bluuebunny/crossref_metadata_2025 huggingface dataset:
Optical, electrical and magnetic properties of transparent, n‐type conductive Zn0.90−xV0.10Alx O thin films elaborated from aerogel nanoparticles
Authors: Mir L. El , Ayadi Z. Ben , Saadoun M. , von Bardeleben H. J. , Djessas K , Zeinert A.
Published: July 2007

Vanadium–aluminium co‐doped ZnO thin films have been grown by rf‐magnetron sputtering of Zn0.90−x V0.10Alx O (x = 0.01 to 0.03) aerogel nanoparticles. Even though the films were deposited at room temperature they were of good crystal quality and showed c‐axis texturing normal to the film surface. The films are highly transparent in the visible with a transmittance higher than 90%. The highest conductivity of 5.103 Ω−1 cm−1 is obtained for 1% Al doping. The incorporation of V, a notoriously difficult dopant in ZnO, is confirmed by the observation of different absorption bands near 800 nm which we attribute to intracenter transitions of Zn substituted V2+. The magnetic properties of the aerogel particles have been studied by electron paramagnetic resonance (EPR) spectroscopy. No evidence for a ferromagnetic phase is found contrary to theoretical predictions. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical and structural characteristics of tin oxide thin films deposited by filtered vacuum arc and spray pyrolysis
Authors: Çetinörgü E. , Gümüş C. , Goldsmith S. , Mansur F.
Published: July 2007

Tin oxide (SnO2) thin films were deposited on commercial microscope glass and UV fused silica substrates (UVFS) using spray pyrolysis and filtered vacuum arc deposition (FVAD) system. During deposition, the substrates temperature was kept at 400 °C. The structure and composition were determined using X‐ray diffraction (XRD) and X‐ray photoelectron spectroscopy (XPS), respectively. The XRD patterns of SnO2 thin films deposited with the two systems on hot substrates were found to be polycrystalline. The average transmission of the films in the VIS was 80% to 85%. The film optical constants were determined by normal incidence transmission measurements. The refractive indices of FVA deposited films were in the range 2.11 to 2.0, and those of spray deposited ones were 1.97 to 1.93. The extinction coefficients of the deposited films were in the range 0.29 and 0.11 to approximately 0 for FVAD and spray pyrolysis, respectively, depending on wavelengths. The optical band gap, Eg, was determined from the dependence of the absorption coefficient on the photon energy at short wavelengths, and were 3.80 eV and 3.90 eV for spray pyrolysis and FVA deposited SnO2 thin films, respectively. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrical properties of individual gold nanowires arrayed in a porous anodic alumina template
Authors: Biswas K. , Qin Y. , DaSilva M. , Reifenberger R. , Sands T.
Published: July 2007

A procedure to fabricate a highly ordered electrodeposited nanowire array in a porous anodic alumina template with nanowires of uniform length and exposed tips for establishing low‐resistance ohmic contacts has been demonstrated. In this work, contacts to Au nanowire arrays have been investigated as a model system. The structural, topographical and electrical characteristics of the nanowire array have been studied using field emission scanning electron microscopy and conductive atomic force microscopy. Measurements showed that an electrical contact between the conducting AFM probe and the exposed Au nanowire tips was initiated only after a force of 14.4 ± 2 nN was applied. The I –V characteristics were linear up to the maximum applied current density of 1.5 × 1012 A/m2, and the resistivity of the individual Au nanowires in the template was estimated to be between 1.4 and 7 times the resistivity of large grained bulk Au. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Light controlled spin properties and radiative coupling of CdSe based quantum dots
Authors: Schmidt T. , Worschech L. , Scheibner M. , Slobodskyy T. , Schmidt G. , Molenkamp L. W. , Passow T. , Hommel D. , Forchel A.
Published: July 2007

The authors have studied the photoluminescence of large and small ensembles of CdSe based quantum dots (QDs) in magnetic fields for different polarizations and powers of the exciting laser light. By means of polarization spectroscopy the g factors and spin lifetimes were determined for semimagnetic CdMnSe QDs with nominal Mn contents of 0%, 1% and 2%. Also the corresponding exciton lifetimes were analyzed. A sign reversal of the QD exciton g factor was identified comparing the polarization of QD luminescence with 0% and 2% Mn. For small excitation powers QDs with 1% Mn have a vanishing small value of g. Interestingly, by ramping up the excitation power of the exciting laser the exciton g factor increases by up to a factor of 30. Different heating mechanism were identified by characteristic power dependencies. For low excitation powers indirect heating of the spin systems occurs whereas above a critical power direct heating due to photoexcited carriers dominates. It is also demonstrated that in CdMnSe QDs the circular polarization of the luminescence can be inverted solely controlled by the laser power. Applying mesa techniques, collective radiance of QDs is demonstrated. For that purpose the radiative lifetimes of QDs with such a density that there are many dots within an area proportional to the square of the optical wavelength were studied for different numbers of QDs removed from that area. A comparison of photoluminescence decay times obtained for non‐resonant and quasi‐resonant excitation conditions and different mesa sizes is given. Radiative coupling of QDs takes place at least on the order of 150 nm. This length is comparable to the dimensions of lithographically well definable nanostructures and may therefore provide a mechanism to couple discrete quantum objects on a large scale. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of chemical treatment on the mechanical properties, water vapour permeability and sorption isotherms of gelatin‐based films
Authors: Carvalho R. A. , Grosso C. R. F. , Sobral P. J. A.
Published: July 2007

