bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of low‐fidelity endoscopic sinus surgery simulators on surgical skill
Authors: Wais Marta , Ooi Eng , Leung Randy M. , Vescan Allan D. , Lee John , Witterick Ian J.
Published: September 2011

Background:

Surgical training models are being increasingly used to provide an environment for surgical trainees to improve their skills without risk to patients. This study uses previously validated, inexpensive, low‐fidelity training models to determine how pretraining affects endoscopic sinus surgery (ESS) skills.

Methods:

Fourteen Otolaryngology residents were randomized to 1 of 2 groups that were stratified for training level. The first group took part in a pretraining session where they practiced on all 5 different modules whereas the second group did not receive any pretraining. The following day, all participants took part in a cadaveric ESS course. Participants were instructed to complete a set of tasks and their performances were videotaped. The videos were then evaluated using a Global Rating Scale (GRS) and a Task‐Specific Checklist (TSC). The performances of those who trained using the models were compared to the performances of those who did not.

Results:

The intervention (pretraining) group performed better than the nonintervention (no pretraining) group on the cadaveric ESS tasks (p < 0.05). As well, there was a statistical difference between the senior residents who had the pretraining with the simulator models performing better than those who did not.

Conclusion:

The modules appear to have made a positive impact on ESS skills. These low‐cost, easily‐constructed training modules have the potential to be integrated into Otolaryngology–Head and Neck Surgery resident training. Assessment of long‐term training effects with a larger number of participants is planned for future studies. © 2011 ARS‐AAOA, LLC.
Ionic Liquids as Hypergolic Fuels
Authors: Zhang Yanqiang , Gao Haixiang , Joo Young‐Hyuk , Shreeve Jean'ne M.
Published: September 2011

In propellant systems, fuels of choice continue to be hydrazine and its derivatives, even though they comprise a class of acutely carcinogenic and toxic substances which exhibit rather high vapor pressures and require expensive handling procedures and costly safety precautions. Only recently (2008), ionic liquids (salts with melting points less than 100 °C) with the dicyanamide anion were shown to exhibit hypergolic properties (instantaneous ignition when contacted with oxidizers (100 % nitric acid, WFNA)). Such liquids tend to have low volatilities, and high thermal and chemical stabilities, and often exhibit long liquid ranges which could allow utilization of these substances as bipropellant fuels over a variety of conditions. A new family of dicyanoborates is presented, which can be synthesized in water, with substituted N‐acyclic, N‐cyclic, and azolium cations has met nearly all of the desired important criteria needed for well‐performing fuels.
Learning to Make Selection and Detection Decisions: The Roles of Base Rate and Feedback
Authors: Stewart Thomas R. , Mumpower Jeryl L. , James Holzworth Robert
Published: September 2011

The effects of type of feedback and base rate on threshold learning in a multiple‐cue decision task were examined. In most such decision experiments, participants receive feedback after every trial (full feedback), and a single base rate (usually 0.5) is used. Our experiment explored conditional feedback (feedback only after positive decisions) representing common selection and detection tasks (such as hiring), where the decision maker receives no feedback unless the decision is positive (e.g., hire the applicant). We used three base rates (0.2, 0.5, and 0.8). As expected, performance was best in full feedback, but after 300 learning trials, the difference was small. Conditional feedback generally resulted in fewer positive decisions than full feedback, but this difference was not found in the low (0.2) base rate condition. There were interactions between base rates and types of feedback. Results provide partial support for the constructivist encoding hypothesis of Elwin and colleagues. Simulation results suggest that our results may reflect overconfidence when feedback is not given. With respect to rate of learning, when the base rate was 0.2, conditional feedback participants reached approximately the same selection rate but did so more slowly than the full feedback participants. Partial feedback participants learned slower and appeared to be still learning after 500 trials. When the base rate was 0.5 or 0.8, partial feedback was nearly as good as full feedback, but conditional feedback resulted in a systematically lower rate of positive decisions. Copyright © 2011 John Wiley & Sons, Ltd.
Metabolic characterization and genes for the conversion of biphenyl in Dyella ginsengisoli LA‐4
Authors: Li Ang , Qu Yuan‐Yuan , Pi Wen‐Qing , Zhou Ji‐Ti , Gai Zhong‐Hui , Xu Ping
Published: September 2011

A complete bph gene cluster (bphLA‐4) containing 12,186 bp was amplified from Dyella ginsengisoli LA‐4. The bphLA‐4 was composed of bphABCXD, and an additional gene encoding a meta‐fission product hydrolase was located in the bphX region. BphLA‐4 was independently transcribed by the two operons, bphA1A2orf1A3A4BCX0 and bphX1orf2X2X3D, and significantly differed from bphKF707. Both benzoate and catechol induced the expression of both operons. 2‐Hydroxypenta‐2,4‐dienoate was identified as the intermediate of the biphenyl degradation by strain LA‐4. This finding suggested that there existed a novel lower pathway of biphenyl degradation in strain LA‐4. Biotechnol. Bioeng. 2012; 109:609–613. © 2011 Wiley Periodicals, Inc.
Integrating computational methods to retrofit enzymes to synthetic pathways
Authors: Brunk Elizabeth , Neri Marilisa , Tavernelli Ivano , Hatzimanikatis Vassily , Rothlisberger Ursula
Published: September 2011

