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1.
J Electrocardiol ; 59: 84-87, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-32023498

RESUMO

We present the case of one premature infant who developed bradycardia due to hyperkalemia and hypocalcemia with continuous ECG recording showing second-degree atrioventricular block and wide QRS complex rhythm. TAKE-HOME MESSAGE: Multiple ECG changes can occur with combined hyperkalemia and hypocalcemia in newborns. If left unchecked, these electrolyte disorder can be fatal. Early recognition enables prompt appropriate treatment, preventing serious complications.

2.
J Invertebr Pathol ; 170: 107335, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-32007504

RESUMO

The cell wall is crucial for fungal growth, proliferation and interaction with the environment and host. Understanding the regulatory mechanism of cell wall integrity may help with improvement of fungal biocontrol agents. Here, a putative target of the cell wall integrity pathway-involved Slt2 MAP kinase, Mb1, an orthologue of MADS-box transcription factor Rlm1, was characterized in an economically important insect fungal pathogen, Beauveria bassiana. Mb1 disruption mutant (ΔMb1) displayed reduced growth and increased conidial production on minimal medium but not on rich-nutrient media, which is different from ΔSlt2 to a great extent. Loss of Mb1 resulted in a significant increase in sensitivity to cell wall-perturbing agents (Congo red and calcofluor white), with alteration in cell composition that was inconsistent with ΔSlt2 strain, including increased chitin content and reduced chitin-binding ß-1, 3/1,6-glucan levels in the absence of any stress. Transcription levels of 15 chitin synthesis and metabolism-associated and 17 Pkc1-Slt2 CWI (cell wall integrity) pathway, glucan synthesis, and cell wall remodeling enzyme synthesis-involved genes were significantly increased and repressed in ΔMb1 strain, respectively, some of which were verified to be the targets of Mb1. Insect bioassays revealed decreased virulence for the ΔMb1 strain in both topical and intrahemocoel injection assays. Our results demonstrated that Mb1 control fungal biocontrol potential-associated traits, including growth, conidiation and cell wall integrity, in B. bassiana. The difference of Mb1 and Slt2 in contribution to cell wall integrity is discussed.

3.
J Mater Chem B ; 2020 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-32067015

RESUMO

Basal insulin therapy plays a key role in diabetes management. An ideal therapy should mimic the steady physiologic basal insulin secretion, and provide a peak-free, prolonged and steady insulin supply. Herein, a new drug carrier was designed by first PEGylating insulin and then incorporating the conjugate into layer-by-layer assembled films with tannic acid (TA). Because PEG-insulin and TA in the films were linked with reversible, dynamic hydrogen bonds, the films disintegrate gradually when soaked in aqueous solutions, and thus release PEG-insulin into the media. In vitro release tests revealed that the release of PEG-insulin follows a zero-order kinetics. Theoretical analysis based on the unique release mechanism also supports a zero-order kinetics. In vivo tests using a streptozotocin-induced diabetic rat model demonstrated that subcutaneous implantation of the film could maintain a steady plasma drug level and hence maintain a fasting blood glucose level (BGL) close to normal. The duration of action depends on the thickness of the film. Using a 50-bilayer film, fasting BGL was kept within the normoglycemic range for ∼16 days. Initial burst release, a severe problem for other release systems, was successfully avoided.

4.
Bioorg Med Chem ; 28(4): 115306, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31926774

RESUMO

Leuprolide, a gonadotropin-releasing hormone (GnRH) agonist widely used in androgen deprivation therapy for the treatment of advanced prostate cancer, suffers from a short circulating half-life like other peptide therapeutics. As an attempt to improve its pharmacokinetic properties, two PEGylated leuprolides with different molecular weight were synthesized utilizing N-hydroxysuccinimidyl (NHS) conjugation chemistry. The reaction conditions, including reaction temperature, reaction time and feed ratio of the reactants, were optimized to obtain a higher yield. Reverse-phase high performance liquid chromatography (RP-HPLC) characterization indicates a high purity of the resulting conjugates. Matrix-assisted laser desorption mass spectrometry (MALDI-MS) characterization suggests a 1:1 PEGylation. 1H NMR study reveals that the reaction occurs on the imidazolyl group on the histidine residue and the conjugates are stable in pH7.4 aqueous solutions. The in vitro bioactivity of the conjugates was evaluated using both hormone-sensitive and hormone-insensitive cell lines. It was found that the PEGylated peptides can still counteract the stimulatory action of androgens and the mitogenic action of epidermal growth factor on cell proliferation. The in vivo bioactivity of the conjugates was also tested. Like the unmodified peptide, administration of the conjugates to male rats leads to an initial testosterone surge, followed by a suppression of testosterone secretion. Pharmacokinetics of the drugs after i.v. and s.c. administrations were determined. In both cases, a prolonged circulating half-life, an increased AUC, and a decreased Cl_F were observed for the PEGylated drugs.

