bluuebunny/crossref_metadata_2025_split huggingface dataset:
Value‐added derivatives of soda lignin Alfa grass (Stipa tenacissima). II. Uses as lubricants in plastic processing
Authors: Nadji H. , Rodrigue D. , Benaboura A. , Bédard Y. , Stevanovic T. , Riedl B. 
Published: July 2009

AbstractEsparto (Stipa tenacissima) grass, also called Alfa is the raw material for the manufacture of paper pulp in North Africa. To add value to one of its processing by‐products, we aimed to develop lubricants from modified Soda‐Lignin (SL), which could eventually compete with industrial lubricants such as zinc stearates. Linear low density polyethylene mixed formulations prepared with zinc stearate and each modified lignin was studied by rheological tests using a rotational parallel plate system to investigate the effects of such esterified SL additives. One type, made up of SL esterified with 100% stearic anhydride (W/W) was found to promote excellent external lubrication. The same result was confirmed by contact angle and thermal analysis. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
An investigation of melt rheology and thermal stability of poly(lactic acid)/ poly(butylene succinate) nanocomposites
Authors: Bhatia Amita , Gupta Rahul K. , Bhattacharya Sati N. , Choi H. J. 
Published: July 2009

AbstractA systematic investigation of the rheological and thermal properties of nanocomposites prepared with poly(lactic acid) (PLA), poly(butylene succinate) (PBS), and organically modified layered silicate was carried out. PLA/PBS/Cloisite 30BX (organically modified MMT) clay nanocomposites were prepared by using simple melt extrusion process. Composition of PLA and PBS polymers were fixed at a ratio of 80 to 20 by wt % for all the nanocomposites. Rheological investigations showed that high clay (> 3 wt %) contents strongly improved the viscoelastic behavior of the nanocomposites. Percolation threshold region was attained between 3 and 5 wt % of clay loadings. With the addition of clay content for these nanocomposites, liquid‐like behavior of PLA/PBS blend gradually changed to solid‐like behavior as shown by dynamic rheology. Steady shear showed that shear viscosity for the nanocomposites decreased with increasing shear rates, exhibiting shear‐thinning non‐Newtonian behavior. At higher clay concentrations, pseudo‐plastic behavior was dominant, whereas pure blend showed almost Newtonian behavior. Thermogravimetric analysis revealed that both initial degradation temperature (at a 2% weight loss) and activation energy of thermal decomposition nanocomposite containing 3 wt % of C30BX were superior to those of other nanocomposites as well as to those of PLA/PBS blend. Nanocomposite having 1 wt % of C30BX did not achieve expected level of thermal stability due to the thermal instability of the surfactant present in the organoclay. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Fundamental studies of a new series of anion exchange membranes: Membranes prepared from bromomethylated poly(2,6‐dimethyl‐1,4‐phenylene oxide) and 4‐vinylpyridine
Authors: Li Yuan , Xu Tongwen 
Published: July 2009

AbstractA series of anion exchange membranes with pyridinium groups were prepared by aminating 100% bromomethylated poly(2,6‐dimethyl‐1,4‐phenylene oxide) with 4‐vinylpyridine. These membranes exhibited higher ion exchange capacity, lower water uptake, lower area resistance, and better thermal stabilities than the membranes prepared from pyridine. Trimethylamine was used for further amination, but it did not enhance the membrane's permselectivity for fluoride, chloride, bromide, iodide, hydroxyl, nitrate, nitrite, or thiocyanate anions. Accordingly, 4‐vinylpyridine was the better aminating agent to enhance the permselectivity of membranes for some monovalent anions. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Preparation and characterization of high char yield polybenzoxazine/polyarylacetylene blends for resin‐transfer molding
Authors: Qi Huimin , Pan Guangyan , Yin Lian , Zhuang Yuanqi , Huang Farong , Du Lei 
Published: July 2009

