bluuebunny/crossref_metadata_2025 huggingface dataset:
The neuroanatomy of genetic subtype differences in Prader–Willi syndrome
Authors: Honea Robyn A. , Holsen Laura M. , Lepping Rebecca J. , Perea Rodrigo , Butler Merlin G. , Brooks William M. , Savage Cary R.
Published: January 2012

Despite behavioral differences between genetic subtypes of Prader–Willi syndrome (PWS), no studies have been published characterizing brain structure in these subgroups. Our goal was to examine differences in the brain structure phenotype of common subtypes of PWS [chromosome 15q deletions and maternal uniparental disomy 15 (UPD)]. Fifteen individuals with PWS due to a typical deletion [(DEL) type I; n = 5, type II; n = 10], eight with PWS due to UPD, and 25 age‐matched healthy‐weight individuals (HWC) participated in structural magnetic resonance imaging (MRI) scans. A custom voxel‐based morphometry processing stream was used to examine regional differences in gray and white matter volume (WMV) between groups, covarying for age, sex, and body mass index (BMI). Overall, compared to HWC, PWS individuals had lower gray matter volumes (GMV) that encompassed the prefrontal, orbitofrontal and temporal cortices, hippocampus and parahippocampal gyrus, and lower WMVs in the brain stem, cerebellum, medial temporal, and frontal cortex. Compared to UPD, the DEL subtypes had lower GMV primarily in the prefrontal and temporal cortices, and lower white matter in the parietal cortex. The UPD subtype had more extensive lower gray and WMVs in the orbitofrontal and limbic cortices compared to HWC. These preliminary findings are the first structural neuroimaging findings to support potentially separate neural mechanisms mediating the behavioral differences seen in these genetic subtypes. © 2012 Wiley Periodicals, Inc.
Advances in tryptophan hydroxylase‐2 gene expression regulation: New insights into serotonin–stress interaction and clinical implications
Authors: Chen Guo‐Lin , Miller Gregory M.
Published: January 2012

Serotonin (5‐HT) modulates the stress response by interacting with the hormonal hypothalamic–pituitary–adrenal (HPA) axis and neuronal sympathetic nervous system (SNS). Tryptophan hydroxylase (TPH) is the rate‐limiting enzyme in 5‐HT biosynthesis, and the recent identification of a second, neuron‐specific TPH isoform (TPH2) opened up a new area of research. While TPH2 genetic variance has been linked to numerous behavioral traits and disorders, findings on TPH2 gene expression have not only reinforced, but also provided new insights into, the long‐recognized but not yet fully understood 5‐HT–stress interaction. In this review, we summarize advances in TPH2 expression regulation and its relevance to the stress response and clinical implications. Particularly, based on findings on rhesus monkey TPH2 genetics and other relevant literature, we propose that: (i) upon activation of adrenal cortisol secretion, the cortisol surge induces TPH2 expression and de novo 5‐HT synthesis; (ii) the induced 5‐HT in turn inhibits cortisol secretion by modulating the adrenal sensitivity to ACTH via the suprachiasmatic nuclei (SCN)‐SNS‐adrenal system, such that it contributes to the feedback inhibition of cortisol production; (iii) basal TPH2 expression or 5‐HT synthesis, as well as early‐life experience, influence basal cortisol primarily via the hormonal HPA axis; and (iv) 5′‐ and 3′‐regulatory polymorphisms of TPH2 may differentially influence the stress response, presumably due to their differential roles in gene expression regulation. Our increasing knowledge of TPH2 expression regulation not only helps us better understand the 5‐HT–stress interaction and the pathophysiology of neuropsychiatric disorders, but also provides new strategies for the treatment of stress‐associated diseases. © 2012 Wiley Periodicals, Inc.
Der “unparteiische” Ansatz: Strategien zur Entwicklung von racemischen chiralen Katalysatoren
Authors: Evans Louise A. , Hodnett Neil S. , Lloyd‐Jones Guy C.
Published: January 2012

