A modified balance-type stress relaxation apparatus for chemical relaxation under liquid phase

A relatively simple and inexpensive automatic apparatus for chemical relaxation giving good accuracy has been developed for measurement of chemical relaxation in the gaseous phase in high polymers. The apparatus is based on a previously described balance-type stress relaxation apparatus intended for automatic operation.     

Prevalence and characterization of antimicrobial resistance of foodborne Listeria monocytogenes isolates in Hebei province of Northern China, 2005-2007

A total of 2177 food samples collected from nine cities in northern China during 2005 to 2007 were screened for the presence of Listeria monocytogenes. All L. monocytogenes isolates were subjected to serotyping, antimicrobial susceptibility, pulsed-field gel electrophoresis (PFGE), as well as PCR screening to identify genes responsible for tetracycline resistance [tet(L), tet(M), tet(K), tet(S) and tet(B)], transposon Tn916, and class 1 integron. Contamination with L. monocytogenes was detected in 4.13% (90/2177) of the total samples representing various food products. The pathogen was mainly isolated from frozen food made of wheat flour or rice products (26/252, 10.32%) and raw meat products (46/733, 6.28%). Besides, 3.31% (10/302) of cooked meat, 1.17% (4/343) of seafood, 0.98% (2/204) of non-fermented bean products and 0.62% (2/323) of vegetables samples were contaminated by this bacterium. The L. monocytogenes isolates belonged to five serotypes (1/2a, 1/2b, 1/2c, 4b, and 3a), with serotype 1/2a being dominant (48.88%). Antimicrobial resistance was most frequently observed for ciprofloxacin (17.8%), tetracycline (15.6%) and streptomycin (12.2%). Overall, resistance was observed against 14 out of 18 antimicrobials tested while multiple resistances occurred among 18.9% (17/90) isolates. Interestingly, two isolates were resistant to more than five antimicrobials. Among 14 tetracycline-resistant isolates, 13 carried tet(M) gene including nine possessing Tn916, and one harbored tet(S) gene. PFGE analysis revealed genetic heterogeneity among individual serotypes as well as scattered occurrence of some genotypes without any clear-cut correlation to source or food type. The widespread distribution of epidemiologically important serotypes (1/2a, 1/2b and 4b) of L. monocytogenes, and their resistance to commonly used antibiotics indicate a potential public health risk. Our data also indicate that L. monocytogenes could act as a reservoir of mobile tet genes along the food chain.     

Effects of sulfated fucan,ascophyllan, from the brown Alga Ascophyllum nodosum on various cell lines: A comparative study on ascophyllan and fucoidan

The effects of fucose-containing sulfated polysaccharides, ascophyllan and fucoidan, isolated from the brown alga Ascophyllum nodosum, on the growth of various cell lines (MDCK, Vero, PtK₁, CHO, HeLa, and XC) were investigated. In a colony formation assay, ascophyllan and fucoidan showed potent cytotoxic effects on Vero and XC cells, while other cell lines were relatively resistant to these polysaccharides. Almost no significant effects of these polysaccharides were observed in the cell lines tested using the Alamar blue cytotoxicity assay over 48 h with varying initial cell densities (2500–20,000 cells/well) in growth medium. Interestingly, a significant growth promoting effect of ascophyllan on MDCK cells was observed, whereas treatment with fucoidan showed growth suppressive effects on this cell line under the same experimental conditions. These results suggest that ascophyllan is distinguishable from fucoidan in terms of their bioactivities. This is the first report of the growth promoting effects of a sulfated fucan on a mammalian cell line under normal growth conditions.     

Effect of skimmed milk and its fractions on the inactivation of Escherichia coli K12 by high hydrostatic pressure treatment

We investigated the effects of skimmed milk and its protein fractions (casein, whey, globulin, and albumin) on the injury and inactivation of Escherichia coli K-12 by high hydrostatic pressure (HHP) treatment. The protective effect of skimmed milk on HHP-mediated inactivation and injury of E. coli increased with increases in the skimmed milk concentration. However, protein fractions derived from skimmed milk did not exhibit this protective effect. Microscopy analysis by DAPI/PI staining indicated that some cells were localized in the solid portion of skimmed milk, and some of these cells were alive. The coagulated fraction derived from the autoclaved whey fraction also showed a significant protective effect. We speculate that the solid portion in skimmed milk could provide the protective effect to bacterial cells.     

