Correlating Streptococcus mutans counts in saliva with plaque amount, gingival inflammation and caries experience in school children

The DNA methyltransferases, M.HhaI and M.TaqI, and catechol O-methyl-transferase (COMT) catalyze the transfer of a methyl group from the cofactor S-adenosyl-L-methionine (AdoMet) to carbon-5 of cytosine, to nitrogen-6 of adenine, and to a hydroxyl group of catechol, respectively. The catalytic domains of the bilobal proteins, M.HhaI and M.TaqI, and the entire single domain of COMT have similar folding with an alpha/beta structure containing a mixed central beta-sheet. The functional residues are located in equivalent regions at the carboxyl ends of the parallel beta-strands. The cofactor binding sites are almost identical and the essential catalytic amino acids coincide. The comparable protein folding and the existence of equivalent amino acids in similar secondary and tertiary positions indicate that many (if not all) AdoMet-dependent methyltransferases have a common catalytic domain structure. This permits tertiary structure prediction of other DNA, RNA, protein, and small-molecule AdoMet-dependent methyltransferases from their amino acid sequences.     

Preparation of hydrophobic polymer particles by radical polymerization and subsequent modification into magnetically doped particles

The application potential of hydrophobic polymer is numerous. Lauryl methacrylate (LMA) having long alkyl chain is a commercially available hydrophobic monomer. In this investigation, poly‐LMA (PLMA) latex particles were prepared by suspension polymerization in aqueous media using 2,2′‐azobis(isobutyronitrile) (AIBN) in presence of poly(vinyl alcohol) (PVA) as steric stabilizer. The preparation kinetics was studied in detail in terms of percentage yield and particle size variation. Low glass transition temperature (～ ?65°C) associated with high flexibility did not allow electron micrographic observation though ¹H‐NMR and particle size measurement confirmed the formation of PLMA latex. To improve the glass transition temperature, aqueous emulsion copolymerization of LMA with methyl methacrylate (MMA) was carried out. The solubility of LMA was improved by adding ethanol to the aqueous phase. Two types of polymeric stabilizers, PVA and poly(vinyl pyrrolidone) (PVP) were used to stabilize the colloidal particles. The nature of the stabilizer affected both morphology and final rate of polymerization. The hydrophobic P(LMA‐MMA) copolymer particles were subsequently modified by nanosized magnetic (Fe₃O₄) particles by two different methods. The in situ formation of Fe₃O₄ particles in presence of P(LMA‐MMA) was found to be suitable for the preparation of magnetic latex particles. Scanning electron microscope (SEM), FTIR, transmission electron microscope (TEM), X‐ray diffraction (XRD) and energy‐dispersive X‐ray spectroscopy (EDX) were used for the characterization of magnetically doped particles. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Investigation of Structural,Electronics, Optical,Mechanical and Thermodynamic Properties of YRu2P2 Compound for Superconducting Application

Journal of Superconductivity and Novel Magnetism - The structural, electronic, optical, and thermodynamic properties of the YRu2P2 superconductor are investigated theoretically using the CASTEP...     

Covalent immobilization and characterization of Rhizopus oryzae lipase on core-shell cobalt ferrite nanoparticles for biodiesel production

Rhizopus oryzae lipase (ROL) was immobilized on the surface of silica coated amino modified CoFe2O4 nanoparticles and applied for biodiesel production.The results indicated more affinity of the ROL toward its substrate upon immobilization,as revealed by a lower Km value for the immobilized ROL compared to its free counterpart.Intrinsic fluorescence spectroscopy indicated a lower intensity for ROL immobilized on CoFe2O4 nanoparticles.Besides,immobilized ROL steady state anisotropy measurements presented lower values,which implied assembly of ROL molecules on magnetic nanoparticles upon immobilization as well as their restricted rotation upon covalent attachment.Thermal stability analysis revealed improved activity at higher temperatures for the immobilized enzyme compared to its free counterpart.Accordingly,Pace analysis to determine protein thermal stability revealed preservation of the protein conformation in the presence of increasing temperatures upon immobilization on nanoparticles.Finally,ROL immobilized on CoFe2O4 nanoparticles exhibited improved efficiency of biodiesel production in agreement with thermal activity profile.Therefore,the authors suggest application of the lipase mole-cules immobilized on CoFe2O4 nanoparticles for more efficient biodiesel production.     

