bluuebunny/crossref_metadata_2025 huggingface dataset:
Brief communication: The use of alternative dental measurements on deciduous teeth
Authors: Pilloud Marin A. , Hillson Simon
Published: July 2012

The present study investigates the utility of cervical measurements in deciduous teeth and how they correlate with traditional measurements of the crown. First, this study establishes definitions by which these measurements could reliably be taken. Next, deciduous cervical and traditional crown diameters were taken on three distinct skeletal samples: a Neolithic assemblage from Central Anatolia (Çatalhöyük, n = 85), a precontact sample from Northern California (CA‐ALA‐329, n = 34), and a group of intrusive burials interred at Çatalhöyük that date between AD 60 and 1650 (n = 38). Across the dentition there are positive correlations between crown and cervical measurements, which tend to be higher in anterior teeth than in posterior teeth. Both measurements show low correlations with age; however, cervical measurements show fewer negative correlations with age. An intraobserver error study found low levels of error for both types of measurements. On a subset of the Çatalhöyük sample (n = 9), a principal components and biological distance analysis were conducted comparing the two types of measurements. Also, all three samples were subject to a canonical discriminant function analysis and the results from cervical and crown measurements were compared. All analyses produced slightly different results for each type of data suggesting that crown and cervical measurements capture different aspects of tooth shape. While cervical and crown measurements provide different statistical results, cervical measurements can provide information relevant to anthropological studies and may allow for larger datasets to be used by allowing the inclusion of teeth with modified crowns. Am J Phys Anthropol 149:299–306, 2012. © 2012 Wiley Periodicals, Inc.
Composite fibers from poly(vinyl alcohol) and poly(vinyl alcohol)‐functionalized multiwalled carbon nanotubes
Authors: Fu Changfei , Gu Lixia
Published: July 2012

High‐strength composite fibers were prepared from poly(vinyl alcohol) (PVA) and multiwalled carbon nanotubes (MWNTs) functionalized with PVA matrix. Esterification between MWNTs and PVA was confirmed by Fourier transform infrared, Raman spectroscopy, thermogravimetric analysis, transmission electron microscope, and atomic force microscope. Homogeneous dispersion of PVA‐functionalized MWNTs in dimethyl sulfoxide was affirmed by optical micrographs and particle size analysis. The PVA‐functionalized MWNTs/PVA (1 wt %) composite fibers prepared by gel spinning and hot‐drawing process exhibited tensile strength and modulus as high as 2.1 and 34 GPa, respectively, showing a 75% increase in tensile strength and 35% increase in modulus compared with pure PVA fibers. The mechanical properties were also much higher than untreated MWNTs/PVA (1 wt %) composite fibers and carboxylated MWNTs/PVA (1 wt %) composite fibers. From wide‐angle X‐ray diffraction, scanning electron microscopy, and Raman spectra analysis, higher mechanical properties of PVA‐functionalized MWNTs/PVA composite fibers are attributable to homogeneous dispersion of MWNTs in PVA matrix, stronger interfacial adhesion between MWNTs and PVA matrix, and uniaxial orientation of MWNTs along fiber axis. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Expression and Immunohistochemical Detection of Leptin‐Like Peptide in the Gastrointestinal Tract of the South American Sea Lion (Otaria flavescens) and the Bottlenose Dolphin (Tursiops truncatus)
Authors: Russo Finizia , Gatta Claudia , De Girolamo Paolo , Cozzi Bruno , Giurisato Maristella , Lucini Carla , Varricchio Ettore
Published: July 2012

This study provides an immunohistochemical approach to the expression of leptin in the gastrointestinal tract of the monogastric South American sea lion (Otaria flavescens), and the poligastric bottlenose dolphin (Tursiops truncatus). The specific organization of the gastrointestinal tract is examined in relation to the neuroendocrine regulation of the gut exerted by leptin. In the South American sea lion some leptin‐like‐immunoreactive (ir) cells, and endocrine type cells, were found in the pit of gastric mucosal folds and in the epithelium of duodenum as well as numerous neurons were detected in the submucosal and myenteric plexuses of the stomach. In the bottlenose dolphin, many leptin‐like‐ir cells, and exocrine type cells, were identified in the mucosal layer of the main stomach as well as several neurons and nervous fibers were detected in nervous plexuses of main stomach, pyloric stomach, proximal, and middle intestine. Our data suggest that the distribution of leptin‐like peptides is similar in the two species, notwithstanding the different anatomical organization of the gastrointestinal apparatus of South American sea lion and bottlenose dolphin. These findings “suggest” the presence of a basal plan in the regulation of food intake, body weight, energy balance and of the gastrointestinal functions in general also in marine mammals with different and specific feeding habits. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.
Short time augmented extended Kalman filter for soil analysis: a feasibility study
Authors: Carrassi Alberto , Hamdi Rafiq , Termonia Piet , Vannitsem Stéphane
Published: July 2012

This paper presents a soil analysis scheme based on an extended Kalman filter (EKF), the short time augmented extended Kalman filter (STAEKF), where the model parameters are estimated along with the system state. We use an off‐line version of the interaction soil‐biosphere‐atmosphere model for the assimilation of screen‐level temperature and relative humidity. The leaf area index, the albedo, and the minimum stomatal resistance are estimated with the STAEKF. Results show that the STAEKF gives encouraging results and indicate the benefit of the simultaneous estimation of the state and parameters in soil data assimilation. Copyright © 2012 Royal Meteorological Society
Multi‐enzymatic one‐pot reduction of dehydrocholic acid to 12‐keto‐ursodeoxycholic acid with whole‐cell biocatalysts
Authors: Sun Boqiao , Kantzow Christina , Bresch Sven , Castiglione Kathrin , Weuster‐Botz Dirk
Published: July 2012