5.
J Insect Physiol ; 121: 104012, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31911184

RESUMO

Pheromone binding proteins (PBPs) are well studied in lepidopteran moths and are considered to be crucial in detection of sex pheromones as well as some green leaf volatiles. In contrast, evidence that PBPs interact with sex pheromones of hemipteran species is not available. The mirid plant bug, Adelphocoris lineolatus (Goeze), is a notorious hemipteran pest that uses two butyrate esters, trans-2-hexenyl butyrate (E2HB) and hexyl butyrate (HB), and one hexenoic aldehyde trans-4-oxo-2-hexenal (E4O2H), as sex pheromones. In the present study, we report on an odorant binding protein, AlinOBP4, with particular focus on its potential physiological roles in the detection of A. lineolatus sex pheromone components. Phylogenetic analyses indicated that AlinOBP4 and two mirid orthologs clustered in a general phylogenetic clade with the lepidopteran ABX OBPs, the fly LUSH and the OBP83a/b subfamily. Cellular localization by fluorescence in situ hybridization and immunolabeling further demonstrated that AlinOBP4 was strongly expressed in the multiporous sensilla trichodea (str) and middle long sensilla basiconica (mlsba) of male A. lineolatus adults, suggesting a key role associated with sex pheromone and odorant detection. A ligand binding assay revealed that recombinant AlinOBP4 protein highly bound not only to the sex pheromone components E4O2H but also to some host plant volatiles. These findings together with the evidence of insect PBPs available in the literature support the view that AlinOBP4 is involved in sex pheromone detection in male A. lineolatus and provide foundational information for further elucidating the molecular mechanisms of chemosensory based mating behavior in hemipteran mirid bugs.

6.
Environ Microbiol ; 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31894607

RESUMO

Adaptation to low-oxygen (LO) environment in host tissues is crucial for microbial pathogens, particularly fungi, to successfully infect target hosts. However, the underlying mechanisms responsible for hypoxia tolerance in most pathogens are poorly understood. A mitochondrial protein, BbOhmm, is demonstrated to limit oxidative stress resistance and virulence in the insect fungal pathogen, Beauveria bassiana. Here, we found that BbOhmm negatively affected hypoxic adaptation in the insect haemocoel while regulating respiration-related events, heme synthesis and mitochondrial iron homeostasis. A homologue of the mammalian sterol regulatory element-binding proteins (SREBPs), BbSre1, was shown to be involved in BbOhmm-mediated LO adaptation. Inactivation of BbSre1 resulted in a significant increase in sensitivity to hypoxic and oxidative stress. Similar to ΔBbOhmm, ΔBbSre1 or the ΔBbOhmmΔBbSre1 double mutant accumulated high levels of heme and mitochondrial iron, regulating the similar pathways during hypoxic stress. BbSre1 transcriptional activity and nuclear import were repressed in ΔBbOhmm cells and affected by intracellular reactive oxygen species (ROS) and oxygen levels. These findings have led to a new model in which BbOhmm affects ROS homeostasis in combination with available oxygen to control the transcriptional activity of BbSre1, which in turn mediates LO adaptation by regulating mitochondrial iron homeostasis, heme synthesis and respiration-implicated genes.

