96 research outputs found

    Composite Hydrogels with the Simultaneous Release of VEGF and MCP-1 for Enhancing Angiogenesis for Bone Tissue Engineering Applications

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    Rapid new microvascular network induction was critical for bone regeneration, which required the spatiotemporal delivery of growth factors and transplantation of endothelial cells. In this study, the linear poly(d,l-lactic-co-glycolic acid)-b-methoxy poly(ethylene glycol) (PLGA-mPEG) block copolymer microspheres were prepared for simultaneously delivering vascular endothelial growth factor (VEGF) and monocyte chemotactic protein-1 (MCP-1). Then, vascular endothelial cells (VECs) with growth factor loaded microspheres were composited into a star-shaped PLGA-mPEG block copolymer solution. After this, composite hydrogel (microspheres ratio: 5 wt%) was formed by increasing the temperature to 37 °C. The release profiles of VEGF and MCP-1 from composite hydrogels in 30 days were investigated to confirm the different simultaneous delivery systems. The VECs exhibited a good proliferation in the composite hydrogels, which proved that the composite hydrogels had a good cytocompatibility. Furthermore, in vivo animal experiments showed that the vessel density and the mean vessel diameters increased over weeks after the composite hydrogels were implanted into the necrosis site of the rabbit femoral head. The above results suggested that the VECs-laden hydrogel composited with the dual-growth factor simultaneous release system has the potential to enhance angiogenesis in bone tissue engineering

    Effect of pyrolysis condition on the adsorption mechanism of heavy metals on tobacco stem biochar in competitive mode

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    Abstract(#br)To clarify the adsorption mechanism of multi-ions on biochars in competitive environment is very important for the decontamination of co-existed heavy metals. Herein, tobacco stem was pyrolyzed in different temperatures with selected residences to obtain biochars with various surface chemistry. Then the adsorption of co-existed typical heavy-metal ions like lead, cadmium, and copper was studied, followed with systematic analysis of surface properties of the post-adsorption biochars. After carefully examining the adsorption performance and surface property alteration of the demineralized biochars, the adsorption mechanism of multi-ions in competitive environment was discovered. Lead showed the most competitive nature with co-existence of cadmium and copper, but the adsorption..

    Anisotropic in-plane heat transport of Kitaev magnet Na2_2Co2_2TeO6_6

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    We report a study on low-temperature heat transport of Kitaev magnet Na2_2Co2_2TeO6_6, with the heat current and magnetic fields along the honeycomb spin layer (the abab plane). The zero-field thermal conductivity of Îșxxa\kappa^a_{xx} and Îșxxa∗\kappa^{a*}_{xx} display similar temperature dependence and small difference in their magnitudes; whereas, their magnetic field (parallel to the heat current) dependence are quite different and are related to the field-induced magnetic transitions. The Îșxxa(B)\kappa^a_{xx}(B) data for B∄aB \parallel a at very low temperatures have an anomaly at 10.25--10.5 T, which reveals an unexplored magnetic transition. The planar thermal Hall conductivity Îșxya\kappa^a_{xy} and Îșxya∗\kappa^{a*}_{xy} show very weak signals at low fields and rather large values with sign change at high fields. This may point to a possible magnetic structure transition or the change of the magnon band topology that induces a radical change of magnon Berry curvature distribution before entering the spin polarized state. These results put clear constraints on the high-field phase and the theoretical models for Na2_2Co2_2TeO6_6.Comment: 7 pages, 4 figure

    Subtype-Based Analysis of Cell-in-Cell Structures in Esophageal Squamous Cell Carcinoma

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    Cell-in-cell (CIC) structures are defined as the special structures with one or more cells enclosed inside another one. Increasing data indicated that CIC structures were functional surrogates of complicated cell behaviors and prognosis predictor in heterogeneous cancers. However, the CIC structure profiling and its prognostic value have not been reported in human esophageal squamous cell Carcinoma (ESCC). We conducted the analysis of subtyped CIC-based profiling in ESCC using “epithelium-macrophage-leukocyte” (EML) multiplex staining and examined the prognostic value of CIC structure profiling through Kaplan-Meier plotting and Cox regression model. Totally, five CIC structure subtypes were identified in ESCC tissue and the majority of them was homotypic CIC (hoCIC) with tumor cells inside tumor cells (TiT). By univariate and multivariate analyses, TiT was shown to be an independent prognostic factor for resectable ESCC, and patients with higher density of TiT tended to have longer post-operational survival time. Furthermore, in subpopulation analysis stratified by TNM stage, high TiT density was associated with longer overall survival (OS) in patients of TNM stages III and IV as compared with patients with low TiT density (mean OS: 51 vs 15 months, P = 0.04) and T3 stage (mean OS: 57 vs 17 months, P=0.024). Together, we reported the first CIC structure profiling in ESCC and explored the prognostic value of subtyped CIC structures, which supported the notion that functional pathology with CIC structure profiling is an emerging prognostic factor for human cancers, such as ESCC