Ursodeoxycholic acid (UDCA) is a bile acid of industrial interest as it is used as an agent for the treatment of primary sclerosing cholangitis and the medicamentous, non‐surgical dissolution of gallstones. Currently, it is prepared industrially from cholic acid following a seven‐step chemical procedure with an overall yield of <30%. In this study, we investigated the key enzymatic steps in the chemo‐enzymatic preparation of UDCA—the two‐step reduction of dehydrocholic acid (DHCA) to 12‐keto‐ursodeoxycholic acid using a mutant of 7β‐hydroxysteroid dehydrogenase (7β‐HSDH) from Collinsella aerofaciens and 3α‐hydroxysteroid dehydrogenase (3α‐HSDH) from Comamonas testosteroni. Three different one‐pot reaction approaches were investigated using whole‐cell biocatalysts in simple batch processes. We applied one‐biocatalyst systems, where 3α‐HSDH, 7β‐HSDH, and either a mutant of formate dehydrogenase (FDH) from Mycobacterium vaccae N10 or a glucose dehydrogenase (GDH) from Bacillus subtilis were expressed in a Escherichia coli BL21(DE3) based host strain. We also investigated two‐biocatalyst systems, where 3α‐HSDH and 7β‐HSDH were expressed separately together with FDH enzymes for cofactor regeneration in two distinct E. coli hosts that were simultaneously applied in the one‐pot reaction. The best result was achieved by the one‐biocatalyst system with GDH for cofactor regeneration, which was able to completely convert 100 mM DHCA to >99.5 mM 12‐keto‐UDCA within 4.5 h in a simple batch process on a liter scale. Biotechnol. Bioeng. 2013; 110: 68–77. © 2012 Wiley Periodicals, Inc.
The dynamics of the CHO host cell protein profile during clarification and protein A capture in a platform antibody purification process
Authors: Hogwood Catherine E.M. , Tait Andrew S. , Koloteva‐Levine Nadejda , Bracewell Daniel G. , Smales C. Mark
Published: July 2012

Recombinant protein products such as monoclonal antibodies (mAbs) for use in the clinic must be clear of host cell impurities such as host cell protein (HCP), DNA/RNA, and high molecular weight immunogenic aggregates. Despite the need to remove and monitor HCPs, the nature, and fate of these during downstream processing (DSP) remains poorly characterized. We have applied a proteomic approach to investigate the dynamics and fate of HCPs in the supernatant of a mAb producing cell line during early DSP including centrifugation, depth filtration, and protein A capture chromatography. The primary clarification technique selected was shown to influence the HCP profile that entered subsequent downstream steps. MabSelect protein A chromatography removed the majority of contaminating proteins, however using 2D‐PAGE we could visualize not only the antibody species in the eluate (heavy and light chain) but also contaminant HCPs. These data showed that the choice of secondary clarification impacts upon the HCP profile post‐protein A chromatography as differences arose in both the presence and abundance of specific HCPs when depth filters were compared. A number of intracellularly located HCPs were identified in protein A elution fractions from a Null cell line culture supernatant including the chaperone Bip/GRP78, heat shock proteins, and the enzyme enolase. We demonstrate that the selection of early DSP steps influences the resulting HCP profile and that 2D‐PAGE can be used for monitoring and identification of HCPs post‐protein A chromatography. This approach could be used to screen cell lines or hosts to select those with reduced HCP profiles, or to identify HCPs that are problematic and difficult to remove so that cell‐engineering approaches can be applied to reduced, or eliminate, such HCPs. Biotechnol. Bioeng. 2013; 110: 240–251. © 2012 Wiley Periodicals, Inc.
Fed‐batch and perfusion culture processes: Economic, environmental, and operational feasibility under uncertainty
Authors: Pollock James , Ho Sa V. , Farid Suzanne S.
Published: July 2012

This article evaluates the current and future potential of batch and continuous cell culture technologies via a case study based on the commercial manufacture of monoclonal antibodies. The case study compares fed‐batch culture to two perfusion technologies: spin‐filter perfusion and an emerging perfusion technology utilizing alternating tangential flow (ATF) perfusion. The operational, economic, and environmental feasibility of whole bioprocesses based on these systems was evaluated using a prototype dynamic decision‐support tool built at UCL encompassing process economics, discrete‐event simulation and uncertainty analysis, and combined with a multi‐attribute decision‐making technique so as to enable a holistic assessment. The strategies were compared across a range of scales and titres so as to visualize how their ranking changes in different industry scenarios. The deterministic analysis indicated that the ATF perfusion strategy has the potential to offer cost of goods savings of 20% when compared to conventional fed‐batch manufacturing processes when a fivefold increase in maximum viable cell densities was assumed. Savings were also seen when the ATF cell density dropped to a threefold increase over the fed‐batch strategy for most combinations of titres and production scales. In contrast, the fed‐batch strategy performed better in terms of environmental sustainability with a lower water and consumable usage profile. The impact of uncertainty and failure rates on the feasibility of the strategies was explored using Monte Carlo simulation. The risk analysis results demonstrated the enhanced robustness of the fed‐batch process but also highlighted that the ATF process was still the most cost‐effective option even under uncertainty. The multi‐attribute decision‐making analysis provided insight into the limited use of spin‐filter perfusion strategies in industry. The resulting sensitivity spider plots enabled identification of the critical ratio of weightings of economic and operational benefits that affect the choice between ATF perfusion and fed‐batch strategies. Biotechnol. Bioeng. 2013; 110: 206–219. © 2012 Wiley Periodicals, Inc.
Establishment and characterization of a novel lymphangiosarcoma cell line (MO‐LAS) compared with the hemangiosarcoma cell line (ISO‐HAS)
Authors: Masuzawa Mikio , Masuzawa Mamiko , Hamada Yuhko , Arakawa Nobuko , Mori Mari , Ishii Masako , Nishiyama Shigeo
Published: July 2012

