bluuebunny/crossref_metadata_2025 huggingface dataset:
Flow diversion to treat aneurysms: the free segment of stent
Authors: Darsaut Tim E , Bing Fabrice , Makoyeva Alina , Gevry Guylaine , Salazkin Igor , Raymond Jean
Published: July 2012

Purpose

Flow diverters (FDs) have led to spectacular results in otherwise untreatable aneurysm cases, but complications can occur. There is a pressing need to study factors that might predict their safety and efficacy.

Methods

The anatomical constraints that may impact on the ability of FDs to redirect blood flow and provide a scaffold for neointima formation across the aneurysm or branch ostia are explored and classified. A nomenclature is needed to identify the key factors that should be taken into account before contemplating the use of FDs in clinical aneurysms, and that should be reproduced in experimental models, if they are to guide safe clinical use.

Results

The free stent segment (FSS), the portion of the device that covers an aneurysm or branch origin, dictates whether aneurysms or branches will remain patent. Three levels of increasing complexity must be taken into account to anticipate what will occur at the FSS level. (1) Virtual models can provide basic principles; (2) in vitro studies allow testing FSS deformations that may occur in various anatomical circumstances and impact on efficacy and safety; (3) but only in vivo studies can provide key information on neointimal closure following implantation that will differentiate success from failure.

Conclusions

A nomenclature is necessary to determine the optimal or suboptimal conditions for FDs and to design the virtual, in vitro and in vivo studies that will allow a better understanding of the factors involved in the success or failure of this novel treatment.
Intra and postoperative assessment of re‐sterilised Ligasure Atlas for orchidectomies in horses: clinical study
Authors: Gracia‐Calvo L.A. , Martín‐Cuervo M. , Jiménez J. , Vieítez V. , Durán M. E. , Argüelles D. , Ezquerra L. J.
Published: July 2012

Horses (n=35) underwent orchidectomy in a single institution with a re‐sterilised LSA as sole means of haemostasis. During the surgery, the gross quality of the seal, the stickiness of the forceps to the tissues, bleeding/oozing from the stump and the need for a subsequent application in already severed spermatic cord were assessed for haemostasis quality. After surgery, physical parameters (appearance of the mucous membranes, quality of the peripheral pulse, heart rate, respiratory rate, rectal temperature and blood dripping from the incisions), haematology or packed cell volume and total protein were monitored to assess signs of bleeding or any other condition. For cleanliness and asepsis assessment, signs of surgical infection were recorded.

Complications during surgery were mild degree of sticking of the LSA forceps to the tissues and dulling of the blade. There was no need to reapply LSA a second time except in one horse. This means a haemostasis complication rate of 2.85 per cent of the horses. No postoperative bleeding was detected. Only two horses with fever had associated signs of surgical site infection. This means an infection rate of 5.71 per cent of the horses.
GENERATING PENETRATION RESISTANCE FUNCTIONS WITH A VIRTUAL PENETRATION LABORATORY (VPL): APPLICATIONS TO PROJECTILE PENETRATION AND STRUCTURAL RESPONSE SIMULATIONS
Authors: ADLEY MARK D. , FRANK ANDREAS O. , DANIELSON KENT T. , AKERS STEPHEN A. , CARGILE JAMES D. , PATTERSON BRUCE C. , TERMAATH STEPHANIE
Published: July 2012

A new software package called the Virtual Penetration Laboratory (VPL) has been developed to automatically generate and optimize penetration resistance functions. We have used this VPL code to generate highly "tuned" penetration resistance functions that can distinctly model the penetration trajectory of steel projectiles into rate-independent, elastic-perfectly plastic aluminum targets. Projectiles with arbitrary nose geometry were considered in this example (i.e. conical, ogival, and spherical nose shapes). The penetration resistance of the aluminum target was determined by numerically solving a series of spherical and cylindrical cavity expansion problems. The solution to these cavity expansion problems were obtained with an explicit, dynamic finite element code that accounts for material and geometric nonlinearities. The resulting cavity expansion equations are then transformed to penetration resistance functions using various transformation algorithms, in order to determine an appropriate method to spatially distribute the resisting stresses on the projectile nose. The resulting penetration resistance functions were then used in a penetration trajectory code to predict the actual trajectories observed from a set of similar experiments.
DETECTION OF DAMAGE LOCATION USING A NOVEL SUBSTRUCTURE-BASED FREQUENCY RESPONSE FUNCTION APPROACH WITH A WIRELESS SENSING SYSTEM
Authors: LIN T. K. , HUNG S. L. , HUANG C. S.
Published: July 2012

This paper intends to detect the damage locations for building structures under an earthquake excitation using a novel substructure-based FRF approach with a damage location index (SubFRFDI). An Imote2.NET-based wireless structural health monitoring system was developed and employed in the experimental studies for the sake of deployment flexibility, low maintenance cost, low power consumption, self-organization capability, and wireless communication capability. The feasibility of the proposed approach for damage detection was examined using the numerical response of a six-storey shear plane frame structure subjected to a base excitation. The results demonstrate that the SubFRFDI can be successfully used to identify the damage of different levels at a single site or multiple sites. The SubFRFDI is independent of the responses to various input earthquake excitations. Even with the addition of noises, the SubFRFDI still functions well. The feasibility and robustness of the proposed Imote2.NET-based wireless structural health monitoring system were assessed using a 1/8-scale three-storey steel-frame model. Following this, the proposed SubFRFDI was further applied to identifying the damage locations in a 1/4-scale six-storey steel structure with the proposed Imote2.NET-based wireless monitoring system. It was confirmed experimentally that good data transportation quality can be achieved via reliable data transmission and sensing protocol in identifying the structural dynamic properties, and the proposed SubFRFDI can be used to identify the damage locations effectively.
Aluminum phthalocyanine and gold nanorod conjugates: the combination of photodynamic therapy and photothermal therapy to kill cancer cells
Authors: Wang J. , Tang H. Yan , Yang W. Li , Chen J. Yao
Published: July 2012

