In situ growth of corrosion resistant Mg-Fe layered double hydroxide film on Q235 steel.

HYPOTHESIS: In situ grown layered double hydroxide (LDH) is commonly used one of the anticorrosion ways for metal materials; Due to the dense growth of LDH on the metal surface, its special layered structure can effectively delay the corrosion rate of metal. METHODS: In this study, we use a hydrothermal method to successfully grow Mg-Fe LDH film on steel substrates based on self-supplied Fe3+ ions. The films were characterized by X-ray diffraction, scanning electron microscopy, and X-ray energy dispersive spectrometry. The potential corrosion resistance of the obtained Mg-Fe LDH film was confirmed using electrochemical impedance spectroscopy and polarization curves. FINDINGS: After systematic adjustment and parameter optimization, it was found that Mg-Fe LDH film exhibited the best growth morphology and comprehensive performance with an initial pH value of 10, Mg2+/urea ratio of 1:4 and reaction time of 12 h. The SEM and electrochemical results further demonstrated that Mg-Fe LDH film play a good protection effect on carbon steel surface. This study provides an important reference for the processing of anticorrosion LDHs film.

Intraoperative perfusion-weighted imaging in non-enhanced glioma surgery.

BACKGROUND: The objective of the present study was to observe and analyze the significance of perfusion-weighted imaging for guiding the operation implementation for non-enhanced glioma, and analyze the estimation of the histopathological grade of the non-enhanced glioma and the accuracy of the degree of malignancy degree before surgery. METHODS: Fifty-six patients diagnosed with non-enhanced glioma through conventional magnetic resonance scanning were selected. Before surgery, conventional magnetic resonance scanning and perfusion-weighted imaging were performed on all patients. The property classification was performed with the perfusion-weighted imaging parameters: cerebral blood volume (CBV) and cerebral blood flow (CBF) before surgery. RESULTS: Surgery was performed on the 56 patients. Tumors were excised and processed for histopathological classification and semi-quantitative immunohistochemical analysis of vascular endothelial growth factor (VEGF) levels. Histology was compared after surgery and the classification accuracy rate was analyzed before surgery. Additionally, conventional magnetic resonance scanning and perfusion-weighted imaging were performed on 15 patients during surgery. We compared and analyzed the reference value of perfusion-weighted imaging before and during surgery. Residual diseased tissues were excised; histopathological examination was performed, and semi-quantitative immunohistochemical analysis of VEGF was performed. Regarding maximal magnetic resonance perfusion-weighted imaging measured before surgery, the CBV, CBF, and expression level of VEGF were positively correlated with the pathological grade of tumors. If the CBV and CBF values of the non-enhanced glioma were higher, the grade of malignancy was higher (P<0.01), and the positive expression rate of VEGF was higher (P<0.01). CONCLUSIONS: Magnetic resonance perfusion-weighted imaging can display vessel growth and distribution within non-enhanced gliomas before surgery, and effectively evaluate the histopathological grade and grade of malignancy, and provide accurate guidance for tumor resection during surgery.

Synthesis and application in polypropylene of a novel of phosphorus-containing intumescent flame retardant.

A novel phosphorus-containing triazine oligomer poly(2-morpholinyl-4-penta-erythritol phosphate-1,3,5-triazine) (PMPT) was synthesized as a kind of tri-component intumescent flame retardant (IFR). The chemical structure of PMPT was characterized by FTIR, 1H-NMR and 31P-NMR, and the mechanical and flammability properties of FR-PP were measured. The FTIR results showed that the expected chemical reactions had  happened at each step. The 1H-NMR and 31P-NMR spectra also agreed with the chemical structure of PMPT. The slight effect of PMPT on the mechanical properties of FR-PP suggested that PMPT and PP are compatible. The high limited oxygen index (LOI) values of FR-PP revealed that PMPT was an efficient IFR and there was the synergistic effect between PMPT and ammonium polyphosphate/ pentaerythritol (APP/PER).