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Dynamic mechanical analysis (DMA) applies an oscillating force to a specimen and analyzes the rheological and viscoelastic properties of a material. Since this method is used to characterize the frequency-dependent viscoelastic properties, it is mostly used for polymers, which have high sensitivity to the loading frequency. Cementitious composites are brittle and require more attention to specimen preparation and experimental settings to obtain reliable results. This work develops a DMA test protocol for cementitious composites which includes analyzing the effect of preload test, frequency pretest, and amplitude sweep on properties of cementitious composites. We propose a statistical method to analyze the variation between samples and determine the outliers among the specimens with the same mix to obtain valid test results from a sample group. The dynamic results obtained by using the proposed method are also discussed to serve as the baseline. The experimental setup parameters and statistical analysis presented in this work can be a robust foundation for the DMA analysis of cementitious composites. [ABSTRACT FROM AUTHOR]

Osteoporosis is a degenerative bone disease highly prevalent in older women, causing high morbidity and mortality rates. Fourteen kinds of fucoidan were isolated from Sargassum fusiforme through acid (named as SFS), alkaline (SFJ) and water (SFW). SFW was passed through an anion exchange column to obtain SFW-0, SFW-0.5 and SFW-2. SFW-0.5 and SFW-2 were degraded to obtain different sulfate group contents SFW-x-M/S/O (x for 0.5 or 2). We further confirmed SFW-0.5-O was the most effective fraction of SFW. SFW-0.5-O may have alternating backbones of (Gal)n and (Fuc)n, and the main sulfation may be at C2/C3 of the Fuc/Gal residues. SFW-0.5-O inhibition of OC differentiation was associated with IRF-8 signaling; meanwhile, SFW-0.5-O promoted osteoblast differentiation and bone mineral nodule formation. SFW-0.5-O also effectively ameliorated osteoporosis symptom caused by estrogen deprivation in vivo. We uncovered that the fucoidan active fraction SFW-0.5-O demonstrated effective bone protection, may be exploited for osteoporosis therapy. Fucoidan active ingredient SFW-0.5-O can effectively inhibit osteoclastogenesis, promote osteoblast differentiation, and improve osteoporosis symptoms caused by estrogen deprivation. [ABSTRACT FROM AUTHOR]

The SARS-CoV-2 spike glycoproteins (SGPs) and human angiotensin converting enzyme 2 (ACE2) are the two key targets for the prevention and treatment of COVID-19. Host cell surface heparan sulfate (HS) is believed to interact with SARS-CoV-2 SGPs to facilitate host cell entry. In the current study, a series of polysaccharides from Saccharina japonica were prepared to investigate the structure-activity relationship on the binding abilities of polysaccharides (oligosaccharides) to pseudotype particles, including SARS-CoV-2 SGPs, and ACE2 using surface plasmon resonance. Sulfated galactofucan (SJ-D-S-H) and glucuronomannan (Gn) displayed strongly inhibited interaction between SARS-CoV-2 SGPs and heparin while showing negligible inhibition of the interaction between SARS-CoV-2 SGPs and ACE2. The IC 50 values of SJ-D-S-H and Gn in blocking heparin SGP binding were 27 and 231 nM, respectively. NMR analysis showed that the structure of SJ-D-S-H featured with a backbone of 1, 3-linked α-L-Fuc p residues sulfated at C4 and C2/C4 and 1, 3-linked α-L-Fuc p residues sulfated at C4 and branched with 1, 6-linked β-D-galacto-biose; Gn had a backbone of alternating 1, 4-linked β-D-GlcA p residues and 1, 2-linked α-D-Man p residues. The sulfated galactofucan and glucuronomannan showed strong binding ability to SARS-CoV-2 SGPs, suggesting that these polysaccharides might be good candidates for preventing and/or treating SARS-CoV-2. [ABSTRACT FROM AUTHOR]

Laminarin (LA), a storage glucan, was purified from the brown alga Sargassum thunbergii. After specific oxidation using the stable nitroxyl radical, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), together with NaBr and NaClO, glucoglucuronan (LAO) was obtained. Compositional analysis of LAO showed a molar ratio of glucuronic acid (GlcA) to glucose (Glc) of 12.7: 1. Nuclear magnetic resonance (NMR) and mass spectroscopy (MS) showed LAO to have a backbone of (1 → 3)-linked β-D-Glc p A interspersed with (1 → 3, 1 → 6)-linked β-D-Glc p , that was terminated with β-D-Glc p A. LAO inhibited human lung cancer A549 cell proliferation in vitro. IC 50 values at 12 h and 24 h were 2.70 mg/mL and 2.85 mg/mL, respectively. Western blotting showed that TSC2 was up-regulated at an LAO concentration of 3.80 mg/mL. FAK, PI3K, P-AKT and mTOR were down-regulated, indicating LAO inhibited cancer cell proliferation through the FAK/PI3K/AKT/mTOR pathway. Surface plasmon resonance (SPR) studies revealed that LAO showed an IC 50 of 0.07 mg/mL inhibiting the binding of heparin to fibroblast growth factor 1 (FGF1) LAO inhibition of heparin binding to FGF2 fluctuated between 15% and 28%, suggesting that LAO inhibits A549 cell proliferation by selectively interacting with FGF1. [ABSTRACT FROM AUTHOR]

A total 68 types of marine algae oligosaccharides and polysaccharides were prepared and used to study the structure-activity relationship of oligosaccharides and polysaccharides in their interactions with fibroblast growth factors (FGF) 1 and 2. Factors considered include different types of algae, extraction methods, molecular weight, sulfate content and fractions. In the case of low molecular weight polysaccharide (SJ-D) from Saccharina japonica and its fractions eluting from anion exchange column, both 1.0 M NaCl fraction (SJ-D-I) and 2.0 M NaCl fraction (SJ-D-S) had stronger binding affinity than the parent SJ-D, suggesting that sulfated galactofucans represented the major tight binding component. Nuclear magnetic resonance showed that SJ-D-I was a typical sulfated galactofucan, composed of four units: 1, 3-linked 4-sulfated α-L-fucose (Fuc); 1, 3-linked 2, 4-disulfated α-L-Fuc; 1, 6-linked 4-sulfated β-D-Gal and/or 1, 6-linked 3, 4-sulfated β-D-Gal. Modification by autohydrolysis to oligosaccharides and desulfation decreased the FGF binding affinity while oversulfation increased the affinity. The solution-based affinities of SJ-D-I to FGF1 and FGF2 were 69 nM and 3.9 nM, suggesting that SJ-D-I showed better preferentially binding to FGF1 than a natural ligand, heparin, suggesting that sulfated galactofucan might represent a good regulator of FGF1. [ABSTRACT FROM AUTHOR]