The sulfonated aluminum phthalocyanines (AlPcSs), popularly used photosensitizers, were linked on the surfaces of gold nanorods (AuNRs) by the electrostatic binding to form AlPcS–AuNRs conjugates, in order to improve the photo-therapy efficiency of cancer cells by combining the photodynamic therapy (PDT) of AlPcSs and the photothermal therapy (PTT) of AuNRs . The AlPcS's fluorescence is two-fold enhanced when they adhered on the surfaces of AuNRs probably due to the surface Plasmon coupling, which would facilitate the AlPcS detection. The fluorescence images show that AuNRs can carry loaded AlPcSs to penetrate into human nasopharyngeal carcinoma cells with a fast speed, achieving the effective intracellular delivery of AlPcSs . The PTT effect of cellular AuNRs alone under the white light irradiation of 50 minutes decreased the cell viability to 77%, and the PDT effect of cellular AlPcS–AuNRs with filtered red light (670–710 nm) irradiation of 50 min lowered the cell viability to 79%. However, with the same white light irradiation of 50 min, the AlPcS–AuNRs destroyed most cells leaving the cell viability to 28%, reflecting a typical synergistic effect on cell killing. These results suggest that the combination of PTT and PDT with AlPcS–AuNRs is a promising strategy for improving the phototherapy of cancers.
Synthesis, characterization and solvent/structural effects on spectral and redox properties of cobalt triphenylcorroles in nonaqueous media
Authors: Huang Shi , Fang Yuanyuan , Lü Aixiang , Lu Guifen , Ou Zhongping , Kadish Karl M.
Published: July 2012

Five cobalt(III) triphenylcorroles with different electron-withdrawing or electrondonating substituents and an axially bound triphenylphosphine ligand were synthesized and characterized by spectroscopic and electrochemical techniques. The investigated compounds are represented as (4-XPh)3CorCo(PPh3), where Ph3Cor is the trianion of a triphenylcorrole and X is a OMe , Me , H , F or Cl substituent on the meso-phenyl rings. Each corrole was examined by UV-vis, 1H NMR and IR spectroscopy, mass spectrometry, electrochemistry and thin-layer spectroelectrochemistry. Redox potentials and spectra of each oxidized and reduced species were examined in dichloromethane and N,N′-dimethylformamide containing 0.1 M tetra-n-butylammonium perchlorate. Each Co(III) corrole undergoes up to five one-electron transfer reactions, some of which are reversible and others which are not. The CoIII/CoII process is irreversible in both solvents due to the loss of the triphenylphosphine axial ligand following electron transfer. The CoII/CoI process is reversible in DMF but irreversible in CH2Cl2 due to a homogenous chemical reaction between the electrogenerated Co(I) corrole and the chlorinated solvent. The potential for the first oxidation of the investigated corroles varies little with change of solvent, consistent with the lack of solvent binding to the neutral and singly oxidized forms of (4-XPh)3CorCo(PPh3). However, a single DMF molecule strongly binds to the doubly oxidized corrole in DMF or DMF/ CH2Cl2 mixtures. This results in an easier oxidation and a negative shift of ~200 mV in E1/2 upon going from CH2Cl2 to DMF as solvent. The effect of substitutents and solvent on redox potentials is discussed and an overall electroreduction/electrooxidation mechanism is proposed
FINITE SIZE SCALING OF THE TYPICAL DENSITY OF STATES OF DISORDERED SYSTEMS WITHIN THE KERNEL POLYNOMIAL METHOD
Authors: JUNG DANIEL , CZYCHOLL GERD , KETTEMANN STEFAN
Published: July 2012

We study the (Anderson) metal-insulator transition (MIT) in tight binding models (TBM) of disordered systems using the scaling behavior of the typical density of states (GDOS) as localization criterion. The GDOS is obtained as the geometrical mean value of the local density of states (LDOS) averaged over many different lattice sites and disorder realizations. The LDOS can efficiently be obtained within the kernel polynomial method (KPM). To check the validity and accuracy of the method, we apply it here to the standard Anderson model of disordered systems, for which the results (for instance for the critical disorder strength of the Anderson transition) are well known from other methods.
QUASI TWO-DIMENSIONAL NUCLEON SUPERFLUIDITY UNDER LOCALIZATION WITH PION CONDENSATION
Authors: TAKATSUKA TATSUYUKI
Published: July 2012

The aim here is to show an example for localization and relevant low-dimensional superfluids in nuclear system. Due to a particular property of tensor force originating from the One-Pion-Exchange (OPE) between two nucleons, dense nuclear medium undergoes a layer confinement of the nucleons on one hand and also pion condensation (PC) for pion field mediating two-nucleon interaction on the other hand. The localization is characterized by a layered structure with a specific spin-isospin ordering. In that situation, the pairing problem has a two-dimensional (2D) character, i.e., low-dimensional superfluid realized in the hadronic matter with strong interactions. The pairing description suitable to the 2D nature is presented and possible realization of superfluidity in neutron stars is discussed, togeter with its effect on the cooling scenarios.
DIRECTION DEPENDENCE OF SPIN RELAXATION IN CONFINED TWO-DIMENSIONAL SYSTEMS
Authors: WENK PAUL , KETTEMANN STEFAN
Published: July 2012

