bluuebunny/crossref_metadata_2025 huggingface dataset:
Gas‐Phase Watson–Crick and Hoogsteen Isomers of the Nucleobase Mimic 9‐Methyladenine⋅2‐Pyridone
Authors: Frey Jann A. , Leist Roman , Müller Andreas , Leutwyler Samuel
Published: June 2006

2‐Pyridone (pyridin‐2‐one) is a mimic of the uracil and thymine nucleobases, with only one NH and CO group. It provides a single H‐bonding site, compared to three for the canonical pyrimidine nucleobases. Employing the supersonically cooled 9‐methyladenine⋅2‐pyridone (9MAd⋅2PY) complex, which is the simplest base pair to mimic adenine‐uracil or adenine‐thymine, we show that its gas‐phase UV spectrum consists of contributions from two isomers. Based on the H‐bonding sites of 9‐methyladenine, these are the Watson–Crick and Hoogsteen forms. Combining two‐color two‐photon ionisation (2C‐R2PI), UV‐UV depletion and laser‐induced fluorescence spectroscopies allows separation of the two band systems, revealing characteristic intermolecular in‐plane vibrations of the two isomers. The calculated S0 and S1 intermolecular frequencies are in good agreement with the experimental ones. Ab initio calculations predict the Watson–Crick isomer to be slightly more stable (D0=−16.0 kcal mol−1) than the Hoogsteen isomer (D0=−15.0 kcal mol−1). The calculated free energies ΔfG0 of the Watson–Crick and Hoogsteen isomers agree qualitatively with the experimental isomer concentration ratio of 3:1.
First‐Principles Simulation of the Photoreaction of a Capped Azobenzene: The Rotational Pathway is Feasible
Authors: Nonnenberg Christel , Gaub Hermann , Frank Irmgard
Published: June 2006

We present first‐principles molecular dynamics simulations of azobenzene and a sterically hindered derivative in the first excited state. The restricted open‐shell Kohn–Sham (ROKS) approach is employed to describe the motion in the lowest excited state. The rotational pathway is observed in the molecular dynamics simulations for both azobenzene and its azacrown ether capped derivative.
How Reaction Kinetics with Time‐Dependent Rate Coefficients Differs from Generalized Mass Action
Authors: Grima Ramon , Schnell Santiago
Published: June 2006

Take caution! The two distinct theoretical descriptions of non‐classical kinetics: fractal‐like kinetics (kinetics with time‐dependent rate coefficients) and the power law approximation (generalized mass action kinetics) are shown to be equivalent only for simple reactions of the type A+A→ø or A+B→ø with equal initial concentrations of A and B. In all other cases they are not the same.
Theoretical Characterization of the Gas‐Phase O3⋅⋅⋅HO Hydrogen‐Bonded Complex
Authors: Mansergas Alex , Anglada Josep M.
Published: June 2006

We report a theoretical study on two gas‐phase hydrogen‐bonded complexes formed between ozone and hydroxyl radical that have relevance to atmospheric chemistry. This study was carried out by using CASSCF, CASPT2, QCISD, and CCSD(T) theoretical approaches in conjunction with the 6‐311+G(2df,2p) and aug‐cc‐pVTZ basis sets. Both complexes have a planar structure and differ from each other in the orientation of the electronic density of the unpaired electron associated with the HO radical moiety. Our calculations predict their stabilities to be 0.87 and 0.67 kcal mol−1, respectively, at 0 K and show the importance of anharmonic effects in computing the red shift of the HO stretch originating from the hydrogen‐bonding interaction. We also report two transition states involving the movement of the HO moiety on the potential energy surfaces of these hydrogen‐bonded complexes.
Hydrology and dynamics of a polythermal (mostly cold) High Arctic glacier
Authors: Bingham Robert G. , Nienow Peter W. , Sharp Martin J. , Copland Luke
Published: June 2006

To improve our understanding of the interactions between hydrology and dynamics in mostly cold glaciers (in which water flow is limited by thermal regime), we analyse short‐term (every two days) variations in glacier flow in the ablation zone of polythermal John Evans Glacier, High Arctic Canada. We monitor the spatial and temporal propagation of high‐velocity events, and examine their impacts upon supraglacial drainage processes and evolving subglacial drainage system structure. Each year, in response to the rapid establishment of supraglacial–subglacial drainage connections in the mid‐ablation zone, a ‘spring event’ of high horizontal surface velocities and high residual vertical motion propagates downglacier over two to four days from the mid‐ablation zone to the terminus. Subsequently, horizontal velocities fall relative to the spring event but remain higher than over winter, reflecting channelization of subglacial drainage but continued supraglacial meltwater forcing. Further transient high‐velocity events occur later in each melt season in response to melt‐induced rising supraglacial meltwater inputs to the glacier bed, but the dynamic response of the glacier contrasts with that recorded during the spring event, with the degree of spatial propagation a function of the degree to which the subglacial drainage system has become channelized. Copyright © 2006 John Wiley & Sons, Ltd.
Brachiopod diversity patterns from Carboniferous to Triassic in South China
Authors: Shen Shu‐Zhong , Zhang Hua , LI Wen‐Zhong , Mu Lin , Xie Jun‐Fang
Published: June 2006

