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The surge in RNA therapeutics has revolutionized treatments for infectious diseases like COVID-19 and shows the potential to expand into other therapeutic areas. However, the typical requirement for ultra-cold storage of mRNA-LNP formulations poses significant logistical challenges for global distribution. Lyophilization serves as a potential strategy to extend mRNA-LNP stability while eliminating the need for ultra-cold supply chain logistics. Although recent advancements have demonstrated the promise of lyophilization, the choice of lyoprotectant is predominately focused on sucrose, and there remains a gap in comprehensive evaluation and comparison of lyoprotectants and buffers. Here, we aim to systematically investigate the impact of a diverse range of excipients including oligosaccharides, polymers, amino acids, and various buffers, on the quality and performance of lyophilized mRNA-LNPs. From the screening of 45 mRNA-LNP formulations under various lyoprotectant and buffer conditions for lyophilization, we identified previously unexplored formulation compositions, e.g., polyvinylpyrrolidone (PVP) in Tris or acetate buffers, as promising alternatives to the commonly used oligosaccharides to maintain the physicochemical stability of lyophilized mRNA-LNPs. Further, we delved into how physicochemical and structural properties influence the functionality of lyophilized mRNA-LNPs. Leveraging high-throughput small-angle X-ray scattering (SAXS) and cryogenic transmission electron microscopy (cryo-TEM), we showed that there is complex interplay between mRNA-LNP structural features and cellular translation efficacy. We also assessed innate immune responses of the screened mRNA-LNPs in human peripheral blood mononuclear cells (PBMCs), and showed minimal alterations of cytokine secretion profiles induced by lyophilized formulations. Our results provide valuable insights into the structure-activity relationship of lyophilized formulations of mRNA-LNP therapeutics, paving the way for rational design of these formulations. This work creates a foundation for a comprehensive understanding of mRNA-LNP properties and in vitro performance change resulting from lyophilization.
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RNA-binding proteins (RBPs), as key regulators of mRNA fate, are abundantly expressed in the testis. However, RBPs associated with human male infertility remain largely unknown. Through bioinformatic analyses, we identified 62 such RBPs, including an evolutionarily conserved RBP, DEAD-box helicase 20 (DDX20). Male germ-cell-specific inactivation of Ddx20 at E15.5 caused T1-propsermatogonia (T1-ProSG) to fail to reenter cell cycle during the first week of testicular development in mice. Consequently, neither the foundational spermatogonial stem cell (SSC) pool nor progenitor spermatogonia were ever formed in the knockout testes. Mechanistically, DDX20 functions to control the translation of its target mRNAs, many of which encode cell-cycle-related regulators, by interacting with key components of the translational machinery in prospermatogonia. Our data demonstrate a previously unreported function of DDX20 as a translational regulator of critical cell-cycle-related genes, which is essential for cell-cycle reentry of T1-ProSG and formation of the SSC pool.
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Ciclo Celular , ARN Helicasas DEAD-box , Espermatogénesis , Espermatogonias , Testículo , Animales , Masculino , Ratones , Células Madre Germinales Adultas/metabolismo , Células Madre Germinales Adultas/citología , Ciclo Celular/genética , ARN Helicasas DEAD-box/metabolismo , ARN Helicasas DEAD-box/genética , Regulación del Desarrollo de la Expresión Génica , Ratones Noqueados , Proteínas de Unión al ARN/metabolismo , Proteínas de Unión al ARN/genética , Espermatogénesis/genética , Espermatogénesis/fisiología , Espermatogonias/metabolismo , Espermatogonias/citología , Testículo/metabolismo , Testículo/citologíaRESUMEN
Current cancer vaccines using T cell epitopes activate antitumor T cell immunity through dendritic cell/macrophage-mediated antigen presentation, but they lack the ability to promote B/CD4 T cell crosstalk, limiting their anticancer efficacy. We developed antigen-clustered nanovaccine (ACNVax) to achieve long-term tumor remission by promoting B/CD4 T cell crosstalk. The topographic features of ACNVax were achieved using an iron nanoparticle core attached with an optimal number of gold nanoparticles, where the clusters of HER2 B/CD4 T cell epitopes were conjugated on the gold surface with an optimal intercluster distance of 5-10 nm. ACNVax effectively trafficked to lymph nodes and cross-linked with BCR, which are essential for stimulating B cell antigen presentation-mediated B/CD4 T cell crosstalk in vitro and in vivo. ACNVax, combined with anti-PD-1, achieved long-term tumor remission (>200 days) with 80% complete response in mice with HER2+ breast cancer. ACNVax not only remodeled the tumor immune microenvironment but also induced a long-term immune memory, as evidenced by complete rejection of tumor rechallenge and a high level of antigen-specific memory B, CD4, and CD8 cells in mice (>200 days). This study provides a cancer vaccine design strategy, using B/CD4 T cell epitopes in an antigen clustered topography, to achieve long-term durable anticancer efficacy through promoting B/CD4 T cell crosstalk.