Polysaccharide (HFSGF) was purified from Sargassum fusiforme. Autohydrolysis and gel column chromatography were performed to fractionate HFSGF into three components (HFSGF-S, HFSGF-L and HFSGF-H). Compositional analysis, mass spectrometry and nuclear magnetic resonance spectroscopy were used to elucidate the structural features of HFSGF. HFSGF-S was a mixture of sulfated galacto-fuco-oligomers, from the branches terminal ends; in HFSGF-L, the branches of HFSGF, was a sulfated galactofucan, containing a backbone of 1,3-linked α-L-fucan sulfated at C2/4 and/or C4 and interspersed with galactose (Gal); and in HFSGF-H, the backbone of HFSGF, was composed of alternating 1,2-linked α-D-mannose (Man) and 1,4-linked β-D-glucuronic acid (GlcA), branched with sulfated galactofucan or sulfated fucan, 1,3-linked α-L-fucan sulfated at C2/4 and/or C4 and partly interspersed with Gal. Some fucose (Fuc) residues were also partially branched with xylose (Xyl). The anti-lung cancer activities of HFSGF-L and HFSGF-H against human lung cancer A549 cells in vitro and A549 xenograft tumor growth in vivo were determined. HFSGF-H had higher activity in vitro (IC 50 ~12 mg/mL for 24 h) and in vivo (tumor inhibition ~51%.) than HFSGF-L, indicating that HFSGF-H might be a leading compound for a potential new therapeutics for the treatment of lung cancer. [ABSTRACT FROM AUTHOR]

Polysaccharides were extracted from Grateloupia livida (Harv.) Yamada using hot water (extracted product denoted WGW) and then degraded in dilute sulfuric acid (degraded product denoted WGWD). The degraded mixture was then separated into four fractions through anion exchange chromatography on 2-diethylaminoethanol (DEAE)-Bio-Gel Agarose FF gel. Electrospray ionization collision-induced dissociation tandem mass spectrometry (ESI-CID-MS/MS) was performed to elucidate the structural features of all fractions. In combination with nuclear magnetic resonance spectroscopy (NMR) and infrared spectroscopy (IR) data, the major polysaccharide structures were concluded to be µ-carrageenan and κ-carrageenan. µ-Carrageenan usually has a backbone of alternating 1,3-linked ß-D-galactopyranose residues sulfated at C-4 and 1-4-linked α-D-galactopyranose residues sulfated at C-6, while κ-carrageenan consists of alternating 1,3-linked ß-D-galactopyranose residues sulfated at C-4 and 1,4-linked α-D-3,6-anhydrogalactopyranose residues. Trace v-carrageenan- composed of 1,3-linked ß-D-galactopyranose residues sulfated at C-4 and 1,4-linked α-D-galactopyranose residues sulfated at C-2 and C-6, was also detected. Furthermore, the polysaccharide had a backbone comprising 1,3-linked ß-D-galactopyranose and 1,4-linked α-L-galactopyranose sulfated at C-6, which is the agarose precursor. The hydroxy groups in the galactopyranose were partially substituted by methyl and pyruvic acid acetal (PA) groups. The anti-complementary activities of WGW and its derivatives against classical pathways were measured. The native polysaccharides in WGW had higher activities, while the derivatives had much weaker activities. This indicated that the molecular weight and sulfate content were important factors affecting the anti-complement activity. [ABSTRACT FROM AUTHOR]

Abstract The present work was focused on studying the strain rate sensitivity of cementitious syntactic foams (CSF), which are particulate composites reinforced with hollow glass microspheres (HMG). Different density CSFs (1.31–1.74 g/cm3) with different volume fractions (20–40%) of HGMs were tested with a split-Hopkinson pressure bar setup. The true particle densities of the HGMs were in the range of 0.38–0.60 g/cm3. In addition, the macro- and micro-scale failure mechanisms were investigated with high-speed camera imaging, micro-CT scanning, and electron microscopy. The results showed that both the CSFs and the baseline material (control sample), which is the cement paste matrix of the CSFs, showed strain rate sensitivity in mechanical properties in the 102–103 s−1 strain rate range. CSFs had relatively lower strain rate sensitivity in comparison to the matrix material. In the same range of strain rate, both the CSFs and the control sample showed significant changes in their macro and micro failure mechanisms depending on their age, composition and loading rate. The level of damage at the peak load for the high strain rate was higher in comparison to the same materials tested under quasi-static loading conditions for CSFs and the cement matrix. [ABSTRACT FROM AUTHOR]

Heparan sulfate (HS), is a glycosaminoglycan (GAG) involved in various biological processes, including blood coagulation, wound healing and embryonic development. HS 3- O -sulfotransferases (3-OST), which transfer the sulfo group to the 3-hydroxyl group of certain glucosamine residues, is a key enzyme in the biosynthesis of a number of biologically important HS chains. The 3-OST-1 isoform is one of the 7 known 3-OST isoforms and is important for the biosynthesis of anticoagulant HS chains. In this study, we cloned 3-OST-1 from the rat brain by reverse transcription-polymerase chain reaction (RT-PCR). After codon optimization and removal of the signal peptide, the recombinant plasmid was transformed into Escherichia coli BL21 (DE3) to obtain a His tagged-3-OST-1 fusion protein. SDS-PAGE analysis showed that the expressed 3-OST-1 was mainly found in inclusion bodies. The 3-OST-1 was purified by Ni affinity column and refolded by dialysis. The activity of obtained 3-OST-1 was 0.04 U/mL with a specific activity of 0.55 U/mg after renaturation. Furthermore, a co-expressed recombinant plasmid pET-28a-3-OST-1 with the chaperone expression system (pGro7) was constructed and transferred to E. coli BL21 (DE3) to co-express recombinant strain E. coli BL21 (DE3)/pET-28a-3-OST-1 + pGro7. The soluble expression of 3-OST-1 was significantly improved in the co-expressed recombinant strain, with enzyme activity reaching 0.06 U/mL and having a specific activity of 0.83 U/mg. N -sulfo, N -acetylheparosan (NSNAH) was modified by the recombinant expressed 3-OST-1 and the product was confirmed by 1 H NMR showing the sulfo group was successfully transferred to NSNAH. [ABSTRACT FROM AUTHOR]

The advancements in structural materials are guided by the desire of lowering the density and increasing the strength. Composite materials show promise in tuning the density and strength to meet specific design requirements. Lightweight cementitious materials, such as foamed concretes, are generally known to show poor mechanical properties (e.g., compressive strength and elastic modulus). The lack of control over the size, shape, and distribution of air voids severely limits the improvement of mechanical properties in lightweight cementitious materials. This work is focused on manufacturing and examining the mechanical properties of cementitious syntactic foams with hollow glass microspheres. Use of hollow particles to incorporate porosity allows for the control over the size, shape, and volume fraction of voids present in the composite. Hollow glass microspheres with several different densities (0.15–0.60 g/cm 3 ) are used in different volume fractions (20%–50%) to manufacture the cementitious syntactic foams. The results show that cementitious syntactic foams (CSF) have compressive strengths (32–88 MPa) and elastic moduli (10–20 GPa) for a given range of low density (1.15–1.80 g/cm 3 ), which are better than other cellular cementitious materials in the same density range. In-situ micro-CT scan results reveal that the micro-fracture mechanisms in CSFs under compressive loading depend on the microsphere density and aging of the material. [ABSTRACT FROM AUTHOR]