Proteins contain hydrophilic groups, which can bind to water molecules through hydrogen bridges, resulting in water vapour adsorption. An increase in the degree of cross‐linking can be a method to improve the cohesiveness force and functional properties of protein‐based films. Thus, the objective of this work was to evaluate the effect of chemical treatment of gelatin with formaldehyde and glyoxal on the mechanical properties, water vapour permeability (WVP) and water vapour sorption characteristics of gelatin‐based films. Films were produced using gelatin, with and without chemical treatment. The formaldehyde treatments caused a significant increase in the tensile strength and a reduction in the WVP of films. The Guggenheim‐Anderson‐De Boer and Halsey models could be used to model the sorption isotherms of films. It was observed that an increase in temperature produced a decrease in water sorption, and the chemical modifications did not affect the monolayer moisture content. Copyright © 2007 John Wiley & Sons, Ltd.
Paradigm lost, or is top-down forcing no longer significant in the Antarctic marine ecosystem?
Authors: Ainley David , Ballard Grant , Ackley Steve , Blight Louise K. , Eastman Joseph T. , Emslie Steven D. , Lescroël Amélie , Olmastroni Silvia , Townsend Susan E. , Tynan Cynthia T. , Wilson Peter , Woehler Eric
Published: July 2007

Investigations in recent years of the ecological structure and processes of the Southern Ocean have almost exclusively taken a bottom-up, forcing-by-physical-processes approach relating various species' population trends to climate change. Just 20 years ago, however, researchers focused on a broader set of hypotheses, in part formed around a paradigm positing interspecific interactions as central to structuring the ecosystem (forcing by biotic processes, top-down), and particularly on a “krill surplus” caused by the removal from the system of more than a million baleen whales. Since then, this latter idea has disappeared from favour with little debate. Moreover, it recently has been shown that concurrent with whaling there was a massive depletion of finfish in the Southern Ocean, a finding also ignored in deference to climate-related explanations of ecosystem change. We present two examples from the literature, one involving gelatinous organisms and the other involving penguins, in which climate has been used to explain species' population trends but which could better be explained by including species interactions in the modelling. We conclude by questioning the almost complete shift in paradigms that has occurred and discuss whether it is leading Southern Ocean marine ecological science in an instructive direction.
Intrathecal polymer-based interleukin-10 gene delivery for neuropathic pain
Authors: Milligan Erin D. , Soderquist Ryan G. , Malone Stephanie M. , Mahoney John H. , Hughes Travis S. , Langer Stephen J. , Sloane Evan M. , Maier Steven F. , Leinwand Leslie A. , Watkins Linda R. , Mahoney Melissa J.
Published: July 2007

Research on communication between glia and neurons has increased in the past decade. The onset of neuropathic pain, a major clinical problem that is not resolved by available therapeutics, involves activation of spinal cord glia through the release of proinflammatory cytokines in acute animal models of neuropathic pain. Here, we demonstrate for the first time that the spinal action of the proinflammatory cytokine, interleukin 1 (IL-1) is involved in maintaining persistent (2 months) allodynia induced by chronic-constriction injury (CCI). The anti-inflammatory cytokine IL-10 can suppress proinflammatory cytokines and spinal cord glial amplification of pain. Given that IL-1 is a key mediator of neuropathic pain, developing a clinically viable means of long-term delivery of IL-10 to the spinal cord is desirable. High doses of intrathecal IL-10-gene therapy using naked plasmid DNA (free pDNA-IL-10) is effective, but the dose required limits its potential clinical utility. Here we show that intrathecal gene therapy for neuropathic pain is improved sufficiently using two, distinct synthetic polymers, poly(lactic-co-glycolic) and polyethylenimine, that substantially lower doses of pDNA-IL-10 are effective. In conclusion, synthetic polymers used as i.t. gene-delivery systems are well-tolerated and improve the long-duration efficacy of pDNA-IL-10 gene therapy.
Autogenic response of alluvial‐bedrock transition to base‐level variation: Experiment and theory
Authors: Kim Wonsuck , Muto Tetsuji
Published: July 2007

Short‐term autogenic processes are thought to be averaged out by long‐term allogenic forcing and have often been ruled out in stratigraphic interpretation. It is generally difficult to resolve the scale of autogenic effects on landscape evolution and even more so on sedimentary records. Here we analyze short‐term variation in migration rate of the alluvial‐bedrock transition in a series of experiments. The experiments developed a fan delta over a stationary, sloped, nonerodible basement with constant water and sediment discharges. The rate of base‐level change varies between experiments but was constant for a given experiment. The location of the alluvial‐bedrock transition varied autogenically in all experiments. The instantaneous migration rate of the alluvial‐bedrock transition varied by as much as an order of magnitude more than that induced by allogenic forcing. The strong autogenic pulses can be explained by sediment storage and release due to intrinsic variation in the transport efficiency of the fluvial system. Data from experiments with base‐level change indicate that the autogenic signal in the migrating alluvial‐bedrock transition is weakest during landward migration (onlap), when base‐level rises, and strongest during basinward migration (valley incision), when base‐level falls. We use a one‐dimensional geometric model to explain the variations in the autogenic response of the alluvial‐bedrock transition as a function of direction of base‐level change. The model periodically changes fluvial slope to represent the effects of sediment storage and release with base‐level rise and fall. The modeling result reproduces the observed pattern of autogenic variation in alluvial‐bedrock transition.
Short‐term controls on the age of microbial carbon sources in boreal forest soils
Authors: Czimczik Claudia I. , Trumbore Susan E.
Published: July 2007

