13 research outputs found

    Synthesis of thiolated chitosan and preparation nanoparticles with sodium alginate for ocular drug delivery

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    Purpose: The goal of the present study was to synthesize mucoadhesive polymer -thiolated chitosan (TCS) from chitosan (CS), then prepared CS/TCS-sodium alginate nanoparticles (CS/TCS-SA NPs), determined which was more potential for ocular drug delivery. Methods: A new method for preparing TCS was developed, and the characteristics were determined using Fourier transform infrared spectroscopy and the degree of thiol immobilized was measured by Ellman's reagent. Human corneal epithelium (HCE) cells were incubated with different concentrations of TCS for 48 h to determine the cell viabilities. CS/ TCS-SA NPs were prepared and optimized by a modified ionic gelation method. The particle sizes, zeta potentials, Scanning electron microscopy images, mucoadhesion, in vitro cell uptake and in vivo studies of the two types of NP were compared. Results: The new method enabled a high degree of thiol substitution of TCS, up to 1,411.01±4.02 μmol/g. In vitro cytocompatibility results suggest that TCS is nontoxic. Compared to CS-SA NPs, TCS-SA NPs were more stable, with higher mucoadhesive properties and could deliver greater amounts of drugs into HCE cells in vitro and cornea in vivo. Conclusions: TCS-SA NPs have better delivery capability, suggesting they have good potential for ocular drug delivery applications

    Synthesis of thiolated chitosan and preparation nanoparticles with sodium alginate for ocular drug delivery

    No full text
    Purpose: The goal of the present study was to synthesize mucoadhesive polymer - thiolated chitosan (TCS) from chitosan (CS), then prepared CS/TCS-sodium alginate nanoparticles (CS/TCS-SA NPs), determined which was more potential for ocular drug delivery. Methods: A new method for preparing TCS was developed, and the characteristics were determined using Fourier transform infrared spectroscopy and the degree of thiol immobilized was measured by Ellman's reagent. Human corneal epithelium (HCE) cells were incubated with different concentrations of TCS for 48 h to determine the cell viabilities. CS/TCS-SA NPs were prepared and optimized by a modified ionic gelation method. The particle sizes, zeta potentials, Scanning electron microscopy images, mucoadhesion, in vitro cell uptake and in vivo studies of the two types of NP were compared. Results: The new method enabled a high degree of thiol substitution of TCS, up to 1,411.01 +/- 4.02 mu mol/g. In vitro cytocompatibility results suggest that TCS is nontoxic. Compared to CS-SA NPs, TCS-SA NPs were more stable, with higher mucoadhesive properties and could deliver greater amounts of drugs into HCE cells in vitro and cornea in vivo. Conclusions: TCS-SA NPs have better delivery capability, suggesting they have good potential for ocular drug delivery applications.Science and Technology Planning Projects of Xiamen Science & Technology Bureau, China [502Z20093012, 3502Z20103009

    Thickness-tunable growth of ultra-large, continuous and high-dielectric h-BN thin films

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    The outstanding thermal properties, mechanical properties and large optical bandgap of hexagonal boron nitride (h-BN) make it very attractive for various applications in ultrathin 2D microelectronics. However, the synthesis of large lateral size and uniform h-BN thin films with a high breakdown strength still remains a great challenge. Here, we comprehensively investigated the effect of growth conditions on the thickness of h-BN films via low pressure chemical vapor deposition (LPCVD). By optimizing the LPCVD growth parameters with electropolished Cu foils as the deposition substrates and developing customized `` enclosure'' quartz-boat reactors, we achieved thickness-tunable (1.50-10.30 nm) growth of h-BN thin films with a smooth surface (RMS roughness is 0.26 nm) and an ultra-large area (1.0 cm x 1.0 cm), meanwhile, the as-grown h-BN films exhibited an ultra-high breakdown strength of similar to 10.0 MV cm(-1), which is highly promising for the development of electrically reliable 2D microelectronic devices with an ultrathin feature.This work was supported by the China Postdoctoral Science Foundation (Grant No. 2016M602820), the National Natural Science Foundation of China (Grant No. 51607138), the Youth Innovation Foundation of State Key Laboratory of Electrical Insulation and Power Equipment (Grant No. EIPE17312), the Research Foundation of State Key Laboratory of Intense Pulsed Radiation Simulation and Effect (Grant No. SKLIPR.1512) and the Innovative Research Group of National Natural Science Foundation of China (Grant No. 51521065)

