduction of Mn, Co and Ni, and little impact was observed with Zr doping, but Fe showed a negative effect, as compared with the Cu/CeO2 catalyst. Characterization data revealed that the M doping strongly changed the surface composition, revealing the decreased Cu/Ce ratios on the surface, which could be accounted for by the formation of more M/Cu-O-Ce solid solution, or strong Cu-M interactions. When Mn was used, the obtained CuMn/CeO2 catalyst revealed the highest concentration of the oxygen vacancies and Ce3+ ions, which could be correlated well with its superior catalytic performance. Compared with the Cu/CeO2 catalyst, the CO conversion rate increased by 24.7% at a low temperature of 90 °C over the CuMn/CeO2 catalyst. At 130 °C, the maximum CO conversion was 94.7% and the CO2 selectivity was 78.9%. Conversely, the Fe doped Cu/CeO2 catalyst demonstrated the poorest catalytic activity, which was due to the blockage effect of Fe species on Cu showing a high Fe/Cu ratio of 1.9 on the surface.
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BACKGROUND: The genetic association between urticaria and mental disorders and whether inflammatory cytokines mediate this process remains unclear. MATERIALS AND METHODS: A Mendelian randomization (MR) approaches to elucidate the causal relationship between urticaria and mental disorders and to validate the mediation of inflammatory cytokines. Genome-wide association study (GWAS) databases used were obtained from Psychiatric Genomics Cooperation (PGC), GWAS Catalog, and FinnGen Consortium. Our study was conducted using inverse variance weighted (IVW) and Bayesian weighted MR (BWMR) methods for joint analysis. RESULTS: The MR results showed that urticaria increased the risk of attention deficit hyperactivity disorder (ADHD) (odds ratio [OR] = $ = $ 1.088, 95% confidence interval [CI]: 1.026-1.154, p = $ = $ 0.0051); cholinergic urticaria increased the risk of bipolar disorder (BD) (OR = $ = $ 1.012, 95% CI: 1.001-1.022, p = $ = $ 0.0274); dermatographic urticaria increased the risk of ADHD (OR = $ = $ 1.057, 95% CI: 1.005-1.112, p = $ = $ 0.0323); idiopathic urticaria increased the risk of schizophrenia (SCZ) (OR = $ = $ 1.057, 95% CI: 1.005-1.112, p = $ = $ 0.0323); other unspecified urticaria increased the risk of ADHD (OR = $ = $ 1.085, 95% CI: 1.023-1.151, p = $ = $ 0.0063). We found that eight inflammatory cytokines were negatively associated with mental disorders and seven inflammatory cytokines were positively associated with mental disorders. Finally, our results suggested that inflammatory cytokines do not act as mediators between urticaria and mental disorders. CONCLUSIONS: Our study reveals a causal relationship between urticaria and the increased risk of mental disorders. We suggest that the treatment of urticaria could incorporate psychiatric interventions and mental health assessment of patients.
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Transtorno do Deficit de Atenção com Hiperatividade , Citocinas , Estudo de Associação Genômica Ampla , Análise da Randomização Mendeliana , Transtornos Mentais , Urticária , Humanos , Citocinas/genética , Urticária/genética , Transtornos Mentais/genética , Transtornos Mentais/epidemiologia , Transtorno do Deficit de Atenção com Hiperatividade/genética , Predisposição Genética para Doença/genética , Transtorno Bipolar/genética , Polimorfismo de Nucleotídeo ÚnicoRESUMO
AIM: To evaluate the effect of chlorhexidine gluconate-loaded phase-transited lysozyme (CHG@PTL) coating on inhibiting bacterial adhesion and biofilm formation in an ex vivo root canal dentine model. METHODOLOGY: The physicochemical and structural characteristics of CHG@PTL nanoparticle suspension and its coating formed on the dentine surface were analysed by thioflavin T fluorescence assay, transmission electron microscopy and confocal laser scanning microscopy (CLSM). The sustained chlorhexidine release profile of the CHG@PTL coating on the dentine surface was compared with that of the 2% CHG solution. By comparing with phosphate-buffered saline, 1% sodium hypochlorite and 2% CHG solutions, the sustained antibacterial ability of the CHG@PTL coating and its effects on adhesion and biofilm formation of three types of bacteria (E. faecalis, S. mutans, and A. viscous) were analysed in ex vivo root canal dentine models using the serial plate transfer test (SPTT) and CLSM with live/dead bacterial staining, respectively. RESULTS: CHG promoted the lysozyme protein to form a higher proportion of ß-sheet structure during phase transition. In the CHG@PTL nanoparticle suspension, characteristic drug-loaded nanospheres with a high concentration of CHG molecules inside and an outer PTL nanofilm were observed, and they formed a thinner and tighter coating on the dentine surface. The CHG@PTL coating on the dentine surface showed a significantly higher cumulative release amount of chlorhexidine than that of 2% CHG (p < .05). The results of SPTT showed that the CHG@PTL coating had a longer antibacterial duration than the control groups. After 12 h of incubation, a higher number of bacteria were agglutinated on the CHG@PTL coating surface compared to the control groups (p < .05). After 7 days of incubation, the number of agglutinated bacteria significantly decreased. At two time points, the percentage of dead bacteria on the CHG@PTL coating surface was the highest among all experimental groups based on CLSM observation (over 99.9% for all three bacteria, p < .001). CONCLUSIONS: CHG@PTL nanoparticle suspension could form an antimicrobial coating on the surface of dentine with a novel 'agglutinating bacteria and sterilizing' mode.