The concept of “lymphangiosarcoma” remains obscure. Therefore, we reported a patient with lymphangiosarcoma, resistant to immunotherapy. The patient presented with impressive and discriminative features: clinically an ill‐defined edematous lesion with lymphorrhea and pathologically atypical vascular channel formation without extravasation of blood, clearly distinguished from common angiosarcoma with hemorrhage. From this case, a lymphangiosarcoma cell line, MO‐LAS, was established and its characteristics were compared with the hemangiosarcoma cell line, ISO‐HAS. Flow cytometric analysis revealed that MO‐LAS was negative for factor VIII‐related antigen, but positive for CD31, D2‐40, NZ‐1, and vascular endothelial growth factor receptor‐3 (VEGFR‐3), similar to ISO‐HAS. However, MO‐LAS expressed a much higher level of homeobox gene PROX1, indicating a lymphatic phenotype, compared with ISO‐HAS. Furthermore, MO‐LAS showed a much lesser expression of oncogenes and much lower sensitivity against lymphokine‐activated killer (LAK) cells. Lymphangiosarcoma may be difficult to recognize by the immune system. Conclusively, the establishment of MO‐LAS, a novel angiosarcoma cell line bearing lymphatic characters, strongly suggests the entity of lymphangiosarcoma.
A Computational Investigation of the Catalytic Properties of Graphene Oxide: Exploring Mechanisms by using DFT Methods
Authors: Boukhvalov Danil W. , Dreyer Daniel R. , Bielawski Christopher W. , Son Young‐Woo
Published: July 2012

Herein we describe a computational study undertaken in an effort to elucidate the reaction mechanisms behind the experimentally observed oxidations and hydrations catalyzed by graphene oxide (GO). We used the oxidation of benzyl alcohol to benzaldehyde as a model reaction and DFT calculations revealed that the reaction occurred via the transfer of hydrogen atoms from the organic molecule to the GO surface. In particular, neighboring epoxide groups that decorate the GO basal plane were ring‐opened, which resulted in the formation of diols, followed by dehydration. Our calculations were consistent with the experimentally observed dependence of this chemistry on molecular oxygen, and revealed that the partially reduced catalyst was able to be recharged by molecular oxygen, which allows for catalyst turnover. Functional group‐free carbon materials, such as graphite, were calculated as having substantially higher reaction barriers, which indicates that the high chemical potential and rich functionality of GO are necessary for the observed reactivity.
A Computational Approach to Tuning the Photochemistry of Platinum(IV) Anticancer Agents
Authors: Tai Hui‐Chung , Zhao Yao , Farrer Nicola J. , Anastasi Anna E. , Clarkson Guy , Sadler Peter J. , Deeth Robert J.
Published: July 2012

Diazido PtIV complexes are inert stable prodrugs that can be photoactivated to produce PtII species with promising anticancer activity. Our studies of the photochemistry of PtIV complexes, [Pt(X)2(Y)2(Z)2]0/−1 (X=N‐ligands (NH3, pyridine, etc.)/S(CH3)2/H−, Y=(pseudo)halogen (N3−, I−), Z=OR−, R=H, Ac) by time‐dependent density functional theory (TDDFT) show close agreement with spectroscopic data. Broad exploration of cis/trans geometries, trans influences, the nature of the OR− and (pseudo)halogen ligands, electron‐withdrawing/donating/delocalising substituents on the N‐ligands, and intramolecular H bonds shows that: 1) the design of platinum(IV) complexes with intense bands shifted towards longer wavelengths (from 289 to ∼330 nm) can be achieved by introducing intramolecular H bonds involving the OH ligands and 2‐hydroxyquinoline or by iodido ligands; 2) mesomeric electron‐withdrawing substituents on pyridine result in low‐energy absorption with significant intensity in the visible region; and 3) the distinct makeup of the molecular orbitals involved in the electronic transitions for cis/trans‐{Pt(N3)2} isomers results in different photoproducts. In general, the comparison of the optimised geometries shows that PtIV complexes with longer PtL bonds are more likely to undergo photoreduction with longer‐wavelength light. The novel complex trans,trans,trans‐[Pt(N3)2(OH)2(NH3)(4‐nitropyridine)] with predicted absorption in the visible region has been synthesised. The experimental UV/Vis spectrum in aqueous solution correlates well with the intense band in the computed spectrum, whereas the overlay in the low‐energy region can be improved by a solvent model. This combined computational and experimental study shows that TDDFT can be used to tune the coordination environment for optimising photoactive PtIV compounds as anticancer agents.
Highly Enantioselective Iridium‐Catalyzed Hydrogenation of α,β‐Unsaturated Esters
Authors: Li Jia‐Qi , Quan Xu , Andersson Pher G.
Published: July 2012

α,β‐Unsaturated esters have been employed as substrates in iridium‐catalyzed asymmetric hydrogenation. Full conversions and good to excellent enantioselectivities (up to 99 % ee) were obtained for a broad range of substrates with both aromatic‐ and aliphatic substituents on the prochiral carbon. The hydrogenated products are highly useful as building blocks in the synthesis of a variety of natural products and pharmaceuticals.
Sequential Markov Chain Monte Carlo (MCMC) model discrimination
Authors: Masoumi Samira , Duever Thomas A. , Reilly Park M.
Published: July 2012