Effect of pulsed electric field on the secondary structure and thermal properties of soy protein isolate

Changes of structure and thermal stability of soy protein isolate after pulsed electric field treatment were analyzed by Fourier transform infrared spectroscopy and differential scanning calorimetry (DSC). When the applied pulsed electric field (PEF) treatment intensity was over 35 kV/cm, the amino acid side chain, anti-parallel β-sheets, β-turn as well as β-sheets in soy protein isolate (SPI) secondary structure were significantly changed, which suggested that PEF treatment might be a new processing method for SPI; the dipole moments of some bonds, such as C=O, C–O, and C–O–C were partially polarized, accompanying with complete denaturation of β-conglycinin and glycinin obtained from DSC. Furthermore, self-reassembly from β-turn to α-helix in SPI structure abruptly happened under intense PEF treatment condition, which suggested that the PEF treatment had induced change of the orientation of α-helix dipole moment to stabilize α-helix. This observation implies that PEF treatment technique may be a novel method for preparation of protein nanotube.     

Synthesis and Preliminary Evaluation of 11C-Labeled VU0467485/AZ13713945 and Its Analogues for Imaging Muscarinic Acetylcholine Receptor Subtype 4

Muscarinic acetylcholine receptors (mAChRs) have five distinct subunits (M₁–M₅) and are involved in the action of the neurotransmitter acetylcholine in the central and peripheral nervous system. Attributed to the promising clinical efficacy of xanomeline, an M₁/M₄-preferring agonist, in patients of schizophrenia and Alzheimer's disease, M₁- or M₄-selective mAChR modulators have been developed that target the topographically distinct allosteric sites. Herein we report the synthesis and preliminary evaluation of ¹¹C-labeled positron emission tomography (PET) ligands based on a validated M₄R positive allosteric modulator VU0467485 (AZ13713945) to facilitate drug discovery. [¹¹C]VU0467485 and two other ligands were prepared in high radiochemical yields (>30 %, decay-corrected) with high radiochemical purity (>99 %) and high molar activity (>74 GBq μmol⁻¹). In vitro autoradiography studies indicated that these three ligands possess moderate-to-high in vitro specific binding to M₄R. Nevertheless, further physiochemical property optimization is necessary to overcome the challenges associated with limited brain permeability.     

Knowledge discovery in databases for determining formulation in topology optimization

Whereas topology optimization has achieved immense success, it involves an intrinsic difficulty. That is, optimized structures obtained by topology optimization strongly depend on the settings of the objective and constraint functions, i.e., the formulation. Nevertheless, the appropriate formulation is not usually obvious when considering structural design problems. Although trial-and-error to determine appropriate formulations are implicitly performed in several studies on topology optimization, it is important to explicitly support the process of trial-and-error. Therefore, in this study, we propose a new framework for topology optimization to determine appropriate formulations. The basic idea of this framework is incorporating knowledge discovery in databases (KDD) and topology optimization. Thus, we construct a database by collecting various and numerous material distributions that are obtained by solving various structural design problems with topology optimization, and find useful knowledge with respect to appropriate formulations from the database on the basis of KDD. An issue must be resolved when realizing the above idea, namely the material distribution in the design domain of a data record must be converted to conform to the design domain of the target design problem wherein an appropriate formulation should be determined. For this purpose, we also propose a material distribution-converting method termed as design domain mapping (DDM). Several numerical examples are used to demonstrate that the proposed framework including DDM successfully and explicitly supports the process of trial-and-error to determine the appropriate formulation.

     

RGB2AO: Ambient Occlusion Generation from RGB Images

We present RGB2AO, a novel task to generate ambient occlusion (AO) from a single RGB image instead of screen space buffers such as depth and normal. RGB2AO produces a new image filter that creates a non-directional shading effect that darkens enclosed and sheltered areas. RGB2AO aims to enhance two 2D image editing applications: image composition and geometry-aware contrast enhancement. We first collect a synthetic dataset consisting of pairs of RGB images and AO maps. Subsequently, we propose a model for RGB2AO by supervised learning of a convolutional neural network (CNN), considering 3D geometry of the input image. Experimental results quantitatively and qualitatively demonstrate the effectiveness of our model.