The dependence of spin relaxation on the direction of the quantum wire under Rashba and Dresselhaus (linear and cubic) spin-orbit coupling is studied. Comprising the dimensional reduction of the wire in the diffusive regime, the lowest spin relaxation and dephasing rates for (001) and (110) systems are found.
INDIRECT EXCHANGE INTERACTIONS IN GRAPHENE
Authors: LEE HYUNYONG , MUCCIOLO EDUARDO R. , BOUZERAR GEORGES , KETTEMANN STEFAN
Published: July 2012

We study the Ruderman-Kittel-Katsuya-Yoshida (RKKY) interactions in graphene controlling the gate voltage and applying nonmagnetic disorder. It is found that oscillations of the RKKY interactions in undoped graphene are characterized by the interference of two neighbor Dirac nodes K and K′ in the first Brillouin zone and decays with R-3 distance dependence. In the slightly doped graphene, a beating pattern, which consists of two characteristic wavevectors (K - K and kF), starts to appear. The distance dependence in this regime shows a crossover from the R-3 to R-2. We present the effect of weak disorder on the RKKY interactions in diffusive regime. The arithmetic averaged interaction over disorder configurations decreases exponentially at distances exceeding the elastic mean free path, while the geometrical average(typical) value has the same power-law as the clean limit.
CRITICAL EXPONENTS FOR ANTIFERROMAGNETIC SPIN CHAINS OBTAINED FROM BOSONISATION
Authors: KOSSOW MARCEL , SCHUPP PETER , KETTEMANN STEFAN
Published: July 2012

The Heisenberg spin 1/2 chain is revisited in the perturbative RG approach with special focus on the transition of the critical exponents. We give a compact review that first order RG in the couplings is sufficient to derive the exact transition from ν = 1 to ν = 2/3, if the boson radius obtained in the bosonization procedure is replaced by the exact radius obtained in the Bethe approach. We explain the fact, that from the bosonization procedure alone, the critical exponent can not be derived correctly in the isotropic limit Jz → J. We further state that this fact is important if we consider to bosonize the antiferromagnetic super spin chain for the quantum Hall effect.
FINITE SIZE SCALING OF THE CHALKER-CODDINGTON MODEL
Authors: SLEVIN KEITH , OHTSUKI TOMI
Published: July 2012

In Ref. 1, we reported an estimate of the critical exponent for the divergence of the localization length at the quantum Hall transition that is significantly larger than those reported in the previous published work of other authors. In this paper, we update our finite size scaling analysis of the Chalker-Coddington model and suggest the origin of the previous underestimate by other authors. We also compare our results with the predictions of Lütken and Ross.2
BULK AND EDGE QUASIHOLE TUNNELING AMPLITUDES IN THE LAUGHLIN STATE
Authors: HU ZI-XIANG , LEE KI HOON , WAN XIN
Published: July 2012

The tunneling between the Laughlin state and its quasihole excitations are studied by using the Jack polynomial. We find a universal analytical formula for the tunneling amplitude, which can describe both bulk and edge quasihole excitations. The asymptotic behavior of the tunneling amplitude reveals the difference and the crossover between bulk and edge states. The effects of the realistic coulomb interaction with a background-charge confinement potential and disorder are also discussed. The stability of the tunneling amplitude manifests the topological nature of fractional quantum Hall liquids.
A new assemblage of juvenile Ediacaran fronds from the Drook Formation, Newfoundland
Authors: Liu Alexander G. , McIlroy Duncan , Matthews Jack J. , Brasier Martin D.
Published: July 2012

A new assemblage of frondose and filamentous Ediacaran macrofossils is reported from the upper Drook Formation of Pigeon Cove, Newfoundland. The frondose forms, all less than 3 cm in length, are considered to represent the juvenile growth stages of Ediacaran organisms including
Charnia
spp. and
Trepassia
spp. This is the first report of an assemblage wholly dominated by such small juvenile rangeomorph forms, and provides insights into the ontogeny and ecology of these earliest members of the Ediacara biota. The fronds occur alongside filamentous forms with similarities to microbial taxa, and both morphotypes are considered to postdate an assemblage of large ivesheadiomorphs on the same bedding plane. If so, the assemblage represents one of the oldest documented examples of secondary community succession. The new Pigeon Cove fossils also extend the stratigraphic ranges of several key frondose taxa (
Charnia masoni, Charniodiscus
spp.) back into some of the oldest known macrofossil-bearing strata. These revised ranges lend support to the suggestion that the previously observed low diversity within the Drook Formation may represent a combination of taphonomic and sampling artefacts. Furthermore, this assemblage implies that the diversification of architectural morphotypes within the Ediacara biota took place earlier than hitherto suspected.

Supplementary material:

A document containing figures of additional juvenile rangeomorphs and filamentous specimens, a table of specimen dimensions, and a complete digitized map of the Pigeon Cove bedding plane, is available at
www.geolsoc.org.uk/SUP18529
.
Tectonic control on travertine and calcareous tufa deposition in a low-temperature geothermal system (Sarteano, Central Italy)
Authors: Brogi Andrea , Capezzuoli Enrico , Buracchi Elena , Branca Marilì
Published: July 2012