7.
J Biomater Sci Polym Ed ; : 1-21, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31903857

RESUMO

Previous studies have proved that fibrin is an excellent scaffold material for tissue engineered blood vessel. However, the mechanical properties of fibrin are not enough. One way to solve the problem is to combine polymer materials with fibrin to enhance its biomechanical properties. In this study, a novel polycaprolactone (PCL)/fibrin composite scaffold was prepared by electrospinning technology. The morphological, physicochemical analysis, blood compatibility, biomechanical properties, biocompatibility and biodegradability of this vascular scaffold were evaluated. The results showed that electrospun PCL/fibrin scaffold possessed smaller aperture and larger fiber diameter than that of fibrin scaffold. The swelling ratio of the vascular PCL/fibrin scaffold at (0:100), (10:90), (20:80) and (30:70) was 112 ± 5.3, 103 ± 6.9, 94 ± 5.9 and 89 ± 3.4%, respectively. Mechanical properties of fibrin scaffolds were enhanced significantly by the addition of PCL. Furthermore, the time of plasma re-calcification, activated partial thromboplastin time and thromboplastin time in four different proportions of PCL/fibrin scaffolds were similar to that of the control group. Degradation experiments in vitro demonstrated that the degradation rate of PCL/fibrin scaffold was closely related to the content of PCL. MTT assays and immunofluorescence staining indicated that the stem cells cocultured with the PCL/fibrin scaffold had good proliferation behavior. Live/dead assay confirmed that the number of MSCs in the PCL/fibrin (10:90) group was significantly increased as compared to other groups. The tests in vivo results showed PCL/fibrin scaffold could promote cell infiltration and tissue regeneration and its degradation in vivo was faster than that of PCL scaffold. In summary, PCL/fibrin (20:80) scaffold exhibited balanced mechanical properties and degradability, as well as good cell compatibility properties; therefore, it was a promising tissue engineering material for vascular graft.

8.
J Insect Physiol ; 120: 103986, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31778688

RESUMO

Traps baited with female-produced sex pheromones have been very effective in the monitoring and management of mirid bugs in numerous field trials. However, none of the target odorant receptors for sex pheromone components in Apolygus lucorum have been identified. Here, we identified one candidate sex pheromone receptor, AlucOR4, from A. lucorum. Quantitative real-time PCR (qPCR) analysis revealed that AlucOR4 was antennae-enriched and male-biased in adult A. lucorum. Xenopus oocyte expression system assays demonstrated that AlucOR4/AlucOrco was sensitive to two major sex pheromone constituents and exhibited high sensitivity to (E)-2-hexenyl butyrate (E2HB) and lower sensitivity to hexyl butyrate (HB). The expression level of target mRNA was significantly reduced (>80%) in dsAlucOR4-injected bugs after five days. The electroantennogram (EAG) responses of male antennae to E2HB and HB were also reduced significantly (~40%). Our findings suggest that AlucOR4 is essential to sex pheromone perception in A. lucorum.

9.
Sensors (Basel) ; 19(21)2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31689946

RESUMO

Optical sensing that integrates communication and sensing functions is playing a more and more important role in both military and civil applications. Incorporating optical sensing and optical communication, optical sensor networks (OSNs) that undertake the task of high-speed and large-capacity applications and sensing data transmissions have become an important communication infrastructure. However, multiple failures and disasters in OSNs can cause serious sensing provisioning problems. To ensure uninterrupted sensing data transmission, survivability has always been an important research emphasis. This paper focuses on the survivable deployment of OSNs against multiple failures and disasters. We first review and evaluate the existing survivability technologies developed for or applied to OSNs, such as fiber bus protection, self-healing architecture, and 1 + 1 protection. We then elaborate on the disaster-resilient survivability requirement of OSNs. Moreover, we propose a new k-node (edge) sensing connectivity concept, which ensures the connectivity between sensing data and users. Based on k-node (edge) sensing connectivity, the disaster-resilient survivability technologies are developed. The key technologies necessary to implement k-node (edge) sensing connectivity are also elaborated. Recently, artificial intelligence (AI) has developed rapidly. It can be used to improve the survivability of OSNs. This paper details potential development directions of survivability technologies of optical sensing in OSNs employing AI.

10.
Pest Manag Sci ; 2019 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-31714013

RESUMO

BACKGROUND: The Apolygus lucorum is one of the most destructive insect pests in China with a wide range of host plants. Interaction of A. lucorum with surrounding environment heavily relies on chemical communication. Deorphanization of receptors involved in odors detection elevates our understanding of the olfactory system of this pest and may help to develop a chemical ecology-based control strategy. RESULTS: AlucOR80, an odorant receptor (OR) in A. lucorum was newly cloned. Gene expression analysis showed that this receptor was mainly expressed in the antennae and head of both sexes but with a male bias. The Xenopus oocytes heterologous expression system coupled with the two-electrode voltage-clamp (TEVC) recording revealed that AlucOR80 was tuned to 21 selected compounds. Furthermore, electroantennogram (EAG) tests confirmed that all 21 ligands of AlucOR80 were electrophysiologically active in antennae of both sexes. Behavioral trials in a three-cage olfactometer indicated that 16 compounds were behaviorally active, amongst which, 12 components were attractants and four components were repellents for adults of both sexes. Butyl butyrate and Dimethyl disulfide (DMDS) were the strongest attractive and repellant compounds, respectively. Importantly, we found the repellency of 1, 8-Cineole, S-(-)-cis-Verbenol and (1S)-(1)-beta-Pinene against adults of A. lucorum. CONCLUSION: Although AlucOR80 is a general OR, may play important role in the olfactory perception of A. lucorum. Screening of AlucOR80 ligands by behavioral assay provided valuable insights by which olfactory-based management approaches could be developed by utilizing the behaviorally active components as attractants or repellents. © 2019 Society of Chemical Industry.