It has long been recognized that the trend of marine diversity from the Carboniferous to the Triassic includes an approximately 100‐myr‐long stable biodiversity stage ranging from the Late Carboniferous to the late Middle Permian, the most severe end‐Permian mass extinction in the Phanerozoic (pre‐Lopingian crisis and end‐Changhsingian mass extinction together), a bleak stage in the Early Triassic and a rapid recovery stage in the Middle Triassic. However, little attention has been paid to smaller diversity fluctuations among relatively stable stages in the Carboniferous and Permian. Here, we establish a database of the brachiopod fossil records from the Carboniferous to Triassic in South China, including 104 families, 373 genera, 2081 species recorded by 7948 occurrences with relatively detailed biostratigraphic controls. Analyses based on the raw taxonomic richness at familial, generic and specific levels, proportional and total extinction/origination/turnover rates, and rarefaction analyses for 21 different intervals from the Carboniferous to Triassic reveal that the brachiopod diversity trends can be generally divided into two distinctly different stages. Brachiopods were highly diversified during the Carboniferous and Permian Periods, whereas they were dramatically reduced in diversity after the end‐Changhsingian mass extinction. Brachiopods were abundant during the Early Carboniferous Tournaisian and Viséan, and were characterized by many genera extending from the Late Devonian. This was followed by a significant simple diversity decline in the Serpukhovian Stage. The Early Permian (either in Sakmarian or Artinskian) diversity decline previously perceived by coral and fusulinid workers is indicated by the raw generic and familial richness, and taxonomic richness per million years. However, it is not expressed by the rarefied brachiopod trajectory, which is probably affected by sampling effect or taxonomic selectivity. Brachiopods apparently declined from Capitanian to Early Wuchiapingian. Thus, the brachiopod diversity trajectory from Pennsylvanian Bashkirian to Late Guadalupian Capitanian generally characterises a long stable stage. Brachiopods are extremely abundant in the Late Wuchiapingian and Changhsingian in view of raw taxonomic richness, but a rarefied trajectory reveals a flat step following the pre‐Lopingian (end‐Guadalupian) crisis until the end‐Changhsingian mass extinction. Therefore, the previously widely perceived Lopingian radiation after the pre‐Lopingian crisis appears to be at least partly over‐stated. Brachiopods experienced a long bleak stage in the Early Triassic, followed by a rapid recovery in the Anisian, and reached their acme in the Norian, but never recovered to such a flourishing degree during the Carboniferous and Permian Periods. Brachiopods were eliminated in South China by the end‐Triassic withdrawal of the sea from this region. Copyright © 2006 John Wiley & Sons, Ltd.
Effect of syntactic similarity on cortical activation during second language processing: A comparison of English and Japanese among native Korean trilinguals
Authors: Jeong Hyeonjeong , Sugiura Motoaki , Sassa Yuko , Haji Tomoki , Usui Nobuo , Taira Masato , Horie Kaoru , Sato Shigeru , Kawashima Ryuta
Published: June 2006

In this study of native Korean trilinguals we examined the effect of syntactic similarity between first (L1) and second (L2) languages on cortical activation during the processing of Japanese and English, which are, respectively, very similar to and different from Korean. Subjects had equivalent proficiency in Japanese and English. They performed auditory sentence comprehension tasks in Korean, Japanese, and English during functional MRI (fMRI). The bilateral superior temporal cortex was activated during the comprehension of three languages. The pars triangularis of the left inferior frontal gyrus (IFG) was additionally activated for L2 processing. Furthermore, the right cerebellum, the pars opercularis of the left IFG, and the posteriomedial part of the superior frontal gyrus were activated during the English tasks only. We observed significantly greater activation in the pars opercularis of the left IFG, the right cerebellum, and the right superior temporal cortex during the English than Japanese task; activation in these regions did not differ significantly between Korean and Japanese. Differential activation of the pars opercularis of the left IFG and the right cerebellum likely reflects syntactic distance and differential activation in the right superior temporal cortex may reflect the prosodic distance between English from Korean and Japanese. Furthermore, in the pars oparcularis of the left IFG and the right cerebellum, significant negative correlation between the activation and duration of exposure was observed for English, but not for Japanese. Our research supports the notion that linguistic similarity between L1 and L2 affects the cortical processing of second language. Hum Brain Mapp, 2007. © 2006 Wiley‐Liss, Inc.
Influence of body segment position during in‐phase and antiphase hand and foot movements: A kinematic and functional MRI study
Authors: Rocca Maria A. , Gatti Roberto , Agosta Federica , Tortorella Paola , Riboldi Elisa , Broglia Paola , Filippi Massimo
Published: June 2006

Behavioral studies have provided important insights into the mechanisms governing interlimb coordination. In this study, we combined kinematic and functional magnetic resonance imaging (fMRI) analysis to investigate the brain cortical and subcortical areas involved in interlimb coordination and the influence of direction of movement and of body segment position on the activity of those areas. Fifteen right‐handed healthy subjects were studied while performing cyclic in‐phase and antiphase hand and foot movements with the dominant, right limbs, with the upper limb positioned either prone or supine, and in front or behind with respect to the trunk. When contrasting antiphase to in‐phase movements, fMRI analysis demonstrated an increased recruitment of a widespread sensorimotor network (including regions in the frontal and parietal lobes, bilaterally, the cingulated motor area, the thalami, the visual cortex, and the cerebellum) considered to function in motor, sensory, and multimodal integration processing. When contrasting the anterior to the posterior position of the upper limb with respect to the trunk, we found different recruitment patterns in the frontal and parietal regions as well as the preferential recruitment of the basal ganglia, the insula, and the cerebellum during the first condition and of regions located in the temporal lobes during the second one. Different brain areas are engaged at a different extent during interlimb coordination. In addition to the relative difficulty of the movement, the different cognitive and sensorial loads needed to control and perform the motor act might be responsible for these findings. Hum Brain Mapp, 2007. © 2006 Wiley‐Liss, Inc.
Influence of Nitinol wire surface treatment on oxide thickness and composition and its subsequent effect on corrosion resistance and nickel ion release
Authors: Clarke B. , Carroll W. , Rochev Y. , Hynes M. , Bradley D. , Plumley D.
Published: June 2006