This paper presents an integrated study directed toward an understanding of the tectonic control on the hydrothermal circulation and resulting deposition of Middle–Late Pleistocene travertine in a low-temperature geothermal field of southern Tuscany, located in the Sarteano area (Central Italy). The study area is characterized by thermal springs (
c
. 25 °C) and related continental carbonate deposits, structurally controlled by SW–NE-trending oblique to strike-slip faults dissecting previous normal faults. Sedimentological–stratigraphical data and
230
Th/
234
U radiometric age determination for the travertine indicate that continental carbonates were deposited in a tectonically controlled, perched-spring system from 268 ± 22 ka (at least) to the present. The hydrothermal system is (and was) characterized by meteoric waters with a minor contribution from fluids of deeper origin. Meteoric waters infiltrated to depth through tectonically damaged zones of Mesozoic and Cenozoic carbonate rocks and overheated as a result of localized, anomalous geothermal gradient. Then, fluids enriched in bicarbonate–sulphate moved up along highly fractured rock masses at the intersection between strike-slip faults and normal faults. This paper highlights the use of continental carbonates in the reconstruction of palaeohydrothermal systems, in terms of the location of the main conduits for hydrothermal fluid flow, age of faulting and physical properties of hydrothermal fluids.
U–Pb ion-microprobe zircon geochronology from the basement inliers of eastern Graham Land, Antarctic Peninsula
Authors: Riley T. R. , Flowerdew M. J. , Whitehouse M. J.
Published: July 2012

New geological mapping combined with U–Pb ion microprobe zircon geochronology on the isolated but locally extensive exposures of crystalline basement inliers of eastern Graham Land has greatly improved our understanding of the region’s early crustal evolution and has allowed a more thorough evaluation of Patagonia–Antarctic Peninsula connections prior to Gondwana break-up. At Eden Glacier, diorite gneisses yield Early Ordovician protolith ages of 487 ± 3 and 485 ± 3 Ma and represent the oldest
in situ
rocks recorded on the Antarctic Peninsula, and indicate a significant spatial extension of Famatinian-age magmatism of Patagonia. Zircon overgrowths in the Early Ordovician protoliths and granitic leucosomes developed within them record two phases of Permian metamorphism at
c
. 275 and
c
. 257 Ma, coincident in part with diorite plutonism of the area at 272 ± 2 Ma. At Adie Inlet, granitic leucosomes from paragneiss have been dated at 276 ± 3 Ma, and these are in turn cut by 257 ± 3 Ma xenolith-rich diorite gneiss. The diorite intruded during a second phase of deformation, which folded the paragneiss leucosomes into tight folds. This whole assembly is cut by intensely brecciated megacrystic granodiorite, which yielded a 259 ± 3 Ma age. South of Cabinet Inlet a very different sequence of events is evident, with Triassic magmatism at
c
. 236 Ma extensive along the Joerg Peninsula. Migmatitic leucosomes are dated at
c
. 224 Ma and magmatism and deformation events apparently continued to
c
. 209 Ma at Cape Casey. Our data indicate that the Devonian and Carboniferous magmatism at Target Hill, considered to represent the ‘classic’ basement complex of the Antarctic Peninsula, is not representative regionally. The Target Hill crustal block contains a major break along Cabinet Inlet; to the north, Ordovician and Permian protoliths were variably migmatized during two episodes of Permian deformation and metamorphism, whereas to the south, Triassic protoliths and Triassic metamorphism are encountered.

Supplementary material:

U–Pb isotopic data are available at
http://www.geolsoc.org.uk/SUP18526
.
Seismic imaging of ‘broken bridges’: linking seismic to outcrop-scale investigations of intrusive magma lobes
Authors: Schofield Nick , Heaton Lucy , Holford Simon P. , Archer Stuart G. , Jackson Christopher A.-L. , Jolley David W.
Published: July 2012

Three-dimensional seismic datasets have provided unrivalled insights into magma flow within sub-volcanic systems. One of the key revelations is that sills appear to be constructed of a series of discrete magma lobes that form during the emplacement of magma into host-rock. We focus on a large sill, within the Faroe–Shetland Basin, North Atlantic, that is well imaged on seismic data, and identify the presence of ‘broken bridges’ within the sill, developed between elongate magma lobes, and reveal for the first time in three dimensions the development of broken bridges. Critically, by relating the imaged structures to key outcrop-scale examples we confirm that bridge and broken-bridge structures are oriented perpendicular to the magma flow direction. This work thus demonstrates a key link that can be made between seismic-scale investigation of intrusions and sub-seismic (outcrop-scale) processes, highlighting the seemingly scale-invariant nature of the magmatic emplacement process.
Ferulic Acid, anAngelica sinensis-Derived Polyphenol, Slows the Progression of Membranous Nephropathy in a Mouse Model
Authors: Cheng Chao-Wen , Chang Wen-Liang , Chang Li-Cheng , Wu Chia-Chao , Lin Yuh-Feng , Chen Jin-Shuen
Published: July 2012

Membranous nephropathy (MN) is a leading cause of adult nephrotic syndrome but lacks adequate treatment. Different extracts ofAngelica sinensis(AS) and one of its active compounds, ferulic acid (FA), were used to evaluate the therapeutic effects in a MN mouse model. The MN model was grouped into three subgroups: no treatment (N-T), treatment at induction of MN (Pre-T), and treatment after full-blown MN (Post-T). The results showed that the methanol (ME) layer of AS extract exhibited a therapeutic effect on MN-induced proteinuria. The ME layer-enriched compound, FA, improved the hypoalbuminemia, hyperlipidemia, and proteinuria in both Pre-T and Post-T groups. Ferulic acid also reduced the formation of oxidative protein products and increased the synthesis of antioxidant enzymes in groups Pre-T and Post-T. Regarding angiogenesis factors, the antiangiogenic factors in renal glomeruli were increased in group N-T, but, after FA treatment, only one of the antiangiogenic factors, thrombospondin-1, showed a significant decrease. Furthermore, the expression of Th2 predominant showed significant decrease in both Pre-T and Post-T groups when compared to that of N-T group. In summary, FA retarded the progression of MN, and the mechanisms involved the regulation of oxidative stresses, angiogenic and antiangiogenic factors, and attenuation of Th2 response.
Action Research in Action: From University to School Classrooms
Authors: Miskovic Maja , Efron Efrat Sara , Ravid Ruth
Published: July 2012