Microbial production of desired compounds provides an efficient framework for the development of renewable energy resources. To be competitive to traditional chemistry, one requirement is to utilize the full capacity of the microorganism to produce target compounds with high yields and turnover rates. We use integrated computational methods to generate and quantify the performance of novel biosynthetic routes that contain highly optimized catalysts. Engineering a novel reaction pathway entails addressing feasibility on multiple levels, which involves handling the complexity of large‐scale biochemical networks while respecting the critical chemical phenomena at the atomistic scale. To pursue this multi‐layer challenge, our strategy merges knowledge‐based metabolic engineering methods with computational chemistry methods. By bridging multiple disciplines, we provide an integral computational framework that could accelerate the discovery and implementation of novel biosynthetic production routes. Using this approach, we have identified and optimized a novel biosynthetic route for the production of 3HP from pyruvate. Biotechnol. Bioeng. 2012; 109:572–582. © 2011 Wiley Periodicals, Inc.
The Synthesis of Chiral Phosphorus Ligands for use in Homogeneous Metal Catalysis
Authors: Lühr Susan , Holz Jens , Börner Armin
Published: September 2011

Recent developments in the synthesis of chiral phosphorus ligands are summarized. Main emphasis is given to the multitude of protocols for their synthesis starting from compounds of the chiral pool or by using other easily available chiral starting materials. Besides mono‐ and bidentate P‐ligands hybrid ligands bearing N, O, or olefinic groups as second ligating units are addressed. The syntheses of new P‐chirogenic ligands, as well as ligands with supramolecular structures are likewise reviewed. In appropriate cases structures of related privileged ligands are given for comparison. When available, the efficiency of the new ligands for metal catalyzed reactions are briefly assessed.
Delineating Poly(Aniline) Redox Chemistry by Using Tailored Oligo(Aryleneamine)s: Towards Oligo(Aniline)‐Based Organic Semiconductors with Tunable Optoelectronic Properties
Authors: Shao Zhecheng , Rannou Patrice , Sadki Saïd , Fey Natalie , Lindsay David M. , Faul Charl F. J.
Published: September 2011

The simple and elegant Buchwald–Hartwig cross‐coupling reaction has been used to synthesise a designed range of new aniline‐based tetramers in one step, and without the need for protecting groups. Variation of the central aromatic ring has provided the opportunity to carefully tune the optoelectronic properties in this series, thus enabling a structure–activity relationship study by using a range of photophysical and electrochemical techniques. As a result, the long‐proposed sequences of electron‐electron (EE) and electron‐chemical (EC) processes that support the complex redox and proton‐transfer reactions involved in the well‐known switching of redox states of poly‐ and oligo(aniline)s are revealed here for the first time. We also present the initial results from time‐dependent DFT calculations to clarify the optoelectronic behaviour of these oligomers. The dc‐conductivity measurements of conducting thin films of this series, doped with the prototypical poly(aniline) protonating agent d,l‐camphor‐10‐sulfonic acid (CSA), externally plasticised with triphenyl phosphate (TPP), and processed from m‐cresol (MC) solutions, are also presented.
Dynamic Self‐Assembly of Charge‐Transfer Nanofibers of Tetrathiafulvalene Derivatives with F4TCNQ
Authors: Jain Ankit , Rao K. Venkata , Mogera Umesha , Sagade Abhay A. , George Subi J.
Published: September 2011

One‐dimensional charge‐transfer nanostructures were constructed by the supramolecular coassembly of amphiphilic (Amph‐TTF) and hydrophobic (TDD‐TTF) tetrathiafulvalene (TTF) donor derivatives with the acceptor 2,3,5,6‐tetrafluoro‐7,7,8,8‐tetracyanoquinodimethane (F4TCNQ), in appropriate solvent composition mixtures. Microscopic analyses show that TDD‐TTF retains its self‐assembled fibrillar morphology even in the charge‐transfer state, whereas Amph‐TTF undergoes a spherical to nanorod transition upon coassembly. Time‐dependent optical spectroscopy studies have shown a spontaneous change in molecular organization in TDD‐TTF‐based donor–acceptor costacks, which suggests a dynamic behavior, in contrast to the kinetically stable amphiphilic TTF assemblies. We have also tried to get an insight into the observed time‐dependent change in molecular packing of these nanostructures through spectroscopic analyses by commenting on whether the TTF–TCNQ pair is cofacially arranged or present in the classical herringbone (orthogonal) fashion. Furthermore, our two‐probe electrical measurements showed that these charge‐transfer fibers are conducting. A supramolecular approach that yields 1D charge‐transfer nanostructures of donor and acceptor molecules will be an alternative to existing crystalline substances with high conductivity and hence can be a viable tool for nanoelectronics.
Einstein relation for reversible diffusions in a random environment
Authors: Gantert Nina , Mathieu Pierre , Piatnitski Andrey
Published: September 2011

We consider reversible diffusions in a random environment and prove the Einstein relation for this model. It says that the derivative at 0 of the effective velocity under an additional local drift equals the diffusivity of the model without drift. The Einstein relation is conjectured to hold for a variety of models but so far it has only been proved in particular cases. Our proof makes use of homogenization arguments, the Girsanov transform, and a refinement of the regeneration times introduced by Shen. © 2011 Wiley Periodicals, Inc.
Reaction Mechanism and the Role of Copper in the Photooxidation of Alcohol over Cu/Nb2O5
Authors: Furukawa Shinya , Ohno Yasuhiro , Shishido Tetsuya , Teramura Kentaro , Tanaka Tsunehiro
Published: September 2011