Polysaccharide (ST) was prepared from Sargassum thunbergii using hot water. Two fractions (ST-1 and ST-2) were prepared using anion exchange chromatography. One desulfated polysaccharide (ST-1-DS) was also prepared. Electrospray ionization mass spectrometry (ESI–MS) performed on ST-1-DS showed that the desulfated polysaccharides contained methyl glycosides of mono-sulfated and di-sulfated galacto-fucooligosaccharides. This result suggested that ST-1 might contain sulfated galactofucan, which consists of a backbone of alternating (Gal) n and (Fuc) n and sulfated randomly on Gal and mainly on C-2 in Fuc. In addition, ST-1 was degraded in 1 M sulfuric acid. The solution was centrifuged, and the supernatant was concentrated and precipitated in ethanol to obtain the precipitate (ST-1-P). ST-1-P was then separated using gel chromatography and anion exchange chromatography to obtain the oligomers. ESI–MS spectra of oligomers indicated that ST-1 mostly contained sulfated glucuronomannan and fucoglucuronan. ESI–MS with collision-induced dissociation tandem mass spectrometry (ESI-CID-MS/MS) suggested that glucuronomannan contained alternating 2-linked Man and 4-linked GlcA, while fucoglucuronan contained 4-linked glucuronan with branched Fuc at C-3. Finally, the neuroprotective activities of ST, ST-1, ST-2 and MIX (a mixture of ST-1 and ST-2) were determined. ST showed the most neuroprotective activity, which indicated that ST might be a good candidate for curing neurodegenerative diseases. [ABSTRACT FROM AUTHOR]

Monthly variations of polysaccharides from Sargassum thunbergii and their anti-complement and anti-tumour activities were investigated. It was observed that an increase in fucose and total sugar contents occurred during the growth period (from early April to mid-June), accompanied by a decrease in molar ratios of other monosaccharides to fucose. The highest yields were obtained from early July to early September, which was in accordance with the significant increase in molar ratio of glucose to fucose and decrease in molar ratio of other monosaccharides to fucose. And the above results suggested that S. Thunbergii synthesized large amount of laminaran, the storage substance of brown algae, during the senescence period. However, sulfate contents were relatively stable in the life cycle of S. thunbergii . These results suggested that S. thunbergii synthesized complex sulfated heteropolysacchairdes during inactive period, while during other periods, it synthesized more sulfated galactofucan. All polysaccharides showed anti-complement activity, suggesting that the harvesting time did not influence the anti-complement activities. In the anti-tumour assay in vitro , the polysaccharides taken during the senescence period had much lower anti-tumour activity, suggesting that fucoidan, but not laminaran, determined the anti-tumour activities. Therefore, polysaccharides from S. thunbergii might have great potential in anti-complement and anti-tumour application. [ABSTRACT FROM AUTHOR]

Polysaccharides derived from Sargassum thunbergii were prepared to investigate the structure-activity relationship between polysaccharides and anti-tumor activity in vitro . Many factors were examined. Overall, STW (polysaccharide extracted by hot water) had the best activity, followed by STJ (polysaccharide extracted by dilute alkali), and then STA (polysaccharide extracted by dilute acid). Location of algae had no effect at 500 μg/mL and 1000 μg/mL, while STW-QD (algae collected from Qingdao, China) had the best activity, followed by STW-WZ (algae collected from Wenzhou, China) and STW-LJ (algae collected from Lianjiang, China) and then STW-DL (algae collected from Dalian, China) and STW-RC (algae collected from Rongcheng, China) at 250 μg/mL. Moreover, molecular weight had no effect at 1000 μg/mL, while higher molecular weights were associated with better activities at 250 μg/mL and 500 μg/mL. Sulfate content had no effect at 1000 μg/mL, while anti-tumor activities decreased accompanying with the changes of sulfate content. Uronic acid content was an important factor influencing activity. The fractions of STW showed little anti-tumor activity; however, the mixture of the fractions of STW showed approximately 60% inhibition. Overall, these findings suggested that the anti-tumor activity of polysaccharides required multilateral cooperation and that some of the effective components were lost. [ABSTRACT FROM AUTHOR]

Middle East respiratory syndrome coronavirus (MERS-CoV) is a zoonotic virus with high contagion and mortality rates. Heparan sulfate proteoglycans (HSPGs) are ubiquitously expressed on the surface of mammalian cells. Owing to its high negatively charged property, heparan sulfate (HS) on the surface of host cells is used by many viruses as cofactor to facilitate viral attachment and initiate cellular entry. Therefore, inhibition of the interaction between viruses and HS could be a promising target to inhibit viral infection. In the current study, the interaction between the receptor-binding domain (RBD) of MERS-CoV and heparin was exploited to assess the inhibitory activity of various sulfated glycans such as glycosaminoglycans, marine-sourced glycans (sulfated fucans, fucosylated chondroitin sulfates, fucoidans, and rhamnan sulfate), pentosan polysulfate, and mucopolysaccharide using Surface Plasmon Resonance. We believe this study provides valuable insights for the development of sulfated glycan-based inhibitors as potential antiviral agents. [ABSTRACT FROM AUTHOR]

Osteoporosis (OP) is a systemic bone degenerative disease characterized by low bone mass and deteriorated microarchitecture of bone tissue, causing high morbidity and mortality rates. Bone resorption by overactivated osteoclasts (OCs) is the main cause of osteoporosis. Glucuronomannan and its oligomers (Gs) and their sulfated derivatives (SGs) were previously prepared. The anti-osteoporosis activities of these glycans were evaluated. Firstly, we determined the viability of RAW264.7 by CCK-8 test. Nextly, we investigated the inhibitory effects of Gs and SGs on the differentiation of RAW264.7 cells into OCs using tartrate-resistant acid phosphatase (TRAP) staining, F-actin ring staining, qualitative reverse-transcription polymerase chain reaction(qRT-PCR) and western blotting. TRAP staining revealed that Gs significantly blocked RANKL-induced OC generation while SGs did not exhibit this ability. F-actin staining assays demonstrated that Gs inhibits RANKL-induced actin ring formation. qRT-PCR analyses indicated that Gs dose-dependently inhibited the expression of OCs marker genes including Trap , NFATc1 , c-Fos , DC-Stamp and ATP60 during the differentiation process, while SGs did not suppress. Regarding the mechanism of Gs, it was found that Gs suppressed osteoclastogenesis via inhibiting the degradation of IRF-8 and interfering with NF-κB pathway activation. Together, these results suggest that Gs have the ability to inhibit osteoclastogenesis by modulating IRF-8 signaling. • Gs as novel drugs to investigate their therapeutic capacity for osteoporosis. • The inhibitory effect of Gs on OC is associated with the up-regulation of IRF-8. • Gs with low polymerization have better efficacy in the treatment of osteoporosis. [ABSTRACT FROM AUTHOR]

Tau spreading in Alzheimer's disease is mediated by cell surface heparan sulfate (HS). As a class of sulfated polysaccharides, fucoidans might compete with HS to bind tau, resulting in the cessation of tau spreading. The structural determinants of fucoidans for competition with HS binding to tau are not well understood. Sixty previously prepared fucoidans/glycans with different structural determinants were used to determine their binding abilities to tau using SPR and AlphaLISA. Finally, it was found that fucoidans had two fractions (sulfated galactofucan (SJ-I) and sulfated heteropolysaccharide (SJ-GX-3)), which exhibited strong binding abilities than heparin. Tau cellular uptake assays using wild type mouse lung endothelial cell lines were performed. It was shown SJ-I and SJ-GX-3 inhibited tau-cell interaction and tau cellular uptake, suggesting that fucoidans might be good candidates for inhibiting tau spreading. NMR titration mapped fucoidans binding sites, which could provide the theoretical basis for the design of tau spreading inhibitors. [Display omitted] [ABSTRACT FROM AUTHOR]