This multiyear mixed-method study was conducted to understand (a) the perceptions of the preservice and in-service teachers regarding the significance of action research in their teaching career and (b) how teachers draw on skills developed in the research courses as they initiate a reflective inquiry and conduct research in their own classrooms. Based on 176 surveys, we conclude that research plays an important role in the teachers’ professional life and that teachers desire (a) to have more time to do research, and (b) collaboration with and assistance from colleagues and administrators. Ethnographic data from three participants revealed that each understood research differently, which affected what was unfolding in the classrooms. Implications for teacher research are discussed.
Interactions ofmiR-34b/candTP53Polymorphisms on the Risk of Intracranial Aneurysm
Authors: Li Lijuan , Sima Xiutian , Bai Peng , Zhang Lushun , Sun Hong , Liang Weibo , Liu Jianxing , Zhang Lin , Gao Linbo
Published: July 2012

Several lines of evidence indicate that inflammatory processes play a key role in the happening and development of intracranial aneurysm (IA). Recently, polymorphisms in theTP53gene were shown to be associated with inflammation and inflammatory disease. The aim of this study was to investigate the interactions ofmiR-34b/candTP53Arg72-Pro polymorphisms on the risk of IA in a Chinese population. A total of 590 individuals (including 164 patients with IA and 426 controls) were involved in this study. The polymorphisms (i.e.,miR-34b/crs4938723 andTP53Arg72-Pro) were genotyped by polymerase chain reaction-restriction fragment length polymorphism assay and DNA sequencing. We found that the CC genotype ofmiR-34b/crs4938723 was significantly associated with a decreased risk of IA compared with the TT genotype. Moreover, a significant gene interaction of the carriers with the combined genotypes ofmiR-34b/crs4938723CC andTP53Arg72Pro CG/CC/GG had a decreased risk of IA, compared with those carryingmiR-34b/crs4938723CT/TT+TP53Arg72Pro GG/CG/CC combined genotypes. These findings suggest that themiR-34b/crs4938723CC andTP53Arg72-Pro polymorphisms may be involved in the susceptibility to IA.
High Resolution through Graded-Index Microoptics
Authors: Kotlyar Victor V. , Kovalev Alexey A. , Nalimov Anton G. , Stafeev Sergey S.
Published: July 2012

By solving Helmholtz equations, relationships to describe propagating modes in an arbitrary graded-index planar waveguide are derived. We show that in the quadratic- and secant-index waveguides a minimal mode width is 0.4λ/n, where λ is the wavelength in free space and n is the refractive index on the fiber axis. By modeling in FullWAVE, we show that the high-resolution imaging can be achieved with half-pitch graded-index Mikaelian microlenses (ML) and Maxwell’s “fisheye” lenses. It is shown that using a 2D ML, the point source can be imaged near the lens surface as a light spot with the full width at half maximum (FWHM) of 0.12λ. This value is close to the diffraction limit for silicon (n=3.47) in 2D media FWHM=0.44λ/n=0.127λ. We also show that half-pitch ML is able to resolve at half-maximum two close point sources separated by a 0.3λ distance.
Time‐Dependent Variational Inequality for an Oligopolistic Market Equilibrium Problem with Production and Demand Excesses
Authors: Barbagallo Annamaria , Mauro Paolo
Published: July 2012

The paper is concerned with the variational formulation of the oligopolistic market equilibrium problem in presence of both production and demand excesses. In particular, we generalize a previous model in which the authors, instead, considered only the problem with production excesses, by allowing also the presence of demand excesses. First we examine the equilibrium conditions in terms of the well‐known dynamic Cournot‐Nash principle. Next, the equilibrium conditions will be expressed in terms of Lagrange multipliers by means of the infinite dimensional duality theory. Then, we show the equivalence between the two conditions that are both expressed by an appropriate evolutionary variational inequality. Moreover, thanks to the variational formulation, some existence and regularity results for equilibrium solutions are proved. At last, a numerical example, which illustrates the features of the problem, is provided.
PropertyPand Some Fixed Point Results on -Weakly ContractiveG-Metric Spaces
Authors: Khandaqji Mona , Al-Sharif Sharifa , Al-Khaleel Mohammad
Published: July 2012

We prove some fixed point results for -weakly contractive maps inG-metric spaces, we show that these maps satisfy propertyP. The results presented in this paper generalize several well-known comparable results in the literature.
The Effect of Ventilation, Age, and Asthmatic Condition on Ultrafine Particle Deposition in Children
Authors: Olvera Hector A. , Perez Daniel , Clague Juan W. , Cheng Yung-Sung , Li Wen-Whai , Amaya Maria A. , Burchiel Scott W. , Berwick Marianne , Pingitore Nicholas E.
Published: July 2012

Ultrafine particles (UFPs) contribute to health risks associated with air pollution, especially respiratory disease in children. Nonetheless, experimental data on UFP deposition in asthmatic children has been minimal. In this study, the effect of ventilation, developing respiratory physiology, and asthmatic condition on the deposition efficiency of ultrafine particles in children was explored. Deposited fractions of UFP (10–200 nm) were determined in 9 asthmatic children, 8 nonasthmatic children, and 5 nonasthmatic adults. Deposition efficiencies in adults served as reference of fully developed respiratory physiologies. A validated deposition model was employed as an auxiliary tool to assess the independent effect of varying ventilation on deposition. Asthmatic conditions were confirmed via pre-and post-bronchodilator spirometry. Subjects were exposed to a hygroscopic aerosol with number geometric mean diameter of 27–31 nm, geometric standard deviation of 1.8–2.0, and concentration of1.2×106particles cm−3. Exposure was through a silicone mouthpiece. Total deposited fraction (TDF) and normalized deposition rate were 50% and 32% higher in children than in adults. Accounting for tidal volume and age variation, TDF was 21% higher in asthmatic than in non-asthmatic children. The higher health risks of air pollution exposure observed in children and asthmatics might be augmented by their susceptibility to higher dosages of UFP.
Traveling Wave Solutions for the Generalized Zakharov Equations
Authors: Song Ming , Liu Zhengrong
Published: July 2012