Loading of a small amount of copper on Nb2O5 significantly enhances the activity of alcohol photooxidation without organic solvents. Alcohol is adsorbed on the Lewis acid site (NbV) to form an alkoxide species. Photogenerated holes and electrons on Cu/Nb2O5 are trapped by the adsorbed alkoxide and CuII species to form the alkoxide carbon radical and CuI species. The formed alkoxide carbon radical is converted to a carbonyl compound and then desorbed. Finally, the reduced CuI sites are reoxidized by reaction with O2. The alcohol photooxidation over Nb2O5 takes place under not only UV irradiation but also under visible light irradiation up to 450 nm, although the band gap of Nb2O5 is 390 nm (3.2 eV). DFT calculations reveal that 1) the surface donor level derived from the adsorbed alkoxide species is located in the forbidden band, 2) direct electron transition from the surface donor level to the conduction band takes place by absorbing a photon, 3) the excitation energy from surface donor level to the Nb 4d conduction band is lower than that from the O 2p valence band to Nb 4d. The kinetic study and FT/IR spectra suggest that CuI acts as an effective desorption site for the products. Based on these results, we conclude that copper functions as an effective redox promoter and desorption site for the product.
Substituent Effects on Non‐Covalent Interactions with Aromatic Rings: Insights from Computational Chemistry
Authors: Raju Rajesh K. , Bloom Jacob W. G. , An Yi , Wheeler Steven E.
Published: September 2011

Non‐covalent interactions with aromatic rings pervade modern chemical research. The strength and orientation of these interactions can be tuned and controlled through substituent effects. Computational studies of model complexes have provided a detailed understanding of the origin and nature of these substituent effects, and pinpointed flaws in entrenched models of these interactions in the literature. Here, we provide a brief review of efforts over the last decade to unravel the origin of substituent effects in π‐stacking, XH/π, and ion/π interactions through detailed computational studies. We highlight recent progress that has been made, while also uncovering areas where future studies are warranted.
Can We Afford to Waste Carbon Dioxide? Carbon Dioxide as a Valuable Source of Carbon for the Production of Light Olefins
Authors: Centi Gabriele , Iaquaniello Gaetano , Perathoner Siglinda
Published: September 2011

Concerns about climate change have increased the amount of activity on carbon capture and sequestration (CCS) as one of the solutions to the problem of rising levels of CO2 in the troposphere, while the reuse of CO2 (carbon capture and recycling; CCR) has only recently received more attention. CCR is focused on the possibility of using CO2 as a cheap (or even negative‐value) raw material. This Concept paper analyzes this possibility from a different perspective: In a sustainable vision, can we afford to waste CO2 as a source of carbon in a changing world faced with a fast depletion of natural carbon sources and in need of a low‐carbon, resource‐efficient economy? One of the points emerging from this discussion concerns the use of CO2 for the production of olefins (substituting into or integrating with current energy‐intensive methodologies that start from oil or syngas from other fossil fuel resources) if H2 from renewable resources were available at competitive costs. This offers an opportunity to accelerate the introduction of renewable energy into the chemical production chain, and thus to improve resource efficiency in this important manufacturing sector.
Mono‐ and Tetraalkyne Modified Ligands and Their Eu3+ Complexes – Utilizing “Click” Chemistry to Expand the Scope of Conjugation Chemistry
Authors: Suchý Mojmír , Milne Mark , Li Alex X. , McVicar Nevin , Dodd David W. , Bartha Robert , Hudson Robert H. E.
Published: September 2011

The Cu+‐catalyzed Huisgen [3+2] cycloaddition has been used to elaborate analogues of a candidate PARACEST MRI contrast agent, which is a complex of Eu3+ with DOTAM–Gly–Phe–OH. Analogues possessing either one L‐tyrosine in place of an L‐phenylalanine, or with all four phenylalanine units replaced, were transformed into Tyr(O‐propargyl) substrates for “click” chemistry. Conjugation of the Eu3+–DOTAM derivatives with a spectrum of azides, including simple hydrophilic, hydrophobic, and aromatic groups, propyl glucoside, and a nucleoside were successful. The magnetic resonance properties of the resultant conjugates were examined, and their chemical exchange saturation transfer (CEST) properties are reported.
Error estimate and adaptive refinement for incompressible Navier‐Stokes equations using the discrete least squares meshless method
Authors: Firoozjaee A.R. , Afshar Mohammad Hadi
Published: September 2011

In this paper, an adaptive refinement strategy based on a node‐moving technique is proposed and used for the efficient solution of the steady‐state incompressible Navier–Stokes equations. The value of a least squares functional of the residual of the governing differential equation and its boundary conditions at nodal points is regarded as a measure of error and used to predict the areas of poor solutions. A node‐moving technique is then used to move the nodal points to the zones of higher numerical errors. The problem is then resolved on the refined distribution of nodes for higher accuracy. A spring analogy is used for the node‐moving methodology in which nodal points are connected to their neighbors by virtual springs. The stiffness of each spring is assumed to be proportional to the errors of its two end points and its initial length. The new positions of the nodal points are found such that the spring system attains its equilibrium state. Some numerical examples are used to illustrate the ability of the proposed scheme for the adaptive solution of the steady‐state incompressible Navier–Stokes equations. The results demonstrate a considerable improvement of the results with a reasonable computational effort by using the proposed adaptive strategy. Copyright © 2011 John Wiley & Sons, Ltd.
Shape optimization of steady‐state heat‐conduction fields considering temperature dependency of thermal conductivity coefficient
Authors: Katamine Eiji , Mikada Shingo , Azegami Hideyuki
Published: September 2011

