Correction: A-site-deficiency facilitated in situ growth of bimetallic Ni-Fe nano-alloys: a novel coking-tolerant fuel cell anode catalyst.

Correction for 'A-site-deficiency facilitated in situ growth of bimetallic Ni-Fe nano-alloys: a novel coking-tolerant fuel cell anode catalyst' by Yi-Fei Sun et al., Nanoscale, 2015, 7, 11173-11181.

Immunomodulatory activity on macrophage of a purified polysaccharide extracted from Laminaria japonica.

In this work, a novel water-soluble homogeneous polysaccharide (LJP-31) with a molecular mass of 2.24 × 10(6) Da was isolated and purified from Laminaria japonica using DEAE-cellulose and Sephacryl S500 chromatography. Results showed that LJP-31 mainly consists of arabinose, mannose, glucose and galactose in a molar ratio of 1.0:7.8:6.6:0.8. LJP-31 exhibited significant stimulation on macrophages and enhanced the production of NO, TNF-α, IL-1ß, IL-6 and IL-10 as well as the up-regulation of their gene expressions. Western blot analysis suggested that LJP-31 has the positive effects on the translocation of NF-κB p65 from cytoplasm to nucleus and the phosphorylation of IκBα, ERK1/2, JNK1/2 and P38 in macrophages. Flow cytometric and confocal laser-scanning microscopy analysis indicated that toll-like receptor 4 (TLR4) was at least one of the recognition receptors of LJP-31 on the plasma membrane of macrophages. Taken together, LJP-31 may exert its immunostimulating potency via TLR4 activation of MAPK and NF-κB signaling pathways.

Purification, structure features and anti-atherosclerosis activity of a Laminaria japonica polysaccharide.

A homogeneous polysaccharide (LJP12) was isolated from Laminaria japonica by diethylaminoethyl-cellulose and Sephacryl S-500 chromatography, with a molecular weight of 2.31×10(6)Da. Monosaccharide analysis showed that LJP12 was mainly composed of arabinose, xylose, mannose, glucose and galactose in a molar ratio of 1:0.17:1.54:2.64:0.18. For these monosaccharides, mannose was suggested to be 1,4-linked and 1,3,6-linked while glucose was linked by 1,6-glycosidic bond. The xylose, arabinose and galactose were suggested to be the terminal residues. To study the effects of LJP12 on protecting against atherosclerosis, LJP12 was administered to LDL receptor-deficient (LDLr(-/-)) mice (50, 100 and 200mg/kg/day, n=30 for each experimental group). Results showed that LJP12 exhibited the ability to inhibit high-fat-cholesterol diet (HFD)-induced formation of atherosclerotic plaques and plasma lipid levels in a dose-dependent manner. Meanwhile, both the HFD-induced systemic inflammation and local inflammation at the site of atherosclerotic lesion were significantly attenuated by LJP12, which were accompanied by the suppression of the activation of nuclear factor kappa-B (NF-κB) and mitogen-activated protein kinases (MAPKs) signaling pathways. Taken together, we concluded that long-term oral administration of LJP12 protects against atherosclerosis in LDLr(-/-) mice via inhibiting NF-κB/MAPKs-mediated inflammatory responses.

Structural identification and immunostimulating activity of a Laminaria japonica polysaccharide.

In the present study, a new water-soluble polysaccharide (LJP-11) was obtained from Laminaria japonica by anion exchange DEAE-cellulose chromatography and Sephacryl S-500 chromatography. The average molecular weight of this polysaccharide was estimated to be about 2.89×10(6) Da by high performance liquid chromatography system. Gas chromatography showed that LJP-11 was composed of arabinose, mannose and glucose in a molar ratio of 1.0:1.16:6.33. LJP-11 contains a long backbone consisting of (1→4)-ß-D-GlcpAc, (1→4)-α-D-Glcp, (1→6)-ß-D-Glcp and (1→3,6)-α-D-Manp. The 1-linked ß-L-Araf was linked to the C-6 of (1→3)-α-D-Manp and the sulfate group was attached to the C-4 of (1→6)-ß-D-Glcp. Pharmacological tests displayed that LJP-11 can stimulate macrophages to release NO, IL-6, TNF-α and IL-10 as well as the up-regulation of their gene expressions, indicating LJP-11 has beneficial effects on immunostimulation. Moreover, LJP-11 exhibited positive effects on the translocation of NF-κB p65 from cytoplasm to nucleus and the phosphorylation of IκBα, ERK1/2, JNK1/2 and P38 in macrophages. These results suggested that the activation of MAPK and NF-κB signaling pathways is one of the mechanisms responsible for the immunostimulating activity of LJP-11.

A-site-deficiency facilitated in situ growth of bimetallic Ni-Fe nano-alloys: a novel coking-tolerant fuel cell anode catalyst.