Marble thin panels are widely used for external building envelope application, due to their original light transparency effects during day-time and night-time. Considering their application in polluted environments and the interaction with aggressive agents, the aesthetical characteristics of this element could be compromised by degradation processes. To investigate such changes, experimental ageing test analyzing the effects of acid rain aggression on different marble samples is carried out in this research. Marbles’ reactions are studied in terms of: lightness, gloss, and Distinctness Of Image. The main findings demonstrate how the acids hugely degrade both the marble typologies and quantify the modifications. [ABSTRACT FROM AUTHOR]

Highlights: [•] Six heteropolysaccharides were obtained from Sargassum species. [•] Four heteropolysaccharides exhibited the neuroprotective effects. [•] The antioxidant activities of heteroploysaccharides were determined. [•] The relationship of these two activities was discussed. [ABSTRACT FROM AUTHOR]

Highlights: [•] Three polysaccharides HFS-1, HFS-2, and HFS-3 were isolated from S. fusiforme. [•] HFS-1 was composed of soluble laminaran with chains that are terminated by β-d-glucose residues. [•] HFS-2 was a mixture of alginate and sulfated heteropolysaccharide. [•] HFS-3 has a sequence of 3-linked fucopyranose interspersed by galactopyranose or galactooligosaccharides. [Copyright &y& Elsevier]

The satellite power subsystem is responsible for all power supply in a satellite, and is an important component of it. The system's performance has a direct impact on the operations of other systems as well as the satellite's lifespan. Sequence to sequence (seq2seq) learning has recently advanced, gaining even more power in evaluating complicated and large-scale data. The potential of the seq2seq model in detecting anomalies in the satellite power subsystem is investigated in this work. A seq2seq-based scheme is given, with a thorough comparison of different neural-network cell types and levels of data smoothness. Three specific approaches were created to evaluate the seq2seq model performance, taking into account the unsupervised learning mechanism. The findings reveal that a CNN-based seq2seq with attention model under suitable data-smoothing conditions has a better ability to detect anomalies in the satellite power subsystem. [ABSTRACT FROM AUTHOR]

Highlights: [•] Methyl glycosides of multi-sulfated fucooligomers were obtained. [•] Multi-sulfated fucooligosacchairdes were characterized by ESI-CID-MS/MS. [•] Isomers of fucooligosaccharides were determined by ESI-CID-MS/MS/MS. [Copyright &y& Elsevier]

Highlights: [•] Degraded fucoidans were obtained by hydrogen peroxide and ascorbic acid. [•] Low molecular weight fucoidan exhibited the neuroprotective activities. [•] Heteropolysaccharides showed the neuroprotective effects. [ABSTRACT FROM AUTHOR]

Highlights: [•] Polysaccharides displayed the neuroprotective activity. [•] Polysaccharides displayed the antioxidant activity. [•] Polysaccharides derived from water extraction. [Copyright &y& Elsevier]

Highlights: [•] Fucoidan administered could significantly reduce the blood glucose level. [•] Serum insulin levels in diabetic mice were increased by fucoidan. [•] OGTT revealed that fucoidan treatment had some effect on glucose disposal. [•] Furthermore, fucoidan altered plasma lipid levels. [•] Fucoidan could be a potential oral hypoglycemic agents or functional food. [ABSTRACT FROM AUTHOR]

Abstract: In this study, we prepared seven polysaccharides extracted from five algae including one brown alga Saccharina japonica, one red alga Porphyra haitanensis and three green algae Codium fragile, Enteromorpha linza and Bryopsis plumose. The chemical composition and capability of moisture-absorption and moisture-retention were investigated in comparison with those of hyaluronic acid (HA). The low molecular weight polysaccharides extracted from brown seaweed exhibited the highest moisture-absorption and moisture-retention abilities of all of the polysaccharides studied and performed better than HA. The relationships between chemical composition (including sulfated groups, monosaccharide, and molecular weight) and the functions of polysaccharides were also studied. We found the sulfated group was a main active site for moisture-absorption and moisture-retention abilities. These abilities were also related to molecular weight; with the exception of the low molecular weight polysaccharide extracted from red seaweed, lower molecular weight improved moisture-absorption and moisture-retention abilities. [Copyright &y& Elsevier]

Abstract: Desulfation of a fucoidan from Saccharina japonica by treatment with DMSO–MeOH resulted in partial degradation of polymeric molecules by methanolysis giving rise to a mixture of neutral, monosulfated, and disulfated fucooligosaccharides in the form of methyl glycosides. These oligomeric fragments were characterized by ESI-MS and ESI-CID-MS/MS. It was found that oligosaccharide structures coincided with the polysaccharide backbone built up mainly of (1→3)-linked fucose residues sulfated at positions 4 and 2. [Copyright &y& Elsevier]

Abstract: Seven fucoidans that differed only with respect to the average molecular weight and four fucoidans that differed with respect to both the molar ratio of fucose to galactose and the average molecular weight were obtained. The anticoagulant activities of these fucoidans were determined in order to understand the effects of the average molecular weight and the content of galactose. Fucoidans Y5–Y11, with the average molecular weight in the range of 50.1–8.4kDa, showed decreasing activity at three concentrations and dose-dependent activity in the APTT and TT assays. Y1–Y4, which differed with respect to the average molecular weight and the molar ratio of fucose to galactose, exhibited complicated results in the APTT and TT assays. It was shown that not only the average molecular weight but also the molar ratio of fucose to galactose affected the anticoagulant activity of fucoidans. [Copyright &y& Elsevier]

A parallel two-zone and four-zone SMB hybrid process was developed for p-xylene purification. By placing a high-productivity parallel two-zone SMB in front of an existing four-zone SMB, feed was enriched in the parallel two-zone SMB before it was fed to the four-zone SMB, which allows a higher feed rate to the four-zone SMB. A general design procedure for hybrid SMB-SMB process was developed. Simulations were done with Aspen Chromatography and Aspen Plus. Overall adsorbent productivity was increased by more than 100%, but with 3-5% lower overall p-xylene recovery. With overall recovery of the hybrid process matching the base case, the feed rate was doubled and the overall adsorbent productivity was 50% higher than the base case. The heat duties of distillation columns per unit product were similar for these hybrid processes compared to the base case. If a two-feed raffinate distillation column was used, the heat duty of distillation columns per unit product in the hybrid process was 2-4% lower than the base case. Both parallel two-zone and four-zone SMBs were also developed for use in a hybrid SMB-crystallization process for p-xylene purification. SMB productivity can be increased from 31% to 75% by adding additional pumps between columns to operate columns at their pressure limits. Although additional pumps are useful for both systems, the productivities of the parallel two-zone SMBs were 9% and 16% higher than the corresponding four-zone SMBs with the same number of recycle pumps. For a four-zone SMB with two columns per zone and eight recycle pumps, a 114% increase of productivity was achieved, which is 22% higher than a parallel two-zone with one column per zone and four recycle pumps. [ABSTRACT FROM AUTHOR]

