21 research outputs found

    Exopolysaccharide Produced by Pediococcus pentosaceus E8 : Structure, Bio-Activities, and Its Potential Application

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    The novel exopolysaccharide EPS-E8, secreted by Pediococcus pentosaceus E8, was obtained by anion-exchange and gel filtration chromatography. Structural analyses identified EPS-E8 as a heteropolysaccharide containing mannose, glucose, and galactose. Its major backbone consists of -> 2)-alpha-D-Manp-(1 -> 2,6)-alpha-D-Glcp-(1 -> 6)-alpha-D-Manp-(1 ->, and its molecular weight is 5.02 x 10(4) g/mol. Using atomic force microscopy and scanning electron microscopy, many spherical and irregular reticular-like shapes were observed in the microstructure of EPS-E8. EPS-E8 has outstanding thermal stability (305.7 degrees C). Both the zeta potential absolute value and average particle diameter increased gradually with increasing concentration. Moreover, at a concentration of 10 mg/ml, the antioxidant capacities of, 1-Diphenyl-2-picrylhydrazyl (DPPH), ABTS and hydroxyl radical were 50.62 +/- 0.5%, 52.17 +/- 1.4%, and 58.91 +/- 0.7%, respectively. EPS-E8 possesses excellent emulsifying properties against several food-grade oils, and its activity is retained under various conditions (temperature, pH, and ionic strength). Finally, we found that EPS-E8 as a polysaccharide-based coating could reduce the weight loss and malondialdehyde (MDA) content of strawberry, as well as preserving the vitamin C and soluble solid content during storage at 20 degrees C. Together, the results support the potential application of EPS-E8 as an emulsifier, and a polysaccharide-based coating in fruit preservation.Peer reviewe

    Crystal Growth and Investigation of High-Pressure Physical Properties of Fe2As

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    We reported the growth of Fe2As single crystals and the study of its physical properties via comprehensive measurements, such as transport properties under pressure and high-pressure synchrotron radiation X-ray diffraction. Fe2As is an antiferromagnetic metal with TN ~ 355 K. Within the pressure range of 100 GPa, no superconductivity was observed above 2 K. The abrupt drop in resistance from 21 to 31.7 GPa suggests a high-pressure phase transition happens. The high-pressure X-ray experiments indicate a new high-pressure phase appears, starting from 27.13 GPa. After the refinement of the high-pressure X-ray data, the pressure dependence of lattice constants of Fe2As (P4/nmm phase) was plotted and the bulk modulus B0 was obtained to be 168.6 GPa

    Conditioning with Fludarabine-Busulfan versus Busulfan-Cyclophosphamide Is Associated with Lower aGVHD and Higher Survival but More Extensive and Long Standing Bone Marrow Damage

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    Acute graft-versus-host disease (aGVHD) is a major complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT) and a major cause of nonrelapse mortality after allo-HSCT. A conditioning regimen plays a pivotal role in the development of aGVHD. To provide a platform for studying aGVHD and evaluating the impact of different conditioning regimens, we established a murine aGVHD model that simulates the clinical situation and can be conditioned with Busulfan-Cyclophosphamide (Bu-Cy) and Fludarabine-Busulfan (Flu-Bu). In our study, BALB/c mice were conditioned with Bu-Cy or Flu-Bu and transplanted with 2×107 bone marrow cells and 2×107 splenocytes from either allogeneic (C57BL/6) or syngeneic (BALB/c) donors. The allogeneic recipients conditioned with Bu-Cy had shorter survivals (P<0.05), more severe clinical manifestations, and higher hepatic and intestinal pathology scores, associated with increased INF-γ expression and diminished IL-4 expression in serum, compared to allogeneic recipients conditioned with Flu-Bu. Moreover, higher donor-derived T-cell infiltration and severely impaired B-cell development were seen in the bone marrow of mice, exhibiting aGVHD and conditioned with Flu-Bu. Our study showed that the conditioning regimen with Bu-Cy resulted in more severe aGVHD while the Flu-Bu regimen was associated with more extensive and long standing bone marrow damage