We use the bifurcation method of dynamical systems to study the traveling wave solutions for the generalized Zakharov equations. A number of traveling wave solutions are obtained. Those solutions contain explicit periodic wave solutions, periodic blow‐up wave solutions, unbounded wave solutions, kink profile solitary wave solutions, and solitary wave solutions. Relations of the traveling wave solutions are given. Some previous results are extended.
Optimal Pricing of Spectrum Resources in Wireless Opportunistic Access
Authors: Bogucka Hanna
Published: July 2012

We consider opportunistic access to spectrum resources in cognitive wireless networks. The users equipment, or the network nodes in general are able to sense the spectrum and adopt a subset of available resources (the spectrum and the power) individually and independently in a distributed manner, that is, based on their local channel quality information and not knowing the Channel State Information (CSI) of the other nodes' links in the considered network area. In such a network scenery, the competition of nodes for available resources is observed, which can be modeled as a game. To obtain spectrally efficient and fair spectrum allocation in this competitive environment with the nodes having no information on the other players, taxation of resources is applied to coerce desired behavior of the competitors. In the paper, we present mathematical formulation of the problem of finding the optimal taxation rate (common for all nodes) and propose a reduced-complexity algorithm for this optimization. Simulation results for these derived optimal values in various scenarios are also provided.
Increased Hypothalamic Inflammation Associated with the Susceptibility to Obesity in Rats Exposed to High-Fat Diet
Authors: Wang Xiaoke , Ge Aiguo , Cheng Mengjie , Guo Fangfang , Zhao Min , Zhou Xiaoqi , Liu Liegang , Yang Nianhong
Published: July 2012

Inflammation has been implicated in the hypothalamic leptin and insulin resistance resulting defective food intake during high fat diet period. To investigate hypothalamic inflammation in dietary induced obesity (DIO) and obesity resistant (DIO-R) rats, we established rat models of DIO and DIO-R by feeding high fat diet for 10 weeks. Then we switched half of DIO and DIO-R rats to chow food and the other half to high fat diet for the following 8 weeks to explore hypothalamic inflammation response to the low fat diet intervention. Body weight, caloric intake, HOMA-IR, as well as the mRNA expression of hypothalamic TLR4, NF-κB, TNF-α, IL-1β, and IL-6 in DIO/HF rats were significantly increased compared to DIO-R/HF and CF rats, whereas IL-10 mRNA expression was lower in both DIO/HF and DIO-R/HF rats compared with CF rats. Switching to chow food from high fat diet reduced the body weight and improved insulin sensitivity but not affecting the expressions of studied inflammatory genes in DIO rats. Take together, upregulated hypothalamic inflammation may contribute to the overeating and development of obesity susceptibility induced by high fat diet. Switching to chow food had limited role in correcting hypothalamic inflammation in DIO rats during the intervention period.
PDGF Receptor Alpha Is an Alternative Mediator of Rapamycin-Induced Akt Activation: Implications for Combination Targeted Therapy of Synovial Sarcoma
Authors: Ho Alan L. , Vasudeva Shyamprasad Deraje , Laé Marick , Saito Tsuyoshi , Barbashina Violetta , Antonescu Cristina R. , Ladanyi Marc , Schwartz Gary K.
Published: July 2012

Akt activation by the IGF-1 receptor (IGF-1R) has been posited to be a mechanism of intrinsic resistance to mTORC1 inhibitors (rapalogues) for sarcomas. Here we show that rapamycin-induced phosphorylation of Akt can occur in an IGF-1R–independent manner. Analysis of synovial sarcoma cell lines showed that either IGF-1R or the PDGF receptor alpha (PDGFRA) can mediate intrinsic resistance to rapamycin. Repressing expression of PDGFRA or inhibiting its kinase activity in synovial sarcoma cells blocked rapamycin-induced phosphorylation of Akt and decreased tumor cell viability. Expression profiling of clinical tumor samples revealed that PDGFRA was the most highly expressed kinase gene among several sarcoma disease subtypes, suggesting that PDGFRA may be uniquely significant for synovial sarcomas. Tumor biopsy analyses from a synovial sarcoma patient treated with the mTORC1 inhibitor everolimus and PDGFRA inhibitor imatinib mesylate confirmed that this drug combination can impact both mTORC1 and Akt signals in vivo. Together, our findings define mechanistic variations in the intrinsic resistance of synovial sarcomas to rapamycin and suggest therapeutic strategies to address them. Cancer Res; 72(17); 4515–25. ©2012 AACR.
Bugging Tumors
Authors: Hoffman Robert M.
Published: July 2012

Summary: The effects of bacteria on patients with cancer have been observed for at least two centuries. Recent studies in animal models of cancer have shown efficacy of both anaerobic bacteria such as Clostridia and Bifidobacteria and facultative anaerobes such as Salmonella. In this issue of Cancer Discovery, Flentie and colleagues have identified five Salmonella promoters that are specifically stimulated by cancer cells as well as by acidic pH, a property of most tumors. One of these promoters (STM1787) was linked to a Shiga toxin gene and inserted in a wild-type Salmonella typhimurium strain, which showed in vivo antitumor efficacy. Approaches to further improving the efficacy of S. typhimurium with the use of tumor-targeting mutations are discussed. Because the barriers to efficacy of standard therapy of cancer appear to be opportunities for bacterial cancer therapy, the future of bacterial therapy of cancer appears bright. Cancer Discov; 2(7); 588–90. ©2012 AACR.