11.
Pest Manag Sci ; 2019 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-31762173

RESUMO

BACKGROUD: Volatile terpenes can act as ecological signals to affect insect behavior. It has been proposed that the manipulation of terpenes in plants can help to control herbivore pests. In order to investigate the potential pest management function of (E)-ß-caryophyllene in cotton plants, the (E)-ß-caryophyllene synthase gene (GhTPS1) was inserted into Gossypium hirsutum variety R15 to generate overexpression lines. RESULTS: Four GhTPS1-transgenic lines were generated, and GhTPS1 expression in transgenic L18 and L46 lines was 3-5-fold higher than in R15 plants. The transgenic L18 and L46 lines also emitted significantly more (E)-ß-caryophyllene than R15. In laboratory bioassays, L18 and L46 plants reduced pests Apolygus lucorum, Aphis gossypii and Helicoverpa armigera, and attracted parasitoids Peristenus spretus and Aphidius gifuensis, but not Microplitis mediator. In open-field trials, L18 and L46 plants reduced A. lucorum, Adelphocoris suturalis and H. armigera, but had no significant effects on predators. CONCLUSION: Our findings suggest that L18 and L46 plants reduce several major hemipteran and lepidopteran cotton pests, whereas, two parasitoids P. spretus and A. gifuensis, were attracted by L18 and L46 plants. This study shows that overexpressing GhTPS1 in cotton may help to improve pest management in cotton fields. © 2019 Society of Chemical Industry.

12.
Nanomaterials (Basel) ; 9(11)2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31683724

RESUMO

Controlling chemical reactions by plasma is expected to be a new method for improving the structural properties of substrates. An Au nanojar array was prepared when Au was deposited onto a 2D polystyrene (PS) array. The site-selective chemical growth of Ag nanoparticle rings was realized around the Au nanojar necks by a local surface plasmon resonance (LSPR)-assisted chemical reaction. The catalytic hotspots in the nanostructure array could be controlled by both etching the nanojars and Au or TiO2 sputtering onto the nanojars, which were confirmed by the growth sites of the Ag nanoparticle in the LSPR-assisted chemical reaction. The structure of the nanojars and the electric field distributions of the growing nanoparticles were simulated and analyzed using Finite-Difference Time-Domain. FDTD simulations showed that the changes in the nanojar shape led to the changed hotspot distributions. At the same time, tracking the hotspot shifts in the process of structural change was also achieved by the observation of Ag growth. Nanoarray structure prepared by LSPR-assisted chemical reaction is one of the hot fields in current research and is also of great significance for the application of Surface-Enhanced Raman Scattering.

13.
ACS Appl Mater Interfaces ; 11(47): 44617-44623, 2019 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-31689073

RESUMO

Overexpression of the Lens culinaris agglutinin-reactive fraction of alpha-fetoprotein (AFP-L3) is an essential biomarker for early diagnosis of hepatocellular carcinoma (HCC). In this study, we designed a new surface-enhanced Raman spectroscopy active chip for the detection of AFP with high sensitivity and excellent repeatability. This chip was composed of a honeycomb gold nanostructure array with strong electromagnetic field coupling due to the special cavity geometric characteristics of the honeycomb structure. The honeycomb structure exhibited extraordinary performance for the specific detection of AFP in the range of 0.003-3 ng/mL and also determined the proportion of AFP-L3 with a high degree of accuracy, which has shown great potential for application in the clinical diagnosis of HCC.