In this paper a new approach to model discrimination is presented that takes advantage of Markov Chain Monte Carlo (MCMC) methods. It combines an experimental criterion first proposed by Roth (Roth, Design of Experiments for Discrimination Among rival Models, PhD, Thesis, Princeton University, New Jersey, USA, 1965) with an adaptation of a model selection method described by Chib and Jeliazkov [Chib and Jeliazkov, Stat. Neerl. 59, 30–44 (2005)], which uses an Acceptance–Rejection Metropolis–Hastings algorithm to evaluate the model marginal likelihood thus enabling the calculation of model posterior probabilities. It does so without requiring any linearisation of nonlinear models. In designing model discrimination experiments using the Roth criterion, MCMC methods are again used to find the mean of the predicted values by integrating over the entire parameter probability density function. The method is illustrated using the well‐known chemical reaction kinetics example first discussed by Box and Hill [Box and Hill, Technometrics 9, 57–71 (1967)]. The results indicate that the method is very successful in identifying the correct model. Higher error levels and more complex kinetics require on average more model discrimination experiments. © 2012 Canadian Society for Chemical Engineering
Modelling and optimisation of continuous catalytic regeneration process using bee colony algorithm
Authors: Sa'idi Majid , Mostoufi Navid , Sotudeh‐Gharebagh Rahmat
Published: July 2012

The continuous catalytic regeneration (CCR) reforming process optimisation leads to nonlinear programming with nonlinear quality constraints such as octane number and coke concentration on the catalytic particles. A typical CCR reforming process consists of four reactors with recycle. The reaction patterns and reactors have been mathematically modelled on a base of 12‐lumped kinetics reaction network derived from literature. The bee colony optimisation (BCO) algorithm is one of the most recent and efficient swarm intelligence‐based algorithms which simulates the foraging behaviour of honey bee colonies. The performance of the BCO algorithm in the process optimisation was compared with the genetic algorithm (GA). In the present work, BCO algorithm was used for optimising the CCR reforming process. The results show that the BCO algorithm reaches a better optimum point in a lower evaluation time and higher convergence rate with respect to the GA. © 2012 Canadian Society for Chemical Engineering
A cell population that strongly expresses the CB1 cannabinoid receptor in the ependyma of the rat spinal cord
Authors: Garcia‐Ovejero Daniel , Arevalo‐Martin Angel , Paniagua‐Torija Beatriz , Sierra‐Palomares Yolanda , Molina‐Holgado Eduardo
Published: July 2012

The cells surrounding the central canal of the spinal cord are a source of stem/precursor cells that may give rise to neurons, astrocytes, or oligodendrocytes. However, they are a heterogeneous population that remains poorly understood. Here we describe a subpopulation characterized by their strong expression of the CB1 cannabinoid receptor, oval/round soma, apical nucleus, a variable number of cilia (0, 1, or 2), and the presence of a single short and occasionally ramified basal process. These cells are mainly located in the lateral and dorsal central canal throughout the spinal cord. These CB cells are closely related to the basal lamina labyrinths or fractones derived from subependymal microglia. In addition, CB cells express some stem/precursor cell markers, including vimentin, nestin, Sox2, Sox9, and GLAST, but not others such as CD15 or GFAP. In addition, this cell population does not proliferate in the intact adult spinal cord, although up to 50% of these cells express the proliferation marker Ki67 in newly born rats or after a spinal cord contusion. The present findings contribute to our understanding of the spinal cord central canal structure and reveal the targets for endocannabinoids inside this neurogenic niche. J. Comp. Neurol. 521:233–251, 2013. © 2012 Wiley Periodicals, Inc.
Nuclear receptor COUP‐TFII‐expressing neocortical interneurons are derived from the medial and lateral/caudal ganglionic eminence and define specific subsets of mature interneurons
Authors: Cai Yuqun , Zhang Qiangqiang , Wang Congmin , Zhang Yue , Ma Tong , Zhou Xing , Tian Miao , Rubenstein John L.R. , Yang Zhengang
Published: July 2012

Neocortical GABAergic interneurons in rodents originate from subpallial progenitor zones. The majority of mouse neocortical interneurons are derived from the medial and caudal ganglionic eminences (MGE and CGE, respectively) and the preoptic area (POA). It is controversial whether the lateral ganglionic eminence (LGE) also generates neocortical interneurons. Previously it was shown that the transcription factor COUP‐TFII is expressed in the CGE; here we show that COUP‐TFII is also expressed in the dorsal MGE, dorsal LGE (dMGE and dLGE, respectively), and POA. In the adult neocortex, COUP‐TFII+/somatostatin (SOM)+ interneurons are mainly located in layer V. Using a genetic fate‐mapping approach (Shh‐Cre and Nkx2.1‐Cre), we demonstrate that the POA and ventral MGE do not give rise to COUP‐TFII+ neocortical interneurons, suggesting that the dMGE is the source of COUP‐TFII+/SOM+ neocortical interneurons. We also observed a migratory stream of COUP‐TFII+/Sp8+ cells emanating from the dLGE and CGE to the neocortex mainly through the subventricular zone at later embryonic stages. Slice culture experiments in which dLGE progenitors were labeled with BrdU provided additional evidence that the dLGE generates neocortical interneurons. While earlier‐born dMGE‐derived COUP‐TFII+ interneurons occupy cortical layer V, later‐born dLGE‐ and CGE‐derived COUP‐TFII+ ones preferentially occupy superficial cortical layers. A similar laminar distribution was observed following neonatal transplantation of embryonic day (E)14.5 dMGE and E15.5 dLGE. These results provide novel information about interneuron fate and position from spatially and temporally distinct origins in the ganglionic eminences. J. Comp. Neurol. 521:479–497, 2013. © 2012 Wiley Periodicals, Inc.
Growth of PtRu Clusters on Ru(0001)‐Supported Monolayer Graphene Films
Authors: Engstfeld Albert K. , Beckord Stephan , Lorenz Christoph D. , Behm R. Jürgen
Published: July 2012