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Vacunas contra el Cáncer , Nanopartículas del Metal , Neoplasias , Ratones , Animales , Nanovacunas , Epítopos de Linfocito T , Oro , Ratones Endogámicos C57BL , Linfocitos T CD8-positivos , Vacunas contra el Cáncer/uso terapéutico , Microambiente TumoralRESUMEN
The development of highly selective Janus Kinase 1 (JAK1) inhibitors is crucial for improving efficacy and minimizing adverse effects in the clinical treatment of autoimmune diseases. In a prior study, we designed a series of C-5 4-pyrazol substituted pyrrolopyridine derivatives that demonstrated significant potency against JAK1, with a 10 â¼ 20-fold selectivity over Janus Kinase 2 (JAK2). Building on this foundation, we adopted orthogonal strategy by modifying the C-5 position with 3-pyrazol/4-pyrazol/3-pyrrol groups and tail with substituted benzyl groups on the pyrrolopyridine head to enhance both potency and selectivity. In this endeavor, we have identified several compounds that exhibit excellent potency and selectivity for JAK1. Notably, compounds 12b and 12e, which combined 4-pyrazol group at C-5 site and meta-substituted benzyl tails, displayed IC50 value with 2.4/2.2 nM and high 352-/253-fold selectivity for JAK1 over JAK2 in enzyme assays. Additionally, both compounds showed good JAK1-selective in Ba/F3-TEL-JAK1/2 cell-based assays. These findings mark a substantial improvement, as these compounds are 10-fold more potent and over 10-fold more selective than the best compound identified in our previous study. The noteworthy potency and selectivity properties of compounds 12b and 12e suggest their potential utility in furthering the development of drugs for autoimmune diseases.
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Enfermedades Autoinmunes , Compuestos Heterocíclicos , Humanos , Relación Estructura-Actividad , Janus Quinasa 1/metabolismo , Inhibidores de Proteínas Quinasas/farmacología , Janus Quinasa 2/metabolismoRESUMEN
Liposomes as drug carriers for the delivery of therapeutic agents have triggered extensive research but it remains a grand challenge to develop a novel technology for enabling rapid and mass fabrication of monodisperse liposomes. In this work, we constructed a novel ultrasonic microfluidic technology, namely ultrasonic microreactor (USMR) with two different conjunction structure (co-flow and impinge flow, corresponding to USMR-CF and USMR-IF, respectively), to prepare uniform liposomes by antisolvent precipitation method. In this process, the monodisperse liposomes with tunable droplet sizes (DS) in 60-100 nm and a polydispersity index (PDI) less than 0.1 can easily be achieved by tuning the total flow rate, flow rate ratio, ultrasonic power, and lipid concentration within the two USMRs. Impressively, the USMR-IF is superior for reducing the PDI and tuning DS of the liposomes over the USMR-CF. More importantly, the ultrasonic can effectively reduce DS and PDI at the low TFR and support the IF-micromixer in reducing the PDI even at a high TFR. These remarkable performances are mainly due to the rapid active mixing, fouling-free property and high operation stability for USMR-IF. In addition, diverse lipid formulations can also be uniformly assembled into small liposomes with narrow distribution, such as the prepared HSPC-based liposome with DS of 59.6 nm and PDI of 0.08. The liposomes show a high stability and the yield can reach a high throughput with 108 g/h by using the USMR-IF at an initial lipid concentration of 60 mM. The results in the present work highlight a novel ultrasonic microfluidic technology in the preparation of liposomes and may pave an avenue for the rapid, fouling-free, and high throughput fabrication of different and monodisperse nanomedicines with controllable sizes and narrow distribution.