One predicted positive feedback of increasing temperatures in the boreal region is carbon (C) loss through enhanced microbial decomposition of soil organic matter (SOM). The degree to which temperature sensitivity for decomposition varies across a range of C‐substrates remains uncertain. Using incubations, we tested whether microorganisms shift to more recalcitrant substrates (with longer turnover times) at higher temperatures at low or increased soil moisture. We measured the radiocarbon (Δ14C) and stable isotope (δ13C) signature of CO2 respired from organic soils from six black spruce forests (0 to 150 years since fire). We identified major C substrates contributing to decomposition by comparing Δ14C of CO2 to Δ14C of roots, mosses, needles, and wood separated from bulk SOM. The Δ14C signatures of these components allow an estimation of their turnover times, further constraining their relative contribution to respiration. Fastest turnover rates were observed for herbaceous litter and needles (annual to decadal) for mosses, with intermediate turnover times for roots. Dominant microbial C sources in 5 to 40 year old stands were fire remnants and litter of early succession species, while substrates with longer turnover times accounted for a larger proportion of CO2 in mature stands. At both low and increased moisture levels, the increase in CO2 efflux at higher temperatures was accompanied by a decline in δ13CO2, but no shift in Δ14CO2. This suggests that temperature sensitivity is not greater for recalcitrant C and that changes in δ13C likely reflect temperature dependence of microbial fractionation processes rather than a substrate shift.
Reversed deep‐sea carbonate ion basin gradient during Paleocene‐Eocene thermal maximum
Authors: Zeebe Richard E. , Zachos James C.
Published: July 2007

The Paleocene‐Eocene thermal maximum (PETM, ∼55 Ma ago) was marked by widespread CaCO3 dissolution in deep‐sea sediments, a process that has been attributed to massive release of carbon into the ocean‐atmosphere system. The pattern of carbonate dissolution is key to reconstructing changes in deep sea carbonate chemistry and, ultimately, the rate, magnitude, and location of carbon input. Here we show that during the PETM, the deep‐sea undersaturation was not homogeneous among the different ocean basins. Application of a sediment model to a suite of data records from different sites and ocean basins shows that a globally uniform decrease in deep‐sea carbonate ion concentration ([CO32−]) is inconsistent with the data. Rather, we demonstrate that deep‐sea [CO32−] increased from the Atlantic through the Southern Ocean into the Pacific. Our results show that the PETM deep‐sea [CO32−] basin gradient during dissolution was reversed relative to the modern.
Chemical destruction of CH3I, C2H5I, 1‐C3H7I, and 2‐C3H7I in saltwater
Authors: Jones Charlotte E. , Carpenter Lucy J.
Published: July 2007

Destruction of volatile iodocarbons in the oceans can potentially play an important role in determining the predominant chemical forms of iodine emitted to the atmosphere. Here we report chlorination and hydrolysis removal rates for CH3I, C2H5I, 1‐C3H7I, and 2‐C3H7I relevant to oceanic conditions. We have used these rates to calculate oceanic lifetimes for each iodocarbon with respect to total chemical destruction, as a function of seawater temperature. The resulting lifetimes are compared to typical iodocarbon oceanic residence times with respect to volatilization to the MBL. The rate of destruction of 2‐C3H7I is much more rapid than chemical removal of the primary alkyl iodides, potentially explaining previous observations of lower 2‐C3H7I concentrations in seawater compared to 1‐C3H7I. Finally, in light of these results, we briefly discuss the potential impact of rising global seawater temperatures on oceanic iodocarbon concentrations.
Importance of small ice crystals to cirrus properties: Observations from the Tropical Warm Pool International Cloud Experiment (TWP‐ICE)
Authors: McFarquhar Greg M. , Um Junshik , Freer Matt , Baumgardner Darrel , Kok Gregory L. , Mace Gerald
Published: July 2007

During the Department of Energy Atmospheric Radiation Measurement Program (DOE ARM) sponsored Tropical Warm Pool International Cloud Experiment (TWP‐ICE), ice crystals with maximum dimensions (D) < 50 μm were measured in aged cirrus and fresh anvils by a Cloud and Aerosol Spectrometer (CAS) and a Cloud Droplet Probe (CDP). The CAS/CDP ratio of the number concentrations of droplets with 3 < D < 50 μm, N3−50, averaged 0.98 ± 0.69 in liquid clouds. However, N3−50, measured by the CAS averaged 91 ± 127 times larger than N3−50 from the CDP in ice clouds. The CAS/CDP N3−50 ratio had a correlation coefficient of 0.387 with the concentration of particles with D > 100 μm measured by the Cloud Imaging Probe, suggesting that ice crystals may have been shattering or bouncing on the CAS inlet or protruding airflow shroud enhancing N>3−50,CAS. During the Costa Rica Aura Validation Experiment N3−50,CAS measured by a CAS without an airflow shroud were an order of magnitude less than those observed during TWP‐ICE. This, and estimates of the maximum shattering based on the inlet and shroud sizes, suggest that the airflow shroud used during TWP‐ICE was responsible for much of the shattering or bouncing.
Effect of regional tectonic setting on local fault response to episodes of volcanic activity
Authors: Roman Diana C. , Heron Philip
Published: July 2007