Removal of water from fermentation broth by applying horizontal electric field was investigated using yeast as a model system. The effects of the operation conditions including the initial concentration of yeast in the broth, starting pH and electroconductivity of the broth, and the magnitude of electric field indexed by potential drop on liquid removal were examined, respectively. The magnitude of ζ-potential of yeast cell was determined as a function of pH and electroconductivity of the broth. The results indicated the dominating role of ζ-potential of yeast cell on the efficiency of the dewatering process. Compared with the dewatering process operated in a vertical electric field, this new method has advantages in terms of efficient discharge of gases generated at two electrodes and ease of maintaining and controlling of the apparatus. These make the dewatering process in horizontal electric field more suitable for large-scale solid–liquid separations. [ABSTRACT FROM AUTHOR]

Recent studies have shown cementitious syntactic foams (CSF) to have great potential as a low density and high strength structural material. However, CSFs are made with hollow glass microsphere (HGM) inclusions and cementitious materials with amorphous silica inclusions such as glass are known to have a potential for the deleterious alkali silica reaction (ASR). In this study, CSFs containing HGMs are tested for ASR expansion and compressive strength along with solid particles of soda-lime and borosilicate glass to compare. Results show that in the 30–90 μm average particle size range, only solid borosilicate particles lead to more than 0.2% expansion of the composite material in an accelerated ASTM C1260 lab test for ASR, which is considered as the limit for deleterious effects. Similarly, compressive strength tests show that only solid borosilicate particles lead to reduced compressive strengths (from ~95 to ~40 MPa) in the long term, while CSFs showed no sign of loss of compressive strength even at extremely alkaline conditions. Scanning electron microscopy investigations suggest that CSFs are safe from ASR expansion of the composite and internal stresses due to their hollow geometry, which provides reservoir space for the alkaline silica gel expansion and mitigates the ASR effects. [ABSTRACT FROM AUTHOR]

• Glucuronomannan-hexamer showed strong interaction with immunoglobulin G. • The structure-activity relationship between degree of polymerization and its anti-lung cancer activity was investigated. • Glucuronomannan-hexamer exhibited anti-lung cancer activity through immunomodulatory effects. The anti-lung cancer activity of oligosaccharides derived from glucuronomannan was investigated. The inhibition of A549 cell proliferation by glucuronomannan (Gn) and its oligomers (dimer (G2), tetramer (G4) and hexamer (G6)) were concentration dependent. In vivo activities on the A549-derived tumor xenografts showed the tumor inhibition of G2, G4 and G6 were 17 %, 40 % and 46 %, respectively. Organ coefficients in nude mice showed an increase in the kidney with G4, the brain with G6, and the spleen with G6. An advanced tandem mass tag labeled proteomics approach was performed. A significant differential expression was found in 59 out of the 4371 proteins, which involved the immune system. Surface plasmon resonance (SPR) studies revealed G6 was strongly bound to immunoglobulin G. This suggests that glucuronomannan hexamer inhibits the proliferation of lung cancer through its binding to immunoglobulin. [ABSTRACT FROM AUTHOR]

Severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) has resulted in a pandemic and continues to spread around the globe at an unprecedented rate. To date, no effective therapeutic is available to fight its associated disease, COVID-19. Our discovery of a novel insertion of glycosaminoglycan (GAG)-binding motif at S1/S2 proteolytic cleavage site (681–686 (PRRARS)) and two other GAG-binding-like motifs within SARS-CoV-2 spike glycoprotein (SGP) led us to hypothesize that host cell surface GAGs may interact SARS-CoV-2 SGPs to facilitate host cell entry. Using a surface plasmon resonance direct binding assay, we found that both monomeric and trimeric SARS-CoV-2 SGP bind more tightly to immobilized heparin (K D = 40 pM and 73 pM, respectively) than the SARS-CoV and MERS-CoV SGPs (500 nM and 1 nM, respectively). In competitive binding studies, the IC 50 of heparin, tri-sulfated non-anticoagulant heparan sulfate, and non-anticoagulant low molecular weight heparin against SARS-CoV-2 SGP binding to immobilized heparin were 0.056 μM, 0.12 μM, and 26.4 μM, respectively. Finally, unbiased computational ligand docking indicates that heparan sulfate interacts with the GAG-binding motif at the S1/S2 site on each monomer interface in the trimeric SARS-CoV-2 SGP, and at another site (453–459 (YRLFRKS)) when the receptor-binding domain is in an open conformation. The current study serves a foundation to further investigate biological roles of GAGs in SARS-CoV-2 pathogenesis. Furthermore, our findings may provide additional basis for further heparin-based interventions for COVID-19 patients exhibiting thrombotic complications. • SARS-CoV-2 spike glycoprotein binds heparin at picomolar binding affinity. • IC 50 of heparin against heparin and SARS-CoV-2 spike is in the nanomolar range. • Unbiased docking study reveals potential heparin binding sites on SARS-CoV-2 spike. [ABSTRACT FROM AUTHOR]

• SRGA and its oligomers were prepared and characterized. • Strong inhibitory activities towards FGF1 and FGF2 were observed. • SRGA can be utilized for the treatment of lung cancer. A sulfated glucurono-xylo-rhamnan (EP-3-H) was purified from a green alga, Enteromorpha prolifera. EP-3-H and its oligomers were characterized by high performance liquid chromatography, mass spectrometry and one and two-dimensional nuclear magnetic resource spectroscopy. The structural analysis showed EP-3-H has a backbone of glucurono-xylo-rhamnan, branches with glucuronic acid and sulfated at C3 of rhamnose and/or C2 of xylose. The inhibition of EP-3-H on human lung cancer A549 cell proliferation in vitro and its therapeutic effects in BALB/c-nu mice in vivo were determined to evaluate the anti-lung cancer activity of EP-3-H. The tumor inhibition level was 59 %, suggesting that EP-3-H might be a good candidate for the treatment of lung cancer. Surface plasmon resonance (SPR) studies revealed the IC 50 on the binding of fibroblast growth factors, (FGF1 and FGF2), to heparin were 0.85 and 1.47 mg/mL, respectively. These results suggest that EP-3-H inhibits cancer proliferation by interacting with these growth factors. [ABSTRACT FROM AUTHOR]

Satellite telemetry data contains satellite status information, and ground-monitoring personnel need to promptly detect satellite anomalies from these data. This paper takes the satellite power subsystem as an example and presents a reliable anomaly detection method. Due to the lack of abnormal data, the autoencoder is a powerful method for unsupervised anomaly detection. This study proposes a novel stage-training denoising autoencoder (ST-DAE) that trains the features, in stages. This novel method has better reconstruction capabilities in comparison to common autoencoders, sparse autoencoders, and denoising autoencoders. Meanwhile, a cluster-based anomaly threshold determination method is proposed. In this study, specific methods were designed to evaluate the autoencoder performance in three perspectives. Experiments were carried out on real satellite telemetry data, and the results showed that the proposed ST-DAE generally outperformed the autoencoders, in comparison. [ABSTRACT FROM AUTHOR]