This paper presents a numerical analysis method for shape optimization of domains with steady‐state heat‐conduction fields considering the temperature dependence of the thermal conductivity coefficient. In this paper, we formulate two shape optimization problems, namely, maximization of thermal dissipation on heat transfer boundaries and minimization of heat‐conduction fields. The shape gradient functions for these shape optimization problems are derived theoretically using the Lagrange multiplier method and formulae of the material derivative. Reshaping is accomplished using the traction method proposed as a solution to the shape optimization problems. The proposed method is validated from the results of two‐dimensional numerical analysis. © 2011 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library (wileyonlinelibrary.com/journal/htj). DOI 10.1002/htj.20374
A mechanism study of initial droplet formation for dropwise condensation
Authors: Liu Tian‐qing , Sun Wei , Mu Chun‐feng , Xia Song‐bai , Sun Xiang‐yu
Published: September 2011

The mechanism of formation of initial condensate droplets for dropwise condensation in the nanometer scale is still undetermined. In this paper, magnesium was used as the condensation surface since it can react with condensate to produce magnesium hydroxide, which can be regarded as the marker of the initial condensate state on the surface. Then an electron probe microanalyzer (EPMA) and scanning electron microscope (SEM) were used to scan the variation of the chemical compositions on the surfaces in nanometer scale before and after the initial condensation. The results showed that the oxygen contents on the test surfaces increased obviously with subcooling and condensation time after the initial dropwise condensation. In order to further analyze the variation of oxygen content occurring on the whole surface or only at the partial locations, the reaction dynamic relationship of magnesium and the condensate was found. And the calculated result indicated that the area ratio occupied by condensate was less than 1. Meanwhile the detected results of EMPA showed that oxygen on the test surface was distributed non‐uniformly. As a result, the formation mechanism of the initial condensate drops for dropwise condensation agrees with the hypothesis of nucleation sites in nanometer scale. © 2011 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library (wileyonlinelibrary.com/journal/htj). DOI 10.1002/htj.20377
Experimental and computational validation and verification of the Stokes–Darcy and continuum pipe flow models for karst aquifers with dual porosity structure
Authors: Hu Xiaolong , Wang Xiaoming , Gunzburger Max , Hua Fei , Cao Yanzhao
Published: September 2011

In our previous study, we developed the Stokes–Darcy (SD) model was developed for flow in a karst aquifer with a conduit bedded in matrix, and the Beavers–Joseph (BJ) condition was used to describe the matrix–conduit interface. We also studied the mathematical well‐posedness of a coupled continuum pipe flow (CCPF) model as well as convergence rates of its finite element approximation. In this study, to compare the SD model with the CCPF model, we used numerical analyses to validate finite element discretisation methods for the two models. Using computational experiments, simulation codes implementing the finite element discretisations are then verified. Further model validation studies are based on the results of laboratory experiments. Comparing the results of computer simulations and experiments, we concluded that the SD model with the Beavers–Joseph interface condition is a valid model for conduit–matrix systems. On the other hand, the CCPF model with the value of the exchange parameter chosen within the range suggested in the literature perhaps does not result in good agreement with experimental observations. We then examined the sensitivity of the CCPF model with respect to the exchange parameter, concluding that, as has previously been noted, the model is highly sensitive for small values of the exchange parameter. However, for larger values, the model becomes less sensitive and, more important, also produces results that are in better agreement with experimental observations. This suggests that the CCPF model may also produce accurate simulation results, if one chooses larger values of the exchange parameter than those suggested in the literature. Copyright © 2011 John Wiley & Sons, Ltd.
Differential biochemical response of rat kidney towards low and high doses of NiCl2 as revealed by NMR spectroscopy
Authors: Tyagi Ritu , Rana Poonam , Gupta Mamta , Khan Ahmad Raza , Bhatnagar Deepak , Bhalla P. J. S. , Chaturvedi Shubhra , Tripathi Rajendra P , Khushu Subash
Published: September 2011

Heavy metals are known for their associated nephrotoxicity and nickel is no exception. An integrated metabonomic approach, based on high‐resolution 1H NMR spectroscopy, was applied to determine the acute biochemical effects of NiCl2 on the renal tissues of rats. Kidney homogenates from rats treated with NiCl2 at two dose levels (4 and 20 mg kg−1 b.w., i.p.) and those from controls were analysed using 1H NMR spectroscopy and also assessed for antioxidant parameters at days 1, 3 and 5 post‐dose. The major metabolite changes corresponding to nickel exposure were related to amino acids, osmolytes and energy metabolites. Differential responses were observed in 1H NMR spectra with exposure to low and high doses of NiCl2. For high doses, 1H NMR spectral analysis revealed alterations in renal tissues, along with damage to the cortical and papillary region and depletion of renal osmolytes such as betaine, trimethyl amine oxide, myo‐inositol and taurine, which persisted until day 5 post‐dose. The metabolite profile of 1H NMR spectra obtained from animals treated with lower dose of NiCl2 initially increased as an immediate stress response and then showed signs of recovery with the passage of time. NMR spectral analysis was well corroborated with histopathological and oxidative stress results. Nickel‐induced oxidative stress was observed in both groups of animals with increased levels of antioxidant parameters at initial time points, but continued to increase in the high‐dose group. The present study shows a huge potential of metabonomics for mapping organ‐based metabolic response during heavy metal toxicity. Copyright © 2011 John Wiley & Sons, Ltd.
KLF6/Sp1 initiates transcription of the tmsg‐1 gene in human prostate carcinoma cells: An exon involved mechanism
Authors: Gong Miaozi , Yu Wenjuan , Pei Fei , You Jiangfeng , Cui Xianglin , McNutt Michael A. , Li Gang , Zheng Jie
Published: September 2011

