Properties and applications of β‐glycosidase from Bacteroides thetaiotaomicron that specifically hydrolyses isoflavone glycosides

To modify the glycan part of glycosides, the gene encoding β‐glycosidase was cloned from Bacteroides thetaiotaomicron VPI‐5482. The cloned gene, bt_1780, was expressed in Escherichia coli MC1061 and the expressed enzyme was purified using Ni‐NTA affinity chromatography. The purified enzyme, BTBG, showed optimal activity at 50 °C and pH 5.5. Interestingly, this enzyme did not have any hydrolysing activity on ordinary β‐linkage–containing substrates such as xylobiose, lactose and cello‐oligosaccharide, but specifically hydrolysed isoflavone glycosides such as daidzin, genistin and glycitin. Compared to a commercial beta glucosidase, BTBG selectively hydrolysed isoflavone glycosides in soybean extract mixture solution. These results suggest that BTBG may be a specialized enzyme for the hydrolysis of glycosides and that the substrate specificity of BTBG is applicable for the bioconversion of isoflavone glycosides in the food industry.     

Vascularized bone flap for access to the maxillary sinus

PURPOSE: This article describes a vascularized bony window for access to the maxillary sinus and reports the clinical results. PATIENTS AND METHODS: A bony U-shaped window in the anterior sinus wall was pedicled on the surrounding soft tissue and periosteum. After the described sinus was cleared of disease, the window was repositioned in its original site either using resorbable sutures or not. The method was used in 47 maxillary sinus operations in 45 patients. Twenty-four patients were followed-up for more than 48 months. RESULTS: The vascularized bony window technique showed uneventful healing in all patients and none of the 24 patients reported any problems. CONCLUSIONS: The vascularized bony window technique provides a large antrostomy, which gives good access and visibility and results in satisfactory postoperative healing.     

Patterns of knowledge production: The case of information and telecommunication sector in Korea

In recent years, the topic of knowledge production has been widely investigated in the advanced countries. However, the process by which knowledge is produced in the developing countries has not been fully explored or characterized. In Korea, the science and engineering fields strongly reflect systems of knowledge production in the universities and demonstrate the dynamics of systems of innovation for knowledge production. Through using a case study including data for knowledge production, in the field of information and telecommunication, the following general trends were observed. Firstly, there has been a trend towards increasing the capabilities for knowledge production, via domestic and foreign collaboration. Secondly, there has been an increasing trend towards the diversification of knowledge sources such as university-industry, and university-public research institutes. Finally, the establishment of a nation's knowledge base is influenced by governmental research and development policies. This revised version was published online in August 2006 with corrections to the Cover Date.     

Pollutant dispersion over two-dimensional hilly terrain

Numerical prediction of the wind flow and pollutant dispersion over two-dimensional hilly terrain is presented. The wind tunnel experiments are conducted to validate the numerical results of the flow field. Measured mean velocity profiles, turbulence characteristics, and surface pressure distributions show good agreement with the numerical predictions. The hypothesis of Reynolds number independency for an atmospheric boundary layer flow over aerodynamically rough terrain is numerically confirmed. The linear theory provides generally good prediction of speed-up characteristics for gently sloped low hills. The effect of two-dimensional double hills on the dispersion of pollutants from continuously or temporally released line source of different emission heights and locations is also investigated. The ground-level concentrations are considerably reduced as emission heights are increased. The variances of ground-level concentration with respect to time from a temporally released source are strongly influenced by the flow separation.     

Environmental Hazard Analysis - a Variant of Preliminary Hazard Analysis for Autonomous Mobile Robots

Robot manufacturers will be required to demonstrate objectively that all reasonably foreseeable hazards have been identified in any robotic product design that is to be marketed commercially. This is problematic for autonomous mobile robots because conventional methods, which have been developed for automatic systems do not assist safety analysts in identifying non-mission interactions with environmental features that are not directly associated with the robot’s design mission, and which may comprise the majority of the required tasks of autonomous robots. In this paper we develop a new variant of preliminary hazard analysis that is explicitly aimed at identifying non-mission interactions by means of new sets of guidewords not normally found in existing variants. We develop the required features of the method and describe its application to several small trials conducted at Bristol Robotics Laboratory in the 2011–2012 period.     

WO3 and MoO3 addition effect on V2O5/TiO2 as promoters for removal of NOx and SOx from stationary sources

As an attempt to improve the catalytic activity at higher reaction temperatures between 300-450°C, various mole ratios of WO₃ were added to V₂O₅/TiO₂ catalytic systems. And also, in order to suggest a new mixed oxide catalyst system for simultaneous removal of NO_x and SO_x, from stationary sources, MoO₃-V₂O₅/TiO₂catalysts were prepared by a conventional impregnation method together with a newly introduced method of surface fixation (non-aqueous solution method). In case of WO₃ addition, at higher reaction temperature range (300–450°C), WO₃ and WO₃-V₂O₅/TiO₂ catalysts showed significant high conversion in NO reduction with NH₃ while V₂O₅/TiO₂ catalyst showed a significant change in selectivity mainly due to the excess side reaction of NH₃ oxidation. This difference in selectivity due to NH₃ oxidation at high temperature is supposed to be associated with the difference in values of surface excess oxygen between WO₃ and V₂O₅ on titania. The surface acidities of tested catalysts were relatively well correlated with the % conversion of NO at 400°C. In case of MoO₃ addition, the catalytic activity for the simultaneous removal of NO_x and SO_x were quite enhanced by the addition of MoO₃ into V₂O₅/TiO₂ catalysts. The enhanced activities were responsible for the formation of Mo=O bond on the intermediate species produced by solid solutions on MoO₃-V₂O₅/TiO₂ (aqueous). However, in the case of MoO₃-V₂O₅/TiO₂ (non-aqueous), the exact source of active site was not able to detect in IR spectra in spite of more enhanced activity was obtained in this study. After SO₂ contact, VOSO₄ is newly formed on the surface of catalyst, which supposed to be associated with the activity enhancement.     