In this study we examine the interaction of tectonic and volcanically‐generated stress fields, and their combined effect on patterns of volcanotectonic (VT) seismicity, by calculating Coulomb stress changes on local faults induced by a constant dike inflation event in a background stress field of systematically varying magnitude and orientation. We find that patterns of VT seismicity (earthquake locations and fault‐plane solutions) resulting from dike inflation depend strongly on the relative strength and orientation of background tectonic stresses. Patterns of VT seismicity similar to those predicted by our Coulomb stress models have been observed at several recently active volcanoes, and appear to correspond to the relative strength of the regional stress field. Thus, it is critical to consider the regional tectonic setting when interpreting patterns of VT seismicity in terms of magmatic processes.
Long‐term trend and decadal variability of the southward penetration of the East Australian Current
Authors: Ridgway K. R.
Published: July 2007

Observations from a long‐term ocean station off eastern Tasmania show that the southward penetration of the East Australian Current (EAC) has increased over the past 60 years. Changes in temperature and salinity are highly correlated at timescales greater than seasonal, with long‐term trends which differ markedly from global ocean values. The data show that the region has become both warmer and saltier with mean trends of 2.28°C/century and 0.34 psu/century over the 1944–2002 period which corresponds to a poleward advance of the EAC of ∼350‐km. These trends are not directly forced by global surface fluxes but primarily result from changes in the EAC. The summertime trends in temperature and salinity are greater than in winter – there is an augmented summer pulse of warm, high salinity subtropical water associated with the EAC.
Polar cap potential saturation: An energy conservation perspective
Authors: Liu W. William
Published: July 2007

In the long run, energy entering the magnetosphere from the solar wind must be balanced by energy dissipation in or escape from the system. It then follows that the Joule heating rate in the ionosphere statistically should be bounded from the upside by the solar wind energy input function (e.g., the Perrault‐Akasofu parameter). We show that this energy constraint, coupled with some observationally motivated assumptions about the behavior of the auroral oval under escalating solar wind conditions, leads to the prediction of polar cap potential saturation.
Type structure and chiral breaking in the standard model
Authors: Selesnick S. A.
Published: July 2007

In modern theories of computation, a significant role is played by the notions of type and typing, and many benefits accrue from careful attention to the ebb and flow of such structures through the course of a computation. We argue here that types are similarly inherent in quantum theory and that benefits may accrue from their careful handling—something that has apparently not been done in physics proper heretofore. In particular, we investigate the type structure of the interaction Lagrangians of the standard model and deduce the chiral symmetry breaking of the weak interaction as a simple and immediate consequence of the careful maintenance of this structure through the course of a possible computation of the appropriate term.
Shielding of N×M projectiles in a collisional, self-gravitating, generalized Lorentzian dusty plasma
Authors: Sarwar M. Adnan , Mirza Arshad M. , Qaisar M. S.
Published: July 2007

The shielding potential of N×M projectiles passing through a collisional, self-gravitating dust contaminated plasma is studied by mean of linearized dielectric theory for a generalized Lorentzian plasma. The correlation and interference effects of projectiles on the shielded potential as well as on the energy loss are presented. The amplitude of the shielded potential is enhanced with the increase of dust Jeans frequency for separation less than the effective Debye length. The dust charge fluctuations produce a potential well for slow charge relaxation rate and the energy is gained by the test charge projectiles. However, for fast charge relaxation rate with a fixed value of Jeans frequency, the energy loss is enhanced. The dust neutral collisions also enhance the energy loss for the test charge velocities greater than the dust acoustic speeds.
Shear flow over a rotating porous plate subjected to suction or blowing
Authors: Reza M. , Gupta A. S.
Published: July 2007

An analysis is made of the steady shear flow of an incompressible viscous fluid past a uniformly rotating infinite porous flat plate subjected to uniform suction or blowing. Inside the boundary layer, the pressure gradient dominates the momentum transfer of the outer shear flow. Therefore, the shear-induced component of the free-stream shear flow inside the boundary layer is less than its inviscid value. This results in flow reversal in the absence of suction. It is observed that the zone of reverse flow becomes smaller and smaller with an increase in suction, and when the suction parameter exceeds a certain critical value, no reverse flow occurs at all. The axial velocity toward the plate increases with an increase in suction but decreases with an increase in blowing. It turns out that a torque is exerted in a direction opposite to the direction of rotation of the plate, and the magnitude of the torque is an increasing function of suction. Further, this torque is not influenced by the shear in the external flow. The drag on the plate in the direction of free stream shear flow is always positive when the suction at the plate exceeds a certain critical value. However, in the case of blowing at the plate, this drag may be opposite to the direction of external flow for sufficiently high shear.
Fabrication of combinatorial polymer scaffold libraries
Authors: Simon Carl G. , Stephens Jean S. , Dorsey Shauna M. , Becker Matthew L.
Published: July 2007