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With the advent of cancer immunotherapy, there is a growing interest in vaccine development as a means to activate the cellular immune system against cancer. Despite the promise of DNA vaccines in this regard, their effectiveness is hindered by poor immunogenicity, leading to modest therapeutic outcomes across various cancers. The role of Type 1 conventional dendritic cells (cDC1), capable of cross-presenting vaccine antigens to activate CD8+T cells, emerges as crucial for the antitumor function of DNA vaccines. To address the limitations of DNA vaccines, a promising approach involves targeting antigens to cDC1 through the fusion of XCL1, a ligand specific to the receptor XCR1 on the surface of cDC1. Here, female C57BL/6 mice were selected for tumor inoculation and immunotherapy. Additionally, recognizing the complexity of cancer, this study explored the use of combination therapies, particularly the combination of cDC1-targeted DNA vaccine with the chemotherapy drug Gemcitabine (Gem) and the anti-PD1 antibody in a mouse lung cancer model. The study's findings indicate that fusion antigens with XCL1 effectively enhance both the immunogenicity and antitumor effects of DNA vaccines. Moreover, the combination of the cDC1-targeted DNA vaccine with Gemcitabine and anti-PD1 antibody in the mouse lung cancer model demonstrates an improved antitumor effect, leading to the prolonged survival of mice. In conclusion, this research provides important support for the clinical investigation of cDC1-targeting DNA vaccines in combination with other therapies.
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Vacinas Anticâncer , Neoplasias Pulmonares , Vacinas de DNA , Animais , Feminino , Camundongos , Linfócitos T CD8-Positivos , Células Dendríticas , Gencitabina , Neoplasias Pulmonares/terapia , Camundongos Endogâmicos C57BL , Vacinas de DNA/imunologia , Vacinas de DNA/uso terapêutico , Vacinas Anticâncer/imunologia , Vacinas Anticâncer/uso terapêuticoRESUMO
In many developing countries, inefficient waste source separation poses a significant challenge to sustainable waste management systems, hindering progress towards a circular economy. Previous research has shown mixed results regarding the effectiveness of informational interventions and has not thoroughly evaluated regulatory measures. This study innovatively employs a quasi-experimental design, enhanced by successive surveys, to assess the impact of targeted interventions on behavioural changes in waste separation practices. Utilizing the Health Action Process Approach, we introduced three interventions - posters, educational lectures and a supervision policy - over 8 weeks among university students. Our results indicate stepwise improvements in waste separation accuracy: posters modestly increased awareness without significantly altering behaviours; educational lectures led to a 40% increase in the food waste separation rate and supervision achieved over 90% separation purity, but with an increase in 'fly-dumping'. The interventions incurred costs of 36, 60 and 365 RMB per capita annually. This research underlines the importance of customized informational interventions and the costs and challenges of initial regulatory measures in waste management, offering crucial empirical evidence and insights for creating impactful environmental behaviour change interventions.