To date, most investigations of Ni-Fe bimetallic catalysts for solid oxide fuel cells (SOFCs) have focused on materials with micro-scale particle sizes, which severely restrict their catalytic activity. In this study, we fabricated a Ni- and/or Fe-doped A-site-deficient LaSrCrO3 perovskite (A-LSC) bimetallic anode material on which the in situ exsolution of uniformly dispersed nano Ni, Fe and Ni-Fe alloy with an average particle size of 25 to 30 nm was facilitated by the introduction of A-site deficiency under a reducing atmosphere. The dopants were shown to significantly enhance the electrical conductivity of the material by many orders of magnitude. Further characterization of the bimetallic material showed that the addition of Fe changed the reduction behavior and increased the amount of oxygen vacancies in the material. Fuel cell performance tests demonstrated that the prepared bimetallic anode catalyst with a highly catalytically active nano Ni-Fe alloy promoted the electrochemical performance in 5000 ppm H2S-syngas and improved the carbon deposition resistance compared to a monometallic anode catalyst.

Structure and bioactivity of a polysaccharide extracted from protocorm-like bodies of Dendrobium huoshanense.

The crude polysaccharides of Dendrobium huoshanense were fractionated by anion-exchange chromatography and gel permeation chromatography, giving one homogeneous fraction DHP-4A with molecular weight of 2.32 × 10(5)Da. UV spectrum indicated that there was no existence of proteins and nucleic acids in DHP-4A. Monosaccharide analysis revealed that DHP-4A was made up of glucose, arabinose, mannose and rhamnose with a molar ratio of 13.8:3.0:6.1:2.1. The backbone of DHP-4A consisted of (1 → 6)-linked glucose, (1 → 6)-linked mannose and (1 → 3,6)-linked mannose. The ßL-Rhap-(1 → 2)-ß-L-Rhap-(1 → 4)-ß-D-Manp-(1 → and α-L-Araf-(1 → 3)- α-L-Araf -(1 → 3)-α-L-Araf-(1 → were regarded as the branches attached to the C-3 position of (1 → 6)-linked mannose in the backbone. The sugar residue sequence was further determined by NMR spectra including (1)H NMR, (13)C NMR, HSQC and HMBC. Pharmacological tests showed that DHP-4A can significantly stimulate RAW 264.7 macrophage cells to secrete NO, TNF-α, IL-6 and IL-10 via activation of p38, ERK, JNK and translocation of nuclear NF-κB, indicating this polysaccharide possesses good immunoregulatory activity.

Jellyfish skin polysaccharides: extraction and inhibitory activity on macrophage-derived foam cell formation.

In this work, response surface methodology was used to determine optimum conditions for extraction of polysaccharides from jellyfish skin (JSP). The optimum parameters were found to be raw material to water ratio 1:7.5 (w/v), extraction temperature 100°C and extraction time 4h. Under these conditions, the JSP yield reached 1.007 mg/g. Papain (15 U/mL) in combination with Sevag reagent was beneficial in removing proteins from JSP. After precipitation with ethanol at final concentration of 40%, 60% and 80% in turn, three polysaccharide fractions of JSP1, JSP2 and JSP3 were obtained from JSP, respectively. The three fractions exhibited different physicochemical properties with respect to molecular weight distribution, monosaccharide composition, infrared absorption spectra, and glycosyl bond composition. In addition, JSP3 showed strong inhibitory effects on oxidized low-density lipoprotein (oxLDL) induced conversion of macrophages into foam cells, which possibly attributed to the down-regulation of some atherogenesis-related gene expressions.

Pectinase hydrolysis of Dendrobium huoshanense polysaccharide and its effect on protein nonenzymatic glycation.

The aim of this study was to investigate the inhibitory effects of molecular weight alteration of Dendrobium huoshanense polysaccharide on protein nonenzymatic glycation. For this purpose, one homogeneous active polysaccharide DHPD1 with molecular weight 3.2 kDa was extracted from D. huoshanense. GC analysis showed that DHPD1 was mainly composed of glucose, arabinose, galactose in a molar ratio of 0.023:1.023:0.021 with a trace of mannose and xylose. In order to get DHPD1-derived fragments with different molecular weight, response surface methodology was employed to optimize the enzymatic degradation conditions. The maximum reducing sugar production (0.399 mg/mL) was obtained under an optimal condition including pectinase dosage 126 U/mL, reaction pH 4.46 and reaction temperature 48 °C. By applying this condition, three DHPD1-derived fragments with different molecular weights were obtained through changing the hydrolysis time. Infrared spectroscopy analysis indicated that the backbone structure of DHPD1 was not destroyed by pectinase hydrolysis. Monosaccharide composition analysis showed that pectinase preferred to liberate glucose from DHPD1. The inhibitory action of DHPD1 on protein nonenzymatic glycation reduced with the decrease of molecular weight.