AbstractBenzoxazine precursors (BOZP), 6,6′‐bis(2,3‐dihydro‐3‐(3‐ethynylphenyl)‐4H‐1,3‐ benzoxazinyl)ketone and 6,6′‐bis(2,3‐dihydro‐3‐(3‐ethynylphenyl)‐4H‐1,3‐benzoxazinyl)ether were synthesized and characterized by Proton nuclear magnetic resonace (1H‐NMR) and Fourier transform infrared spectroscopy (FTIR). The polyarylacetylene (PAA) was synthesized through thermal polymerization of diethynylbenzene, and characterized by 1H‐NMR, FTIR, and Differential Scanning Calorimetry (DSC). The BOZP/PAA blends were prepared with different contents of PAA, and their viscosity was measured using NDJ‐79 rotating visometer. The curing behavior of BOZP/PAA blends was characterized by DSC. The thermal stability of cured BOZP/PAA blends was studied using Thermogravimetric Analysis, the results show char yield at 800°C was in the range of 78–84%. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Interpreting informational cues: An explorative study on information use among prospective homebuyers
Authors: Savolainen Reijo 
Published: July 2009

AbstractThis article elaborates the picture of information use from the perspective of interpreting informational cues about the attributes of entities. It is assumed that such activity draws on cognitive mechanisms that are employed as the constituents of diverse interpretation approaches to informational cues. The empirical data of the study were gathered by means of think aloud method from 16 prospective homebuyers in 2008. The participants interpreted informational cues available in announcements published in a printed housing listing issue and a Web‐based information system serving the needs of prospective homebuyers. The data were examined by means of qualitative content analysis. By drawing on the findings of Zhang and her associates, the study revealed 7 cognitive mechanisms: identification of key attributes, specification, evaluation, comparison by similarity, comparison by differentiation, explanation, and conclusion. Three major approaches employed in the interpetation of informational cues were identified. The descriptive‐evaluative approach draws on the identification and evaluation of individual attributes of an entity. The comparative approach is more sophisticated because it is based on the evaluation of the attributes by their perceived similarity or differentiation. Finally, the explanatory approach draws on the identification of attributes with causal potential.
Addressing gaps in knowledge while reading
Authors: Jordan Chris , Watters Carolyn 
Published: July 2009

AbstractReading is a common everyday activity for most of us. In this article, we examine the potential for using Wikipedia to fill in the gaps in one's own knowledge that may be encountered while reading. If gaps are encountered frequently while reading, then this may detract from the reader's final understanding of the given document. Our goal is to increase access to explanatory text for readers by retrieving a single Wikipedia article that is related to a text passage that has been highlighted. This approach differs from traditional search methods where the users formulate search queries and review lists of possibly relevant results. This explicit search activity can be disruptive to reading. Our approach is to minimize the user interaction involved in finding related information by removing explicit query formulation and providing a single relevant result. To evaluate the feasibility of this approach, we first examined the effectiveness of three contextual algorithms for retrieval. To evaluate the effectiveness for readers, we then developed a functional prototype that uses the text of the abstract being read as context and retrieves a single relevant Wikipedia article in response to a passage the user has highlighted. We conducted a small user study where participants were allowed to use the prototype while reading abstracts. The results from this initial study indicate that users found the prototype easy to use and that using the prototype significantly improved their stated understanding and confidence in that understanding of the academic abstracts they read.
Autism spectrum disorders in relation to parental occupation in technical fields
Authors: Windham Gayle C. , Fessel Karen , Grether Judith K. 
Published: July 2009

AbstractA previous study reported that fathers of children with autism spectrum disorders (ASD) were more likely to work as engineers, requiring “systemizing skills,” and suggesting a distinct phenotype, but alternatively this may have been related to selection biases. We conducted a population‐based study to explore whether fathers, or mothers, of children with ASD are over‐represented in fields requiring highly technical skills. Subjects included 284 children with ASD and 659 gender‐matched controls, born in 1994 in the San Francisco Bay Area. Parental occupation and industry were abstracted verbatim from birth certificates. Engineering, computer programming, and science were examined as highly technical occupations. To limit bias by parental socio‐economic status, we selected a referent group of occupations that seemed professionally similar but of a less technical nature. Odds ratios (ORs) and 95% confidence intervals (CI) were calculated by logistic regression, adjusting for parental age, education, and child race. Mothers of cases were somewhat more likely to work in hi‐tech occupations (6.7%) than mothers of controls (4.0%, P=0.07), but little difference was observed among fathers, nor for engineering separately. Compared to parents in other “white collar” occupations, the adjusted OR for highly technical occupations among mothers was 2.5 (95% CI: 1.2–5.3) and among fathers was 1.3 (95% CI: 0.79–2.1), with no evidence of a joint effect observed. Our results regarding maternal occupation in technical fields being associated with ASD in offspring suggest further study to distinguish parental occupation as a phenotypic marker of genetic loading vs. other social or exposure factors.
scFv‐based fluorogen activating proteins and variable domain inhibitors as fluorescent biosensor platforms
Authors: Falco Crystal N. , Dykstra Kaitlyn M. , Yates Bradley P. , Berget Peter B. 
Published: July 2009

