Immunomodulatory and antioxidant activity of a Siraitia grosvenorii polysaccharide in mice

The aim of this present study was to investigate the immunomodulatory and antioxidant activities of Siraitia grosvenorii polysaccharide (SGP) using a mouse model. The roles of regulation of SGP were investigated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, fluorescence method and ELISA method. The chemical structures were analyzed by Fourier transform infrared spectroscopy (FTIR) and gas chromatography (GC). The results show that SGP promoted the proliferation of spleen cells and regulated the level of reactive oxygen species (ROS) in vitro. Furthermore, it significantly raised spleen and thymus indices and superoxidase dismutase activity and regulated the cytokine levels of spleen and thymus in mice in vivo. These findings suggest that SGP possesses immunomodulatory and antioxidant effects.Key words: Siraitia grosvenorii polysaccharide (SGP), cell proliferation, reactive oxygen species, superoxidase dismutase, cytokines

A lattice-spring model for damage evolution in cement paste

AbstractTo understand better the fracture processes in cement-based materials, it is essential to predict the evolution of damage in cement paste. A recently proposed site-bond model is developed further to take into account the key microstructure data, such as pore size distribution, porosity, and size distribution and volume fraction of anhydrous cement grains obtained from high resolution X- ray tomography. The grains are associated with lattice sites linked by deformable bonds. The bonds are bundles of elastic-brittle springs, resisting normal and shear relative displacements between grains with potential for failure. The model length scale and thence spring constants are controlled by grain statistics. The spring failure properties are controlled by pore statistics. Macroscopic damage develops by a succession of local failures, represented by spring removal. The model is used to simulate the stress-strain response and damage in cement paste under uniaxial tensile loading. The influence of porosity on tensile strength and damage evolution is estimated in a quantitative manner. The predictions of the model are in a very good agreement with the available experimental data

The association of neutrophil-lymphocyte ratio and lymphocyte-monocyte ratio with 3-month clinical outcome after mechanical thrombectomy following stroke

Background and aim Neutrophil-lymphocyte ratio (NLR) and lymphocyte-monocyte ratio (LMR) are associated with clinical outcomes in malignancy, cardiovascular disease and stroke. Here we investigate their association with outcome after acute ischaemic stroke treated by mechanical thrombectomy (MT). Methods Patients were selected using audit data for MT for acute anterior circulation ischaemic stroke at a UK centre from May 2016–July 2017. Clinical and laboratory data including neutrophil, lymphocyte and monocyte count tested before and 24 h after MT were collected. Poor functional outcome was defined as modified Rankin Scale (mRS) of 3–6 at 3 months. Multivariable logistic regression analyses were performed to explore the relationship of NLR and LMR with functional outcome. Results One hundred twenty-one patients (mean age 66.4 ± 16.7, 52% female) were included. Higher NLR (adjusted OR 0.022, 95% CI, 0.009–0.34, p = 0.001) and lower LMR (adjusted OR − 0.093, 95% CI (− 0.175)−(− 0.012), p = 0.025) at 24-h post-MT were significantly associated with poorer functional outcome when controlling for age, baseline NIHSS score, infarct size, presence of good collateral supply, recanalisation and symptomatic intracranial haemorrhage on multivariate logistic regression. Admission NLR or LMR were not significant predictors of mRS at 3 months. The optimal cut-off values of NLR and LMR at 24-h post-MT that best discriminated poor outcome were 5.5 (80% sensitivity and 60% specificity) and 2.0 (80% sensitivity and 50% specificity), respectively on receiver operating characteristic curve analysis. Conclusion NLR and LMR tested at 24 h after ictus or intervention may predict 3-month functional outcome

Site-bond modelling of structure-failure relations in quasi-brittle media

AbstractThe non-linear behaviour of quasi-brittle media emerges from distributed micro-cracking. This is analysed conveniently by discrete lattice models. A 3D site-bond model is specialised here for materials with three-phase microstructures: stiff inclusions in a compliant matrix containing pores. The deformation behaviour is based on analytically derived relations between bond properties, length scale and macroscopic elastic constants. The microstructure-model mapping is based on size distributions and volume densities of inclusions and pores, typically obtained through analyses of 3D images. Inclusions data is used to calculate the required length scale. Pores data is used to define the failure behaviour of individual bonds. Applications of the methodology to cement-based materials and nuclear graphite are presented separately in this volume

Human induced pluripotent stem cell-derived mesenchymal stem cells are superior to adult bone marrow-derived mesenchymal stem cells in the treatment of limb ischemia

Conference invited speaker: Dr. Lian, QOral Presentation: Session S31 - Genetic Determinants of Heart Disease, Gene and Cell Based Therapies, Basic Research: abstract no. 1489postprintThe 16th World Congress on Heart Disease of the International Academy of Cardiology Annual Scientific Sessions 2011, Vancouver, B.C., 23-27 July 2011

Study of motoring operation of in-wheel switched reluctance motor drives for electric vehicles

Author name used in this publication: X. D. XueAuthor name used in this publication: K. W. E. ChengAuthor name used in this publication: N. C. CheungAuthor name used in this publication: Z. ZhangAuthor name used in this publication: J. K. LinRefereed conference paper2008-2009 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

Glycine receptor in rat hippocampal and spinal cord neurons as a molecular target for rapid actions of 17-β-estradiol

Glycine receptors (GlyRs) play important roles in regulating hippocampal neural network activity and spinal nociception. Here we show that, in cultured rat hippocampal (HIP) and spinal dorsal horn (SDH) neurons, 17-β-estradiol (E2) rapidly and reversibly reduced the peak amplitude of whole-cell glycine-activated currents (IGly). In outside-out membrane patches from HIP neurons devoid of nuclei, E2 similarly inhibited IGly, suggesting a non-genomic characteristic. Moreover, the E2 effect on IGly persisted in the presence of the calcium chelator BAPTA, the protein kinase inhibitor staurosporine, the classical ER (i.e. ERα and ERβ) antagonist tamoxifen, or the G-protein modulators, favoring a direct action of E2 on GlyRs. In HEK293 cells expressing various combinations of GlyR subunits, E2 only affected the IGly in cells expressing α2, α2β or α3β subunits, suggesting that either α2-containing or α3β-GlyRs mediate the E2 effect observed in neurons. Furthermore, E2 inhibited the GlyR-mediated tonic current in pyramidal neurons of HIP CA1 region, where abundant GlyR α2 subunit is expressed. We suggest that the neuronal GlyR is a novel molecular target of E2 which directly inhibits the function of GlyRs in the HIP and SDH regions. This finding may shed new light on premenstrual dysphoric disorder and the gender differences in pain sensation at the CNS level

Disposition of Federally Owned Surpluses

PDZ domains are scaffolding modules in protein-protein interactions that mediate numerous physiological functions by interacting canonically with the C-terminus or non-canonically with an internal motif of protein ligands. A conserved carboxylate-binding site in the PDZ domain facilitates binding via backbone hydrogen bonds; however, little is known about the role of these hydrogen bonds due to experimental challenges with backbone mutations. Here we address this interaction by generating semisynthetic PDZ domains containing backbone amide-to-ester mutations and evaluating the importance of individual hydrogen bonds for ligand binding. We observe substantial and differential effects upon amide-to-ester mutation in PDZ2 of postsynaptic density protein 95 and other PDZ domains, suggesting that hydrogen bonding at the carboxylate-binding site contributes to both affinity and selectivity. In particular, the hydrogen-bonding pattern is surprisingly different between the non-canonical and canonical interaction. Our data provide a detailed understanding of the role of hydrogen bonds in protein-protein interactions