Medical implants and devices are now used successfully in surgical procedures on a daily basis. Alloys of nickel and titanium, and in particular Nitinol are of special interest in the medical device industry, because of their shape memory and superelastic properties. The corrosion behavior of nitinol in the body is also of critical importance because of the known toxicological effects of nickel. The stability of a NiTi alloy in the physiological environment is dependant primarily on the properties of the mostly TiO2 oxide layer that is present on the surface. For the present study, a range of nitinol wires have been prepared using different drawing processes and a range of surface preparation procedures. It is clear from the results obtained that the wire samples with very thick oxides also contain a high nickel content in the oxide layer. The untreated samples with the thicker oxides show the lowest pitting potential values and greater nickel release in both long and short‐term experiments. It was also found that after long‐term immersion tests breakdown potentials increased for samples that exhibited lower values initially. From these results it would appear that surface treatment is essential for the optimum bioperformance of nitinol. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Synthesis of silk fibroin‐insulin bioconjugates and their characterization and activities in vivo
Authors: Zhang Yu‐Qing , Ma Yan , Xia Yun‐Yue , Shen Wei‐De , Mao Jian‐Ping , Zha Xin‐Min , Shirai Koji , Kiguchi Kenji
Published: June 2006

The regenerated liquid silk fibroin with an average molecular mass of about 60 kDa consists of 18 kinds of amino acids containing ∼10% of polar amino acids with hydroxyl and amino groups such as serine and lysine. The liquid silk fibroin is coupled covalently with insulin molecules through these strongly polar side groups by using glutaraldehyde. The physicochemical properties of the silk fibroin‐insulin (SF‐Ins) bioconjugates were investigated by enzyme‐linked immunosorbent assay for the quantitative measurement of insulin. The biological activities of the insulin bioconjugates were characterized in vitro and in vivo. The SF‐Ins constructs obtained by 5 h of covalent crosslinking showed much higher recovery (about 70%) and in vitro stability in human serum than bovine serum albumin‐insulin (BSA‐Ins) derivatives. The results in human serum indicated that the half‐life in vitro of the biosynthesized SF‐Ins derivatives was 2.1 and 1.7 times more than that of BSA‐Ins conjugates and native insulin, respectively. The immunogenicity of the regenerated silk fibroin and the antigenicity of silk fibroin‐modified insulin were not observed in both rabbits and rats. The pharmacological activity of the SF‐Ins bioconjugates in diabetic rats evidently lengthened and was about 3.5 times as long as that of the native insulin, nearly 21 h. The bioconjugation of insulin with the regenerated silk fibroin greatly improved its physicochemical and biological stability. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
Community‐acquired pneumonia: A practical approach to management for the hospitalist
Authors: Sharpe Bradley A. , Flanders Scott A.
Published: June 2006

Community‐acquired pneumonia (CAP) is common, and inpatient physicians should be familiar with the most current evidence about and guidelines for CAP management. Our conclusions and recommendations include: Streptococcus pneumoniae is the most common identified cause of CAP requiring hospitalization, whereas Legionella pneumophila is a common cause of severe CAP. The chest radiograph remains an essential initial test in the diagnosis of CAP and should be supplemented by blood cultures sampled prior to antibiotic therapy and sputum for gram stain and culture if a high‐quality specimen can be rapidly processed. Once the diagnosis is made, the Pneumonia Severity Index (PSI) should be used to optimize the location of treatment and to provide prognostic information. Absent other mitigating factors, patients in PSI risk classes I, II, and III can safely be treated as outpatients. Hospitalized patients with CAP should be treated promptly with empiric antibiotics. Nonsevere pneumonia should be treated with a parenteral β‐lactam plus either doxycycline or a macrolide. Patients admitted to the intensive care unit should be treated with a β‐lactam plus either a macrolide or a fluoroquinolone as well as be evaluated for pseudomonal risk factors. Most patients with nonsevere CAP reach clinical stability in 2–3 days and should be considered for a switch to oral therapy and discharge shortly thereafter. Patients should receive pneumococcal vaccination, influenza vaccination, and tobacco cessation counseling prior to discharge if eligible. Multiple quality indicators are measured and publicly reported in the management of CAP, which provides hospitals with an opportunity to improve care processes and patient outcomes. Journal of Hospital Medicine 2006;1:177–190. © 2006 Society of Hospital Medicine.
Effect of using local arterial input functions on cerebral blood flow estimation
Authors: Lorenz Cory , Benner Thomas , Lopez Chloe Joan , Ay Hakan , Zhu Ming Wang , Aronen Hannu , Karonen Jari , Liu Yawu , Nuutinen Juho , Sorensen A. Gregory
Published: June 2006

Purpose

To investigate a previously developed method for perfusion‐weighted MRI (PWI) cerebral blood flow (CBF) estimation that uses local arterial input functions (AIFs) in stroke patients, and determine its ability to correct delay and/or dispersion (D/D) errors.