AbstractSingle chain antibodies (scFvs) are engineered proteins composed of IgG variable heavy (VH) and variable light (VL) domains tethered together by a flexible peptide linker. We have characterized the individual VH or VL domain activities of several scFvs isolated from a yeast surface‐display library for their ability to bind environmentally sensitive fluorogenic dyes causing them to fluoresce. For many of the scFvs, both VH and VL domains are required for dye binding and fluorescence. The analysis of other scFvs, however, revealed that either the VH or the VL domain alone is sufficient to cause the fluorogenic dye activation. Furthermore, the inactive complementary domains in the original scFvs either contribute nothing to, or actually inhibit the activity of these active single domains. We have explored the interactions between active variable domains and inactive complementary domains by extensive variable domain swapping through in vitro gene manipulations to create hybrid scFvs. In this study, we demonstrate that significant alteration of the fluorogenic dye activation by the active VH or VL domains can occur by partnering with different VH or VL complementary domains in the scFv format. Hybrid scFvs can be generated that have fluorogen‐activating domains that are completely inhibited by interactions with other domains. Such hybrid scFvs are excellent platforms for the development of several types of genetically encoded, fluorescence‐generating biosensors.
Cloning and overexpression of a thermostable signal peptide peptidase (SppA) from Thermoplasma volcanium GSS1 in E. coli
Authors: Kocabıyık Semra , Demirok Burçak 
Published: July 2009

AbstractOn page 1064, 5 lines from the bottom, it states “Lys is found at position 461 (Ec umbering) instead of Ala [28, 29].”The correct sentence should be “However, in the E.coli enzyme, instead of Lys at position 461 (Ec numbering), there is Ala‐461 [28, 29].”
Improved triglyceride transesterification by circular permuted Candida antarctica lipase B
Authors: Yu Ying , Lutz Stefan 
Published: July 2009

AbstractLipases represent a versatile class of biocatalysts with numerous potential applications in industry including the production of biodiesel via enzyme‐catalyzed transesterification. In this article, we have investigated the performance of cp283, a variant of Candida antarctica lipase B (CALB) engineered by circular permutation, with a series of esters, as well as pure and complex triglycerides. In comparison with wild‐type CALB, the permutated enzyme showed consistently higher catalytic activity (2.6‐ to 9‐fold) for trans and interesterification of the different substrates with 1‐butanol and ethyl acetate as acyl acceptors. Differences in the observed rates for wild‐type CALB and cp283 are believe to be related to changes in the rate‐determining step of the catalytic cycle as a result of circular permutation. Biotechnol. Bioeng. 2010;105: 44–50. © 2009 Wiley Periodicals, Inc.
Improvement of low‐temperature caseinolytic activity of a thermophilic subtilase by directed evolution and site‐directed mutagenesis
Authors: Zhong Chuan‐Qi , Song Shengli , Fang Nan , Liang Xiaoliang , Zhu Hui , Tang Xiao‐Feng , Tang Bing 
Published: July 2009