The tumor metastasis suppressor gene‐1 (tmsg‐1) was first cloned as a new tumor suppressor gene in our laboratory several years ago. Since then, however, despite the substantial progression that has been made in investigation of the biologic roles played by this gene, the manner in which it exerts its regulatory influence is still unknown. With transfection of various deletion or mutation constructs, we identified a potential enhancer and three potential silencers in the 5′‐flanking region. However, it was particularly interesting to find that a region (+59 to +123 bp) of exon 1 exhibited a strong role in initiation of tmsg‐1 gene transcription. Deletion of this region led to essentially complete loss of driving activity of exon‐1 sequence on luciferase. Further analysis showed that transcription factors KLF6 and Sp1 are able to interact with each other and bind to their elements in this region. Co‐transfection of pGL3‐114/+123 with KLF6‐ and/or Sp1‐expressing plasmids resulted in an elevation of luciferase activity and transcription level of tmsg‐1, which was abolished by knockdown of KLF6 or Sp1. Analysis of metastatic capacity showed that cells with high metastatic capability exhibited a lower level of KLF6/TMSG‐1 proteins with higher invasive capability and vice versa. Thus, we concluded that interaction of KLF6 and Sp1, together with their binding of elements in exon 1 are critical events in initiation of transcription of the tmsg‐1 gene. These results reveal a hitherto unreported mechanism for initiation of transcription of the tmsg‐1 gene. J. Cell. Biochem. 113: 329–339, 2012. © 2011 Wiley Periodicals, Inc.
Functional characterization of a novel FGFR2 mutation, E731K, in craniosynostosis
Authors: Park Jounghyen , Park Ok‐Jin , Yoon Won‐Joon , Kim Hyun‐Jung , Choi Kang‐Young , Cho Tae‐Joon , Ryoo Hyun‐Mo
Published: September 2011

Craniosynostosis is a condition in which some or all of the sutures in the skull of an infant close prematurely. Fibroblast growth factor receptor 2 (FGFR2) mutations are a well‐known cause of craniosynostosis. Many syndromes that comprise craniosynostosis, such as Apert syndrome, Crouzon syndrome, and Pfeiffer syndrome, have one of the phenotypes that have been reported in FGFR2 mutant patients. FGFRs have been reported in four types (FGFR1–4), and upon binding with FGF ligands, signal transduction occurs inside of cells. Activated FGFR stimulates an osteogenic master transcription factor, Runx2, through the MAP kinase and PKC pathways. We obtained a genetic analysis of six Korean patients who have craniosynostosis as a phenotype. All of the patients had at least one mutation in the FGFR2 gene; five of those mutations have already been reported elsewhere, while one mutation is novel and was hypothesized to lead to Apert syndrome. In this study, we reported and functionally analyzed a novel mutation of the FGFR2 gene found in a craniosynostosis patient, E731K. The mutation is in the 2nd tyrosine kinase domain in the C‐terminal cytoplasmic region of the molecule. The mutation caused an enhanced phosphorylation of the FGFR2E731K and ERK‐MAP kinase, the stimulation of transcriptional activity of Runx2, and consequently, the enhancement of osteogenic marker gene expression. We conclude that the substitution of E731K in FGFR2 is a novel mutation that resulted in a constitutive activation of the receptor and ultimately resulted in premature suture obliteration. J. Cell. Biochem. 113: 457–464, 2012. © 2011 Wiley Periodicals, Inc.
Suppression of RANKL‐dependent heme oxygenase‐1 is required for high mobility group box 1 release and osteoclastogenesis
Authors: Sakai Eiko , Shimada‐Sugawara Megumi , Nishishita Kazuhisa , Fukuma Yutaka , Naito Mariko , Okamoto Kuniaki , Nakayama Koji , Tsukuba Takayuki
Published: September 2011

The differentiation of osteoclasts is regulated by several essential cytokines, such as receptor activator of nuclear factor κB ligand (RANKL) and macrophage colony‐stimulating factor. Recently, high mobility group box 1 (HMGB1), a chromatin protein, also has been identified as one of these osteoclast differentiation cytokines. However, the molecular mechanisms that control HMGB1 release from osteoclast precursor cells are not known. Here, we report that RANKL‐induced suppression of heme oxygenase‐1 (HO‐1), a heme‐degrading enzyme, promotes HMGB1 release during osteoclastogenesis. In contrast, induction of HO‐1 with hemin or curcumin in bone marrow‐derived macrophages or RAW‐D murine osteoclast precursor cells inhibited osteoclastogenesis and suppressed HMGB1 release. Since an inhibitor for p38 mitogen‐activated protein kinase (MAPK) prevented the RANKL‐mediated HO‐1 suppression and extracellular release of HMGB1, these effects were p38 MAPK‐dependent. Moreover, suppression of HO‐1 in RAW‐D cells by RNA interference promoted the activation of caspase‐3 and HMGB1 release, whereas overexpression of HO‐1 inhibited caspase‐3 activation as well as HMGB1 release. Furthermore, these effects were regulated by redox conditions since antioxidant N‐acetylcysteine abolished the HO‐1/HMGB1/caspase‐3 axis. These results suggest that RANKL‐dependent HO‐1 suppression leads to caspase‐3 activation and HMGB1 release during osteoclastogenesis. J. Cell. Biochem. 113: 486–498, 2012. © 2011 Wiley Periodicals, Inc.
Multiply balanced edge colorings of multigraphs
Authors: Bahmanian M. A. , Rodger C. A.
Published: September 2011