We have designed a novel combinatorial research platform to help accelerate tissue engineering research. Combinatorial methods combine many samples into a single specimen to enable accelerated experimentation and discovery. The platform for fabricating combinatorial polymer scaffold libraries can be used to rapidly identify scaffold formulations that maximize tissue formation. Many approaches for screening cell-biomaterial interactions utilize a two-dimensional format such as a film or surface to present test substrates to cells. However, cells in vivo exist in a three-dimensional milieu of extracellular matrix and cells in vitro behave more naturally when cultured in a three-dimensional environment than when cultured on a two-dimensional surface. Thus, we have designed a method for fabricating combinatorial biomaterial libraries where the materials are presented to cells in the form of three-dimensional, porous, salt-leached, polymer scaffolds. Many scaffold variations and compositions can be screened in a single experiment so that optimal scaffold formulations for tissue formation can be rapidly identified. In summary, we have developed a platform technology for fabricating combinatorial polymer scaffold libraries that can be used to screen cell response to materials in a three-dimensional, scaffold format.
Theoretical studies on the structures, properties, and aromaticity of germatropylium cations
Authors: Ghiasi Reza
Published: July 2007

The electronic structures and properties of the germatropylium cation series have been investigated using basis set 6–31G (d,p) and hybrid density functional theory. Basic measurements of aromatic character derived from structure, molecular orbitals and a variety of magnetic criteria (magnetic isotropic, anisotropic susceptibilities, and nucleus-independent chemical shift) are considered. Energetic criteria suggest that Ge12, Ge123, C123, and C12 enjoy conspicuous stability. Also, by magnetic criteria: Χiso, Χaniso and NICS, these systems are among the most aromatic of the family. NICS criteria and the presence of (4n + 2) π electrons confirm that these compounds exhibit aromatic characteristics.
Bilateral Cochlear Implantation: An Evidence‐Based Medicine Evaluation
Authors: Murphy John , O'Donoghue Gerard
Published: July 2007

Objectives/Hypothesis: The aim of this study was to evaluate the extent and quality of evidence reported on the outcomes of bilateral cochlear implantation and thereby to inform opinion about future patient management.

Study Design: Retrospective literature review.

Methods: A detailed search of the medical literature was performed using the Medline, Embase, and CINAHL databases starting from the date of their conception. The quality of evidence in each article was assessed according to the categories of evidence as defined by the Oxford Centre for Evidence‐based Medicine, Levels of Evidence (May 2001).

Results: A total of 37 studies were included; 28 (76%) investigated adult participants only, 7 (19%) investigated child participants, and 2 (5%) contained both groups. Of the studies presented, 9 (24%) studies contained level 2b evidence, 2 (6%) level 3b, 16 (43%) level 4, and 10 (27%) level 5 evidence. No studies were identified as representing evidence level 1. Adult bilateral recipients demonstrated an increase in sentence recognition of 21% correct over their first implanted ear (P < .001) and mean bilateral localization errors of 24° against a monaural error of 67° (P < .005).

Conclusions: The available evidence indicates that bilateral cochlear implantation confers material benefits not achievable with unilateral implantation, specifically in terms of sound localization and understanding of speech in noise. Well‐designed prospective studies of sufficient size are now needed to precisely quantify these benefits, to validate outcome measures, especially in children, and to define the criteria for intervention.
Effects of Purinergic Stimulation on Ciliary Beat Frequency and Chloride Secretion in Sinusitis
Authors: Kim In‐Sang , Rhee Chae‐Seo , Lee Jun Ho , Heo Jeong‐Hwa , Park Jerry , Lee Chul Hee
Published: July 2007

Objectives: We aimed to identify the functional abnormality of sinusitis‐affected mucosa by observing the responsiveness of the mucosa to purinergic stimulation after the onset of sinusitis and during the recovery period. We also aimed to identify possible beneficial effects of purinergic agonists on sinusitis.

Methods: A rabbit sinusitis model was developed by blocking maxillary ostia. Sinus mucosae were harvested immediately and 1 and 4 weeks after reopening the ostia. We measured chloride secretion and ciliary beat frequencies responding to purinergic stimulation.

Results: The increases of ciliary beat frequency by adenosine triphosphate (100 μmol/L) were 3.2% ± 8.5%, 7.9% ± 2.3%, and 12.2% ± 1.9% immediately after establishment of sinusitis and 1 week and 4 weeks after reopening of ostia, respectively. Chloride secretion stimulated by adenosine triphosphate also showed gradual increase during the recovery period. Grossly, the mucosae appeared to have normalized in 80% (4 of 5) after 4 weeks; however, functional and microscopic improvements were still incomplete.

Conclusions: Mucosal functions, assessed by increase of ciliary activity and ion secretion by purinergic stimulation, and microscopic findings showed gradual but incomplete recovery after 4 weeks of recovery, in contrast to the gross normalization. Purinergic agonists may have beneficial effects on sinusitis by stimulating decreased ciliary motility and chloride secretion in sinusitis.
Life Threatening Hemorrhage From Osteoradionecrosis of the Ribs and Clavicle
Authors: Syed Mohammed Iqbal , Clark Louise J. , Adams Calum
Published: July 2007