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Lithium-oxygen batteries possess an extremely high theoretical energy density, rendering them a prime candidate for next-generation secondary batteries. However, they still face multiple problems such as huge charge polarization and poor life, which lay a significant gap between laboratory research and commercial applications. In this work, we adopt 15-crown-5 ether (C15) as solvent to regulate the generation of discharge products in lithium-oxygen batteries. The coronal structure endows C15 with strong affinity to Li+, firmly stabilizes the intermediate LiO2 and discharge product Li2O2. Thus, the crystalline Li2O2 is amorphized into easily decomposable amorphous products. The lithium-oxygen batteries assembled with 0.5â M C15 electrolyte show an increased discharge capacity from 4.0â mAh cm-2 to 5.7â mAh cm-2 and a low charge overpotential of 0.88â V during the whole lifespan at 0.05â mA cm-2. The batteries with 1â M C15 electrolyte can cycle stably for 140â cycles. Furthermore, the amorphous characteristic of Li2O2 product is preserved when matched with redox mediators such as LiI, with the charge polarization further decreasing to 0.74â V over a cycle life of 190â cycles. This provides new possibilities for electrolyte design to promote Li2O2 amorphization and reduce charge overpotential in lithium-oxygen batteries.
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Light-driven dry reforming of methane is a promising and mild route to convert two greenhouse gas into valuable syngas. However, developing facile strategy to atomically-precise regulate the active sites and realize balanced and stable syngas production is still challenging. Herein, we developed a spatial confinement approach to precisely control over platinum species on TiO2 surfaces, from single atoms to nanoclusters. The configuration comprising single atoms and sub-nanoclusters engenders pronounced electronic metal-support interactions, with resultant interfacial states prompting surface charge rearrangement. The unique geometric and electronic properties of these atom-cluster assemblies facilitate effective activation of CH4 and CO2, accelerating intermediate coupling and minimizing side reactions. Our catalyst exhibits an outstanding syngas generation rate of 34.41â mol gPt -1 h-1 with superior durability, displaying high apparent quantum yield of 9.1 % at 365â nm and turnover frequency of 1289â h-1. This work provides insightful understanding for exploring more multi-molecule systems at an atomic scale.
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The first wide-view image of multiple structural and phase transformations for MOFs from crystal state transformations further to the extreme limit approaching liquid/glass phase, was presented based on a square-layer framework of [Co2(pybz)2(CH3COO)2]·DMF (Co2). The process involves i) an initial crystalline transformation brings to a 3-fold interpenetrated and ordered vacancies contained framework [Co(pybz)2(CH3OH)2]·2CH3OH (CoM) due to in-situ disassemble-reassemble, ii) thermal induced departure of a pair of cis-form coordinated methanol in CoM leads to amorphous framework (a-dCoM), iii) glass transition (Tg = 566 K) to super-cooled liquid (scl-dCoM, spanning 38 K), iv) obtaining MOF glass g-dCoM upon quenching the super-cooled liquid, and v) re-crystallization of super-cooled liquid to six-fold interpenetrated dia-net framework [Co(pybz)2]6n (rec-dCoM) under heating above 604 K. The access to glass from CoM, provides a new self-perturbation strategy to create more MOF glasses without melting. The wider pore size distribution in amorphous/glassy MOFs than crystalline precursor realized the first time selective hydrocarbon gas separation by breakthrough experiments, which bring efficient separation of 1:99 C2H2/C2H4 by either a-dCoM or g-dCoM and produce polymer grade C2H4 with purity ≥ 99.5% after a single adsorption process. Furthermore, the mixture of 50:50 C3H6/C3H8 can be separated by a-dCoM.
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Powdery hexagonal boron nitride (h-BN), as an important material for electrochemical energy storage, has been typically synthesized in bulk and one/two-dimensional (1/2D) nanostructured morphologies. However, until now, no method has been developed to synthesize powdery three-dimensional (3D) h-BN. This work introduces a novel NaCl-glucose-assisted strategy to synthesize micron-sized 3D h-BN with a honeycomb-like structure and its proposed formation mechanism. We propose that NaCl acts as the template of 3D structure and promotes the nitridation reaction by adsorbing NH3 . Glucose facilitates the homogeneous coating of boric acid onto the NaCl surface via functionalizing the NaCl surface. During the nitridation reaction, boron oxides (BO4 and BO3 ) form from a dehydration reaction of boric acid, which is then reduced to O2 -B-N and O-B-N2 intermediates before finally being reduced to BN3 by NH3 . When incorporated into polyethylene oxide-based electrolytes for Li metal batteries, 5â wt % of 3D h-BN significantly enhances ionic conductivity and mechanical strength. Consequently, this composite electrolyte demonstrates superior electrochemical stability. It delivers 300â h of stable cycles in the Li//Li cell at 0.1â mA cm-2 and retains 89 % of discharge capacity (138.9â mAh g-1 ) after 100 cycles at 1â C in the LFP//Li full cell.