In this article, a theorem is proved that generalizes several existing amalgamation results in various ways. The main aim is to disentangle a given edge‐colored amalgamated graph so that the result is a graph in which the edges are shared out among the vertices in ways that are fair with respect to several notions of balance (such as between pairs of vertices, degrees of vertices in both the graph and in each color class, etc.). The connectivity of color classes is also addressed. Most results in the literature on amalgamations focus on the disentangling of amalgamated complete graphs and complete multipartite graphs. Many such results follow as immediate corollaries to the main result in this article, which addresses amalgamations of graphs in general, allowing for example the final graph to have multiple edges. A new corollary of the main theorem is the settling of the existence of Hamilton decompositions of the family of graphs K(a1, …, ap; λ1, λ2); such graphs arise naturally in statistical settings. © 2011 Wiley Periodicals, Inc. J Graph Theory 70: 297–317, 2012
Large cliques or stable sets in graphs with no four‐edge path and no five‐edge path in the complement
Authors: Chudnovsky Maria , Zwols Yori
Published: September 2011

Erdős and Hajnal [Discrete Math 25 (1989), 37–52] conjectured that, for any graph H, every graph on n vertices that does not have H as an induced subgraph contains a clique or a stable set of size nɛ(H) for some ɛ(H)>0. The Conjecture 1. known to be true for graphs H with |V(H)|≤4. One of the two remaining open cases on five vertices is the case where H is a four‐edge path, the other case being a cycle of length five. In this article we prove that every graph on n vertices that does not contain a four‐edge path or the complement of a five‐edge path as an induced subgraph contains either a clique or a stable set of size at least n1/6. © 2011 Wiley Periodicals, Inc. J Graph Theory
Excluding Induced Subdivisions of the Bull and Related Graphs
Authors: Chudnovsky Maria , Penev Irena , Scott Alex , Trotignon Nicolas
Published: September 2011

For any graph H, let Forb*(H) be the class of graphs with no induced subdivision of H. It was conjectured in [J Graph Theory, 24 (1997), 297–311] that, for every graph H, there is a function fH: ℕ→ℝ such that for every graph G∈Forb*(H), χ(G)≤fH(ω(G)). We prove this conjecture for several graphs H, namely the paw (a triangle with a pendant edge), the bull (a triangle with two vertex‐disjoint pendant edges), and what we call a “necklace,” that is, a graph obtained from a path by choosing a matching such that no edge of the matching is incident with an endpoint of the path, and for each edge of the matching, adding a vertex adjacent to the ends of this edge. © 2011 Wiley Periodicals, Inc. J Graph Theory 71:49–68, 2012
Low b‐value diffusion‐weighted imaging for diagnosing strangulated small bowel obstruction: A feasibility study
Authors: Takahara Taro , Kwee Thomas C. , Sadahiro Sotaro , Yamashita Tomohiro , Toyoguchi Yuki , Yoshizako Takeshi , Horie Tomohiro , Luijten Peter R. , Imai Yutaka
Published: September 2011

Purpose:

To assess the feasibility of low b‐value diffusion‐weighted imaging (DWI) for diagnosing strangulated small bowel obstruction (SBO).

Materials and Methods:

Five volunteers and 14 patients with SBO underwent DWI at b‐values of 0 and 50 s/mm2. Apparent diffusion coefficients (ADCs) and signal preservation ratios (SPRs) were measured in the distal jejunum in the volunteers before and after butylscopolamine administration, and in the (strangulated) closed loop, near the obstructive site, and far from the obstructive site in the patients. Low b‐value diffusion‐weighted images in the patients were quantitatively evaluated for diagnosing strangulation.

Results:

In the volunteers, mean ADC (10−3 mm2/s) and SPR (%) before butylscopolamine administration (18.3 ± 5.9 and 41.4 ± 11.5) were significantly different (P < 0.05) from those after butylscopolamine administration (6.4 ± 3.6 and 73.7 ± 12.9). In the patients, mean ADCs and SPRs among the strangulated closed loop (3.8 ± 2.2 and 83.3 ± 9.3), near the obstructive site (12.1 ± 6.9 and 57.3 ± 18.5), and far from the obstructive site (26.8 ± 10.7 and 29.9 ± 16.4) were significantly different (P < 0.05). Areas under the receiver operating characteristic curve for the diagnosis of strangulation varied between 0.937 and 1.000.

Conclusion:

Low b‐value DWI is a feasible technique to distinguish the strangulated closed loop from nonstrangulated loops in SBO, and show promise for diagnosing strangulated SBO. J. Magn. Reson. Imaging 2011;. © 2011 Wiley Periodicals, Inc.
The p75 neurotrophin receptor has nonapoptotic antineurotrophic actions in the basal forebrain
Authors: Greferath Ursula , Trieu Jennifer , Barrett Graham L.
Published: September 2011