Materials and Methods

Analysis was performed on dynamic susceptibility contrast data from 36 stroke patients, and CBF maps were calculated with global‐ and local‐AIF techniques using standard SVP based methods. The ratios of these maps were calculated and the mean ratios were calculated for voxels with both normal and abnormal time to peak or width. The locations of the voxels with high locally‐defined to globally‐defined CBF ratios were also mapped and the average underlying concentration‐time curves for these voxels were calculated.

Results

The ratio of CBF estimates based on local AIFs to global AIFs was on average increased for D/D voxels. The voxels in which this ratio was high were commonly concentrated in the ipsilateral hemisphere, and these voxels also displayed underlying concentration‐time curves that showed delay or dispersion. Conversely, there were no such findings based on high globally‐defined to locally‐defined CBF ratios.

Conclusion

The local‐AIF technique results in an increase in the calculated CBF values for tissues with D/D, consistent with a reduction in the errors associated with D/D. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Combined diffusion‐weighted and dynamic contrast‐enhanced MRI for prostate cancer diagnosis—Correlation with biopsy and histopathology
Authors: Kozlowski Piotr , Chang Silvia D. , Jones Edward C. , Berean Kenneth W. , Chen Henry , Goldenberg S. Larry
Published: June 2006

Purpose

To determine whether the combination of diffusion‐weighted (DW) and dynamic contrast‐enhanced (DCE) MRI provides higher diagnostic sensitivity for prostate cancer than each technique alone.

Materials and Methods

Fourteen patients with a clinical suspicion of prostate cancer underwent endorectal MRI on a 1.5T scanner prior to transrectal ultrasound (TRUS)‐guided biopsies. The average values of the apparent diffusion coefficient (ADC, calculated from b‐values of 0 and 600), Ktrans, ve, maximum gadolinium (Gd) concentration, onset time, mean gradient, and maximum enhancement were determined. Correlation with histology was based on biopsy (six patients) and prostatectomy specimen (eight patients) results. The Tukey‐Kramer test was used for statistical analysis.

Results

The average values of all MRI parameters, except ve and maximum Gd concentration, showed significant differences between tumor and normal prostate. The sensitivity and specificity values were respectively 54% (35–72%) and 100% (95–100%) for the ADC data, and 59% (39–77%) and 74% (63–83%) for the DCE data. When both ADC and DCE results were combined, the sensitivity increased to 87% (68–95%) and specificity decreased to 74% (62–83%).

Conclusion

All but two DW‐ and DCE‐MRI parameters showed significant differences between tumor and normal prostate. Combining both techniques provides better sensitivity, with a small decrease in specificity. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Staggered ethane changes to eclipsed conformation upon adsorption
Authors: Priebe A. , Pucci A. , Akemann W. , Grabhorn H. , Otto A.
Published: June 2006

Previous comparison of the infrared and Raman spectra of bulk and adsorbed C2H6 has shown that the CC axis is parallel to the local surface of Cu. The conformation of ethane in thick condensed layers is staggered. The clear appearance of a Raman band of a bending mode, not Raman active in the staggered conformation, proves that ethane is adsorbed in eclipsed conformation on silver, indium, and potassium, and probably on other quasi‐free electron metals. A relatively low‐lying Raman band is assigned to the 0 to 2 internal torsional rotation, with about half the frequency in the staggered conformation. This is to be expected when forcing the molecule from staggered‐ to eclipsed conformation by adsorption. Copyright © 2006 John Wiley & Sons, Ltd.
Cervical dystonia responsive to acoustic and galvanic vestibular stimulation
Authors: Rosengren Sally M. , Colebatch James G.
Published: June 2006

Abstract: We examined the effects of acoustic and galvanic vestibular stimulation in a patient with cervical dystonia. Acoustic stimulation consisted of three conditions: “baseline” (no stimulation), “vestibular” (500 Hz bone‐conducted tone bursts), and “control” (5,000 Hz tone bursts). Rectified electromyographic activity in the sternocleidomastoid was measured. Galvanic stimulation (1.5–2.5 mA current steps) was delivered to the mastoids, and head acceleration was measured. Vestibular acoustic stimulation reduced neck muscle activity between 16% and 44% (P < 0.001), and galvanic stimulation reduced head acceleration by 22.5% (P = 0.028). The patient reported subjective improvement in head control. Vestibular stimulation can reduce neck muscle activity in cervical dystonia and give symptomatic relief. © 2006 Movement Disorder Society
Requirements for effective IgE cross‐linking on mast cells and basophils
Authors: Knol Edward F.
Published: June 2006

This article reviews the characteristics of high affinity IgE receptors (FcεRI) and their role in the response to allergenic proteins. The requirements for successful cross‐linking of FcεRI on basophils and mast cells and subsequent degranulation by allergenic proteins will be explained in detail. Methods for in vitro analysis of allergen‐induced mast cell and basophil degranulation will be described and issues/problems in applying these methods will be discussed. Finally, implications for manipulation of protein allergens will be discussed.
Solid‐state NMR characterization of 69Ga and 71Ga in crystalline solids
Authors: Ash Jason T. , Grandinetti Philip J.
Published: June 2006