    [Fe(CN)6] vacancy-boosting oxygen evolution activity of Co-based Prussian blue analogues for hybrid sodium-air battery

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    Prussian blue analogues (PBAs) have emerged as efficient catalysts for oxygen evolution reaction (OER) due to their porous structure with well-dispersed active sites. However, Co-based PBA (Co-PBA) electrocatalysts are characterized by moderate OER kinetics. In this study, we developed a facile high-yield strategy to fabricate defective Co-PBA (D-Co-PBA) with [Fe(CN)6] vacancies and exposed Co (III) active sites by post-oxidation treatment of the pristine Co-PBA with aqueous H2O2. Rietveld refinement results show that the lattice parameter (a) and unit-cell volume (V) of D-Co-PBA are smaller than those of the pristine Co-PBA, thereby confirming the generation of [Fe(CN)6] vacancies. Density functional theory calculations reveal that the [Fe(CN)6] vacancy can effectively regulate the electronic structure of D-Co-PBA; this condition reduces the reaction barrier of the rate-determining step toward OER. In OER, the D-Co-PBA catalyst achieves a lower overpotential of 400 mV at a current density of 10 mA cm−2, which is superior to that of Ir/C (430 mV) and Co-PBA (450 mV). A hybrid sodium-air battery assembled with Pt/C and D-Co-PBA catalysts displays a discharge voltage of 2.75 V, an ultralow charging–discharging gap of 0.15 V, and a round-trip efficiency of 94.83% on the 1000th cycle at the current density of 0.01 mA cm-2. This study is highly promising for large-scale production of affordable and effective PBA-based materials with desirable OER activity for metal-air batteries and water-alkali electrolyzers, thus helping achieve the goal of sustainability

    Verification of specific G-quadruplex structure by using a novel cyanine dye supramolecular assembly: II. The binding characterization with specific intramolecular G-quadruplex and the recognizing mechanism

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    The supramolecular assembly of a novel cyanine dye, 3,3â€Č-di(3-sulfopropyl)-4,5,4â€Č,5â€Č-dibenzo-9-ethyl-thiacarbocyanine triethylammonium salt (ETC) was designed to verify specific intramolecular G-quadruplexes from duplex and single-strand DNAs. Spectral results have shown that ETC presented two major distinct signatures with specific intramolecular G-quadruplexes in vitro: (i) dramatic changes in the absorption spectra (including disappearance of absorption peak around 660 nm and appearance of independent new peak around 584 nm); (ii) ∌70 times enhancement of fluorescence signal at 600 nm. Furthermore, based on 1H-nuclear magnetic resonance and circular dichroism results, the preferring binding of ETC to specific intramolecular G-quadruplexes probably result from end-stacking, and the loop structure nearby also plays an important role

    Oral microbiome and risk of malignant esophageal lesions in a high-risk area of China: A nested case-control study.

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    OBJECTIVE: We aimed to prospectively evaluate the association of oral microbiome with malignant esophageal lesions and its predictive potential as a biomarker of risk. METHODS: We conducted a case-control study nested within a population-based cohort with up to 8 visits of oral swab collection for each subject over an 11-year period in a high-risk area for esophageal cancer in China. The oral microbiome was evaluated with 16S ribosomal RNA (rRNA) gene sequencing in 428 pre-diagnostic oral specimens from 84 cases with esophageal lesions of severe squamous dysplasia and above (SDA) and 168 matched healthy controls. DESeq analysis was performed to identify taxa of differential abundance. Differential oral species together with subject characteristics were evaluated for their potential in predicting SDA risk by constructing conditional logistic regression models. RESULTS: A total of 125 taxa including 37 named species showed significantly different abundance between SDA cases and controls (all P0.84. CONCLUSIONS: The oral microbiome may play an etiological and predictive role in esophageal cancer, and it holds promise as a non-invasive early warning biomarker for risk stratification for esophageal cancer screening programs

    Rapid Identification of <i>HSA</i> Genetically Modified Goats by Combining Recombinase Polymerase Amplification (RPA) with Lateral Flow Dipstick (LFD)

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    Genetically modified (GM) animals have attracted considerable attention and faced challenges. Human serum albumin (HSA) GM goats have been used to produce goat milk with serum albumin from humans, which has shown great potential in the market. Establishing an accurate method to distinguish goats with a genome modified by HSA has become necessary. Here, we established a platform to detect HSA GM goats by combining the advantages of recombinase polymerase amplification (RPA) and lateral flow dipstick (LFD) strategies. The whole detection process could be completed within 1 h, obtaining a direct result that could be visualized by a characteristic red band after a quick amplification under a constant temperature of 42 °C in the RPA experiments. Moreover, the GM goats could be identified with a detection limit of 0.1 ng using our method. Therefore, this study provided a rapid and convenient RPA-LFD method for the immediate detection of HSA GM goats. This will be useful for the identification of HSA GM goats, which may be used to distinguish the mixture of GM mutton and normal mutton
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