Die asymmetrische Katalyse ist in erster Linie mit der Anwendung von enantiomerenreinen chiralen Liganden und Katalysatoren verbunden. Obwohl racemische chirale Katalysatoren in relativ großem Umfang in Polymerisationen eingesetzt wurden, blieben sie in der organischen Synthese und Katalysatorentwicklung bisher weitgehend außen vor. Dieser Kurzaufsatz trägt verschiedene Aspekte der strategischen Anwendung von racemischen Liganden und Katalysatoren zusammen, angefangen von der Abschätzung ihrer Selektivität und Bestimmung des Enantiomerenüberschusses, über die regio‐ und stereochemische Kontrolle von Reaktionsverläufen, bis hin zu mechanistischen Studien. Die Ausführungen lassen klar erkennen, dass der “unparteiische” Ansatz, ob für sich allein oder in Verbindung mit enantiomerenreinen Katalysatoren, vielversprechende Perspektiven bietet.
The Even‐Handed Approach: Strategies for the Deployment of Racemic Chiral Catalysts
Authors: Evans Louise A. , Hodnett Neil S. , Lloyd‐Jones Guy C.
Published: January 2012

Asymmetric catalysis is predominantly associated with the use of enantiomerically pure chiral ligands and catalysts. Although racemic chiral catalysts have been employed quite extensively in polymerization, their utility in mainstream organic synthesis and catalyst development has arguably been rather overlooked. This Minireview collates various themes for the strategic application of racemic ligands and catalysts, ranging from the estimation of selectivity and determination of enantiomeric excess, through to control of regio‐ and stereochemical outcomes, and mechanistic studies. What emerges is a clear picture that, in isolation or in concert with enantiopure catalysts, the “even‐handed” approach has much to offer.
Preparation of sulfonated poly(ethylene terephthalate) submicron fibrous membranes for removal of basic dyes
Authors: Chegoonian P. , Feiz M. , Ravandi S. A. Hosseini , Mallakpour S.
Published: January 2012

In this investigation, a nanofibrous sulfonated poly(ethylene terephthalate) (SPET) membrane was prepared by electrospinning of the SPET solution in trifluoroaceticacid (TFA)/dichloromethane (DCM) mixture. The produced nanofibers had diameter ranging from 300 nm to 1 μm. The performance of this membrane's separation process was evaluated under different operating conditions. The influence of the electrospinning and filtration process parameters, such as concentration, applied voltage, deposition time, operating pressure, and filtration time on rejection of C.I. Basic Blue 3 were studied. The dead‐end recirculation ultrafiltration set‐up was employed. Under optimum conditions (concentration of 20% (w/v) of SPET, applied voltage of 20 kV and deposition time of 3 h) the removal of the aforementioned dye was 98%. Operating pressure has posed a significant influence on the membrane's separation performance, whereas the operating time had some effect on the separation performance. Two equilibrium adsorption isotherms: Langmuir and Freundlich were fitted to the dyes' equilibrium sorption data on SPET membrane at different feed concentrations. The Freundlich isotherm was found to well represent the measured adsorption data based on the higher coefficient of determination (r2). © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
River dolphin distribution in regulated river systems: implications for dry‐season flow regimes in the Gangetic basin
Authors: Choudhary Sunil , Dey Sushant , Dey Subhashish , Sagar Viveksheel , Nair Tarun , Kelkar Nachiket
Published: January 2012

River flow regulation and fragmentation is a global threat to freshwater biodiversity, ecosystem processes, and associated human activities. Large dams in the Ganges river basin of the Indian subcontinent have severely altered natural flow regimes, particularly in the low‐flow dry season. Altered flows could have negative impacts on endangered species such as the Ganges river dolphin Platanista gangetica.

Habitat use by river dolphins was investigated in relation to river channel depth and morphology, over 332 km of the flow‐regulated Gandak River in India. Dolphin distribution patterns were compared across multiple spatial scales in the Gandak, Kosi, Chambal, Sone Rivers and the upper and lower sections of the Ganges main stem.