A new sulfated polysaccharide (SP7) was obtained and purified from Laminarina japonica with the guidance of kidney protective activity. Analysis of physicochemical features exhibited that SP7 consisted of mannose, amino glucose, rhamnose, glucuronic acid, galactose and fucose at a ratio of 0.82:3.05:2.68:3.11:5.86:1. SP7 had the molecular weight of 4.2 kDa. Cyclophosphamide (CTX) induced oxidative kidney damage mice was used to test the activity and mechanism of SP7 in vivo. Metabolites of CTX caused the over production of reactive oxygen species (ROS). It was found that SP7 inhibited 10 mg/kg CTX-induced renal oxidative damage in mice model. After intraperitoneal injection of SP7 at a dose of 20 mg/kg each day, ferritin heavy chain 1 (FTH1) and glutathione peroxidase 4 (GPX4) protein expression were largely increased (P < 0.05). TCMK-1 cells incubated with erastin were built as ferroptosis model. Intracellular malondialdehyde (MDA) level was decreased by SP7 treatment time and concentration dependently (P < 0.05). Electron microscopy showed mitochondria in SP7 treated cells had a 41% increase in length. Test of labile iron pool (LIP) exhibited a 31% decrease of iron concentration in SP7 treated cells. All results proved SP7 would inhibit ferroptosis via downregulating ferritinophagy, which led to a large decrease in kidney oxidative damage. [Display omitted] • SP7 is a new sulfated heterpolysaccharide with the molecular weight of 4.2 kDa. • SP7 strongly inhibited cyclophosphamide-induced oxidative damage in mice kidney. • SP7 inhibited ferroptosis in TCMK-1 cells by down-regulating ferrous ion level. • SP7 reduced ferroptosis level via inhibition of autophagy degrading ferritin. [ABSTRACT FROM AUTHOR]

Hepatocellular carcinoma (HCC) is an aggressive tumor triggered by various factors such as virus infection and alcohol abuse. Glucuronomannan polysaccharide (Gx) is a subtype of fucoidans that possesses many bioactivities, but its anti-tumor activities in HCC have not been reported. In this paper, the anti-tumor effects of glucuronomannan oligosaccharides (Gx) and its sulfated derivatives (GxSy) on hepatocarcinoma Huh7.5 cells were investigated. The anti-proliferation, anti-metastasis activities, and underlying mechanism of Gx and GxSy on Huh7.5 cells were analyzed and compared by MTT, wound healing, transwell, and western blotting assays, respectively. Results showed that the best anti-proliferation effects were G4S1 and G4S2 among 13 drugs, which were 38.67% and 30.14%, respectively. The cell migration rates were significantly inhibited by G2S1, G4S2, G6S2, and unsulfated Gn. In addition, cell invasion effects treated with G4S1, G4S2, and G6S1 decreased to 48.62%, 36.26%, and 42.86%, respectively. Furthermore, sulfated G4 regulated the expression of (p-) FAK and MAPK pathway, and sulfated G6 down-regulated the MAPK signaling pathway while activating the PI3K/AKT pathway. On the contrary, sulfated G2 and unsulfated Gx had no inhibited effects on the FAK-mTOR pathway. These results indicated that sulfated Gx derivatives have better anti-tumor activities than unsulfated Gx in cell proliferation and metastasis process in vitro , and those properties depend on the sulfation group levels. Moreover, degrees of polymerization of Gx also played a vital role in mechanisms and bioactivities. This finding shows the structure-activity relationship for developing and applying the marine oligosaccharide candidates. • The anti-tumor activities of glucuronomannan oligosaccharides (Gx) and its sulfated derivatives (GxSy) were determined. • The effects of different degrees of polymerization of Gx on the FAK-mTOR signaling pathways were detected. • The effects of sulfation levels of GxSy on the FAK-mTOR signaling pathways were analyzed. [ABSTRACT FROM AUTHOR]

Background: Pancreatic beta cell dysfunction and activated macrophage infiltration are early features in type 1 diabetes pathogenesis. A tricarboxylic acid cycle metabolite that can strongly activate NF-E2-related factor 2 (Nrf2) in macrophages, itaconate is important in a series of inflammatory-associated diseases via anti-inflammatory and antioxidant properties. However, its role in type 1 diabetes is unclear. We used 4-octyl itaconate (OI), the cell-permeable itaconate derivate, to explore its preventative and therapeutic effects in mouse models of type 1 diabetes and the potential mechanism of macrophage phenotype reprogramming. Methods: The mouse models of streptozotocin (STZ)-induced type 1 diabetes and spontaneous autoimmune diabetes were used to evaluate the preventative and therapeutic effects of OI, which were performed by measuring blood glucose, insulin level, pro- and anti-inflammatory cytokine secretion, histopathology examination, flow cytometry, and islet proteomics. The protective effect and mechanism of OI were examined via peritoneal macrophages isolated from STZ-induced diabetic mice and co-cultured MIN6 cells with OI-pre-treated inflammatory macrophages in vitro. Moreover, the inflammatory status of peripheral blood mononuclear cells (PBMCs) from type 1 diabetes patients was evaluated after OI treatment. Results: OI ameliorated glycemic deterioration, increased systemic insulin level, and improved glucose metabolism in STZ-induced diabetic mice and non-obese diabetic (NOD) mice. OI intervention significantly restored the islet insulitis and beta cell function. OI did not alter the macrophage count but significantly downregulated the proportion of M1 macrophages. Additionally, OI significantly inhibited MAPK activation in macrophages to attenuate the macrophage inflammatory response, eventually improving beta cell dysfunction in vitro. Furthermore, we detected higher IL-1β production upon lipopolysaccharide stimulation in the PBMCs from type 1 diabetes patients, which was attenuated by OI treatment. Conclusions: These results provided the first evidence to date that OI can prevent the progression of glycemic deterioration, excessive inflammation, and beta cell dysfunction predominantly mediated by restricting macrophage M1 polarization in mouse models of type 1 diabetes. [ABSTRACT FROM AUTHOR]

A sulfated galactofucan designated as UpG was obtained from the brown algae Undaria pinnatifida by calcium chloride extraction. Chemical analyses showed that UpG is composed of galactose and fucose at a high sulfation level. Low-molecular weight UpGP-0.5 was prepared from UpG through acid hydrolysis for structure characterization. The backbones of UpG are determined to be α-(1,3)-Fuc, α-(1,4)-Gal, α-(1,3)-Gal, and α-(1,6)-Gal by GC-MS, FT-IR, NMR, and LC-MS analyses. Sulfate groups are modified at C2 and/or C4 of fucose and C3 and/or C4 of galactose. UpG could partially lower blood sugar and serum lipid levels in type 2 diabetic mice. Moreover, UpG treatment regulates the abundance of some specific gut microbiota, such as enriching the abundance of Muribaculum and Christensenellaceae, and reducing that of Bilophila, Tannerellaceae, Candidatus Saccharimonas and Anaerotruncus. The findings characterized the detailed structure of a sulfated galactofucan and investigated its potential for the treatment of type 2 diabetes mellitus. [ABSTRACT FROM AUTHOR]