Commentary on Flentie et al., p. 624.
Hypothalamic Deep Brain Stimulation Influences Autonomic and Limbic Circuitry Involved in the Regulation of Aggression and Cardiocerebrovascular Control in the Göttingen Minipig
Authors: Ettrup K.S. , Sørensen J.C. , Rodell A. , Alstrup A.K.O. , Bjarkam C.R.
Published: July 2012

Background: Deep brain stimulation (DBS) in the ventral tuberal hypothalamus (VTH) is currently under investigation for the treatment of severe obesity. Stimulation impact on a number of closely related hypothalamic neural systems could potentially influence normal hypothalamic function and thereby generate adverse side effects. Objective: To assess the feasibility and safety of VTH DBS in a non-primate large animal model. Methods: In the VTH of 6 Göttingen minipigs, quadropolar leads were implanted bilaterally (n = 2) or unilaterally (n = 4), using optimized MRI sequences allowing identification of major diencephalic landmarks. Heart rate, weight, behavior and nighttime locomotor activity were recorded throughout the study period. Two of the unilaterally implanted minipigs were examined with [15O]H2O positron emission tomography (PET) scans performed in DBS-off and DBS-on mode. Results: VTH DBS elicited an amplitude-dependent increase in heart rate and transient aggressive behavior. PET demonstrated that VTH DBS caused a global increase in cerebral blood flow velocities and decreased mean transit time. Conclusions: VTH DBS results in behavioral and physiological changes, which may derive from activation of closely related limbic and autonomic networks. Caution and further studies of longer length should be requested before this procedure is used more widely in humans.
Impact of Parameters of Radiofrequency Coagulation on Volume of Stereotactic Lesion in Pallidotomy and Thalamotomy
Authors: Hirabayashi Hidehiro , Hariz Marwan I. , Wårdell Karin , Blomstedt Patric
Published: July 2012

Background: One of the many reasons why lesional surgery for movement disorders has been more or less abandoned may have been the difficulty in predicting the shape and size of the stereotactic radiofrequency (RF) lesion. Objectives: To analyse the contribution of various RF coagulation parameters towards the volume of pallidotomies and thalamotomies. Methods: The relationship between temperature of coagulation, length of coagulated area and duration of coagulation on the one hand, and lesion volume on the other was retrospectively evaluated. Lesion diameters were measured on stereotactic thin-slice CT and MRI scans, and volumes of lesions were calculated concerning 36 pallidotomies and 14 thalamotomies in 46 patients who were operated using the same RF generator and same RF electrode. Results: The coagulation temperature, length of coagulated area and duration of coagulation were all correlated to the lesion volume. However, for a given length of coagulated area, the lesion´s size was most strongly influenced by the temperature. Despite this clear correlation, and the relatively homogenous coagulation parameters, the lesions’ volumes were markedly scattered. Conclusions: The volume of the stereotactic RF lesions could be correlated with the coagulation parameters, especially the temperature, at a group level, but could not be predicted in individual patients based solely on the RF coagulation parameters.
Wound Repair and Regeneration
Authors: Reinke J.M. , Sorg H.
Published: July 2012

The skin is the biggest organ of the human being and has many functions. Therefore, the healing of a skin wound displays an extraordinary mechanism of cascading cellular functions which is unique in nature. As healing and regeneration processes take place in all parts of the human body, this review focuses on the healing processes of the skin and highlights the classical wound healing phases. While regeneration describes the specific substitution of the tissue, i.e. the superficial epidermis, mucosa or fetal skin, skin repair displays an unspecific form of healing in which the wound heals by fibrosis and scar formation. The first stage of acute wound healing is dedicated to hemostasis and the formation of a provisional wound matrix, which occurs immediately after injury and is completed after some hours. Furthermore, this phase initiates the inflammatory process. The inflammatory phase of the wound healing cascade gets activated during the coagulation phase and can roughly be divided into an early phase with neutrophil recruitment and a late phase with the appearance and transformation of monocytes. In the phase of proliferation the main focus of the healing process lies in the recovering of the wound surface, the formation of granulation tissue and the restoration of the vascular network. Therefore, next to the immigration of local fibroblasts along the fibrin network and the beginning of reepithelialization from the wound edges, neovascularization and angiogenesis get activated by capillary sprouting. The formation of granulation tissue stops through apoptosis of the cells, characterizing a mature wound as avascular as well as acellular. During the maturation of the wound the components of the extracellular matrix undergo certain changes. The physiological endpoint of mammalian wound repair displays the formation of a scar, which is directly linked to the extent of the inflammatory process throughout wound healing.
Oxidative stress and platelet activation in subjects with moderate hyperhomocysteinaemia due to MTHFR 677 C→T polymorphism
Authors: Dragani Alfredo , Falco Angela , Santilli Francesca , Basili Stefania , Rolandi Giancarlo , Cerasa Loredana , Lattanzio Stefano , Ciabattoni Giovanni , Patrono Carlo , Davì Giovanni
Published: July 2012