Dolphin presence was recorded in 40% of segments in the Gandak river, with a best count of 257 (range 250–267) and average individual encounter rates at 0.75 dolphins km‐1 (SD 0.89). Bayesian zero-inflated spatial models showed that river dolphin abundance was positively influenced by river depth, presence of meanders and corresponded closely with gillnet fishing. Minimum mid‐channel depth requirements were estimated at 5.2 m for dolphin adults and between 2.2 and 2.4 m for mother–calf pairs.

Adult dolphins showed highly similar habitat preferences across regulated or unregulated rivers, for depths >5 m, and meandering channels. Dry‐season habitat availability was reduced as the degree of flow regulation increased across rivers, mainly owing to loss of lateral and longitudinal channel connectivity.

Overall encounter rates were reduced from >3 km‐1 in less regulated stretches, to <0.3 km‐1 in regulated rivers. Clustering of dolphins in deep pools increased along the gradient of river flow reduction, with dolphins almost absent from intervening segments because of low flow rates. These results indicate the importance of maintaining adequate dry‐season flows to ensure river habitat availability and connectivity for dolphins.

Copyright © 2012 John Wiley & Sons, Ltd.
A breath of fresh air: avoiding anoxia and mortality of freshwater turtles in fyke nets by the use of floats
Authors: Larocque Sarah M. , Cooke Steven J. , Blouin‐Demers Gabriel
Published: January 2012

Freshwater turtles are susceptible to drowning in commercial fishing nets and this is a major conservation concern. Methods to mitigate turtle bycatch mortality typically involve reducing the capture of bycatch using gear modifications. Another method to reduce mortality is to keep bycatch alive following capture.

Using physiological measures of anoxia, this study determined whether providing air spaces using floats within fyke nets could prevent turtles from drowning. In a controlled setting, blood lactate and pH of painted turtles (Chrysemys picta) experimentally introduced into submerged nets, nets with floats, and nets that breached the surface were compared. While emulating commercial fishing practices – where turtles and fish voluntarily entered nets – catch rates and compositions as well as blood lactate in turtles captured were compared in submerged nets with and without floats.

Painted turtles in submerged nets exhibited elevated blood lactate and pronounced acidosis compared with turtles from nets with floats and surfaced nets.

Catch rates and compositions from emulated fishing were statistically similar in nets with and without floats; however, total fish catches were roughly one‐third less in nets with floats. The same pattern of physiological disturbance was observed with turtles captured in submerged nets with and without floats as in the controlled experiment.

Overall, blood physiology indicated that anoxia occurred in turtles in submerged nets while nets with floats reduced physiological disturbance. However, variation in blood lactate levels when fishing fyke nets with floats suggests that turtles were experiencing slight anoxia and so the size of air spaces may be important in allowing access to air. Creating air spaces in fyke nets using floats is a simple and cost‐effective method to avoid the drowning of turtles.

Copyright © 2012 John Wiley & Sons, Ltd.
The absorption and emission spectrum of the magnetic Herbig Ae star HD 190073
Authors: Cowley C.R. , Hubrig S.
Published: January 2012

We determine abundances from the absorption spectrum of the magnetic Herbig Ae star HD 190073 (V1295 Aql). The observations are primarily from HARPS spectra obtained at a single epoch. We accept arguments that the presence of numerous emission lines does not vitiate a classical abundance analysis, though it likely reduces the achievable accuracy. Most abundances are closely solar, but several elements show departures of a factor of two to three, as an earlier study has also shown. We present quantitative measurements of more than 60 emission lines, peak intensities, equivalent widths, and FWHM's. The latter range from over 200 km s–1(Hα, He D3) down to 10–20 km s–1(forbidden lines). Metallic emission lines have intermediate widths. We eschew modeling, and content ourselves with a presentation of the observations a successful model must explain. Low‐excitation features such as the Na I D‐lines and [O I] appear with He I D3, suggesting proximate regions with widely differing Te and Ne as found in the solar chromosphere. The [O I] and [Ca II] lines show sharp, violet‐shifted features. Additionally, [Fe II] lines appear tobe weakly present in emission (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A magnetic cycle of τ Bootis? The coronal and chromospheric view
Authors: Poppenhaeger K. , Günther H.M. , Schmitt J.H.M.M.
Published: January 2012

