9 research outputs found
Fouling-Resistant Behavior of Silver Nanoparticle-Modified Surfaces against the Bioadhesion of Microalgae
Unwanted adhesion of microalgae on
submerged surfaces is a ubiquitous
problem across many maritime operations. We explored the strategy
of developing a silver nanoparticle (AgNP) coating for antifouling
applications in marine and freshwater environments. In situ growth
of AgNPs was achieved by a polydopamine (PDA)-based method. A range
of most used industrial materials, including glass, polystyrene, stainless
steel, paint surface, and even cobblestone, were employed, on which
AgNP coatings were built and characterized. We described the fouling-resistant
behavior of these AgNP-modified surfaces against two typical fouling
organisms: a marine microalga Dunaliella tertiolecta and a freshwater green alga community. The PDA-mediated AgNP deposition
strategy was demonstrated applicable for all the above materials;
the resulting AgNP coatings showed a significant surface inhibitory
effect against the adhesion of microalgae by above 85% in both seawater
and freshwater environments. We observed that contact killing was
the predominant antifouling mechanism of AgNP-modified surfaces, and
the viability of the microalgae cells in bulk media would not be affected.
In addition, silver loss from PDA-mediated AgNPs was relatively slow;
it could allow the coating to persist for long-term usage. This study
showed the potential of preparing environmentally friendly surfaces
that can effectively manage biofouling through the direct deposition
of AgNP coatings
Anticoagulant Surface Coating Using Composite Polysaccharides with Embedded Heparin-Releasing Mesoporous Silica
Release
of heparin from the surface of biomaterials is a feasible
and efficient manner for preventing blood coagulation because of the
high bioactivity of free heparin and a low application dosage compared
to intravenous injection of heparin. Here we report a novel method
featuring a blend of heparin-loaded SBA-15, catechol-modified chitosan
(CCS), and heparin as a heparin-releasing film. The release of heparin
was based on its leakage from heparin-loaded amino-functionalized
mesoporous silica SBA-15 (SBA-15-NH<sub>2</sub>), which was controlled
by the amino density of the SBA-15-NH<sub>2</sub>. Heparin-loaded
SBA-15-NH<sub>2</sub>, CCS, and heparin were mixed together, and the
mixture was cast onto the surface of a polydopamine-modified substrate,
forming a heparin-releasing film on the surface of the substrate.
The polydopamine acted as an adhesive interlayer that stabilized the
film coated on the substrate. The sustained release rates of heparin
from the film ranged from 15.8 to 2.1 μg/cm<sup>2</sup>/h within
8 h. The heparin-releasing film showed low fibrinogen adsorption,
platelet adhesion, and hemolysis rate, indicating that it has good
blood compatibility. This new approach would be very useful for modifying
the surface of versatile blood-contacting biomaterials and ultimately
improve their anticoagulation performance
Single-Atom Iron Catalyst Based on Functionalized Mesophase Pitch Exhibiting Efficient Oxygen Reduction Reaction Activity
Designing highly efficient and low-cost electrocatalysts is of great importance in the fields of energy conversion and storage. We report on the facile synthesis of a single atom (SA) iron catalyst via the pyrolysis of a functionalized mesophase pitch. Monomers of naphthalene and indole underwent polymerization in the presence of iron chloride, which afterwards served as the pore-forming agent and iron source for the resulting catalyst. The SA-Fe@NC catalyst has a well-defined atomic dispersion of iron atoms coordinated by N-ligands in the porous carbon matrix, exhibiting excellent oxygen reduction reaction (ORR) activity (E1/2 = 0.89 V) that outperforms the commercial Pt/C catalyst (E1/2 = 0.84 V). Moreover, it shows better long-term stability than the Pt/C catalyst in alkaline media. This facile strategy could be employed in versatile fossil feedstock and develop promising non-platinum group metal ORR catalysts for fuel cell technologies
Image1_Prognostic value of glucose to lymphocyte ratio for patients with renal cell carcinoma undergoing laparoscopic nephrectomy: A multi-institutional, propensity score matching cohort study.jpeg
BackgroundWe evaluated the prognostic value of preoperative blood glucose to lymphocyte ratio (GLR) in renal cell carcinoma (RCC) patients who underwent laparoscopic nephrectomy through a multi-institutional clinical study.MethodsA total of 420 patients with RCC from three medical centers from 2014 to 2019 were included in this study. The effect of GLR on overall survival (OS) and cancer-specific survival (CSS) in RCC patients was assessed by Kaplan-Meier survival curves, univariate and multivariate Cox regression analysis. Moreover, a 1:1 propensity score matching (PSM) analysis of different GLR groups was utilized to further confirm the prognostic ability of GLR.ResultsThe optimal cut-off value for GLR was 6.8. Patients were divided into high GLR and low GLR groups according to the optimal cut-off value. GLR was significant association with diabetes, cardiovascular disease and AJCC stage. High GLR predicted adverse OS (P = 0.002) and CSS (P ConclusionsHigh GLR is associated with adverse prognosis in RCC patients, and GLR can serve as an independent prognostic marker for OS and CSS in RCC patients receiving laparoscopic nephrectomy.</p