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Liposomas , Ultrasonido , Liposomas/química , Portadores de Fármacos/química , Microfluídica , Lípidos/química , Tamaño de la PartículaRESUMEN
Conversion of CO2 into value-added products by electrocatalysis provides a promising way to mitigate energy and environmental problems. However, it is greatly limited by the scaling relationship between the adsorption strength of intermediates. Herein, Mn and Ni single-atom catalysts, homonuclear dual-atom catalysts (DACs), and heteronuclear DACs are synthesized. Aberration-corrected annular dark-field scanning transmission electron microscopy (ADF-STEM) and X-ray absorption spectroscopy characterization uncovered the existence of the MnâNi pair in MnâNi DAC. X-ray photoelectron spectroscopy and X-ray absorption near-edge spectroscopy reveal that Mn donated electrons to Ni atoms in MnâNi DAC. Consequently, MnâNi DAC displays the highest CO Faradaic efficiency of 98.7% at -0.7 V versus reversible hydrogen electrode (vs RHE) with CO partial current density of 16.8 mA cm-2. Density functional theory calculations disclose that the scaling relationship between the binding strength of intermediates is broken, resulting in superior performance for ECR to CO over MnâNiâNC catalyst.
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In this work, a novel conservative memristive chaotic system is constructed based on a smooth memristor. In addition to generating multiple types of quasi-periodic trajectories within a small range of a single parameter, the amplitude of the system can be controlled by changing the initial values. Moreover, the proposed system exhibits nonlinear dynamic characteristics, involving extreme multistability behavior of isomorphic and isomeric attractors. Finally, the proposed system is implemented using STMicroelectronics 32 and applied to image encryption. The excellent encryption performance of the conservative chaotic system is proven by an average correlation coefficient of 0.0083 and an information entropy of 7.9993, which provides a reference for further research on conservative memristive chaotic systems in the field of image encryption.
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Fullerene transformation emerges as a powerful route to construct defect-rich carbon electrocatalysts, but the carbon bond breakage and reformation that determine the defect states remain poorly understood. Here, we explicitly reveal that the spatial proximity of disintegrated fullerene imposes a crucial impact on the bond reformation and electrocatalytic properties. A counterintuitive hard-template strategy is adopted to enable the space-tuned fullerene restructuring by calcining impregnated C60 not only before but also after the removal of rigid silica spheres (â¼300 nm). When confined in the SiO2 nanovoids, the adjacent C60 fragments form sp3 bonding with adverse electron transfer and active site exposure. In contrast, the unrestricted fragments without SiO2 confinement reconnect at the edges to form sp2-hybridized nanosheets while retaining high-density intrinsic defects. The optimized catalyst exhibits robust alkaline oxygen reduction performance with a half-wave potential of 0.82 V via the 4e- pathway. Copper poisoning affirms the intrinsic defects as the authentic active sites. Density functional theory calculations further substantiate that pentagons in the basal plane lead to localized structural distortion and thus exhibit significantly reduced energy barriers for the first O2 dissociation step. Such space-regulated fullerene restructuring is also verified by heating C60 crystals confined in gallium liquid and a quartz tube.