Preparation and optimisation of liposome‐in‐alginate beads containing oyster hydrolysate for sustained release

Oyster (Crassostrea gigas) hydrolysate shows antihypertensive effect in our previous study. Oral administration of oyster hydrolysate can loss bioactive peptides due to enzymatic degradation in vivo. To maximise its bioavailability, liposome‐in‐alginate (LA) beads were used to encapsulate the oyster hydrolysates to protect from degradation and obtain sustained release. The preparation conditions of the LA beads were optimised by response surface method using a model peptide of tyrosylalanine (YA). Their characterisation, swelling and release properties were investigated. The optimised conditions for the concentration of calcium chloride, sodium alginate and the amount of ethanol‐dissolved lecithin (EDL) were 0.5 m , 3% and 95.4 mg, respectively. The encapsulation efficiencies of YA and the oyster hydrolysate in the optimised condition were 74.9% and 84.3%, respectively. The release time of the oyster hydrolysate in the simulated gastrointestinal fluid was up to 16 h. The LA beads can be recommended to encapsulate oyster hydrolysate for bioavailability improvement.     

Adsorption characteristics of SO2 on activated carbon prepared from coconut shell with potassium hydroxide activation

The adsorption characteristics of SO2 were studied with KOH-impregnated granular activated carbon (K-IAC). To confirm selective SO2 adsorptivity of K-IAC using a fixed bed adsorption column, experiments were conducted on the effects of KOH and of linear velocity, temperature, and concentration. In addition, changes in features before and after adsorption were observed by utilizing FTIR, XRD, ToF-SIMS, and AES/SAM, examining the surface chemistry. K-IAC adsorbed 13.2 times more SO2 than did general activated carbon (GAC). The amount of SO2 adsorbed increased as linear velocity and concentration increased and as temperature decreased. At lower temperature, the dominant reaction between KOH and SO2 produces K2-SO3 and H2O. Any H2O remaining on the surface is converted into H2SO4 as SO2 and O2 are introduced. Then, the KOH and SO2 reaction produces K2SO4 and H2O. The surface characterization results proved that adsorption occurred through chemical reaction between KOH and SO2. The SO2 adsorbed K-IAC exists in the form of stable oxide crystal, K2SO3 and K2SO4, due to potassium. The basic feature given to the surface of activated carbon by KOH impregnation was confirmed to be acting as the main factor in enhancing SO2 adsorptivity.     

Synthesis and characterization of photocrosslinkable poly(organophosphazene)-bearing cinnamyloxide side groups

Two different poly(organophosphazene)s-bearing single-substituents (two cinnamyloxide side groups per repeating unit) and phenoxide-co-substituents (one phenoxide and one cinnamyloxide group per repeating unit) were prepared to study their photochemical reaction behavior. Structural formulas confirmed by the NMRs (¹H, ³¹P) and IR were ? [NP(OCH₂CH = CH ? C₆H₅)₂]_n ? ( I ) and ? [NP(OCH₂CH = CH ? C₆H₅)_0.8 (O ? C₆H₅)_1.2]_n ? ( II ). Molecular characterization yielded $ \overline {M_w {\rm s}} $ of the order of 10³ kg/mol for both the polymers. The onset temperature of decomposition found by TGA was about 250°C. DSC measurements gave T_gs as 1°C for I and 3°C for II . Their photolytic crosslinking behaviors were monitored by UV spectroscopy. The single-substituents polymer I showed a faster rate of photo reaction than the polymer II . The potential use for practical photosensitive application is considered to be greater for the polymer I .     

Anthocyanin compositions and biological activities from the red petals of Korean edible rose (Rosa hybrida cv. Noblered)

The objectives of the present study were to investigate anthocyanin profiles and their biological properties, including antioxidant, anticancer, and antiallergic, from the red petals of Korean edible rose (Rosa hybrida cv. Noblered). The acidic methanol extract of this species showed potent biological activities at a concentration of 50 μg/mL. Its anthocyanins were characterised as cyanidin 3,5-di-O-glucoside and pelargonidin 3,5-di-O-glucoside using reversed-phase C₁₈ column chromatography, NMR spectroscopy, and HPLC-DAD-ESI/MS analysis. Cyanidin 3,5-di-O-glucoside was the predominant constituent (375 mg/100 g), representing about 85% of total content. Cyanidin 3,5-di-O-glucoside exhibited good scavenging activity against DPPH radical with IC₅₀ value of 55.2 μg/mL; pelargonidin 3,5-di-O-glucoside showed potent anticancer effects against LNCap (human prostate cell line), ACHN (human renal cell line) and MOLT-4F (human leukaemia cell line) cell cultures, with IC₅₀ values of 6.43, 18.3, and 6.78 μg/mL, respectively. Antiallergic activities were only moderate.