Gallium model systems containing four‐ and six‐coordinate gallium sites have been investigated using solid‐state NMR. Measurement of the isotropic chemical shift and electric field gradient (EFG) have been performed at 9.4 T on α‐Ga2O3, β‐Ga2O3, LiGaO2, NaGaO2, KGaO2, Ga2(SO4)3, and LaGaO3 using a variety of techniques on both NMR active nuclei (69Ga and 71Ga) including static, high speed magic‐angle spinning (MAS), satellite transition (ST) spectroscopy, and rotor‐assisted population transfer (RAPT). The chemical shift is found to correlate well with the coordination number, with four‐coordinate gallium having values of approximately 50 ppm and six‐coordinate gallium having values near 225 ppm (referenced to 1 M gallium nitrate solution). The magnitude of the EFG is found to be correlated to the distortion of the gallium polyhedra, with the strained systems having EFGs of 3 × 1021 Vm−2 or more, while the less strained systems have values of 1.5 × 1021 Vm−2 or less. A plot of chemical shift versus EFG suggests that solid‐state NMR of gallium oxyanions can be more discriminating than liquid state NMR chemical shifts alone. Copyright © 2006 John Wiley & Sons, Ltd.
Clusterin expression in follicular dendritic cells associated with prion protein accumulation
Authors: Sasaki K , Doh‐ura K , Ironside JW , Mabbott N , Iwaki T
Published: June 2006

Peripheral accumulation of abnormal prion protein (PrP) in variant Creutzfeldt–Jakob disease and some animal models of transmissible spongiform encephalopathies (TSEs) may occur in the lymphoreticular system. Within the lymphoid tissues, abnormal PrP accumulation occurs on follicular dendritic cells (FDCs). Clusterin (apolipoprotein J) has been recognized as one of the molecules associated with PrP in TSEs, and clusterin expression is increased in the central nervous system where abnormal PrP deposition has occurred. We therefore examined peripheral clusterin expression in the context of PrP accumulation on FDCs in a range of human and experimental TSEs. PrP was detected immunohistochemically on tissue sections using a novel highly sensitive method involving detergent autoclaving pretreatment. A dendritic network pattern of clusterin immunoreactivity in lymphoid follicles was observed in association with the abnormal PrP on FDCs. The increased clusterin immunoreactivity appeared to correlate with the extent of PrP deposition, irrespective of the pathogen strains, host mouse strains or various immune modifications. The observed co‐localization and correlative expression of these proteins suggested that clusterin might be directly associated with abnormal PrP. Indeed, clusterin immunoreactivity in association with PrP was retained after FDC depletion. Together these data suggest that clusterin may act as a chaperone‐like molecule for PrP and play an important role in TSE pathogenesis. Copyright © 2006 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Human endothelial cell septins: SEPT11 is an interaction partner of SEPT5
Authors: Bläser S , Röseler S , Rempp H , Bartsch I , Bauer H , Lieber M , Lessmann E , Weingarten L , Busse A , Huber M , Zieger B
Published: June 2006

The septin SEPT11 is a novel member of the highly conserved septin family. Septins are cytoskeletal GTPases, which form heteropolymeric complexes. They are involved in cytokinesis and other cellular processes, such as vesicle trafficking and exocytosis. SEPT11 has strong homology to SEPT8. Previously, we identified the interaction of SEPT5 and SEPT8. Using the yeast two‐hybrid system, we now demonstrate that SEPT11 partners with SEPT5. The molecular interaction of SEPT11 with SEPT5 was verified by coprecipitation of SEPT5 and SEPT11 from lysates of the human T‐cell leukaemia cell line JURKAT and by fluorescence resonance energy transfer. The interaction between SEPT5 and SEPT11 requires the GTP‐binding domain and the C‐terminal extension. Western analysis in various mouse and human tissues revealed that expression of SEPT11 is restricted to the same tissues as those expressing SEPT5, suggesting that SEPT11 and SEPT5 are components of a cell‐specific septin complex. SEPT5, which is expressed in human umbilical vein endothelial cells (HUVECs), has been reported to play an important role in exocytosis. We now report that HUVECs also express SEPT11. Given the interactivity between SEPT5 and SEPT11 as shown above and their coexpression in HUVECs, it may be that a complex formed by these two proteins is involved in the exocytosis mechanism in HUVECs. Copyright © 2006 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Cervical paraganglioma—A case report and review of all cases reported to the Manchester Children's Tumour Registry 1954–2004
Authors: Challapalli Amarnath , Howell Lisa , Farrier Martin , Kelsey Anna , Birch Jillian , Eden Tim
Published: June 2006

We report a 6‐year‐old male with left‐sided ptosis, aniscoria and an initially missed slow growing left‐sided neck mass, which was surgically excised when he was 9 years old and confirmed to be a paraganglioma. Seven years later he developed recurrent symptoms and was found to have a recurrence in the anterior mediastinum. We also report on all cases of cervical paragangliomas registered with the Manchester Children's Tumour Registry (MCTR) for the 50‐year period 1954–2004. Paragangliomas are very rare tumours in the head and neck but should be considered in the differential diagnosis of neck masses especially when presenting with Horner syndrome. Recurrent symptoms and signs of hypertension herald recurrence. As these tumours can form part of a familial syndrome, long‐term follow‐up is necessary. Family members should be screened for early detection. Pediatr Blood Cancer 2007;48:112–116. © 2006 Wiley‐Liss, Inc.
Luminescent copolymers for applications in multicolor‐light‐emitting devices
Authors: Buchgraber Christian , Pogantsch Alexander , Kappaun Stefan , Spanring Julia , Kern Wolfgang
Published: June 2006