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The IMpower010 and KEYNOTE-091 trials have demonstrated the benefit of adjuvant immunotherapy (IO) after chemotherapy (C+IO) in resected non-small cell lung cancer (NSCLC), including those with epidermal growth factor receptor gene (EGFR) mutation. Meanwhile, several studies have reported that EGFR-tyrosine kinase inhibitor (EGFR-TKI) may prolong disease-free survival (DFS) in these patients. However, there is currently a lack of head-to-head comparison between these two adjuvant therapy strategies. Therefore, we designed a comparative analysis of their efficacy to inform clinical decision-making by assessing DFS as the primary outcome. The results of direct meta-analysis indicated that EGFR-TKI reduced the risk of recurrence and/or death in completely resected NSCLC (HREGFR-TKI/chemo = 0.41, 95% CI: 0.23 to 0.74, p=0.003), while C+IO did not significantly improve DFS compared with chemotherapy alone (HRC+IO/chemo=0.68, 95% CI: 0.31 to 1.50, p=0.338). Indirect comparison suggested that EGFR-TKI has a trend to prolong DFS compared with C+IO (HR EGFR-TKI/C+IO = 0.60, 95% CI: 0.23 to 1.61, p=0.312), while the third-generation TKI (3rd-TKI) osimertinib significantly outperformed C+IO (HR3rd-TKI/C+IO = 0.29, 95% CI: 0.12 to 0.70, p=0.006). In conclusion, osimertinib rather than immunotherapy should be regarded as the preferred adjuvant therapy in completely resected, EGFR-mutant NSCLC.
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Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Humanos , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/genética , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/genética , Genes erbB-1 , Antígeno B7-H1/genética , Receptores ErbB , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéutico , Resultado del TratamientoRESUMEN
Programmed cell death ligand 1 (PD-L1) expression remains the most widely used biomarker for predicting response to immune checkpoint inhibitors (ICI), but its predictiveness varies considerably. Identification of factors accounting for the varying PD-L1 performance is urgently needed. Here, using data from three independent trials comprising 1239 patients, we have identified subsets of cancer with distinct PD-L1 predictiveness based on tumor transcriptome. In the Predictiveness-High (PH) group, PD-L1+ tumors show better overall survival, progression-free survival, and objective response rate with ICI than PD-L1- tumors across three trials. However, the Predictiveness-Low (PL) group demonstrates an opposite trend towards better outcomes for PD-L1- tumors. PD-L1+ tumors from the PH group demonstrate the superiority of ICI over chemotherapy, whereas PD-L1+ tumors from the PL group show comparable efficacy between two treatments or exhibit an opposite trend favoring chemotherapy. This observation of context-dependent predictiveness remains strong regardless of immune subtype (Immune-Enriched or Non-Immune), PD-L1 regulation mechanism (adaptative or constitutive), tumor mutation burden, or neoantigen load. This work illuminates avenues for optimizing the use of PD-L1 expression in clinical decision-making and trial design, although this exploratory concept should be further confirmed in large trials.
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In adult mammals, spermatogenesis embodies the complex developmental process from spermatogonial stem cells (SSCs) to spermatozoa. At the top of this developmental hierarchy lie a series of SSC subpopulations. Their individual identities as well as the relationships with each other, however, remain largely elusive. Using single-cell analysis and lineage tracing, we discovered both in mice and humans the quiescent adult SSC subpopulation marked specifically by forkhead box protein C2 (FOXC2). All spermatogenic progenies can be derived from FOXC2+ SSCs and the ablation of FOXC2+ SSCs led to the depletion of the undifferentiated spermatogonia pool. During germline regeneration, FOXC2+ SSCs were activated and able to completely restore the process. Germ cell-specific Foxc2 knockout resulted in an accelerated exhaustion of SSCs and eventually led to male infertility. Furthermore, FOXC2 prompts the expressions of negative regulators of cell cycle thereby ensures the SSCs reside in quiescence. Thus, this work proposes that the quiescent FOXC2+ SSCs are essential for maintaining the homeostasis and regeneration of spermatogenesis in adult mammals.