    Association of neutrophil to lymphocyte ratio and D-dimer with functional outcome in patients with cerebral venous sinus thrombosis

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    Abstract Background Investigations on the risk factors for the prognosis of cerebral venous sinus thrombosis (CVST) are limited. This study aimed to explore whether specific inflammatory factors and coagulation indictors are associated with functional outcome in patients treated for CVST. Methods This retrospective study included 137 patients admitted to our hospital between January 2010 and October 2021. The functional outcome was assessed with the modified Rankin Scale (mRS) score at discharge. Patients were divided into two groups, 102 patients with favorable outcomes (mRS 0-1) and 35 patients with poor outcomes (mRS 2-6). The clinical indexes were compared between two groups. Multivariable logistic regression was performed to identify the independent influencing factors for poor outcomes of CVST patients. The prognostic indicators were analyzed using the receiver operating characteristic (ROC) curve. Results Compared with the favorable outcome group, the incidence of impaired consciousness and brain lesion, the levels of D-dimer, RDW, neutrophil count, neutrophil to lymphocyte ratio (NLR) and red blood cell distribution width to platelet ratio (%) on admission were significantly higher in the poor outcome group, while the level of lymphocyte count was significantly lower. After multivariable logistic regression analysis, baseline D-dimer level (odds ratio (OR), 1.180; 95% confidence interval (CI), 1.019-1.366, P = 0.027) and NLR (OR, 1.903; 95%CI, 1.232-2.938, P = 0.004) were significantly associated with unfavorable outcome at discharge. The ROC curve analysis showed that the areas under the curve of D-dimer, NLR and their combined detection for predicting worse outcome were 0.719, 0.707 and 0.786, respectively. Conclusions Elevated D-dimer level and NLR on admission were associated with an increased risk of poor functional outcome in patients with CVST

    Nonenzymatic biosensor based on CuxO nanoparticles deposited on polypyrrole nanowires for improving detection range

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    National Nature Science Foundation of China [30500127, 31070845]; Natural Science Foundation of Fujian Province of China [2011J01331]; Fundamental Research Funds for the Central Universities [2011121001]CuxO (CuO and Cu2O composite) nanoparticles modified polypyrrole (PPy) nanowires were fabricated and used as a biosensor for detecting glucose (GLC). PPy nanowires were prepared through electrodeposition, while CuxO nanoparticles were deposited on PPy nanowires by electrodeposition and electrochemical oxidation in situ. The scanning electron microscopy images showed the CuxO nanoparticles aligned along the PPy nanowires uniformly and the average size of CuxO nanoparticles is about 90 nm. The electrocatalytic activity of CuxO/PPy/Au towards GLC was investigated under alkaline conditions using cyclic voltammetry and chronoamperometry. The sensor exhibited a linear range up to 8 mM of GLC, which is more than two times of most of the existing non-enzymatic GLC sensors based on CuO or Cu2O. The sensitivity of the sensor is 232.22 mu AmM(-1)cm(-2) and detection limit is 6.2 mu M (at signal/noise=3). Moreover, the sensor showed excellent selectivity, reproducibility and stability properties. These excellent performances make CuxO/PPy/Au a good nonenzymatic GLC sensor. (C) 2012 Elsevier B.V. All rights reserved

    Synergistic passivation and stepped-dimensional perovskite analogs enable high-efficiency near-infrared light-emitting diodes

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    Formamidinium lead iodide (FAPbI3) perovskites are promising emitters for near-infrared light-emitting diodes. However, their performance is still limited by defect-assisted nonradiative recombination and band offset-induced carrier aggregation at the interface. Herein, we introduce a couple of cadmium salts with acetate or halide anion into the FAPbI3 perovskite precursors to synergistically passivate the material defects and optimize the device band structure. Particularly, the perovskite analogs, containing zero-dimensional formamidinium cadmium iodide, one-dimensional δ-FAPbI3, two-dimensional FA2FAn-1PbnI3n+1, and three-dimensional α-FAPbI3, can be obtained in one pot and play a pivotal and positive role in energy transfer in the formamidinium iodide-rich lead-based perovskite films. As a result, the near-infrared FAPbI3-based devices deliver a maximum external quantum efficiency of 24.1% together with substantially improved operational stability. Combining our findings on defect passivation and energy transfer, we also achieve near-infrared light communication with device twins of light emitting and unprecedented self-driven detection
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