Because of controversy about the role of the p75 neurotrophin receptor (p75NTR) in the cholinergic basal forebrain (CBF), we investigated this region in p75NTR third exon knockout mice that were congenic with 129/Sv controls. They express a shortened intracellular form of p75NTR, permitting detection of p75NTR‐expressing cells. We performed separate counts of choline acetyltransferase (ChAT)‐expressing and p75NTR‐expressing neurons. In agreement with past reports, the number of ChAT‐immunoreactive neurons in knockout mice was greater than in wild‐type mice, and this was evident in each of the main anatomical divisions of the CBF. In contrast, the number of p75NTR‐immunoreactive neurons did not differ between genotypes. The biggest increase in ChAT neurons (27%) was in the horizontal limb of the diagonal band of Broca (HDB), in which region the number of p75NTR‐positive neurons was unchanged. Double staining revealed that some neurons in wild‐type mice expressed p75NTR but not ChAT. In the knockout mice, all p75NTR‐expressing neurons expressed ChAT. The increase in cholinergic neurons, therefore, was at least partially attributable to a higher proportion of ChAT immunoreactivity within the population of p75NTR‐expressing neurons. Cholinergic neurons were also larger in knockout mice than in controls. In the hippocampal CA1 region, knockout mice had a greater number of cholinergic fibers. There was a 77% increase in hippocampal ChAT activity in knockout mice and a 38% increase in heterozygotes. The data do not support an apoptotic role but indicate a broad antineurotrophic role of p75NTR in the cholinergic basal forebrain. © 2011 Wiley Periodicals, Inc.
Murine tendon function is adversely affected by aggrecan accumulation due to the knockout of ADAMTS5
Authors: Wang Vincent M. , Bell Rebecca M. , Thakore Ruchir , Eyre David R. , Galante Jorge O. , Li Jun , Sandy John D. , Plaas Anna
Published: September 2011

The present study examined the effect of ADAMTS5 (TS5) knockout on the properties of murine flexor digitorum longus (FDL) and Achilles tendons. FDL and Achilles tendons were analyzed using biomechanical testing, histology, and immunohistochemistry; further characterization of FDL tendons was conducted using transmission electron microscopy (collagen fibril ultrastructure), SDS–PAGE (collagen content and type), fluorescence‐assisted carbohydrate electrophoresis for chondroitin sulfate and hyaluronan, and Western blotting for aggrecan, versican, and decorin abundance and distribution. FDL tendons of TS5−/− mice showed a 33% larger cross‐sectional area, increased collagen fibril area fraction, and decreased material properties relative to those of wild type mice. In TS5−/− mice, aggrecan accumulated in the pericellular matrix of tendon fibroblasts. In Achilles tendons, cross‐sectional area, stress relaxation, and structural properties were similar in TS5−/− and wild type mice; however, the TS5−/− tendons exhibited a higher tensile modulus and a weakened enthesis. These results demonstrate that TS5 deficiency disturbs normal tendon collagen organization and alters biomechanical properties. Hence, the role of ADAMTS5 in tendon is to remove pericellular and interfibrillar aggrecan to maintain the molecular architecture responsible for normal tissue function. © 2011 Orthopaedic Research Society. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 30:620–626, 2012
Tendon‐derived stem cells (TDSCs) promote tendon repair in a rat patellar tendon window defect model
Authors: Ni Ming , Lui Pauline Po Yee , Rui Yun Feng , Lee Yuk Wa , Lee Yuk Wai , Tan Qi , Wong Yin Mei , Kong Siu Kai , Lau Pui Man , Li Gang , Chan Kai Ming
Published: September 2011

Injured tendons heal slowly and often result in the formation of mechanically and functionally inferior fibrotic scar tissue or fibrous adhesions. This study investigated the use of tendon‐derived stem cells (TDSCs) for tendon repair in a rat patellar tendon window defect model. Fibrin glue constructs with or without GFP‐TDSCs were transplanted into the window defect. The patellar tendons were harvested for histology, ex vivo fluorescent imaging and biomechanical test at various time points up to week 4. Our results showed that TDSCs significantly enhanced tendon healing as indicated by the increase in collagen production as shown by hematolxylin stain‐ability of the tissue, improvement of cell alignment, collagen fiber alignment and collagen birefringence typical of tendon. The labeled cells were observed at weeks 1 and 2 and became almost undetectable at week 4. Both the ultimate stress and Young's modulus were significantly higher in the TDSCs group compared to those in the fibrin glue group at week 4. In conclusion, TDSCs promoted earlier and better repair in a rat patellar tendon window defect model. © 2011 Orthopaedic Research Society. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 30:613–619, 2012
Age‐related expression of MCP‐1 and MMP‐3 in mouse intervertebral disc in relation to TWEAK and TNF‐α stimulation
Authors: Fujita Koji , Ando Takashi , Ohba Tetsuro , Wako Masanori , Sato Nobutaka , Nakamura Yuki , Ohnuma Yuko , Hara Yasushi , Kato Ryohei , Nakao Atsuhito , Haro Hirotaka
Published: September 2011

This study was undertaken to investigate the age‐related differences of monocyte chemotactic protein‐1 (MCP‐1) and matrix metalloproteinase‐3 (MMP‐3) expression in mouse intervertebral disc (IVD) and to determine whether MMP‐3 plays a role in disc degeneration. Expression of MCP‐1 and MMP‐3 mRNA in mouse IVD was assessed by quantitative PCR. The ability of MCP‐1 and MMP‐3 expression in IVD to respond to TNF‐α or TWEAK stimulation was examined by quantitative PCR, WB, ELISA, and immunohistochemistry. IVD derived from MMP‐3‐deficient and wild‐type mice were compared using Safranin‐O staining and immunohistochemistry. mRNA levels of MCP‐1 and MMP‐3 in IVD significantly diminished and the ability of MCP‐1 or MMP‐3 expression to respond to TNF‐α or TWEAK stimulation was significantly reduced as age increased. IVD derived from 64‐week‐old wild‐type mice showed clearly diffuse proteoglycan loss by Safranin‐O staining and immunohistochemistry compared with younger mice. However, no loss of proteoglycan and typeII collagen were observed in IVD derived from 64‐week‐old MMP‐3‐deficient mice. MCP‐1 and MMP‐3 expression in mouse IVD showed age‐related decreases. The response to inflammation in IVD also displayed age‐related changes. Therefore, disc degeneration may vary with the patients' age and targeting MMP‐3 may be a possible future therapeutic strategy for disc degeneration. © 2011 Orthopaedic Research Society. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 30:599–605, 2012
Reliability and validity of three quality rating instruments for systematic reviews of observational studies
Authors: Hootman Jennifer M. , Driban Jeffrey B. , Sitler Michael R. , Harris Kyle P. , Cattano Nicole M.
Published: September 2011