We report on results of a detailed scanning tunnelling microscopy study on the formation, size and size distribution, and internal structure of small bimetallic PtRu clusters on a graphene monolayer film supported on a Ru(0001) substrate. These clusters, with sizes around ∼15 (Ru) or ∼40 (Pt) atoms per cluster at the lowest coverage, are interesting model systems for the catalytic behaviour of small metal PtRu particles, for example for application in electrocatalytic oxidation reactions. The clusters were generated by sequential deposition of the two metals at room temperature. The data reveal a distinct influence of the deposition sequence on the cluster formation process, with Ru pre‐deposition followed by Pt deposition leading to predominantly bimetallic clusters, possibly with a core–shell‐type structure, while the reverse sequence results in co‐existent mono‐ and bimetallic clusters, where the latter are likely to intermix at the interface. The observations are related to the nucleation process of the respective metals on the templated surface, and the 2D growth behaviour of the two metals.
Synthesis and Mechanical Properties of Organic–Inorganic Hybrid Materials from Lignin and Polysiloxanes
Authors: Lippach Andreas K. W. , Krämer Ramona , Hansen Michael R. , Roos Stephan , Stöwe Klaus , Stommel Markus , Wenz Gerhard , Maier Wilhelm F.
Published: July 2012

The preparation of silica‐containing organic–inorganic hybrid materials composed of kraft lignin, alkoxysilanes, and organic linkers was investigated. 3‐Glycidyloxypropyltrimethoxysilane, 3‐(triethoxysilyl)propylisocyanate (IPTES), and bis(trimethoxysilyl)hexane were selected as the most promising linkers. The best materials obtained showed improved mechanical and thermal properties compared with lignin itself. The reaction of the hydroxyl groups with IPTES and the sol–gel reaction between the organic linker molecules were studied by attenuated total reflectance FTIR and solid‐state 29Si magic‐angle spinning NMR spectroscopy. The homogeneous composition was demonstrated by electron microscopy and energy‐dispersive X‐ray spectroscopy mapping. The mechanical properties were investigated by microindentation and dynamic mechanical thermal analysis.
Delay statistics of cooperative automatic repeat request over wireless networks with link adaptation
Authors: Liu Yanli , Huang Shengye , Chen Chun
Published: July 2012

This paper proposes a method to analyze the delay distribution at the transmitter side for cooperative diversity wireless networks with link adaptation, which uses decode‐and‐forward as a relay strategy. The equivalent end‐to‐end channel model is captured by a finite state Markov channel model representing the multiple states of the Nakagami fading channel, and the delay statistics are obtained by using matrix geometry method. Cooperative diversity wireless network has a better delay performance compared with noncooperation wireless network. Copyright © 2012 John Wiley & Sons, Ltd.
Novel quantization‐based spectrum sensing scheme under imperfect reporting channel and false reports
Authors: Birkan Yilmaz H. , Tugcu Tuna , Alagoz Fatih
Published: July 2012

In this paper, a novel sensing scheme, uniform quantization for cooperative sensing (UniQCS), that employs a uniform quantizer is proposed. UniQCS is based on energy detection and uses weight vector for global decision function. It performs better than hard decision algorithms such as majority and k‐out‐of‐n in terms of probability of detection and false alarm at the cost of a marginal increase in overhead bits under imperfect reporting channel and false reports. The probability of detection is maximized for a given probability of false alarm constraint by the proposed method. For detailed analysis, the UniQCS is compared with equal gain combiner scheme, which performs far better than hard decision algorithms, via highest bandwidth requirement. The proposed algorithm performs close to equal gain combiner. Moreover, the robustness of UniQCS to sensing error is analyzed when some nodes always report false decisions to the fusion center and the reporting channel is imperfect. For probability of false alarm equal to 0.01, performance gain of UniQCS is at least 45% compared with the other methods when there are two false reporting nodes. UniQCS performance gain is at least 15% compared with other methods for probability of reporting channel error equal to 0.001. Copyright © 2012 John Wiley & Sons, Ltd.
CoII/ZnII–(L‐Tyrosine) Magnetic Metal–Organic Frameworks
Authors: Zhou Bo , Silva Nuno J. O. , Shi Fa‐Nian , Palacio Fernando , Mafra Luís , Rocha João
Published: July 2012

Three chiral coordination polymers assembled from L‐tyrosine (L‐tyr) and cobalt, cobalt/zinc and zinc salts, with a new three‐dimensional (3D) structure and formulated as [M(L‐tyr)]n (M = Co, Co/Zn, Zn) have been prepared by mild hydrothermal synthesis. These three compounds are isostructural, crystallize with monoclinic symmetry in the C2 space group and possess four crystallographically unique metal sites in tetrahedral (two) and octahedral (two) coordination environments resulting in two slightly distinct edge‐sharing metal dimers with L‐tyr linking the metal atoms in pillars. These features result in a dense framework. The study of the magnetic properties of the cobalt‐bearing solid reveals a ferromagnetic exchange interaction within the Co2+ dimers. The racemic compound of dl‐tyrosine and cobalt was also synthesized and its structure characterized.
α,ω‐Di([5]trovacenyl) Sulfides TVC–Sn–TVC (n = 1–4) and TVC–SCH2S–TVC: a Study in Intramolecular Communication
Authors: Elschenbroich Christoph , Lu Feng , Harms Klaus , Burghaus Olaf , Pietzonka Clemens , Pebler Jürgen
Published: July 2012