τ Bootis is a late F‐type main sequence star orbited by a Hot Jupiter. During the last years spectropolarimetric observations led to the hypothesis that this star may host a global magnetic field that switches its polarity once per year, indicating a very short activity cycle of only one year duration. In our ongoing observational campaign, we have collected several X‐ray observations with XMM‐Newton and optical spectra with TRES/FLWO in Arizona to characterize τ Boo's corona and chromosphere over the course of the supposed one‐year cycle. Contrary to the spectropolarimetric reconstructions, our observations do not show indications for a short activity cycle (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modeling spatio‐temporal nonlocality in mean‐field dynamos
Authors: Rheinhardt M. , Brandenburg A.
Published: January 2012

When scale separation in space or time is poor, the mean‐field α effect and turbulent diffusivity have to be replaced by integral kernels by which the dependence of the mean electromotive force on the mean magnetic field becomes nonlocal. Earlier work in computing these kernels using the test‐field method is now generalized to the case in which both spatial and temporal scale separations are poor. The approximate form of the kernel for isotropic stationary turbulence is such that it can be treated in a straightforward manner by solving a partial differential equation for the mean electromotive force. The resulting mean‐field equations are solved for oscillatory α –shear dynamos as well as α2 dynamos with α linearly depending on position, which makes this dynamo oscillatory, too. In both cases, the critical values of the dynamo number is lowered due to spatio‐temporal nonlocality.When scale separation in space or time is poor, the mean‐field α effect and turbulent diffusivity have to be replaced by integral kernels by which the dependence of the mean electromotive force on the mean magnetic field becomes nonlocal. Earlier work in computing these kernels using the test‐field method is now generalized to the case in which both spatial and temporal scale separations are poor. The approximate form of the kernel for isotropic stationary turbulence is such that it can be treated in a straightforward manner by solving a partial differential equation for the mean electromotive force. The resulting mean‐field equations are solved for oscillatory α –shear dynamos as well as α2 dynamos
Measurement of quetiapine and four quetiapine metabolites in human plasma by LC‐MS/MS
Authors: Fisher Danielle S. , Handley Simon A. , Taylor David , Flanagan Robert J.
Published: January 2012

There is interest in monitoring plasma concentrations of N‐desalkylquetiapine in relation to antidepressant effect. A simple LC‐MS/MS method for quetiapine and four metabolites in human plasma (50 μL) has been developed to measure concentrations of these compounds attained during therapy. Analytes and internal standard (quetiapine‐d8) were extracted into butyl acetate–butanol (10:1, v/v) and a portion of the extract analysed by LC‐MS/MS (100 × 2.1 mm i.d. Waters Spherisorb S5SCX; eluent: 50 mmol/L methanolic ammonium acetate, pH* 6.0; flow‐rate 0.5 mL/min; positive ion APCI‐SRM, two transitions per analyte). Assay calibration (human plasma calibrators) was linear across the ranges studied (quetiapine and N‐desalkylquetiapine 5–800, quetiapine sulfoxide 100–15,000, others 2–100 µg/L). Assay validation was as per FDA guidelines. Quetiapine sulfone was found to be unstable and to degrade to quetiapine sulfoxide. In 47 plasma samples from patients prescribed quetiapine (prescribed dose 200–950 mg/day), the (median, range) concentrations found (µg/L) were: quetiapine 83 (7–748), N‐desalkylquetiapine, 127 (7–329), O‐desalkylquetiapine 12 (2–37), 7‐hydroxyquetiapine 3 (<1–48), and quetiapine sulfoxide 3,379 (343–21,704). The analyte concentrations found were comparable to those reported by others except that the concentrations of the sulfoxide were markedly higher. The reason for this discrepancy in unclear. Copyright © 2012 John Wiley & Sons, Ltd.
Applications of Shannon's Entropy Theory to Naphtha Pyrolysis Simulation
Authors: Zhang L. , Chen B.
Published: January 2012