Light‐emitting diodes based on organic materials [organic light‐emitting diodes (OLEDs)] have attracted much interest over the past decade. Several different attempts have been made to realize multicolor OLEDs. This article describes a new approach based on energy transfer in a donor/acceptor system. A copolymer containing both donor and acceptor compounds as comonomer units is prepared. The polymer consists of a derivative of a luminescent dye [4‐dicyanmethylene‐2‐methyl‐6‐4H‐pyran (DCM); acceptor compound], which is copolymerized with fluorene (donor compound) to combine the properties of an electroactive polymer with a highly luminescent dye. Photochemical processing is achieved by UV irradiation of this copolymer in the presence of gaseous trialkylsilanes. This reagent selectively saturates the CC bonds in the DCM comonomer units while leaving the fluorene units essentially unaffected. As a result of the photochemical process, the red electroluminescence of the acceptor compound vanishes, and the blue‐green electroluminescence from the polyfluorene units is recovered. Compared with previous approaches based on polymer blends, this copolymer approach avoids problems associated with phase‐separation phenomena in the active layer of OLEDs. © 2006Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4317–4327, 2006
Amino acid residues that determine functional specificity of NADP‐ and NAD‐dependent isocitrate and isopropylmalate dehydrogenases
Authors: Kalinina Olga V. , Gelfand Mikhail S.
Published: June 2006

Isocitrate and isopropylmalalte dehydrogenases are homologous enzymes important for the cell metabolism. They oxidize their substrates using NAD or NADP as cofactors. Thus, they have two specificities, towards the substrate and the cofactor, appearing in three combinations. Although many three‐dimensional (3D) structures are resolved, identification of amino acids determining these specificities remains a challenge. We present computational identification and analysis of specificity‐determining positions (SDPs). Besides many experimentally proven SDPs, we predict new SDPs, for example, four substrate‐specific positions (103Leu, 105Thr, 337Ala, and 341Thr in IDH from E. coli) that contact the cofactor and may play a role in the recognition process. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Influence of annealing temperature on the structural and optical properties of sol–gel prepared ZnO thin films
Authors: Wang Mingsong , Kim Eui Jung , Chung Jin Suk , Shin Eun Woo , Hahn Sung Hong , Lee Ka Eun , Park Chinho
Published: June 2006

Zinc oxide thin films have been prepared via a sol–gel process. The influence of annealing temperature on the structural and optical properties of the ZnO thin films has been investigated. The prepared ZnO thin films had a polycrystalline hexagonal wurtzite structure with no preferred orientation. The annealing temperature had a great effect on the optical properties of the ZnO thin films: the optical band gap became narrow due to the increase in crystallite size and the reduction in amorphous phase amount with increasing annealing temperature. Absorption or desorption of oxygen in the annealing process caused the observed yellow or green emission. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Mixed partial dislocation core structure in GaN by high resolution electron microscopy
Authors: Kioseoglou J. , Dimitrakopulos G. P. , Komninou Ph. , Kehagias Th. , Karakostas Th.
Published: June 2006

The core structures of a 1/6 [2$\bar 2$03] mixed partial dislocation in wurtzite GaN have been investigated using a combination of high resolution transmission electron microscopy, circuit mapping, and image simulation of relaxed models. HRTEM simulated images of relaxed atomic models, derived by energetic calculations with a modified Stillinger–Weber‐type empirical interatomic potential, were calculated and compared to the experimental images. Among twenty‐four stable core configurations the 12‐ and 10‐atom rings satisfied the experimental contrast. A pattern registration procedure was used for the matching of simulated and experimental HRTEM images. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fast spin relaxation in InGaN/GaN multiple quantum wells
Authors: Brown J. , Wells J.‐P. R. , Hashemizadeh S. A. , Parbrook P. J. , Wang T. , Fox A. M. , Mowbray D. J. , Skolnick M. S.
Published: June 2006

We report measurements of a fast spin relaxation in InGaN multi‐quantum wells (MQW) using femtosecond circularly polarised pump–probe spectroscopy. These reveal quantum beats in the spin polarisation arising from a 1.6 meV fine structure splitting of the excitonic levels. We attribute this splitting to exchange interactions in the narrow quantum wells studied. The 5 K spin coherence time was measured to be 450 fs, a value which decreases by a factor of approximately two by 50 K. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Relaxation in crack‐free AlN/GaN superlattices
Authors: Kröger R. , Kruse C. , Roder C. , Hommel D. , Rosenauer A.
Published: June 2006

An AlN/GaN superlattice structure for the use as low index material in distributed Bragg reflectors in the blue‐violet spectral region was studied by transmission electron microscopy in cross section and plan view. The superlattice is found to partially relax during growth via the introduction of threading dislocations. Dislocation loops are found to form spontanously at discrete superlattice thicknesses indicating the accumulation of point defects. Such defects might hamper the light transmission in the targeted wavelength range. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Generalized Wannier functions: An efficient way to construct ab‐initio tight‐binding parameters for group‐III nitrides
Authors: Wahn M. , Neugebauer J.
Published: June 2006