14.
Water Environ Res ; 2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31650659

RESUMO

A p-type TiO2 with Ti vacancies (D-TiO2 ) was synthesized by a facile solvothermal treatment, and Ag/TiO2 with different Ag loading amount was prepared through a photo-reduction deposition method. The samples were characterized through scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The adsorption and photocatalytic characteristics of tetrabromobisphenol A (TBBPA) on D-TiO2 and Ag/TiO2 were investigated. The adsorption of TBBPA on Ag/TiO2 was significantly enhanced and was five times greater than that of pure TiO2 . The increase in pH significantly inhibited the adsorption of TBBPA. The 2%-Ag/TiO2 nearly completely degraded TBBPA in 10 min under UV-Vis light (λ > 360 nm), and the apparent reaction rate constant (kapp ) reached 0.63 min-1 . The significantly enhanced UV-Vis light catalytic properties of the Ag/TiO2 in comparison with that of TiO2 were attributed to the increased adsorption capacity and electron transfer ability of the Ag/TiO2 . Free radical trap experiments results showed that holes and superoxide radicals play a major role in the catalytic degradation of TBBPA by Ag/TiO2 . Moreover, the Ag/TiO2 catalyst exhibits high stability during TBBPA degradation even after three cycles. PRACTITIONER POINTS: Ti-defected TiO2 and Ag/TiO2 were synthesized using a solvothermal and photo-reduction deposition, respectively. Ag/TiO2 exhibited outstanding adsorption and photocatalytic activity for TBBPA removal under UV-Vis light. Holes and superoxide radicals play a major role in the photocatalytic degradation of TBBPA.

16.
CNS Neurosci Ther ; 2019 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-31471952

RESUMO

AIMS: Phenylketonuria (PKU), which is caused by mutations in the phenylalanine hydroxylase (PAH) gene, is one of the most common inherited diseases of amino acid metabolism. Phenylketonuria is characterized by an abnormal accumulation of phenylalanine and its metabolites in body fluids and brain tissues, subsequently leading to severe brain dysfunction. Various pathophysiological and molecular mechanisms underlying brain dysfunction in PKU have been described. However, the metabolic changes and their impacts on the function of cerebral cortices of patients with PKU remain largely unknown. METHODS: We measured the levels of small molecule metabolites in the cerebrocortical tissues of PKU mice and wild-type control mice using liquid chromatography-mass spectrometry (LC-MS)-based metabolome analysis. Differential metabolites were further subjected to metabolic pathway and enrichment analysis. RESULTS: Metabolome analysis revealed 35 compounds among 143 detected metabolites were significantly changed in PKU mice as compared to those in their wild-type littermates. Metabolic pathway and enrichment analysis of these differential metabolites showed that multiple metabolic pathways, including phenylalanine, tyrosine, and tryptophan biosynthesis; valine, leucine, and isoleucine biosynthesis; alanine, aspartate, and glutamate metabolism; purine metabolism; arginine and proline metabolism and methionine metabolism, were impacted in the cerebral cortices of PKU mice. CONCLUSIONS: The data revealed that multiple metabolic pathways in cerebral cortices of PKU mice were disturbed, suggesting that the disturbances of the metabolic pathways might contribute to neurological or neurodevelopmental dysfunction in PKU, which could thus provide new insights into brain pathogenic mechanisms in PKU as well as mechanistic insights for better understanding the complexity of the metabolic mechanisms of the brain dysfunction in PKU.

17.
Int J Biol Macromol ; 141: 1293-1303, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31499116

RESUMO

We employed a single factor and response surface methodology based on Box-Behnken design (BBD) to optimize the extraction of pumpkin polysaccharides. We then simulated pumpkin polysaccharide gastrointestinal digestion in vitro and investigated their biodistribution in mice. The optimal extraction conditions, with a yield of 7.38 ±â€¯0.21%, were as follows: a concentration of NaOH 1.20%, a ratio of material to liquid of 1:11, and an extraction time of 2.1 h, respectively, according to single factor and BBD experiments. In the gastrointestinal experiment in vitro, the molecular weight of the polysaccharides markedly decreased after gastric digestion for 30 min, suggesting the decline is due to the breakdown of polysaccharide glycosidic bonds. The simulated intestinal fluid had little effect on polysaccharides digestion within 240 min. Analysis of the biodistribution in mice indicated that the polysaccharides distribute in the duodenum, jejunum, and ileum 30 to 60 min after intragastrical administration, and are absorbed in the jejunum and ileum after 60 to 360 min. These results provide information on the digestion and biodistribution of pumpkin polysaccharides and offer a theoretical basis for further understanding the absorption mechanisms in vivo.