Shannon's theory is applied for the first time to the simulation of naphtha pyrolysis for estimating selective coefficients of the primary reaction and predicting the feedstock component content. Compared with other methods, this approach can be extrapolated and provides more accurate results. Furthermore, it requires much less experimental data. Not only can exact constraints be used but also uncertainties can be specified by the user, resulting in a highly flexible model. The results demonstrate the effectiveness of Shannon's maximum entropy theory in obtaining the missing information for models of the naphtha pyrolysis process.
Relevance of Photocatalysis prior to Biological Treatment of Organic Pollutants – Selection Criteria
Authors: Fourcade F. , Yahiat S. , Elandaloussi K. , Brosillon S. , Amrane A.
Published: January 2012

The relevance of a photocatalytic pretreatment prior to a biological process for removal of organic pollutants was examined. Owing to the significant residual amount and toxicity, amitrole was not relevant. High mineralization allowed to remove bisphenol A and 2,4‐dichlorophenoxyacetic acid. Isoproturon and diuron cannot be considered due to the slight evolution of chemical oxygen demand/total organic carbon (COD/TOC) and average oxidation state during irradiation. After photocatalysis, the ratio of biological oxygen demand (BOD5)/COD remained below the biodegradability limit (0.4) for the rest of the molecules. A favorable COD/TOC trend (decrease during irradiation) was recorded for dimethoate and antibiotics. However, dimethoate and sulfamethoxazole seemed not pertinent due to the long time span for their removal. Since a decrease of toxicity was only recorded for tylosine, it can be selected for subsequent tests.
Reaction Pathways from Single‐Molecule Trajectories
Authors: Yuan Haifeng , Orrit Michel
Published: January 2012

Signal‐pair histograms map transitions between different states of a single molecule and open new opportunities for the reconstruction of kinetic pathways.
Nuclear features in endometrial cytology: Comparison of endometrial glandular and stromal breakdown and endometrioid adenocarcinoma grade 1
Authors: Norimatsu Yoshiaki , Shigematsu Yumie , Sakamoto Shingo , Ohsaki Hiroyuki , Yanoh Kenji , Kawanishi Namiki , Kobayashi Tadao K.
Published: January 2012

This study was to clarify the nuclear features of “condensed clusters of stromal cells (EGBD‐stromal cells)” and “metaplastic clumps with irregular protrusions (EGBD‐metaplastic cells)” which may be recognized in endometrial glandular and stromal breakdown (EGBD) cases in liquid‐based cytologic (LBC) preparations of endometrial brushings. The material consists of cytologic smears of 20 cases of proliferative endometrium (PE), 20 cases of EGBD, and 20 cases of endometrioid adenocarcinoma grade 1 (G1) for which histopathological diagnosis was obtained by endometrial curettage. Nuclear findings were examined in PE cells, EGBD‐stromal cells, EGBD‐metaplastic cells, and G1 cells, respectively.

It was examined about the following items: (1) Nuclear shape; (2) A long/minor axis ratio in cell nuclei; (3) An area of cell nuclei; (4) Overlapping nuclei; (5) The distribution pattern of nuclei within cell clusters.

The following observations were made: (1) In PE cells, round‐oval nuclei appeared to predominate, overlapping nuclei were not observed, and a slightly abnormal distribution pattern of nuclei was recorded; (2) In EGBD‐stromal cells, reniform nuclei were characteristically observed, nuclei had small size and a generally elongated appearance, overlapping nuclei were recognized, and a remarkable abnormal distribution pattern of nuclei was found; (3) In EGBD‐metaplastic cells, spindle nuclei were a characteristic feature, nuclei were larger in size and had a bipolar appearance, overlapping nuclei with moderately abnormal distribution pattern of nuclei were identified; (4) In G1 cells round‐oval nuclei predominated, overlapping nuclei with moderately abnormal distribution pattern of nuclei were found.