Osteoradionecrosis (ORN) is a familiar complication of radiotherapy. ORN of the clavicle and ribs is well documented after radiation therapy for breast and pulmonary malignancy. ORN of the clavicle after radiation therapy to the neck is very rare. We report the first case in which both clavicles and first ribs underwent ORN 14 years after neck irradiation and surgery for laryngeal malignancy. The presentation was atypical; erosion of the right internal mammary artery causing life‐threatening hemorrhage. Otolaryngologists should be aware that ORN can occur at an unusual site and can have an atypical presentation.
Improving the Design of the Pedicled Nasoseptal Flap for Skull Base Reconstruction: A Radioanatomic Study
Authors: Pinheiro‐Neto Carlos Diogenes , Prevedello Daniel M. , Carrau Ricardo L. , Snyderman Carl H. , Mintz Arlan , Gardner Paul , Kassam Amin
Published: July 2007

Background: Reconstruction of the skull base after an expanded endonasal approach (EEA) is critical to achieve a good outcome. A novel technique based on the use of a pedicled nasoseptal flap has proven to be a reliable and versatile reconstructive option for extensive defects of the skull base. Data regarding the potential dimensions of a nasoseptal flap are lacking in the literature. This pilot study was developed to help optimize the design of the nasoseptal flap and to ensure that when harvesting the flap, its width and length are adequate to reconstruct the defects that are created by various EEAs.

Methods: We analyzed the computed tomographic (CT) scans of four patients who underwent EEAs for skull base lesions. Sagittal and coronal CT reconstructions were generated from axial images. The measurements were divided into skull base measurements, flap dimensions required to cover skull base defects resulting from various EEAs, and potential maximal dimensions of the nasoseptal flap. Measurements were studied for three different EEAs: sellar/transplanar, transclival, and transcribiform/anterior skull base. We measured the potential defects for each of these EEAs and the nasoseptal flap dimensions that would be required to reconstruct them. We estimated all dimensions based on the most extensive defect that could result with each EEA. We then compared these with various modifications of the nasoseptal flap.

Results: Two male and two female patients were studied. Twenty‐seven measurements were taken to compare the different skull base defects and nasoseptal flaps.

Conclusions: The length of the nasal septum comprises sufficient mucoperichondrium and mucoperiosteum to allow the harvesting of a nasoseptal flap that could cover any defect resulting from an anterior skull base, a transsellar/transplanar, or a transclival EEA. Similarly, the height of the nasal septum has the potential to yield a nasoseptal flap with a width that is adequate to cover the laterolateral aspect of any defect of the anterior skull base and clivus. Skull base defects resulting from combined EEAs, such as those that would create a defect that comprises the skull base from sella turcica to frontal sinus, are beyond the potential dimensions of a single nasoseptal flap. This and other defects resulting from a combination of EEAs require other strategies, such as the use of bilateral nasoseptal flaps, or the use of other reconstructive options.
Facial Dismasking Flap for Removal of Tumors in the Craniofacial Region
Authors: Koda Hiroko , Tsunoda Atsunobu , Iida Hideo , Akita Keiichi , Kishimoto Seiji
Published: July 2007

Objective: This study was aimed at estimating the usefulness of the facial dismasking flap for craniofacial surgery.

Study Design: Anatomical study and retrospective case study.

Materials and Methods: The facial dismasking flap is a combination of a coronal skin incision and a circumpalpebral incision. By adding a circumpalpebral incision, the skin can be detached from the orbital structures and the coronal skin flap can be elevated more inferiorly together with the facial nerves and muscles. We retrospectively reviewed patients who underwent the facial dismasking flap with regard to the extent of the surgical field and resectability under this flap. Postoperative facial scarring and movements were also evaluated. Facial palsy was estimated according to the House‐Brackmann grading system.

Result: Twenty‐three patients with tumors in various locations, such as, the nasal cavity, paranasal sinus, zygoma, and infratemporal fossa, who had undergone a facial dismasking flap, were studied. Sufficient surgical fields were obtained for removal of the tumor in all patients. Tumors were totally resected in 21 patients and were subtotally resected in two patients to avoid optic nerve damage. Facial nerves were anatomically preserved and facial scarring was minimal in all patients. No facial palsy remained in any patients except one who showed a deterioration of the facial palsy (House‐Brackmann grade V–VI).

Conclusion: This flap allows the surgeon to obtain wide exposure of the upper two‐thirds of the facial skull. Moreover, damage to the facial skin is minimal and facial movements are well preserved. This technique is not well known to head and neck surgeons, and this is the first comprehensive report of this technique applied to removal of craniofacial lesions.
Extremely fast prey capture in pipefish is powered by elastic recoil
Authors: Van Wassenbergh Sam , Strother James A , Flammang Brooke E , Ferry-Graham Lara A , Aerts Peter
Published: July 2007

The exceptionally high speed at which syngnathid fishes are able to rotate their snout towards prey and capture it by suction is potentially caused by a catapult mechanism in which the energy previously stored in deformed elastic elements is suddenly released. According to this hypothesis, tension is built up in tendons of the post-cranial muscles before prey capture is initiated. Next, an abrupt elastic recoil generates high-speed dorsal rotation of the head and snout, rapidly bringing the mouth close to the prey, thus enabling the pipefish to be close enough to engulf the prey by suction. However, no experimental evidence exists for such a mechanism of mechanical power amplification during feeding in these fishes. To test this hypothesis, inverse dynamical modelling based upon kinematic data from high-speed videos of prey capture in bay pipefishSyngnathus leptorhynchus, as well as electromyography of the muscle responsible for head rotation (the epaxial muscle) was performed. The remarkably high instantaneous muscle-mass-specific power requirement calculated for the initial phase of head rotation (up to 5795 W  kg−1), as well as the early onset times of epaxial muscle activity (often observed more than 300 ms before the first externally discernible prey capture motion), support the elastic power enhancement hypothesis.
RGS10-null mutation impairs osteoclast differentiation resulting from the loss of [Ca2+]i oscillation regulation
Authors: Yang Shuying , Li Yi-Ping
Published: July 2007