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Espermatogonias , Células Madre , Adulto , Animales , Humanos , Masculino , Ratones , Ciclo Celular , División CelularRESUMEN
INTRODUCTION: Conflicting findings have been reported regarding the association between STK11/LKB1 mutations and immune checkpoint inhibitor (ICB) efficacy in NSCLC. It has been reported that tumors could exhibit impaired STK11/LKB1 function even without STK11 mutations. We hypothesized that STK11 phenotype rather than mutation may better stratify ICB outcomes. METHODS: Selected functional STK11 events and LKB1 protein data were leveraged to establish a transcriptomics-based classifier of STK11 phenotype (STK11-deficient [-def] or -proficient [-prof]). We analyzed in-house and Genentech/Roche's data of three randomized trials of programmed cell death protein-1 or programmed death-ligand 1 (PD-L1) inhibition in NSCLC (ORIENT-11, n = 171; OAK, n = 699; POPLAR, n = 192) and The Cancer Genome Atlas-NSCLC cohort. RESULTS: Tissue STK11 mutation did not affect ICB outcomes. However, the survival benefit of ICB versus chemotherapy were lost or reversed in STK11-def tumors (hazard ratios for death, 95% confidence interval: OAK [0.97, 0.69-1.35]; POPLAR [1.61, 0.88-2.97]; ORIENT-11 [1.07, 0.50-2.29]), while remaining in STK11-prof tumors (hazard ratios for death, 95% confidence interval: OAK [0.81, 0.66-0.99]; POPLAR [0.66, 0.46-0.95]; ORIENT-11 [0.59, 0.37-0.92]). In tumors differentially classified by phenotype and mutation status, STK11-wild-type/def tumors had significantly worse ICB outcomes than STK11-mutated (STK11-MUT)/prof tumors (p < 0.05). The deleterious impact of STK11 deficiency was independent of STK11/KRAS/KEAP1 status or PD-L1 expression. The STING/interferon-I signaling, which was previously shown to be suppressed in STK11-MUT models, was perturbed in patients with STK11-def tumors rather than those with STK11-MUT tumors. Surprisingly, whereas high CD8+ T-cell infiltration was significantly associated with prolonged survival with ICB in STK11-prof tumors (p < 0.05 for 3 trials), it predicted an opposite trend toward worse ICB outcomes in STK11-def tumors across three trials. This suggested an association between STK11 deficiency and CD8+ T-cell dysfunction, which might not be reversed by programmed cell death protein 1 or PD-L1 blockade. CONCLUSIONS: STK11 phenotype rather than mutation status can accurately identify patients with ICB-refractory NSCLC and reflect immune suppression. It can help refine stratification algorithms for future clinical research and also provide a reliable resource aiding basic and translational studies in identifying therapeutic targets.
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Carcinoma de Pulmón de Células no Pequeñas , Interferón Tipo I , Neoplasias Pulmonares , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/genética , Antígeno B7-H1/metabolismo , Proteína 1 Asociada A ECH Tipo Kelch/genética , Interferón Tipo I/genética , Interferón Tipo I/metabolismo , Interferón Tipo I/uso terapéutico , Factor 2 Relacionado con NF-E2/genética , Carcinoma de Pulmón de Células no Pequeñas/terapia , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Inmunoterapia , Linfocitos T CD8-positivos , Fenotipo , Mutación , Quinasas de la Proteína-Quinasa Activada por el AMPRESUMEN