The oligosulfur‐bridged dinuclear paramagnetic complexes di([5]trovacenyl) sulfide (3··), di([5]trovacenyl) trisulfide (5··), di([5]trovacenylthio)methane (6··), and di([5]trovacenyl) tetrasulfide (7··) have been prepared by the metathesis reactions of [5]trovacenyllithium with SCl2, and [5]lithiotrovacenylthiolate (2·) with SCl2, CH2Cl2, and S2Cl2, respectively, in which 2· was obtained by the reaction of [5]trovacenyllithium with 1 equiv. of elemental sulfur at ambient temperature. Combined with the previously reported di([5]trovacenyl) disulfide (4··), these complexes have been systematically investigated by means of cyclic voltammetry, electron paramagnetic resonance (EPR) spectroscopy, magnetic susceptometry, and/or X‐ray diffraction analysis, which reveal weak antiferromagnetic spin–spin exchange interactions. The monosulfur‐bridged 3··, in particular, displays the strongest intramolecular spin–spin exchange interaction of |JEPR| = 2.8 cm–1 and Jχ = –1.39 cm–1. This study also indicates that with an increasing number of sulfur atoms in the bridge, the intramolecular communication of biradicals throught the 1D saturated sulfur atom bridge significantly weakens both in solution and in the solid state compared to those of unsaturated carbon‐based bridges.
Palladium‐Catalyzed Improved Regio‐ and Stereoselective O‐Glycosylation of D‐Glucal‐Derived β‐ and α‐Vinyl Oxiranes
Authors: Reddy Y. Suman , Lahiri Rima , Vankar Yashwant D.
Published: July 2012

A Pd0‐catalyzed glycosylation of D‐glucal‐derived vinyloxiranes as excellent glycosyl donors has been accomplished in a regio‐ and stereoselective manner. Various glycosyl acceptors upon reaction with vinyl oxiranes 1a and 1b produced the corresponding 2,3‐unsaturated O‐glycosides in good to excellent yields within five minutes. The above reaction has also been utilized in the synthesis of 2,3‐unsaturated trisaccharides, which are potential precursors of fully oxygenated, deoxy and dideoxy sugars.
Seismic response of a bridge–soil–foundation system under the combined effect of vertical and horizontal ground motions
Authors: Wang Zhenghua , Dueñas‐Osorio Leonardo , Padgett Jamie E.
Published: July 2012

Different levels of model sophistication have recently emerged to support seismic risk assessment of bridges, but mostly at the expense of neglecting the influence of vertical ground motions (VGMs). In this paper, the influence of VGMs on bridge seismic response is presented and the results are compared with the case of horizontal‐only excitations. An advanced finite element model that accounts for VGMs is first developed. Then, to investigate the effect of soil–structure interaction (SSI) including liquefaction potential, the same bridge with soil‐foundation and fixed boundary conditions is also analyzed. Results show that the inclusion of the VGMs has a significant influence on the seismic response, especially for the axial force in columns, normal force of bearings, and the vertical deck bending moments. However, VGMs do not have as much influence on the seismic demand of the pile cap displacements or pile maximum axial forces. Also, the significant fluctuation of the column axial force can reduce its shear and flexural capacity, and a heightened reversal of flexural effects may induce damage in the deck. In addition, relative to the fixed base case, SSI effects tend to reduce response quantities for certain ground motions while increasing demands for others. This phenomenon is explained as a function of the frequency content of the ground motions, the shift in natural vertical periods, and the VGM spectral accelerations at higher modes. Moreover, the mechanisms of liquefaction are isolated relative to SSI effects in nonliquefiable soils, revealing the influence of liquefaction on bridge response under VGMs. Copyright © 2012 John Wiley & Sons, Ltd.
Analysis of the sources of uncertainty for portfolio‐level earthquake loss estimation
Authors: Aslani Hesaam , Cabrera Carlos , Rahnama Mohsen
Published: July 2012

Earthquake catastrophe models provide probabilistic estimations of building portfolio losses that result from seismic hazards. Models that are designed to be used with large numbers of buildings often implicitly account for uncertainty associated with model components, but do not allow for an explicit comparison of different sources of uncertainty. We propose probabilistic methodologies that allow for explicit differentiation of the uncertainty in estimated portfolio losses as a function of the uncertainties associated with seismic hazard and building vulnerability. Our work is motivated by recent earthquakes in New Zealand and Japan, which highlighted the importance of understanding the sources of uncertainty that contribute to portfolio‐level loss estimates. The proposed methodologies allow us to differentiate seismic risk between building portfolios as a function of the level of knowledge (epistemic) uncertainty associated with modeling seismic rates and the levels of aleatory variability and epistemic uncertainty associated with the buildings' vulnerabilities. A sample analysis incorporates epistemic uncertainty corresponding to Southern California's seismic rates into modeled losses for a Southern California building portfolio and then compares the impact of that particular source of uncertainty to the results from a portfolio in Northern California. For sources of uncertainty associated with buildings' vulnerability, we use our methodology to compare the impacts of aleatory and epistemic uncertainties on estimated portfolio losses as a function of the buildings' attributes, including their types of construction and numbers of stories. Component uncertainties (i.e., uncertainties corresponding to the seismic hazard and vulnerability) are assumed for our analyses so that the methodologies can be demonstrated. Copyright © 2012 John Wiley & Sons, Ltd.
Can the Indicative Price System Mitigate Expiration‐Day Effects?
Authors: Chay J.B. , Kim Sol , Ryu Hyeuk‐Sun
Published: July 2012

We investigate whether the indicative price system, introduced in the Korean derivatives market on July 1, 2003, has helped mitigate the options and futures expiration‐day effects. Prior to introduction of this system, we find evidence of high trading volume and significant price reversals during the first half hour of trading for the day immediately following the expiration day. These effects decline significantly after July 1, 2003. Our evidence suggests that the indicative price system can mitigate the expiration‐day effects.
Viral load, physical status, and E6/E7 mRNA expression of human papillomavirus in head and neck squamous cell carcinoma
Authors: Deng Zeyi , Hasegawa Masahiro , Kiyuna Asanori , Matayoshi Sen , Uehara Takayuki , Agena Shinya , Yamashita Yukashi , Ogawa Kazuhiko , Maeda Hiroyuki , Suzuki Mikio
Published: July 2012

Background

The purpose of this study was to determine prospectively both human papillomavirus (HPV) load and physical status in different types of head and neck squamous cell carcinoma (HNSCC).