An ab‐initio tight‐binding (TB) parametrization has successfully been accomplished for the group‐III nitrides GaN and InN as well as for GaAs. The approach allows for multi‐scale electronic structure calculations while conserving the accuracy of the atomic scale. The method has been implemented into the plane‐wave pseudopotential code S/PHI/nX (http://www.sfhingx.de [1]). Based on it we have performed careful checks of the efficiency (number of non‐vanishing matrix elements of the TB Hamiltonian) and the accuracy (description of the bandstructure in comparison to the plane‐wave basis). The effect of different exchange‐correlation functionals (LDA, EXX) has also been investigated. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Organic mass spectrometry and control of fragmentation using a fast flow glow discharge ion source
Authors: Newman Karla , Mason Rod S.
Published: June 2006

Representative organic vapors have been introduced into the flowing afterglow of a low power (<5 W) dc‐glow discharge, coupled to a quadrupole mass spectrometer. When a positive bias was applied to the ion sampling orifice, the very surprising result was that molecular mass spectra were obtained with a high sensitivity. When a negative bias was applied to the ion sampling orifice, fragmentation of the analyte was observed with an increase in the extent of ion dissociation as the voltage was increased. The breakdown pattern is compound‐specific and would be useful in confirming the identity of an unknown sample. When combined with chromatographic separation, the FFGD‐MS technique could be used for chemical speciation studies at the sub‐picogram level. Copyright © 2006 John Wiley & Sons, Ltd.
Use of a low‐cost substrate in a continuous recirculation process to stimulate plumewide anaerobic dechlorination of chlorinated solvents
Authors: Laughlin David , Timmins Brian
Published: June 2006

Over the past 20 years, significant time and money have been spent on better understanding and successfully applying bioremediation in the field. The results of these efforts provide a deeper un‐derstanding of aerobic and anaerobic microbial processes, the microbial species and environ‐mental conditions that are desirable for specific degradation pathways, and the limitations that may prevent full‐scale bioremediation from being successfully applied in heterogeneous subsur‐face environments. Numerous substrates have been identified as effective electron donors to stimulate anaerobic dechlorination of chlorinated ethenes, but methods of delivering these sub‐strates for in situ bioremediation (direct‐push injections, slug injections, high‐pressure injections, fracture wells, etc.) have yet to overcome the main limitation of achieving contact between these substrates and the contaminants. Therefore, although it is important (from a full‐scale remedia‐tion standpoint) to select an appropriate, low‐cost substrate that can be supplied in sufficient quantity to promote remediation of a large source area and its associated plume, it is equally im‐portant to ensure that the substrate can be delivered throughout the impacted plume zone. Failure to achieve substrate delivery and contact within the chlorinated solvent plume usually re‐sults in wasted money and limited remediation benefit. Bioremediation is a contact technology that cannot be effectively implemented on a large scale unless a method for rapidly delivering the low‐cost substrate across the entire source and plume areas is utilized. Unfortunately, many cur‐rent substrate delivery methods are not achieving sitewide distribution or treatment of the sorbed contaminant mass that exists in the organic fraction of a soil matrix. The following discussion sum‐marizes substrate delivery using an aggressive groundwater recirculation approach that can achieve plumewide contact between the contaminants and substrate, thus accelerating dechlori‐nation rates and shortening the overall remediation time frame. © 2006 Wiley Periodicals, Inc.
A taxonomy of market‐based resource management systems for utility‐driven cluster computing
Authors: Yeo Chee Shin , Buyya Rajkumar
Published: June 2006

In utility‐driven cluster computing, cluster Resource Management Systems (RMSs) need to know the specific needs of different users in order to allocate resources according to their needs. This in turn is vital to achieve service‐oriented Grid computing that harnesses resources distributed worldwide based on users' objectives. Recently, numerous market‐based RMSs have been proposed to make use of real‐world market concepts and behavior to assign resources to users for various computing platforms. The aim of this paper is to develop a taxonomy that characterizes and classifies how market‐based RMSs can support utility‐driven cluster computing in practice. The taxonomy is then mapped to existing market‐based RMSs designed for both cluster and other computing platforms to survey current research developments and identify outstanding issues. Copyright © 2006 John Wiley & Sons, Ltd.
Nanokristalline Diamantschichten für die Zerspanung
Authors: Frank Martin , Breidt Dirk , Cremer Rainer
Published: June 2006

Die Geschichte der CVD‐Diamantsynthese geht bis in die fünfziger Jahre zurück. Das wissenschaftliche und wirtschaftliche Potenzial wurde aber erst allmählich erkannt. Erst in den achtziger Jahren wurden in intensiven und weltweiten Forschungsarbeiten die Synthese‐ und Anwendungsmöglichkeiten eruiert. Industrielle Produkte kamen erst Mitte der neunziger Jahre auf den Markt. Hier sind im Besonderen diamantbeschichtete Zerspanwerkzeuge zu nennen. Der Artikel zeigt die neusten Entwicklungen in diesem Bereich, die besonders Diamantschichtsysteme mit nanokristallinen Strukturen umfassen.
Hochbelastbare kohlenstoffbasierte Mehrschichtsysteme für die Umformtechnik
Authors: Weber M. , Bewilogua K. , Thomasen H. , Wittorf R.
Published: June 2006