Background: Human cytomegalovirus (HCMV), a member of the β-herpesvirus family, causes the establishment of a latent infection that persists throughout the life of the host and can be reactivated when immunity is weakened. To date, there is no vaccine to prevent HCMV infection, and clinically approved drugs target the stage of viral replication and have obvious adverse reactions. Thus, development of novel therapeutics is urgently needed. Methods: In the current study, we identified a naturally occurring pterostilbene that inhibits HCMV Towne strain replication in human diploid fibroblast WI-38 cells through Western blotting, qPCR, indirect immunofluorescence assay, tissue culture infective dose assays. The time-of-addition experiment was carried out to identify the stage at which pterostilbene acted. Finally, the changes of cellular senescence biomarkers and reactive oxygen species production brought by pterostilbene supplementation were used to partly elucidate the mechanism of anti-HCMV activity. Results: Our findings revealed that pterostilbene prevented lytic cytopathic changes, inhibited the expression of viral proteins, suppressed the replication of HCMV DNA, and significantly reduced the viral titre in WI-38 cells. Furthermore, our data showed that pterostilbene predominantly acted after virus cell entry and membrane fusion. The half-maximal inhibitory concentration was determined to be 1.315 μM and the selectivity index of pterostilbene was calculated as 26.73. Moreover, cell senescence induced by HCMV infection was suppressed by pterostilbene supplementation, as shown by a decline in senescence-associated β-galactosidase activity, decreased production of reactive oxygen species and reduced expression of p16, p21 and p53, which are considered biomarkers of cellular senescence. Conclusion: Together, our findings identify pterostilbene as a novel anti-HCMV agent that may prove useful in the treatment of HCMV replication. [ABSTRACT FROM AUTHOR]

Bacterial pneumonia is one of the leading causes of death worldwide and exerts a significant burden on health-care resources. Antibiotics have long been used as first-line drugs for the treatment of bacterial pneumonia. However, antibiotic therapy and traditional antibiotic delivery are associated with important challenges, including drug resistance, low bioavailability, and adverse side effects; the existence of physiological barriers further hampers treatment. Fortunately, these limitations may be overcome by the application of nanotechnology, which can facilitate drug delivery while improving drug stability and bioavailability. This review summarizes the challenges facing the treatment of bacterial pneumonia and also highlights the types of nanoparticles that can be used for antibiotic delivery. This review places a special focus on the state-of-the-art in nanomaterial-based approaches to the delivery of antibiotics for the treatment of pneumonia. [ABSTRACT FROM AUTHOR]

Parkinson's disease (PD) is associated with progressive loss of dopaminergic neurons and more-widespread neuronal changes that cause complex symptoms. The aim of this study was to investigate the structure–activity relationship of sulfated hetero-polysaccharides (DF1) and sulfated galactofucan polysaccharides (DF2) on dopaminergic neuron in vivo and in vitro . Treatment with samples significantly ameliorated the depletion of both DA and TH-, Bcl-2- and Bax-positive neurons in MPTP-induced PD mice, DF1 showed the highest activity. The in vitro results found that DF1 and DF2 could reverse the decreased mitochondrial activity and the increased LDL release induced by MPP + ( P < 0.01 or P < 0.001) which provides further evidence that DF1 and DF2 also exerts a direct protection against the neuronal injury caused by MPP + . Furthermore, the administration of samples effectively decreased lipid peroxidation and increased the level/activities of GSH, GSH-PX, MDA and CAT in MPTP mice. Thus, the neuron protective effect may be mediated, in part, through antioxidant activity and the prevention of cell apoptosis. The chemical composition of DF1, DF2 and DF differed markedly, the DF1 fraction had the most complex chemical composition and showed the highest neuron protective activity. These results suggest that diverse monosaccharides and uronic acid might contribute to neuron protective activity. [ABSTRACT FROM AUTHOR]

Reinfection risk is a great concern with regard to the COVID-19 pandemic because a large proportion of the population has recovered from an initial infection, and previous reports found that primary exposure to SARS-CoV-2 protects against reinfection in rhesus macaques without viral presence and pathological injury; however, a high possibility for reinfection at the current stage of the pandemic has been proven. We found the reinfection of SARS-CoV-2 in Syrian hamsters with continuous viral shedding in the upper respiratory tracts and few injuries in the lung, and nasal mucosa was exploited by SARS-CoV-2 for replication and shedding during reinfection; meanwhile, no viral replication or enhanced damage was observed in the lower respiratory tracts. Consistent with the mild phenotype in the reinfection, increases in mRNA levels in cytokines and chemokines in the nasal mucosa but only slight increases in the lung were found. Notably, the high levels of neutralizing antibodies in serum could not prevent reinfection in hamsters but may play roles in benefitting the lung recovery and symptom relief of COVID-19. In summary, Syrian hamsters could be reinfected by SARS-CoV-2 with mild symptoms but with obvious viral shedding and replication, and both convalescent and vaccinated patients should be wary of the transmission and reinfection of SARS-CoV-2. [ABSTRACT FROM AUTHOR]

Seaweeds represent a rich source of sulfated polysaccharides with similarity to heparan sulfate, a facilitator of myriad virus host cell attachment. For this reason, attention has been drawn to their antiviral activity, including the potential for anti-SARS-CoV-2 activity. We have identified and structurally characterized several fucoidan extracts, including those from different species of brown macroalga, and a rhamnan sulfate from a green macroalga species. A high molecular weight fucoidan extracted from Saccharina japonica (F Sj RPI-27), and a rhamnan sulfate extracted from Monostroma nitidum (RS Mn), showed potent competitive inhibition of spike glycoprotein receptor binding to a heparin-coated SPR chip. This inhibition was also observed in cell-based assays using hACE2 HEK-293 T cells infected by pseudotyped SARS-CoV-2 virus with IC 50 values <1 μg/mL. Effectiveness was demonstrated in vivo using hACE2–transgenic mice. Intranasal administration of F Sj RPI-27 showed protection when dosed 6 h prior to and at infection, and then every 2 days post-infection, with 100 % survival and no toxicity at 104 plaque-forming units per mouse vs. buffer control. At 5-fold higher virus dose, F Sj RPI-27 reduced mortality and yielded reduced viral titers in bronchioalveolar fluid and lung homogenates vs. buffer control. These findings suggest the potential application of seaweed-based sulfated polysaccharides as promising anti-SARS-CoV-2 prophylactics. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: After the starfish was defatted with isopropyl alcohol and ethanol, crude polysaccharide was extracted by 0.15mol/L HCl. Anion exchange chromatography was performed to fractionate the sample into two fractions, SF-1 and SF-2. Chemical analysis showed that the major component of SF-1 was a glucan consisting of a backbone of 1→3 linked β-d-glucopyranose residues, and it had a minor glucan component containing a backbone of 1→3 linked α-d-glucopyranose residues. SF-2 was a mannoglucan sulfate. SF-2 displayed the highest antioxidant activity among the polysaccharides. Moreover, SF-1 and SF-2 exhibited neuroprotective activities in a neurotoxicity model of Parkinson's disease (PD). [Copyright &y& Elsevier]

Abstract: Conditions of fucoidan degradation by hydrogen peroxide and the antioxidant activities of fucoidans with different molecular weights (Mws) were studied. Fucoidan degradation was monitored by gel permeation chromatography (GPC). Results showed that higher reaction temperature, hydrogen peroxide concentration and reaction time were the main factors that determined the decrease in Mw. There were no significant chemical changes in the backbones of the fucoidans treated with hydrogen peroxide, and the sulphate group contents barely change as compared to the raw polysaccharide. The antioxidant activities of seven fucoidans with different Mws (1.0kDa, 3.8kDa, 8.3kDa, 13.2kDa, 35.5kDa, 64.3kDa, 144.5kDa) were assessed. The results showed that the relationship between Mws of fucoidans and their antioxidant activities is not simply linear. The samples with Mws of 3.8kDa, 1.0kDa and >8.3kDa have better hydroxyl radical scavenging activity, reducing power and superoxide anion scavenging activity, respectively. [Copyright &y& Elsevier]

