Polypropylene Blend with Polyphenols through Dynamic Vulcanization: Mechanical, Rheological, Crystalline, Thermal, and UV Protective Property

International audienceTannin and lignin were blended with polypropylene (PP) through dynamic vulcanization technique. Their influence of mechanical property, crystallinity, thermal stability, as well as ultraviolet (UV) protection property on the PP matrix was investigated and compared with native tannin and lignin. According to our experimental results, tannin and lignin undergo dynamic vulcanization and were more compatible with the PP matrix. Besides, tannin and vulcanized tannin can perform as nucleating agents of PP because of their relatively small particle size. Moreover, vulcanized tannin/lignin have a better performance on the thermal stability of PP compared with native tannin/lignin, especially PP/vulcanized lignin blend. Furthermore, vulcanized tannin/lignin present better UV protective performance, concluded from fewer changes on surface morphology, carbonyl index, crystallinity, viscosity, and tensile property

Cytotoxicity Study of Cyclopentapeptide Analogues of Marine Natural Product Galaxamide towards Human Breast Cancer Cells

Herein, we report the cytotoxicity of cyclopentapeptide analogues of marine natural product galaxamide towards breast carcinoma cells and the underlying mechanisms. We examined the effect of the novel galaxamide analogues on cancer cell proliferation by MTT assay and also further examined the most active compound for morphological changes using Hoechst33342 staining technique, induction of apoptosis, cell cycle phases, mitochondrial membrane potential (MMP), and reactive oxygen species (ROS) generation using flow cytometry in human breast cancer MCF-7 cells in vitro. Galaxamide and its analogues effectively induced toxicity in human hepatocellular carcinoma HepG2, human breast carcinoma MCF-7, human epitheloid cervix carcinoma HeLa, and human breast carcinoma MB-MDA-231 cell lines. Amongst them, compound 3 exhibited excellent toxicity towards MCF-7 cells. This galaxamide analogue significantly induced apoptosis in a dose-dependent manner in MCF-7 cells involves cell cycle arrest in the G1 phase, a reduction of MMP, and a marked increase in generation of ROS. Particularly, compound 3 of galaxamide analogues might be a potential candidate for the treatment of breast cancer

Diagnosis of post-neurosurgical bacterial meningitis in patients with aneurysmal subarachnoid hemorrhage based on the immunity-related proteomics signature of the cerebrospinal fluid

IntroductionPost-neurosurgical bacterial meningitis (PNBM) is a serious complication for patients who receive neurosurgical treatment, but the diagnosis is difficult given the complicated microenvironment orchestrated by sterile brain injury and pathogenic infection. In this study, we explored potential diagnostic biomarkers and immunological features using a proteomics platform.MethodsA total of 31 patients with aneurysmal subarachnoid hemorrhage (aSAH) who received neurosurgical treatment were recruited for this study. Among them, 15 were diagnosed with PNBM. The remaining 16 patients were categorized into the non-PNBM group. Proteomics analysis of the cerebrospinal fluid (CSF) was conducted on the Olink platform, which contained 92 immunity-related molecules.ResultsWe found that the expressions of 27 CSF proteins were significantly different between the PNBM and non-PNBM groups. Of those 27 proteins, 15 proteins were upregulated and 12 were downregulated in the CSF of the PNBM group. The receiver operating characteristic curve analysis indicated that three proteins (pleiotrophin, CD27, and angiopoietin 1) had high diagnostic accuracy for PNBM. Furthermore, we also performed bioinformatics analysis to explore potential pathways and the subcellular localization of the proteins.ConclusionIn summary, we found a cohort of immunity-related molecules that can serve as potential diagnostic biomarkers for PNBM in patients with aSAH. These molecules also provide an immunological profile of PNBM

Functional maps of human auditory cortex : effects of acoustic features and attention

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Technological properties of a branched polyethyleneimine derivative as a cross-linker for low molar ratio urea-formaldehyde resins

To address formaldehyde release problem, low-molar-ratio UF resin has become the industry's major adhesive for bonding wood-based panels. Unfortunately, its drawbacks of poor water resistance, low bonding strength and slow curing rate lead to low production efficiency and inferior dimensional stability of wood-based products. In this work, a branched polymer-based functional agent (BPG) as a crosslinker was synthesized from branched polyethyleneimine (BPEI), urea and glyoxal via two steps with deamination and Mannich reaction for promoting the performance of low-molar-ratio UF resin in wood bonding. The FTIR confirmed the successful synthesis of the long-branched BPG-bearing active aldehyde group (-CHO) as expected. The effects of BPG on curing characteristics, bonding strength and water resistance of UF resin were evaluated using DSC and tensile shearing strength measurement, respectively. Results showed that UF resin cured by BPG displayed a lower curing temperature, faster curing rate and exhibited superior wet bonding strength, 1.37 MPa, nearly two times higher than that cured by a traditional curing agent (NH4Cl). In addition, TG, XRD, FT-IR and SEM analysis confirmed that UF/BPG mixture showed excellent thermostability, compact and continuous microstructure, and decreased crystal structure due to the dense network structures in cured UF/BPG resin. These results demonstrated that BPG was an efficient crosslinker for improving the bonding strength and water resistance of low-molar-ratio UF polymer

A subregular model for calculating the mixing enthalpies in 10 binary IIB-IIIB alloy systems

Up to now there existed no theoretical calculations of the mixing enthalpies for the group-B alloy systems using the famous Miedema's theory or by the theoretical methods of the first principle. Therefore such calculations for the 10 group–IIB-IIIB binary alloy systems are performed for the first time by a subregular model. The results show that the agreement between the experimental data and calculations is pretty good and could be accepted both from the theoretical viewpoint and from the experimental one. It also can be concluded from the results that the subregular model could be used for calculating the mixing enthalpies for the group-B alloys, at least for the IIB-IIIB alloy systems. The positive mixing enthalpies for all of the 10 alloy systems are discussed