Amorphe Kohlenwasserstoffschichten (metallfreies a‐C:H und metallhaltiges a‐C:H:Me) reagieren sehr empfindlich auf lokale Überlastungen, wie sie z. B. bei Anwendungen in der Umformtechnik auftreten können. Harte abrasive Partikel, prozessbedingte Spannungsspitzen auf der Werkzeugoberfläche oder auch Überlastungen durch Fehler in der Werkzeuggeometrie führen häufig zur Rissbildung und zum vorzeitigen Versagen der Schichten. Verglichen mit der hohen Härte und Verschleißbeständigkeit sowie den sehr guten Reibeigenschaften ist die Haftfestigkeit der Kohlenstoffschichten häufig unbefriedigend. Die Haftfestigkeit und Belastbarkeit von reaktiv gesputtertem a‐C:H und a‐C:H:Me, kann in hohem Maße durch Zwischenschichten beeinflusst werden. In diesem Beitrag werden die Versagensmechanismen von amorphen Kohlenwasserstoffschichten untersucht und der Einfluss von verschiedenen metallischen, nitridischen und carbidischen Zwischenschichten auf die Wachstumsstruktur, Haftung und Belastbarkeit von a‐C:H und a‐C:H:Me‐Schichten beschrieben. Zwei hoch belastbare Mehrschichtsysteme für Werkzeuge und Komponenten werden vorgestellt.
Pregnancy issues in inherited metabolic disorders
Authors: Lee Philip J.
Published: June 2006

Increasing numbers of individuals with inherited metabolic disorders are surviving into adulthood and considering their reproductive options. This paper discusses a practical approach to supporting such individuals, focusing on issues concerning fertility, the impact of pregnancy on metabolism and the metabolic disorder itself on the pregnancy, as well as highlighting the need to pay special attention during the postpartum period. Apart from pregnancies in women with phenylketonuria, there is a dearth of data in this area and a great need for collection of information within registries to aid our understanding of potential problems and counselling of women and their partners.
Carnitine supplementation induces long‐chain acylcarnitine production—Studies in the VLCAD‐deficient mouse
Authors: Liebig M. , Gyenes M. , Brauers G. , Ruiter J. P. N. , Wendel U. , Mayatepek E. , Strauss A. W. , Wanders R. J. A. , Spiekerkoetter U.
Published: June 2006

Carnitine supplementation does not affect carnitine concentrations in tissues of wild‐type and very long‐chain acyl‐CoA dehydrogenase‐deficient mice, but results in an increase in long‐chain acylcarnitine production.
Direct multiplex assay of enzymes in dried blood spots by tandem mass spectrometry for the newborn screening of lysosomal storage disorders
Authors: Gelb Michael H. , Turecek Frantisek , Scott C. Ron , Chamoles Nestor A.
Published: June 2006

Tandem mass spectrometry is currently used in newborn screening programmes to quantify the level of amino acids and acylcarnitines in dried blood spots for detection of metabolites associated with treatable diseases. We have developed assays for lysosomal enzymes in rehydrated dried blood spots in which a set of substrates is added and the set of corresponding enzymatic products are quantified using tandem mass spectrometry with the aid of mass‐differentiated internal standards. We have developed a multiplex assay of the set of enzymes that, when deficient, cause the lysosomal storage disorders Fabry, Gaucher, Hurler, Krabbe, Niemann–Pick A/B and Pompe diseases. These diseases were selected because treatments are now available or expected to emerge shortly. The discovery that acarbose is a selective inhibitor of maltase glucoamylase allows the Pompe disease enzyme, acid α‐glucosidase, to be selectively assayed in white blood cells and dried blood spots. When tested with dried blood spots from 40 unaffected individuals and 10–12 individuals with the lysosomal storage disorder, the tandem mass spectrometry assay led to the correct identification of the affected individuals with 100% sensitivity. Many of the reagents needed for the new assays are commercially available, and those that are not are being prepared under Good Manufacturing Procedures for approval by the FDA. Our newborn screening assay for Krabbe disease is currently being put in place at the Wadsworth Center in New York State for the analysis of ∼1000 dried blood spots per day. Summary We have developed tandem mass spectrometry for the direct assay of lysosomal enzymes in rehydrated dried blood spots that can be implemented for newborn screening of lysosomal storage disorders. Several enzymes can be analysed by a single method (multiplex analysis) and in a high‐throughput manner appropriate for newborn screening laboratories.
Nutrition therapy of organic acidaemias with amino acid‐based formulas: Emphasis on methylmalonic and propionic acidaemia
Authors: Yannicelli Steven
Published: June 2006

Failure to thrive has been described in patients with organic acidaemias due to a variety of causes, both organic and inorganic. Failure to thrive in patients with methylmalonic acidaemia (MMA) and propionic acidaemia (PA) may be related to inadequate protein and energy intake rather than pathology of disease. Inadequate protein intake can also result in decreased resting energy expenditure, clinical signs and symptoms of amino acid deficiency, increased risk of infection, and developmental delay. Amino acid‐based formulas (also referred to as ‘medical foods’) provide a key source of nitrogen, energy, vitamins and minerals which, when prescribed appropriately, can promote anabolism and growth. Although protein requirements in patients with organic acidaemias have not been elucidated, providing an adequate balance of protein, energy and other nutrients will help promote growth.
Komrower lecture: Treatment of inborn errors of metabolism: A review
Authors: Leonard J. V.
Published: June 2006

Although the treatment of a small number of inborn errors is very good, for the majority the outcome is less satisfactory. This review examines current treatment critically and suggests how the information on which decisions about the management of patients with inborn errors might be improved.