Methods

HPV DNA, E6/E7 mRNA expression, viral load, and physical status of 184 patients with HNSCC were examined simultaneously by polymerase chain reaction (PCR)‐based methods.

Results

The HPV genome was detected in 54 HNSCC samples (29.3%), particularly in tonsillar carcinomas (69.6%). Compared with nonoropharyngeal HNSCC, oropharyngeal carcinoma harbored a relatively higher viral load, especially in tonsillar carcinoma. Although integrated or mixed status was observed in 75.6% of HPV‐16–positive samples, E6/E7 mRNA transcripts were detected in only 27.5% of HPV DNA‐positive cases. High HPV‐16 load correlated significantly with E6/E7 mRNA expression.

Conclusion

E6/E7 mRNA expression in patients with HNSCC with low viral load remains low even in cases of integration to the host genome. Tonsillar carcinomas were significantly associated with HPV among various types of HNSCC. © 2012 Wiley Periodicals, Inc. Head Neck, 2012
Tonsillar carcinoma metastatic to the spleen presenting as trauma: A case report
Authors: Lee Janet T. , Hugec Vladimir , McGuire Warren , Gendron Kristin , Semmler Steven , Endorf Frederick W.
Published: July 2012

Background. Cancers of the head and neck rarely metastasize to the spleen. To the best of our knowledge, there is no reported case of a tonsillar carcinoma metastasizing to the spleen. Method and Results. This patient had a splenic capsular rupture likely related to his metastases that presented as a traumatic splenic injury. The patient had received neoadjuvant chemotherapy followed by concurrent chemoradiotherapy. Two months after completion of radiotherapy, he fell out of bed. The next day he had acute abdominal pain and hypotension. CT findings were consistent with splenic rupture, and he underwent splenectomy. Pathologic assessment of the specimen showed metastatic SCC. Conclusion. New splemic lesions in patients with head and neck cancer should be investigated. Head Neck, 2013
Phase II 2‐arm trial of the proteasome inhibitor, PS‐341 (bortezomib) in combination with irinotecan or PS‐341 alone followed by the addition of irinotecan at time of progression in patients with locally recurrent or metastatic squamous cell carcinoma of the head and neck (E1304): A trial of the Eastern Cooperative Oncology Group
Authors: Gilbert Jill , Lee Ju Whei , Argiris Athanassios , Haigentz Missak , Feldman Lawrence Eric , Jang Minyoung , Arun Pattatheyil , Van Waes Carter , Forastiere Arlene A.
Published: July 2012

Background

Constitutive activation of nuclear factor κB (NF‐κB) is associated with poor prognosis. Irinotecan demonstrates single‐agent activity in head and neck cancer but activates NF‐κB, promoting cell survival and resistance. Bortezomib is a proteasome inhibitor that inactivates NF‐κB.

Patients and Methods

We performed a randomized phase II trial of bortezomib on days 1, 4, 8, and 11 and irinotecan on days 1 and 8 of each 21‐day cycle or single‐agent bortezomib on days 1, 4, 8, and 11 on a 21‐day cycle. The addition of irinotecan to bortezomib was allowed in patients who progressed on bortezomib alone.

Results

The response rate of bortezomib and irinotecan was 13%. One patient had a partial response to bortezomib alone (response rate 3%). No responses were seen in patients with addition of irinotecan at time of progression on bortezomib.

Conclusions

The bortezomib‐based regimens evaluated in this study have minimal activity in recurrent or metastatic head and neck cancer. Head Neck, 2013
Intraoperative cone‐beam CT for head and neck surgery: Feasibility of clinical implementation using a prototype mobile C‐arm
Authors: King Emma , Daly Michael J. , Chan Harley , Bachar Gideon , Dixon Benjamin J. , Siewerdsen Jeffrey H. , Irish Jonathan C.
Published: July 2012

Background

Intraoperative 3‐dimensional (3D) imaging in head and neck surgery was developed using a prototype mobile C‐arm for cone‐beam CT (CBCT). This article summarizes its implementation in a prospective pilot and feasibility study.

Methods

The CBCT C‐arm was used in 12 head and neck surgical oncology cases. Human‐factors engineering methods and expert feedback from surgeons, nurses, and anesthetists were used to evaluate the impact of intraoperative imaging on the surgical environment and clinical workflow. Image quality of CBCT and the perceived clinical utility were evaluated.

Results

The CBCT C‐arm was successfully incorporated in 12 head and neck cases and streamlined into the surgical environment. Reviewed 3D‐CBCT images were qualitatively sufficient for intraoperative‐guidance for bony detail. Additional artifact management is required to improve soft‐tissue visualization.

Conclusions

Intraoperative CBCT provides high‐quality images for visualization of bony detail and is feasible during major head and neck surgery with acceptable workflow interruptions. Operations with significant bone ablation and/or reconstruction involving complex 3D anatomical structures are likely to benefit from the updated imaging. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
Orosphere assay: A method for propagation of head and neck cancer stem cells
Authors: Krishnamurthy Sudha , Nör Jacques E.
Published: July 2012

Background

Recent evidence suggests that head and neck squamous cell carcinomas (HNSCCs) harbor a small subpopulation of highly tumorigenic cells, designated cancer stem cells. A limiting factor in cancer stem cell research is the intrinsic difficulty of expanding cells in an undifferentiated state in vitro.