Four examples of N,N-bis(aryl)butane-2,3-diimine-nickel(II) bromide complexes, [ArN=C(Me)-C(Me)=NAr]NiBr2 (where Ar = 2-(C5H9)-4,6-(CHPh2)2C6H2 (Ni1), Ar = 2-(C6H11)-4,6-(CHPh2)2C6H2 (Ni2), 2-(C8H15)-4,6-(CHPh2)2C6H2 (Ni3) and 2-(C12H23)-4,6-(CHPh2)2C6H2 (Ni4)), disparate in the ring size of the ortho-cycloalkyl substituents, were prepared using a straightforward one-pot synthetic method. The molecular structures of Ni2 and Ni4 highlight the variation in the steric hindrance of the ortho-cyclohexyl and -cyclododecyl rings exerted on the nickel center, respectively. By employing EtAlCl2, Et2AlCl or MAO as activators, Ni1-Ni4 displayed moderate to high activity as catalysts for ethylene polymerization, with levels falling in the order Ni2 (cyclohexyl) > Ni1 (cyclopentyl) > Ni4 (cyclododecyl) > Ni3 (cyclooctyl). Notably, cyclohexyl-containing Ni2/MAO reached a peak level of 13.2 × 106 g(PE) of (mol of Ni)-1 h-1 at 40 °C, yielding high-molecular-weight (ca. 1 million g mol-1) and highly branched polyethylene elastomers with generally narrow dispersity. The analysis of polyethylenes with 13C NMR spectroscopy revealed branching density between 73 and 104 per 1000 carbon atoms, with the run temperature and the nature of the aluminum activator being influential; selectivity for short-chain methyl branches (81.8% (EtAlCl2); 81.1% (Et2AlCl); 82.9% (MAO)) was a notable feature. The mechanical properties of these polyethylene samples measured at either 30 °C or 60 °C were also evaluated and confirmed that crystallinity (Xc) and molecular weight (Mw) were the main factors affecting tensile strength and strain at break (εb = 353-861%). In addition, the stress-strain recovery tests indicated that these polyethylenes possessed good elastic recovery (47.4-71.2%), properties that align with thermoplastic elastomers (TPEs).
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Electrochemical CO2 reduction (ECR) through single-atom catalysts (SACs) consisting of transition metals (TMs) anchored on nitrogenated carbon (TM-N-C) has shown promise for carbon neutralization. However, high overpotentials and low selectivity are still issues. Regulating the coordination environment of anchored TM atom is important to address these problems. In this study, we evaluated nonmetal atom (NM = B, O, F, Si, P, S, Cl, As and Se) modified TM (TM = Fe, Co, Ni, Cu and Zn)@N4-C catalysts for their ECR to CO performance using density functional theory (DFT) calculations. NM dopants can induce active center distortion and tune electron structure, promoting intermediate formation. Doping heteroatoms can improve ECR to CO activity on Ni and Cu@N4 but worsen it on Co@N4 catalysts. Fe@N4-F1(I), Ni@N3-B1, Cu@N4-O1(III), and Zn@N4-Cl1(II) have excellent activity for ECR to CO, with overpotentials of 0.75, 0.49, 0.43, and 0.15 V, respectively, and improved selectivity. The catalytic performance is related to the intermediate binding strength, as evidenced by d band center, charge density difference, crystal orbital Hamilton population (COHP), and integrated COHP (ICOHP). It is expected that our work can be used as the design principle to guide the synthesis of the high-performance heteroatoms modified SACs for ECR to CO.
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Ce2(MoO4)3 was prepared using dielectric barrier discharge (DBD) plasma method, co-precipitation method and hydrothermal method, respectively, with water/ethanol (W/O) as solvent, oleylamine (OAm) and oleic acid (OAc) as additives. Preparation method showed significant influence on the morphological and structural properties, as well as photocatalytic performance. Ce2(MoO4)3 synthesized with DBD plasma (MO-P) was mainly flowerlike nanosheets, which were beneficial to promoting electron transfer and providing more space for catalytic activity. Also, MO-P samples exhibited more oxygen vacancies, which were conducive to the photocatalytic performance. What's more, MO-P showed lower PL intensity and narrow energy gap, which implied a slow photoelectron-hole pair recombination rate and an increased electron transfer rate. The degradation rate of methyl orange (50 mg/L) could achieve 98% within 12 min with 0.5 g/L MO-P. Hydroxyl radicals (·OH) and superoxide radicals (·O2-) played a major effect. Plasma synthesis method exhibited potential application prospect in photocatalysts preparation.