The study demonstrates that the analysis of selected nuclear findings appears to be very useful in the cytopathological assessment of endometrial lesions in LBC samples, especially for the discrimination of EGBD and G1. Diagn. Cytopathol. 2012. © 2012 Wiley Periodicals, Inc.
A case of blastic plasmacytoid dendritic cell neoplasm: Cytomorphological findings of the touch imprint specimen of lymph node
Authors: Nakatsuka Shin‐ichi , Nagano Teruaki , Kimura Hayato , Nagatomo Tadasuke , Urase Yuriko , Hashimoto Koji
Published: January 2012

The patient is a 75‐year‐old man with axillary lymphadenopathy presenting an indurated papule on his buttock. Touch imprint cytology of the biopsied axillary lymph node revealed the monotonous appearance of medium‐sized tumor cells. The nuclei had a slightly irregular contour, finely dispersed chromatin, and a conspicuous nucleolus. Some tumor cells had intracytoplasmic microvacuoles. Immunohistochemistry of the imprint specimens showed that the tumor cells were positive for CD56 and CD123. Histological diagnosis of the lesion was blastic plasmacytoid dendritic cell neoplasm (BPDCN). Epstein‐Barr virus‐encoded RNAs were not detected in the tumor cells. Neither immunoglobulin heavy chain genes nor T‐ cell receptor genes was clonally rearranged. BPDCN should be strongly considered during the differential diagnosis of CD56‐positive neoplasms of the skin. We demonstrated a possible contribution of the cytomorphological and immunohistochemical findings of the touch imprint specimens to the diagnosis of BPDCN. Diagn. Cytopathol. 2013. © 2012 Wiley Periodicals, Inc.
Intrapancreatic accessory spleen: A case report and review of literature
Authors: Rodriguez Erika , Netto George , Li Qing Kay
Published: January 2012

Intrapancreatic accessory spleen is not an uncommon entity and usually located in the tail of the pancreas. Most of them are asymptomatic and incidental findings on radiologic study or at autopsy. On imaging study, it appears to be a well‐defined, solitary, and hypervascular lesion; therefore, it may be confused with pancreatic neoplasms, such as neuroendocrine neoplasm, well‐differentiated adenocarcinoma, solid pseudopapillary tumor, or metastatic tumor to the pancreas. As such, the diagnostic fine‐needle aspiration biopsy of the lesion may be performed. Several case reports describing cytological features of the lesion have been published in recent years. Among them, the most commonly identified cytological findings are sheets of a heterogeneous population of lymphocytes and prominent traversing blood vessels. Herein, we report an unusual EUS‐FNA case of intrapancreatic accessory spleen. In addition to above previously well‐described cytological features, our case revealed many cells with fine granular chromatin and areas with pseudo rosette‐like architecture, mimicking and engendering the differential diagnosis of pancreatic neuroendocrine tumors. Although cytological findings of our case are rare, they may extend our current knowledge and provide additional differential diagnostic information for this entity. Diagn. Cytopathol. 2013. © 2012 Wiley Periodicals, Inc.
Primary squamous cell carcinoma of the endometrium: Two cases and a review of the literature
Authors: Goodrich Sarah , Kebria‐Moslemi Mehdi , Broshears John , Sutton Gregory P. , Rose Peter
Published: January 2012

Primary squamous cell carcinoma of the endometrium (PSCCE) is a rare entity, with fewer than 100 cases reported in the literature. We report two cases of PSCCE and review the literature regarding associated markers and treatment outcomes. Many different markers have been tested for association with PSCCE, with mixed results. Thus, it is likely that several etiologic factors are responsible for the development of PSCCE. Further, due to the rarity of the condition, the optimal postoperative management of patients with PSCCE remains to be defined. Diagn. Cytopathol. 2013;41:817–820. © 2012 Wiley Periodicals, Inc.
Ca2NiSn2 – A Polymorphic Intermetallic Phase: Atomic and Electronic Structure as well as a Topological Description of the Phase Transition by a Sigmatropic‐Type Rearrangement of Ni and Sn Atoms
Authors: Siggelkow Lisa , Hlukhyy Viktor , Fässler Thomas F.
Published: January 2012