To assess the inter‐rater reliability, validity, and inter‐instrument agreement of the three quality rating instruments for observational studies. Inter‐rater reliability, criterion validity, and inter‐instrument reliability were assessed for three quality rating scales, the Downs and Black (D&B), Newcastle–Ottawa (NOS), and Scottish Intercollegiate Guidelines Network (SIGN), using a sample of 23 observational studies of musculoskeletal health outcomes. Inter‐rater reliability for the D&B (Intraclass correlations [ICC] = 0.73; CI = 0.47–0.88) and NOS (ICC = 0.52; CI = 0.14–0.76) were moderate to good and was poor for the SIGN (κ = 0.09; CI = −0.22–0.40). The NOS was not statistically valid (p = 0.35), although the SIGN was statistically valid (p < 0.05) with medium to large effect sizes (f2 = 0.29–0.47). Inter‐instrument agreement estimates were κ = 0.34, CI = 0.05–0.62 (D&B versus SIGN), κ = 0.26, CI = 0.00–0.52 (SIGN versus NOS), and κ = 0.43, CI = 0.09–0.78 (D&B versus NOS). Reliability and validity are quite variable across quality rating scales used in assessing observational studies in systematic reviews. Copyright © 2011 John Wiley & Sons, Ltd.
Improvement in regression of corn yield with plant height using relative data
Authors: Yin Xinhua , McClure M Angela , Hayes Robert M
Published: September 2011

BACKGROUND: The traditional approach of analyzing absolute variable data across multiple locations and/or years has drawbacks in precision agriculture. This study was conducted to evaluate the impacts of using relative yield and plant height data of corn (Zea mays L.) on the regression of yield with plant height using linear and exponential models in a nitrogen (N) rate field trial under four cropping systems.

RESULTS: The use of relative yield to replace absolute yield frequently increased the determination coefficient (R2) values in the regression of yield with plant height on datasets combined across cropping systems or/and years. Relative yield and relative plant height sometimes further enhanced the R2 values compared with relative yield and absolute plant height. All these improvements mostly occurred when the fit of the model was not strong with absolute yield and absolute plant height or relative yield and absolute plant height. The advantages of using relative data of yield or/and plant height were similar for the two regression models.

CONCLUSION: The use of relative yield or relative data of both yield and plant height may be effective in improving the regression of corn yield with plant height across multiple cropping systems/locations and years in precision agriculture. Copyright © 2011 Society of Chemical Industry
Signal enhancement by trapping in microscale liquid chromatography: Numerical modelling
Authors: Verstraeten Matthias , Desmet Gert
Published: September 2011

We report on a series of computer simulations that have been made to explore the operation and performance limits of a periodically heated and cooled trapping segment (liquid analog of the modulator device used in GC×GC) interfacing the separation column and the detector. The initial peak width and the retention of the molecules on the trapping segment have the most important influence on the trapping efficiency. Higher retention of the trapping segment and smaller peaks will lead to higher signal enhancements. However when the resulting concentration gradients become too large, as is the case for very small peaks and/or for very high retention factors on the trapping segment, the dispersion will strongly decrease the focussing efficiency. The molar diffusion coefficient and the linear velocity mainly have an impact on the dispersive behaviour, which can be directly calculated from the associated plate height values. General design rules for the trapping segment, validated with the computer simulations, give a good estimate of the required trapping time and the length of the trapping segment. Equations for the estimation of the trapped peak width and signal enhancement are also given.
Stereoselective liquid chromatographic determination of 1′‐oxobufuralol and 1′‐hydroxybufuralol in rat liver microsomal fraction using hollow‐fiber liquid‐phase microextraction for sample preparation
Authors: Barth Thiago , Simões Rodrigo A. , Pupo Mônica T. , Okano Laura T. , Bonato Pierina S.
Published: September 2011

A three‐phase hollow‐fiber liquid‐phase microextraction (HF‐LPME) method for the stereoselective determination of bufuralol metabolites 1′‐oxobufuralol (1′‐Oxo‐BF) and 1′‐hydroxybufuralol (1′‐OH‐BF) in microsomal preparations is described for the first time. The HPLC analysis was carried out using a Chiralcel OD‐H column with hexane/2‐propanol/methanol (97.5:2.0:0.5, v/v/v) plus 0.5% diethylamine as the mobile phase, and UV detection at 248 and 273 nm. The HF‐LPME optimized conditions involved: n‐octanol as the organic solvent, 0.2 mol/L acetic acid as the acceptor phase, donor phase pH adjusted to 13, sample agitation at 1500 rpm and extraction for 30 min. By using this extraction procedure, the recovery rates were in the range of 63–69%. The method was linear over the concentration range of 100–5000 ng/mL for each enantiomer of 1′‐Oxo‐BF (r>0.9978) and of 100–2500 ng/mL for each stereoisomer of 1′‐OH‐BF (r>0.9957). The quantification limits were 100 ng/mL for all analytes. The validated method was used to assess the in vitro biotransformation of bufuralol using rat liver microsomal fraction that demonstrated predominant formation of (S)‐1′‐Oxo‐BF and (R,R)‐1′‐OH‐BF.