AbstractBy directed evolution and subsequent site‐directed mutagenesis, cold‐adapted variants of WF146 protease, a thermophilic subtilase, have been successfully engineered. A four‐amino acid substitution variant RTN29 displayed a sixfold increase in caseinolytic activity in the temperature range of 15–25°C, a down‐shift of optimum temperature by ∼15°C, as well as a decrease in thermostability, indicating it follows the general principle of trade‐off between activity and stability. Nevertheless, to some extent RTN29 remained its thermophilic nature, and no loss of activity was observed after heat‐treatment at 60°C for 2 h. Notably, RTN29 exhibited a lower hydrolytic activity toward suc‐AAPF‐pNA, due to an increase in Km and a decrease in kcat, in contrast to other artificially cold‐adapted subtilases with increased low‐temperature activity toward small synthetic substrates. All mutations (S100P, G108S, D114G, M137T, T153A, and S246N) identified in the cold‐adapted variants occurred within or near the substrate‐binding region. None of these mutations, however, match the corresponding sites in naturally psychrophilic and other artificially cold‐adapted subtilases, implying there are multiple routes to cold adaptation. Homology modeling and structural analysis demonstrated that these mutations led to an increase in mobility of substrate‐binding region and a modulation of substrate specificity, which seemed to account for the improvement of the enzyme's catalytic activity toward macromolecular substrates at lower temperatures. Our study may provide valuable information needed to develop enzymes coupling high stability and high low‐temperature activity, which are highly desired for industrial use. Biotechnol. Bioeng. 2009; 104: 862–870. © 2009 Wiley Periodicals, Inc.
Optimization of pH and nitrogen for enhanced hydrogen production by Synechocystis sp. PCC 6803 via statistical and machine learning methods
Authors: Burrows Elizabeth H. , Wong Weng‐Keen , Fern Xiaoli , Chaplen Frank W. R. , Ely Roger L. 
Published: July 2009

AbstractThe nitrogen (N) concentration and pH of culture media were optimized for increased fermentative hydrogen (H2) production from the cyanobacterium, Synechocystis sp. PCC 6803. The optimization was conducted using two procedures, response surface methodology (RSM), which is commonly used, and a memory‐based machine learning algorithm, Q2, which has not been used previously in biotechnology applications. Both RSM and Q2 were successful in predicting optimum conditions that yielded higher H2 than the media reported by Burrows et al., Int J Hydrogen Energy. 2008;33:6092–6099 optimized for N, S, and C (called EHB‐1 media hereafter), which itself yielded almost 150 times more H2 than Synechocystis sp. PCC 6803 grown on sulfer‐free BG‐11 media. RSM predicted an optimum N concentration of 0.63 mM and pH of 7.77, which yielded 1.70 times more H2 than EHB‐1 media when normalized to chlorophyll concentration (0.68 ± 0.43 μmol H2 mg Chl−1 h−1) and 1.35 times more when normalized to optical density (1.62 ± 0.09 nmol H2 OD730−1 h−1). Q2 predicted an optimum of 0.36 mM N and pH of 7.88, which yielded 1.94 and 1.27 times more H2 than EHB‐1 media when normalized to chlorophyll concentration (0.77 ± 0.44 μmol H2 mg Chl−1 h−1) and optical density (1.53 ± 0.07 nmol H2 OD730−1 h−1), respectively. Both optimization methods have unique benefits and drawbacks that are identified and discussed in this study. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009
Invariability of central metabolic flux distribution in Shewanella oneidensis MR‐1 under environmental or genetic perturbations
Authors: Tang Yinjie J. , Martin Hector Garcia , Deutschbauer Adam , Feng Xueyang , Huang Rick , Llora Xavier , Arkin Adam , Keasling Jay D. 
Published: July 2009

AbstractAn environmentally important bacterium with versatile respiration, Shewanella oneidensis MR‐1, displayed significantly different growth rates under three culture conditions: minimal medium (doubling time ∼3 h), salt stressed minimal medium (doubling time ∼6 h), and minimal medium with amino acid supplementation (doubling time ∼1.5 h). 13C‐based metabolic flux analysis indicated that fluxes of central metabolic reactions remained relatively constant under the three growth conditions, which is in stark contrast to the reported significant changes in the transcript and metabolite profiles under various growth conditions. Furthermore, 10 transposon mutants of S. oneidensis MR‐1 were randomly chosen from a transposon library and their flux distributions through central metabolic pathways were revealed to be identical, even though such mutational processes altered the secondary metabolism, for example, glycine and C1 (5,10‐Me‐THF) metabolism. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009
An efficient algorithm for Parafac with uncorrelated mode‐A components applied to large I × J × K data sets with I >> JK
Authors: Kiers Henk A. L. , Harshman Richard A. 
Published: July 2009

AbstractHarshman and Lundy (Comput. Stat. Data Anal. 1994; 18: 39–72) described an option in the Parafac algorithm for constraining one or more component matrices to have uncorrelated columns. In cases where an algorithm using this constraint is to be applied to a three‐way array that has too many entries in one mode, the algorithm is computationally impractical. The present paper describes two modifications of their algorithm to handle the multiplications involving the large mode efficiently for cases where the product of the sizes of the other two modes is smaller than that of the larger mode. By means of a simulation study, it is demonstrated that these procedures (which are similarly efficient) are much more efficient than the original algorithm. Copyright © 2009 John Wiley & Sons, Ltd.
A case study illustrating traps, pitfalls and concerns for the hypnodontist
Authors: Filo Gabor 
Published: July 2009