    Extraction, Structural Analysis, and Biofunctional Properties of Exopolysaccharide from Lactiplantibacillus&nbsp;pentosus B8 Isolated from Sichuan Pickle

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    Two novel exopolysaccharides, named LPB8-0 and LPB8-1, were isolated and purified from Lactiplantibacillus pentosus B8. Moreover, their structure and bioactivities were evaluated through chemical and spectral means. The study results demonstrated that LPB8-0 was primarily composed of mannose and glucose and had an average molecular weight of 1.12 &times; 104 Da, while LPB8-1 was composed of mannose, glucose, and galactose and had an average molecular weight of 1.78 &times; 105 Da. Their carbohydrate contents were 96.2% &plusmn; 1.0% and 99.1% &plusmn; 0.5%, respectively. The backbone of LPB8-1 was composed of (1&rarr;2)-linked &alpha;-D-Manp and (1&rarr;6)-linked &alpha;-D-Manp. LPB8-0 and LPB8-1 had semicrystalline structures with good thermal stability (308.3 and 311.7 &deg;C, respectively). SEM results displayed that both LPB8-0 and LPB8-1 had irregular thin-slice shapes and spherical body structures. Additionally, an emulsifying ability assay confirmed that LPB8-0 and LPB8-1 had good emulsifying activity against several edible oils, and this activity was retained under acidic, neutral, and high temperature conditions. Furthermore, an antioxidant assay confirmed that LPB8-1 had stronger scavenging activity than LPB8-0. Overall, these results provide a theoretical basis for the potential application of these two novel exopolysaccharides as natural antioxidants and emulsifiers in the food and pharmaceutical industries

    Cytosolic protection against ultraviolet induced DNA damage by blueberry anthocyanins and anthocyanidins in hepatocarcinoma HepG2 cells

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    Tianjin city government for "1000 talents plan" programUV-induced DNA damage plays a key role in the etiology of certain diseases. The ability of blueberry anthocyanins and anthocyanidins (BA) to protect cellular DNA from UV-induced damage was investigated. BA were extracted by water (BAW), ethanol (BAE) or methanol (BAM). These extracts partially restored proliferation of UV-irradiated HepG2 cells as shown by MTT assay. Treatment with BA extracts at 75 mu g/ml decreased reactive oxygen species and decreased DNA damage by tail moment of comet assay and expression of gamma H2AX in situ. BAM significantly decreased gene and protein expression of p53, phospho-p53 (Ser15), and p21 in UV-irradiated HepG2 cells. BA thus efficiently protects cells from DNA damage in vitro. Blueberry may potentially be used as a good source of naturally radioprotective agents

    Artificial Synapses Based on in-Plane Gate Organic Electrochemical Transistors

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    Realization of biological synapses using electronic devices is regarded as the basic building blocks for neuromorphic engineering and artificial neural network. With the advantages of biocompatibility, low cost, flexibility, and compatible with printing and roll-to-roll processes, the artificial synapse based on organic transistor is of great interest. In this paper, the artificial synapse simulation by ion-gel gated organic field-effect transistors (FETs) with poly­(3-hexylthiophene) (P3HT) active channel is demonstrated. Key features of the synaptic behaviors, such as paired-pulse facilitation (PPF), short-term plasticity (STP), self-tuning, the spike logic operation, spatiotemporal dentritic integration, and modulation are successfully mimicked. Furthermore, the interface doping processes of electrolyte ions between the active P3HT layer and ion gels is comprehensively studied for confirming the operating processes underlying the conductivity and excitatory postsynaptic current (EPSC) variations in the organic synaptic devices. This study represents an important step toward building future artificial neuromorphic systems with newly emerged ion gel gated organic synaptic devices
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