Increased osteoclastic resorption leads to many bone diseases, including osteoporosis and rheumatoid arthritis. While rapid progress has been made in characterizing osteoclast differentiation signaling pathways, how receptor activator of nuclear factor κB (NF-κB) ligand (RANKL) evokes essential [Ca2+]i oscillation signaling remains unknown. Here, we characterized RANKL-induced signaling proteins and found regulator of G-protein signaling 10 (RGS10) is predominantly expressed in osteoclasts. We generated RGS10-deficient (RGS10−/−) mice that exhibited severe osteopetrosis and impaired osteoclast differentiation. Our data demonstrated that ectopic expression of RGS10 dramatically increased the sensitivity of osteoclast differentiation to RANKL signaling; the deficiency of RGS10 resulted in the absence of [Ca2+]i oscillations and loss of NFATc1; ectopic NFATc1 expression rescues impaired osteoclast differentiation from deletion of RGS10; phosphatidylinositol 3,4,5-trisphosphate (PIP3) is essential to PLCγ activation; and RGS10 competitively interacts with Ca2+/calmodulin and PIP3 in a [Ca2+]i-dependent manner to mediate PLCγ activation and [Ca2+]i oscillations. Our results revealed a mechanism through which RGS10 specifically regulates the RANKL-evoked RGS10/calmodulin–[Ca2+]i oscillation–calcineurin–NFATc1 signaling pathway in osteoclast differentiation using an in vivo model. RGS10 provides a potential therapeutic target for the treatment of bone diseases.
Reliability of the ‘pop’ sign as an indicator of dural puncture during obstetric spinal anaesthesia: a prospective observational clinical study*
Authors: Kathirgamanathan A. , Hawkins N.
Published: July 2007

Anaesthetists rely upon a loss of resistance and flow of cerebrospinal fluid to indicate when a spinal needle has breached the dura. The loss of resistance is not always felt, with the danger that the needle may be advanced into neurological tissue. One hundred women undergoing elective caesarean section were recruited and spinal anaesthesia, using a 27‐G Whitacre needle, was performed using an incremental advancement technique. After each advancement of the needle, and before removing the stylet, it was recorded whether the anaesthetist had perceived any sign that the dura had been breached, and then whether cerebrospinal fluid had been obtained. Six patients were not included in the study due to technical difficulties. In 27 of 94 patients (29%) there was no clear tactile sign that the dura had been breached when cerebrospinal fluid was obtained. This study demonstrates that loss of resistance is not always felt when a 27‐G spinal needle breaches the dura in the pregnant woman.
Remifentanil for tracheal tube tolerance: a case control study*
Authors: Machata A. M. , Illievich U. M. , Gustorff B. , Gonano C. , Fäßler K. , Spiss C. K.
Published: July 2007

We assessed the minimal remifentanil dosage required for tracheal tube tolerance in awake and spontaneously breathing patients after major abdominal surgery. Forty postoperative patients received remifentanil 0.1 μg.kg−1.min−1, which was reduced in steps of 0.025 μg.kg−1.min−1 every 30 min. Respiratory response subscore of comfort scale (CSRR), Ramsay sedation scale (RSS), visual analogue scale (VAS), respiratory rate, and minute ventilation were recorded. Spontaneous respiration with no or little response to ventilation (CSRR 2) in co‐operative, oriented and tranquil patients (RSS 2) was defined as the main outcome and study endpoint. Thirty‐one patients (77.5%) reached a CSRR 2 and RSS 2 with remifentanil 0.025 μg.kg−1.min−1 and nine patients (22.5%) required remifentanil 0.05 μg.kg−1.min−1. Analgesia was sufficient in all patients (VAS = 30). Remifentanil 0.025−0.05 μg.kg−1.min−1 achieves satisfactory tracheal tube tolerance in awake and spontaneously breathing patients.
Profound vasodilatory hypotension in a patient with known empty sella syndrome following cardiac surgery
Authors: Lamont S. N. J. , McBride W. T. , Bill K. M. , Varadarajan B.
Published: July 2007

A 63‐year‐old female with known empty sella syndrome underwent coronary artery bypass grafting surgery. She became hypotensive immediately postoperatively and this did not respond to fluid resuscitation and inotropic therapy. Surgical re‐exploration was undertaken and did not reveal any surgical cause. Pulmonary artery catheterisation confirmed a profound vasodilatory component to her shock. We believe this was due to unmasking of posterior pituitary hypofunction, in particular vasopressin insufficiency, due to metabolic stress. This rapidly corrected with an exogenous vasopressin infusion.
Beriplex P/N: an alternative to fresh frozen plasma in severe haemorrhage
Authors: Bhardwaj M. , Bunsell R.
Published: July 2007