18.
PLoS One ; 14(9): e0221374, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31487295

RESUMO

BACKGROUND: Studies have shown that D-dimer levels are significantly correlated with the differential diagnosis and clinicopathological features of breast cancer. However, the results are currently limited and controversial. Therefore, we performed this meta-analysis to evaluate the relationship between D-dimer levels and breast cancer. MATERIALS AND METHODS: The PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, Chinese Biomedical Literature, and Wanfang databases were searched to find studies that assessed the association of D-dimer with clinicopathological features of breast cancer and its usefulness in aiding with differential diagnosis. The standardized mean difference (SMD) was applied as the correlation measure. RESULTS: A total of 1244 patients with breast cancer from 15 eligible studies were included in the meta-analysis. D-dimer levels were higher in the breast cancer group than in the benign (SMD = 1.02; 95% confidence interval [CI] = 0.53-1.52) and healthy (SMD = 1.27; 95% CI = 0.85-1.68) control groups. In addition, elevated D-dimer levels were associated with progesterone receptor-negative tumors (SMD = -0.25; 95% CI = -0.44--0.05). Similarly, there was a significant correlation between D-dimer levels and tumor node metastasis staging (n = 11, SMD = 0.82; 95% CI = 0.57-1.06) and lymph node involvement (n = 8, SMD = 0.79; 95% CI = 0.50-1.09). In contrast, other clinicopathological factors, including estrogen receptor expression and human epidermal growth factor receptor 2 expression, were not associated with D-dimer levels. CONCLUSION: The results of this meta-analysis indicate that plasma D-dimer levels can be used as an important reference for the early identification and staging of breast cancer.

19.
Int J Biol Macromol ; 141: 1304-1313, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31493454

RESUMO

The present study investigated the effects of the accumulated polysaccharides in Chlorella vulgaris microalgae on the growth characteristics of Trachemys scripta elegans. Sodium alginate was used to prepare immobilized C. vulgaris, and the antioxidant effects of the accumulated polysaccharides in it were determined using Caenorhabditis elegans as a model. We determined the specific growth rates of T. s. elegans (10 in each group) and their levels of non-specific immune-related indexes (including alkaline phosphatase; total superoxide dismutase; catalase; malondialdehyde). Under optimal culturing conditions, the accumulated polysaccharide content in C. vulgaris reached 32.7% (dry weight). Polysaccharides from C. vulgaris significantly improved the hydrogen peroxide-induced oxidative stress resistance and resulted in the enhancement of stress resistance-related antioxidant enzymes, including total superoxide dismutase and catalase (p < 0.05). The accumulated polysaccharides in C. vulgaris were heteropolysaccharides comprising rhamnose, ribose, arabinose, xylose, 2-deoxy-D-glucose, mannose, glucose, galactose, and glucosamine with a molar ratio of 0.26: 0.62: 0.21: 0.10: 0.08: 0.18: 1.00: 0.42: 0.17. Compared with the control group with common feeds, suspended and immobilized C. vulgaris with higher accumulated polysaccharide levels had a positive effect on the specific growth rate of the T. s. elegans (p < 0.05). Further, the suspended and immobilized C. vulgaris with higher accumulated polysaccharide levels significantly increased serum alkaline phosphatase, total superoxide dismutase and catalase activity (p < 0.05) and decreased serum malondialdehyde levels of T. s. elegans (p < 0.05).

20.
R Soc Open Sci ; 6(7): 190351, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31417737

RESUMO

In this study, natural manganese oxides (MnO x ), an environmental material with high redox potential, were used as a promising low-cost oxidant to degrade the widely used dyestuff methylene blue (MB) in aqueous solution. Although the surface area of MnO x was only 7.17 m2 g-1, it performed well in the degradation of MB with a removal percentage of 85.6% at pH 4. It was found that MB was chemically degraded in a low-pH reaction system and the degradation efficiency correlated negatively with the pH value (4-8) and initial concentration of MB (10-50 mg l-1), but positively with the dosage of MnO x (1-5 g l-1). The degradation of MB fitted well with the second-order kinetics. Mathematical models were also built for the correlation of the kinetic constants with the pH value, the initial concentration of MB and the dosage of MnO x . Furthermore, several transformation products of MB were identified with HPLC-MS, which was linked with the bond energy theory to reveal that the degradation was initiated with demethylation.

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