Methods

Here, we describe the development of the orosphere assay, a method for the study of putative head and neck cancer stem cells. An orosphere is defined as a nonadherent colony of cells sorted from primary HNSCCs or from HNSCC cell lines and cultured in 3‐dimensional soft agar or ultralow attachment plates. Aldehyde dehydrogenase activity and CD44 expression were used here as stem cell markers.

Results

This assay allowed for the propagation of head and neck cancer cells that retained stemness and self‐renewal.

Conclusion

The orosphere assay is well suited for studies designed to understand the pathobiology of head and neck cancer stem cells. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
Impact of secondary lymphedema after head and neck cancer treatment on symptoms, functional status, and quality of life
Authors: Deng Jie , Murphy Barbara A. , Dietrich Mary S. , Wells Nancy , Wallston Kenneth A. , Sinard Robert J. , Cmelak Anthony J. , Gilbert Jill , Ridner Sheila H.
Published: July 2012

Background

Lymphedema may disrupt local function and affect quality of life (QOL) in patients with head and neck cancer. The purpose of this study was to examine the associations among severity of internal and external lymphedema, symptoms, functional status, and QOL in patients with head and neck cancer.

Methods

The sample included 103 patients who were ≥3 months after head and neck cancer treatment. Variables assessed included severity of internal and external lymphedema, physical/psychological symptoms, functional status, and QOL.

Results

Severity of internal and external lymphedema was associated with physical symptoms and psychological symptoms. Patients with more severe external lymphedema were more likely to have a decrease in neck left/right rotation. The combined effects of external and internal lymphedema severity were associated with hearing impairment and decreased QOL.

Conclusions

Lymphedema severity correlates with symptom burden, functional status, and QOL in patients after head and neck cancer treatment. Head Neck, 2013
Asymmetric Counteranion‐Directed Catalysis (ACDC): A Remarkably General Approach to Enantioselective Synthesis
Authors: Mahlau Manuel , List Benjamin
Published: July 2012

Asymmetric counteranion‐directed catalysis (ACDC) is a powerful new concept, which can potentially be used to achieve enantioselectivity in any type of reaction proceeding through positively charged intermediates. It has already been applied in different areas of catalysis, such as organocatalysis, transition‐metal catalysis, and Lewis acid catalysis. Due to its complementarity with traditional approaches to achieve enantioselection, ACDC holds special promise for long‐standing challenges from all areas of catalysis, where matched cases can be designed. ACDC also represents a new way of thinking during method development, which could be of help to chemists from a variety of research areas.
Supramolecular Self‐Assembled Ligands in Asymmetric Transition Metal Catalysis
Authors: Bellini Rosalba , van der Vlugt Jarl Ivar , Reek Joost N. H.
Published: July 2012

The design of novel chiral ligands is at the core of asymmetric catalysis. The catalytic characteristics of a transition metal catalyst such as activity, selectivity and stability can be fine‐tuned by optimization of the steric and electronic properties of the coordinating ligands. In asymmetric transformations, catalyst optimization still relies to a large extent on trial‐and‐error and educated guesses. New strategies based on combinatorial screening and high‐throughput experimentation have been introduced for the design and optimization of new ligands and catalytic systems. Supramolecular bidentate ligands that form by self‐assembly of building blocks are particularly suited for this combinatorial approach as the potential number of catalysts grows exponentially with the number of building blocks synthesized. Catalytic systems based on supramolecular interactions have proven to be highly advantageous in creating large ligand libraries for high‐throughput screening, which allows optimization of activity and selectivity for a variety of reactions. In this review we describe the progress in this field.
Influence of the antifolate drug Methotrexate on the development of murine neural tube defects and genomic instability
Authors: Zhao Jie , Guan Tao , Wang Jianhua , Xiang Qian , Wang Mingsheng , Wang Xiuwei , Guan Zhen , Xie Qiu , Niu Bo , Zhang Ting
Published: July 2012

Impaired folate metabolism is considered a risk factor for neural tube defects (NTDs). However, the relationship between folate deficiency and the risk of NTDs remains unclear, because experimentally induced dietary folate deficiency is insufficient to cause NTDs in non‐mutant mice. Methotrexate (MTX) is a specific folate antagonist that competitively inhibits dihydrofolate reductase (DHFR) activity. The objective of this study was to develop a folate dysmetabolism murine model, and study the development of NTDs and its mechanism. Pregnant mice were injected with different doses of MTX [0, 0.5, 1.0, 3.0, 4.5 and 6.0 mg kg–1 body weight (b/w) intraperitoneally (i.p.)] on gestational day 7.5 and sacrificed on gestational day 11.5. DHFR activity in embryonic tissues was detected, and folate concentrations were analyzed using LC/MS/MS. Copy number variations (CNVs) in neural tube tissues were detected using array comparative genomic hybridization (aCGH). A dose of MTX 4.5 mg kg–1 b/w, resulted in the highest incidence of NTDs (31.4%) compared with the other groups, and DHFR activities, 5‐MeTHF and 5‐FoTHF concentrations in embryonic tissues decreased significantly after MTX injection. Furthermore, we found three high‐confidence CNVs on chromosome X using aCGH, which was confirmed by RT‐PCR and MassARRAY. These results indicate that MTX could cause a folate‐associated dysmetabolism, which is similar to that of dietary folate deficiency in mice. The presence of CNVs in neural tube tissues was associated with the development of NTDs. Copyright © 2012 John Wiley & Sons, Ltd.