The management of Jehovah's Witnesses suffering from severe haemorrhage can be very difficult. Those patients who are taking oral anticoagulant therapy pose an additional risk and the difficulty may be compounded by the development of coagulopathy. Several alternatives to blood products have been reported to be useful in this situation. We report the successful management of an emergency postsurgical wound bleeding in a Jehovah's Witness using Beriplex (a concentrate of factors II, VII, IX and X). The patient, who was taking warfarin, presented 10 days after an elective laminectomy with significant bleeding from the surgical wound and coagulopathy. Despite early surgical measures, there was continuing haemorrhage. This was arrested by giving Beriplex intra‐operatively. To our knowledge this is the first reported case of the use of Beriplex in a Jehovah's Witness for control of emergency haemorrhage and coagulopathy.
A comparison of the laryngeal mask airway with facemask and oropharyngeal airway for manual ventilation by critical care nurses in children*
Authors: Rechner J. A. , Loach V. J. , Ali M. T. , Barber V. S. , Young J. D. , Mason D. G.
Published: July 2007

The laryngeal mask airway is included as a first line airway device during adult resuscitation by first responders. However, there is little evidence for its role in paediatric resuscitation. Using anaesthetised children as a model for paediatric cardiopulmonary arrest, we compared the ability of critical care nurses to manually ventilate the anaesthetised child via the laryngeal mask airway compared with the facemask and oropharyngeal airway. The airway devices were inserted in random order and chest expansion was measured using an ultrasound distance transducer. The critical care nurses were able to place the laryngeal mask airway and achieve successful ventilation in 82% of children compared to 70% using the facemask and oropharyngeal airway, although the difference was not statistically significant (p = 0.136). The median time to first successful breath using the laryngeal mask airway was 39 s compared to 25 s using the facemask (p < 0.001). In this group of nurses, we did not show a difference in ventilation via a laryngeal mask airway or facemask, although facemask ventilation was achieved more quickly.
Acute lung injury probably associated with infusion of propofol emulsion
Authors: Chondrogiannis K. D. , Siontis G. C. M. , Koulouras V. P. , Lekka M. E. , Nakos G.
Published: July 2007

We present a case of acute lung injury associated with propofol infusion in a mechanically ventilated patient with intracerebral haemorrhage. Diagnosis was based on the exclusion of other risk factors inducing acute lung injury and on the clinical improvement after discontinuation of the propofol emulsion. Laboratory data such as the increase in total phospholipids, neutral lipids and free fatty acids in the broncho‐alveolar lavage fluid, the remarkably high percentage of alveolar macrophages including fat droplets and the similar lipid composition of propofol and broncho‐alveolar lavage fluid support the relationship between propofol and acute lung injury.
A comparison of the Truview®blade with the Macintosh blade in adult patients
Authors: Barak M. , Philipchuck P. , Abecassis P. , Katz Y.
Published: July 2007

The Truview®blade facilitates a view of the vocal cords by indirect laryngoscopy. We prospectively compared the view obtained at laryngoscopy and intubating conditions of Truview (Group 1) or Macintosh (Group 2) blades in 170 patients who were scheduled to undergo general anaesthesia. We studied pre‐operative airway evaluation, laryngoscopic view, duration of intubation, maximal force applied during intubation, anaesthetist's estimation of intubation effort on a 1–3 scale, bleeding, teeth and soft tissue damage, and postoperative stridor and hoarseness. The results demonstrated that, whilst the Truview produced a better laryngoscopic view and less maximal force applied during intubation, the duration of intubation was longer. No significant difference was found in the anaesthetist's estimation of intubation effort, tooth damage or postoperative stridor and hoarseness. Significantly fewer patients suffered bleeding and soft tissue damage following intubation with the Truview than with the Macintosh blade. The Truview blade is a useful option for tracheal intubation in patients with normal and anticipated difficult airways.
Zygosity at the major histocompatibility class IIB locus predicts susceptibility to Renibacterium salmoninarum in Atlantic salmon (Salmo salar L.)
Authors: Turner S. M. , Faisal M. , DeWoody J. A.
Published: July 2007

Major histocompatibility (MH) class II genes play an important role in the vertebrate immune response. Here, we investigate the relationship between Atlantic salmon (Salmo salar) MH class IIB zygosity and susceptibility to Renibacterium salmoninarum, the causal agent of bacterial kidney disease. By combining DNA sequences from the salmon MH class IIB gene with quantitative ELISA data on R. salmoninarum antigen levels, we found that MH class IIB homozygotes were significantly more susceptible to R. salmoninarum than heterozygotes. These findings are discussed in the context of current evolutionary theory.
Biogeographic area relationships in southern New Zealand: a cladistic analysis of Lepidoptera distributions
Authors: Emerson Brent C. , Wallis Graham P. , Patrick Brian H.
Published: July 2007

ABSTRACT. Recently, attention has been directed toward the application of cladistic techniques to reconstruct the history of areas from species distribution data. In this study, hypotheses of area relationships for southern New Zealand are generated from lepidopteran distribution data analysed at two taxonomic levels. Data are shown to possess cladistic structure and area relationships presented here are consistent with the geological history of the southern region of New Zealand. Our results suggest a recolonization of inland lowland regions from the south following a period of extinction during the early Pliocene. Analysis of selected data including only flightless or locally endemic species resulted in little resolution of area relationships but topologies were significantly congruent with a total species dataset. Hypotheses generated from this study are open to testing with congruence analysis using independent species phylogenies.