Abstract: In the present study, the beneficial effects of two sulfated polysaccharides DF and UF on adenine-induced chronic kidney disease (CKD) were investigated. Compare the chemical composition of DF and UF, DF had more sulfated group than UF, however, UF had more uronic acid. The results showed DF and UF had significant protective role in deleting the peroxidative and renal damage in CKD rats. Both samples exhibited nearly the same effect on the SUN and SCR level, however, DF showed greater effect on activity/level of CAT, GSH-PX, GSH and MDA in serum and liver compared to UF. That was to say the sample with higher content of sulfate group exhibited greater antioxidant activity. There was a positive correlation between MDA level and renal membrane damage indicating a striking relation between free radical formation and cellular injury. The mechanism of DF and UF on the CKD rats had relationship with their antioxidant activities, the samples which could enhance the activity of antioxidant enzymes and reduce the LPO level could alleviate the symptom of CKD complications. [ABSTRACT FROM AUTHOR]

The potential neuroprotective capacity of four different sulfated glycans: Botryocladia occidentalis-derived sulfated galactan (BoSG) (MW > 100 kDa), Lytechinus variegatus-derived sulfated fucan (LvSF) (MW~90 kDa), high-molecular weight dextran sulfate (DxS) (MW 100 kDa), and unfractionated heparin (UFH) (MW~15 kDa), was assessed in response to the HIV-1 proteins, R5-tropic glycoprotein 120 (gp120) and/or trans-activator of transcription (Tat), using primary murine neurons co-cultured with mixed glia. Compared to control-treated cells in which HIV-1 proteins alone or combined were neurotoxic, BoSG was, among the four tested sulfated glycans, the only one capable of showing significant concentration-dependent neuroprotection against Tat and/or gp120, alone or combined. Surface plasmon resonance-based data indicate that BoSG can bind both HIV-1 proteins at nM concentrations with preference for Tat (7.5 × 10−8 M) over gp120 (3.2 × 10−7 M) as compared to UFH, which bound gp120 (8.7 × 10−7 M) over Tat (5.7 × 10−6 M). Overall, these data support the notion that sulfated glycan extracted from the red alga B. occidentalis, BoSG, can exert neuroprotection against HIV-1 Tat and gp120, potentially via direct molecular interactions. [ABSTRACT FROM AUTHOR]

Gut microbiome critically contributes to host health status. Thus, investigating the relationship between the gut microbiome and toxic chemicals is a hot topic in toxicology research. Exposure to malachite green (MG) has been linked to various health disorders. Thus, exploring the gut microbiota changes in response to MG would provide a new perspective on the toxicity effects of this chemical substance. MG exposure resulted in the significantly lower alpha diversity (Mann–Whitney U test, z = − 6.83, p = 0.00) but higher beta diversity (Mann–Whitney U test, z = − 1.98, p = 0.04) of gut microbiota, and significantly decreased ecosystem stability (alpha and beta variability; Mann–Whitney U test, all p < 0.05) of gut microbial communities. Gut bacterial networks showed that the interactions became more complex and stronger after MG exposure, which could decrease the stability of the network. Changes in gut microbiota composition were mainly reflected in the enrichment of opportunistic bacteria (i.e., Aeromonas and Vibrio) and the depression of fermentative bacteria (i.e., Bacteroides and Paludibacter). MG exposure leads to a significantly increased gut permeability (lipopolysaccharide-binding protein; Mann–Whitney U test, z = − 6.92, p = 0.00), which could reduce the host selective pressures on particular bacterial species (such as members in Aeromonas and Vibrio). This result was further supported by the weakened importance of a deterministic microbial assembly after MG exposure. All these findings indicated that MG exposed fishes might have more possibilities to be infected, as demonstrated by the enrichment of opportunistic pathogenic bacteria, high-level immune responses, and increased gut permeability. These findings greatly improve our understanding of the toxicity effects of MG. [ABSTRACT FROM AUTHOR]

Fasting influences the overall physiology of fish, and the knowledge how the gut microbiota, growth performances, and immune function in response to intermittent and long-term fasting is still insufficient. Here, we characterized the effects of fasting on the host-gut microbiota in crucian carp, which would enhance our insight into physiological adaptation to fasting. To achieve this, we investigated the gut microbial communities of crucian carp with different fasting stress, and corresponding immune and growth parameters. The gut microbial communities were structured into four clusters according to different fasting stress, namely one control group (feed regularly), two intermittent fasting groups (fasting period and re-feeding period, respectively), and one long-term fasting group. Intermittent fasting significantly improved the activity of superoxide dismutase (SOD) and lysozyme (LZM) (ANOVA, p < 0.05) and significantly increased alpha diversity and ecosystem stability of gut microbiota (ANOVA, p < 0.05). Gut length (GL) and condition factor (CF) showed no significant difference between the control group (CG) and intermittent fasting group under re-feeding period (RIF) (ANOVA, p = 0.11), but relative gut length (RGL) in group RIF was higher than that in the CG (ANOVA, p = 0.00). The bacterial genera Bacteroides, Akkermansia, and Erysipelotrichaceae were enriched in fishes under intermittent fasting. Two Bacteroides OTUs (OTU50 and OTU1292) correlated positively with immune (SOD, complement, and LZM) and growth (GL and RGL) parameters. These results highlight the possible interplay between growth performances, immune function, and gut microbiota in response to fasting. [ABSTRACT FROM AUTHOR]

Crude polysaccharide obtained from Saccharina japonica using acid hydrolysis and precipitation was separated into sulfated fuco-oligosaccharide ( HDF1 ) and heteropolysaccharide ( HDF2 ). To further explore the bioactive fraction, HDF2 was successfully separated using membrane filtration into HDF2A and HDF2B , which differed in chemical composition and molecular weight. The bioactivity of all the fractions was tested in vitro , including immunomodulatory activity in RAW 264.7 cells and the protective activity in aristolochic acid (AA)-induced NRK-52E cell injury. HDF1 and HDF2B (low-molecular weight sulfated fucans/fuco-oligosaccharides) did not increase the nitric oxide production in RAW 264.7 cells, whereas HDF2 and HDF2A exhibited potential immunomodulatory activity. All the tested compounds showed different degrees of protective activity in AA-induced injury; HDF2A exhibited superior protective activity. Through chemical analysis, HPLC analysis, and IR spectroscopy and MS, it was determined that HDF2A was a galactose-enriched heteropolysaccharide- glucofucogalactan with a distinctive 2:1 ratio of galactose to fucose. In addition, HDF2A also contained a high amount of glucose and minor amounts of mannose, rhamnose, and xylose, with a low content of sulfate. Thus, HDF2A , a complex heterogeneous polysaccharide mixture with a unique monosaccharide composition, could be studied for further structural characterization and pharmaceutical applications. [ABSTRACT FROM AUTHOR]