The methylenetetrahydrofolate reductase (MTHFR) 677 C→T polymorphism may be associated with elevated total homocysteine (tHcy) levels, an independent risk factor for cardiovascular disease. It was the study objective to evaluate in vivo lipid peroxidation and platelet activation in carriers of the MTHFR 677 C→T polymorphism and in non-carriers, in relation to tHcy and folate levels. A cross-sectional comparison of urinary 8-iso-prostaglandin (PG)F2α and 11-dehydro-thromboxane (TX)B2 (markers of in vivo lipid peroxidation and platelet activation, respectively) was performed in 100 carriers and 100 non-carriers of the polymorphism. A methionine-loading test and folic acid supplementation were performed to investigate the causal relationship of the observed associations. Urinary 8-iso-PGF2α and 11-dehydro-TXB2 were higher in carriers with hyperhomocysteinaemia than in those without hyperhomocysteinaemia (p<0.0001). Hyperhomocysteinaemic carriers had lower folate levels (p=0.0006), higher urinary 8-iso-PGF2α (p<0.0001) and 11-dehydro-TXB2 (p<0.0001) than hyperhomocysteinaemic non-carriers. On multiple regression analysis, high tHcy (p<0.0001), low folate (p<0.04) and MTHFR 677 C→T polymorphism (p<0.001) independently predicted high rates of 8-iso-PGF2α excretion. Methionine loading increased plasma tHcy (p=0.002), and both urinary prostanoid metabolites (p=0.002). Folic acid supplementation was associated with decreased urinary 8-iso-PGF2α and 11-dehydro-TXB2 excretion (p<0.0003) in the hyperhomocysteinaemic group, but not in the control group, with substantial inter-individual variability related to baseline tHcy level and the extent of its reduction. In conclusion, hyperhomocysteinaemia due to the MTHFR 677 C→T polymorphism is associated with enhanced in vivo lipid peroxidation and platelet activation that are reversible, at least in part, following folic acid supplementation. An integrated biomarker approach may help identifying appropriate candidates for effective folate supplementation.
Does the Inclusion of Stroke Severity in a 30-Day Mortality Model Change Standardized Mortality Rates at Veterans Affairs Hospitals?
Authors: Keyhani Salomeh , Cheng Eric , Arling Greg , Li Xinli , Myers Laura , Ofner Susan , Williams Linda S. , Phipps Michael , Ordin Diana , Bravata Dawn M.
Published: July 2012

Background—

The Centers for Medicare and Medicaid Services is considering developing a 30-day ischemic stroke hospital-level mortality model using administrative data. We examined whether inclusion of the National Institutes of Health Stroke Scale (NIHSS), a measure of stroke severity not included in administrative data, would alter 30-day mortality rates in the Veterans Health Administration.

Methods and Results—

A total of 2562 veterans admitted with ischemic stroke to 64 Veterans Health Administration Hospitals in the fiscal year 2007 were included. First, we examined the distribution of unadjusted mortality rates across the Veterans Health Administration. Second, we estimated 30-day all-cause, risk standardized mortality rates (RSMRs) for each hospital by adjusting for age, sex, and comorbid conditions using hierarchical models with and without the inclusion of the NIHSS. Finally, we examined whether adjustment for the NIHSS significantly changed RSMRs for each hospital compared with other hospitals. The median unadjusted mortality rate was 3.6%. The RSMR interquartile range without the NIHSS ranged from 5.1% to 5.6%. Adjustment with the NIHSS did not change the RSMR interquartile range (5.1%–5.6%). Among veterans ≥65 years, the RSMR interquartile range without the NIHSS ranged from 9.2% to 10.3%. With adjustment for the NIHSS, the RSMR interquartile range changed from 9.4% to 10.0%. The plot of 30-day RSMRs estimated with and without the inclusion of the NIHSS in the model demonstrated overlapping 95% confidence intervals across all hospitals, with no hospital significantly below or above the mean-unadjusted 30-day mortality rate. The 30-day mortality measure did not discriminate well among hospitals.

Conclusions—

The impact of the NIHSS on RSMRs was limited. The small number of stroke admissions and the narrow range of 30-day stroke mortality rates at the facility level in the Veterans Health Administration cast doubt on the value of using 30-day RSMRs as a means of identifying outlier hospitals based on their stroke care quality.
Daytime Sleepiness and Risk of Stroke and Vascular Disease
Authors: Boden-Albala Bernadette , Roberts Eric T. , Bazil Carl , Moon Yeseon , Elkind Mitchell S. V. , Rundek Tatjana , Paik Myunghee C. , Sacco Ralph L.
Published: July 2012

Background—

Recent studies have suggested that poor quality and diminished quantity of sleep may be independently linked to vascular events although prospective and multiethnic studies are limited. This study aimed to explore the relationship between daytime sleepiness and the risk of ischemic stroke and vascular events in an elderly, multiethnic prospective cohort.

Methods and Results—

As part of the Northern Manhattan Study, the Epworth Sleepiness Scale was collected during the 2004 annual follow-up. Daytime sleepiness was trichotomized using previously reported cut points of no dozing, some dozing, and significant dozing. Subjects were followed annually for a mean of 5.1 years. Cox proportional hazards models were used to calculate hazard ratios and 95% confidence intervals for stroke, myocardial infarction, and death outcomes. We obtained the Epworth Sleepiness Scale on 2088 community residents. The mean age was 73.5 ± 9.3 years; 64% were women; 17% were white, 20% black, 60% Hispanic, and 3% were other. Over 44% of the cohort reported no daytime dozing, 47% some dozing, and 9% significant daytime dozing. Compared with those reporting no daytime dozing, individuals reporting significant dozing had an increased risk of ischemic stroke (hazard ratio, 2.74 [95% confidence interval, 1.38–5.43]), all stroke (3.00 [1.57–5.73]), the combination of ischemic stroke, myocardial infarction, and vascular death (2.38 [1.50–3.78]), and all vascular events (2.48 [1.57–3.91]), after adjusting for medical comorbidities.

Conclusions—

Daytime sleepiness is an independent risk factor for stroke and other vascular events. These findings suggest the importance of screening for sleep problems at the primary care level.