Visual object tracking—classical and contemporary approaches

Visual object tracking (VOT) is an important subfield of computer vision. It has widespread application domains, and has been considered as an important part of surveillance and security system. VOA facilitates finding the position of target in image coordinates of video frames.While doing this, VOA also faces many challenges such as noise, clutter, occlusion, rapid change in object appearances, highly maneuvered (complex) object motion, illumination changes. In recent years, VOT has made significant progress due to availability of low-cost high-quality video cameras as well as fast computational resources, and many modern techniques have been proposed to handle the challenges faced by VOT. This article introduces the readers to 1) VOT and its applications in other domains, 2) different issues which arise in it, 3) various classical as well as contemporary approaches for object tracking, 4) evaluation methodologies for VOT, and 5) online resources, i.e., annotated datasets and source code available for various tracking techniques.     

Silane grafting and moisture crosslinking of polyethylene: The effect of molecular structure

The silane grafting and moisture crosslinking of different grades of polyethylene have been investigated. Three types of polyethylene (HDPE, LLDPE, and LDPE) with different molecular structures and similar melt flow indices were selected. The initiator was dicumyl peroxide (DCP), and the silane was vinyltrimethoxysilane. The grafting reaction was carried out in an internal mixer. The extent of grafting and the degree of crosslinking were determined, and hot‐set tests were carried out to evaluate the crosslink structure of the different polyethylenes. The LLDPE had the highest degree of grafting, while the LDPE had the least. The rate of crosslinking for LDPE was higher than that of HDPE and LLDPE. The gel content of LDPE was higher than that of HDPE and LLDPE. Hot‐set elongation and the number‐average molecular weight between crosslinks (M_c) were lower for LLDPE and LDPE than for HDPE. Increasing the silane/DCP percentage led to peroxide crosslinking, thereby decreasing the M_c and hot‐set elongation. The number‐average molecular weight (M_n), molecular weight distribution, and number of chain branches were the most important parameters affecting the silane grafting and moisture crosslinking. J. VINYL ADDIT. TECHNOL., 2009. © 2009 Society of Plastics Engineers     

Growth dynamics and characteristics of fabricated Fiber Bragg Grating using phase mask method

In this paper, Fiber Bragg Gratings (FBGs) are written by photoinduced refractive index changes in optical fibers. Experimental setup and results are presented to show the growth dynamics and the characteristics of the FBG that are written using phase mask method with different exposure time. In this paper, the effect of various UV exposure times and pulse energy during fabrication onto the reflectivity and Bragg wavelength has been defined.     

Aggregate crash prediction models: Introducing crash generation concept

Safety conscious planning is a new proactive approach towards understanding crashes. It requires a planning-level decision-support tool to facilitate proactive approach to assessing safety effects of alternative urban planning scenarios. The objective of this research study is to develop a series of aggregate crash prediction models (ACPM) that are consistent with the trip generation step of the conventional four-step demand models. The concept of crash generation models (CGMs) is introduced utilizing trip generation data in a generalized linear regression with the assumption of a negative binomial error structure. The relationship of crash frequencies in traffic analysis zones (TAZ) and number of trips generated by purpose is investigated. This translates into immediate checking of the impact of future trip generations on crash frequencies in comprehensive transportation-planning studies (i.e. ability to forecast crashes at each time-step trips are being forecasted). A good relation was seen between crash frequency and number of trips produced/attracted by purpose per TAZ.