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Aminas , Ácido Oléico , Agua , Radical HidroxiloRESUMEN
Pregnant women of advanced maternal age (AMA) are vulnerable to exposure to the surrounding environment. Assessment of trace elements in pregnant women living in specific areas is important for biomonitoring. However, exposure levels and variation patterns during pregnancy remains controversial and attracts extensive public concern. Therefore, we aimed to evaluate exposure of 18 toxic and/or essential trace elements in maternal plasma and in paired cord plasma during pregnancy at AMA. A total of 48 pregnant women of AMA were recruited in Peking University Third Hospital from 2018 to 2021. Eighteen elements found in maternal plasma during the 1st, 2nd, or 3rd trimester of pregnancy and paired cord plasma were measured by 7700x ICP-MS (Agilent Technologies, Palo Alto, CA, USA) and Elan DRC type II ICP-MS (The Perkin-Elmer Corporation, Waltham, MA USA). Concentrations of Pb, Se, Fe, Zn, and Mo all decreased during pregnancy, while Cu increased. Interestingly, concentrations of Rb decreased initially but then increased. Elements as Al, Co, Se, Cu, and Ni showed significantly lower levels in cord than in maternal plasma, while elements as Sr, Fe, Rb, Mn and Zn displayed significantly higher levels in cord than in maternal plasma. Moreover, positively- interacted clusters were found in Ni-Co-Cu-Al-Rb-Zn and Zn-Mn-Al-Pb in maternal blood. Similar positively-interacted clusters were found in Zn-Ni-Co, Zn-Ni-Fe, Mn-Al-Pb, Fe-Pb-Mn, Fe-Ni-Cu, and Rb-Cu-Sb-Fe-Mn in cord plasma. Furthermore, correlations between paired maternal and cord blood samples for As, Sr, and Mo were statistically significant, indicating that the fetus burden may reflect maternal exposure to some extent. Admittedly, levels of toxic and essential elements in our cohort study were comparatively lower than those in the scientific literature.
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Oligoelementos , Femenino , Embarazo , Humanos , Oligoelementos/análisis , Estudios de Cohortes , Plomo , Edad Materna , Monitoreo BiológicoRESUMEN
The following family of N,N-diaryl-2,3-dimethyl-1,4-diazabutadienes, ArN[double bond, length as m-dash]C(Me)C(Me)[double bond, length as m-dash]NAr (Ar = 2,6-Me2-4-{CH(4-FC6H4)2}C6H2L1, 2-Me-6-Et-4-{CH(4-FC6H4)2}C6H2L2, 2,4-{CH(4-FC6H4)2}2-6-MeC6H2L3, 2,4-{CH(4-FC6H4)2}2-6-EtC6H2L4, 2,4-{CH(4-FC6H4)2}2-6-iPrC6H2L5), each incorporating para-substituted 4,4-difluorobenzhydryl groups but differing in the ortho-pairing, have been synthesized and used as precursors to their respective nickel(ii) bromide complexes, Ni1-Ni5. Compound characterization has been achieved through a combination of FT-IR, multinuclear NMR spectroscopy (1H, 13C, 19F) and elemental analysis. In addition, L1, Ni1 and Ni5 have been structurally characterized with Ni1 and Ni5 revealing similarly distorted tetrahedral geometries about nickel but with distinct differences in the steric protection offered by the ortho-substituents. All nickel complexes, under suitable activation, showed high activity for ethylene polymerization with a predilection towards forming branched high molecular weight polyethylene with narrow dispersity. Notably the most sterically bulky Ni5, under activation with either EtAlCl2, Et2AlCl or EASC, was exceptionally active (0.9-1.0 × 107 g of PE per (mol of Ni) per h) at an operating temperature of 40 °C. Furthermore, the polyethylene generated displayed molecular weights close to one million g mol-1 (M w range: 829-922 kg mol-1) with high branching densities (86-102/1000 carbons) and a selectivity for short chain branches (% Me = 94.3% (EtAlCl2), 87.2% (Et2AlCl), 87.7% (EASC)). Further analysis of the mechanical properties of the polymers produced at 40 °C and 50 °C using Ni5 highlighted the key role played by crystallinity (X c) and molecular weight (M w) on tensile strength (σ b) and elongation at break (ε b). In addition, stress-strain recovery tests reveal these high molecular weight polymers to exhibit characteristics of thermoplastic elastomers (TPEs).