AbstractThis case study is about hypnosis for intractable pain in the case of a patient who had trigeminal neuralgia, which through medical intervention had become anaesthesia dolorosa. The study will address the demand characteristics set up by the patient. Inherent in the demands were pitfalls and traps that ultimately resulted in a pyrrhic victory. This case illustrates the need to know the limits for the hypnodontist: of their jurisdictionally permitted scope of practice; their own abilities; whose goals are being met by the intervention; and what outcomes define success for the patient and the hypnodontist. Copyright © 2009 British Society of Experimental & Clinical Hypnosis. Published by John Wiley & Sons, Ltd.
Noncovalent Synthesis of Protein Dendrimers
Authors: Lempens Edith H. M. , van Baal Ingrid , van Dongen Joost L. J. , Hackeng Tilman M. , Merkx Maarten , Meijer E. W. 
Published: July 2009

AbstractThe covalent synthesis of complex biomolecular systems such as multivalent protein dendrimers often proceeds with low efficiency, thereby making alternative strategies based on noncovalent chemistry of high interest. Here, the synthesis of protein dendrimers using a strong but noncovalent interaction between a peptide and complementary protein is proposed as an efficient strategy to arrive at dendrimers fully functionalized with protein domains. The association of S‐peptide to S‐protein results in the formation of an active enzyme (ribonuclease S) and therefore serves as an ideal system to explore this synthetic approach. Native chemical ligation was used to couple four S‐peptides by means of their C‐terminal thioester to a cysteine‐functionalized dendritic scaffold, thus yielding a tetravalent S‐peptide wedge. A fully functional ribonuclease S tetramer was prepared by addition of four equivalents of S‐protein. Biophysical techniques (isothermal titration calorimetry (ITC), surface plasmon resonance (SPR), and mass spectrometry) and an enzymatic activity assay were used to verify the formation of the multivalent complex. The noncovalent synthetic strategy presented here provides access to well‐defined, dynamic, semisynthetic protein assemblies in high yield and is therefore of interest to the field of nanomedicine as well as biomaterials.
Transition‐Metal Complexes [(PMe3)2Cl2M(E)] and [(PMe3)2(CO)2M(E)] with Naked Group 14 Atoms (E=C–Sn) as Ligands; Part 2: Complexation with W(CO)5
Authors: Parameswaran Pattiyil , Frenking Gernot 
Published: July 2009

AbstractDensity functional calculations at the BP86/TZ2P level were carried out to understand the ligand properties of the 16‐valence‐electron(VE) Group 14 complexes [(PMe3)2Cl2M(E)] (1ME) and the 18‐VE Group 14 complexes [(PMe3)2(CO)2M(E)] (2ME; M=Fe, Ru, Os; E=C, Si, Ge, Sn) in complexation with W(CO)5. Calculations were also carried out for the complexes (CO)5W–EO. The complexes [(PMe3)2Cl2M(E)] and [(PMe3)2(CO)2M(E)] bind strongly to W(CO)5 yielding the adducts 1ME–W(CO)5 and 2ME–W(CO)5, which have C2v equilibrium geometries. The bond strengths of the heavier Group 14 ligands 1ME (E=Si–Sn) are uniformly larger, by about 6–7 kcal mol−1, than those of the respective EO ligand in (CO)5W‐EO, while the carbon complexes 1MC–W(CO)5 have comparable bond dissociation energies (BDE) to CO. The heavier 18‐VE ligands 2ME (E=Si–Sn) are about 23–25 kcal mol−1 more strongly bonded than the associated EO ligand, while the BDE of 2MC is about 17–21 kcal mol−1 larger than that of CO. Analysis of the bonding with an energy‐decomposition scheme reveals that 1ME is isolobal with EO and that the nature of the bonding in 1ME–W(CO)5 is very similar to that in (CO)5W–EO. The ligands 1ME are slightly weaker π acceptors than EO while the π‐acceptor strength of 2ME is even lower.