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BACKGROUND: Brucea javanica oil (BJO) is the active substance extracted from the dry and mature fruit of Brucea javanica. Its pharmaceutical preparation, BJO emulsion (BJOE), is one of the most widely studied traditional Chinese medicine preparations for the treatment of malignancy. However, the unrevealed anti-tumor mechanism immensely limits further development of BJOE. PURPOSE: In this study, we delved into the anti-tumor mechanism of commercial BJOE, including its influence on the tumor microenvironment (TME) and the treatment effect when combined with anti-programmed cell death protein-1 (PD-1) therapy. METHODS: The cytotoxicity of BJOE was tested in different cells in vitro, and a Förster resonance energy transfer system was also constructed to predict the release behavior of BJOE in vivo. Then, a B16 melanoma mouse model was used to explore the combination of BJOE and anti-mouse PD-1 antibody therapy. In addition, mass cytometry was used to test the impact of both drugs on the TME. RESULTS: Out data revealed that BJOE did not directly kill tumor cells in vitro. However, BJOE was mainly released at the tumor site, converting an immunosuppressive TME into an immune-activated state, and its combination with anti-PD-1 therapy significantly inhibited the growth of melanoma and prolonged the survival time of the mice due to an increase in cytotoxic T lymph (CD8+ T) and helper/inducible T lymph (CD4+ T) cells in lymph nodes and tumors. CONCLUSIONS: Our work explored the anti-tumor mechanism of commercial BJOE and the regulation of cytokines by BJOE when it was combined with anti-PD-1 therapy in vivo. The combination of these therapies could increase the numbers of CD4+ T-cells, CD8+ T-cells, and effective natural killer cells and the ratio of MI/M2 macrophages in tumor tissues, promoting inflammatory activity and enhancing the anti-tumor effect. This study provides a theoretical basis for advancing the modern development of traditional Chinese medicine preparations and stands as a reference for clinically improving the efficacy of PD-1 antibodies.
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Brucea , Animales , Brucea/química , Brucea javanica , Linfocitos T CD8-positivos/metabolismo , Muerte Celular , Línea Celular Tumoral , Citocinas/metabolismo , Emulsiones/farmacología , Factores Inmunológicos , Inmunoterapia , Ratones , Aceites de Plantas/farmacologíaRESUMEN
A carbon shell encapsulating a transition metal-based core has emerged as an intriguing type of catalyst structure, but the effect of the shell thickness on the catalytic properties of the buried components is not well known. Here, we present a proof-of-concept study to reveal the thickness effect by carbonizing the isotropic and homogeneous oleylamine (OAm) ligands that cover colloidal MoS2. A thermal treatment turns OAm into a uniform carbon shell, while the size of MoS2 monolayers remains identical. When evaluated toward an acidic hydrogen evolution reaction, the calcined MoS2 catalysts deliver a volcano-type activity trend that depends on the calcination temperature. Rutherford backscattering spectrometry and depth-profiling X-ray photoelectron spectroscopy consistently provide an accurate quantification of the carbon shell thickness. The same variation pattern of catalytic activity and carbon shell thickness, aided by kinetic studies, is then persuasively justified by the respective limitations of electron and proton conductivities on the two branches of the volcano curve.
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Developing highly efficient electrocatalysts for electrochemical CO2 reduction (ECR) to value-added products is important for CO2 conversion and utilization technologies. In this work, a sulfur-doped Ni-N-C catalyst is fabricated through a facile ion-adsorption and pyrolysis treatment. The resulting Ni-NS-C catalyst exhibits higher activity in ECR to CO than S-free Ni-N-C, yielding a current density of 20.5â mA cm-2 under -0.80â V versus a reversible hydrogen electrode (vs. RHE) and a maximum CO faradaic efficiency of nearly 100 %. It also displays excellent stability with negligible activity decay after electrocatalysis for 19â h. A combination of experimental investigations and DFT calculations demonstrates that the high activity and selectivity of ECR to CO is due to a synergistic effect of the S and Ni-NX moieties. This work provides insights for the design and synthesis of nonmetal atom-decorated M-N-C-based ECR electrocatalysts.