The synthesis and structural characterization of two polymorphic modifications of the intermetallic compound Ca2NiSn2 are described. The monoclinic modification mC‐Ca2NiSn2 is obtained by arc melting and rapid cooling and forms two‐dimensional Ni–Sn slabs that contain four‐ and six‐membered rings. These nets are interconnected by Sn2 dumbbells and thus 12‐membered rings form between the slabs. The cavities of the resulting three‐dimensional network are filled with Ca atoms. At annealing temperatures between 800 and 870 °C, an orthorhombic modification oP‐Ca2NiSn2 forms. The two‐dimensional Ni–Sn substructure contains Ni–Sn nets of four‐ and six‐membered rings. Sn2 dumbbells coordinate to these nets end‐on to form additional five‐membered Ni–Sn rings. The resulting slabs are separated by Ca atoms. Temperature‐dependent synthesis and differential thermal analysis experiments indicate that the monoclinic modification mC‐Ca2NiSn2 is a metastable modification. Two approaches to the topological description of the phase transition are presented: 1) a conversion by a simple shift of ribbons of atomic layers and 2) a least‐motion process describing the topology of the phase transformation by an electrocyclic mechanism through Ni–Sn bond scission and formation analogous to sigmatropic shifts known for organic molecules. The electronic structures and chemical bonding are discussed in terms of DFT calculations, including density of states, band structures and a topological analysis of the electron localization function, which revealed covalent Sn2–Sn2 bonds with partial π bonding of the Sn2 dumbbells in mC‐Ca2NiSn2 and a short Sn2–Sn3 contact with dominant lone‐pair character at the terminal Sn2 atom in oP‐Ca2NiSn2.
Synthesis and Evaluation of Lipophilic BTBP Ligands for An/Ln Separation in Nuclear Waste Treatment: The Effect of Alkyl Substitution on Extraction Properties and Implications for Ligand Design
Authors: Lewis Frank W. , Harwood Laurence M. , Hudson Michael J. , Distler Petr , John Jan , Stamberg Karel , Núñez Ana , Galán Hitos , Espartero Amparo G.
Published: January 2012

Four new 6,6′‐bis(1,2,4‐triazin‐3‐yl)‐2,2′‐bipyridine (BTBP) ligands, which contain either additional alkyl groups on the pyridine rings or seven‐membered aliphatic rings attached to the triazine rings, have been synthesized, and the effects of the additional alkyl substitution in the 4‐ and 4′‐positions of the pyridine rings on their extraction properties with LnIII and AnIII cations in simulated nuclear waste solutions have been studied. The speciation of ligand 13 with some trivalent lanthanide nitrates was elucidated by 1H NMR spectroscopic titrations and ESI‐MS. Although 13 formed both 1:1 and 1:2 complexes with LaIII and YIII, only 1:2 complexes were observed with EuIII and CeIII. Quite unexpectedly, both alkyl‐substituted ligands 12 and 13 showed lower solubilities in certain diluents than the unsubstituted ligand CyMe4‐BTBP. Compared to CyMe4‐BTBP, alkyl‐substitution was found to decrease the rates of metal‐ion extraction of the ligands in both 1‐octanol and cyclohexanone. A highly efficient (DAm > 10) and selective (SFAm/Eu > 90) extraction was observed for 12 and 13 in cyclohexanone and for 13 in 1‐octanol in the presence of a phase‐transfer agent. The implications of these results for the design of improved extractants for radioactive waste treatment are discussed.
Glucose Dehydrogenase Based Bioelectrode Utilizing a Synergistic Scheme of Substrate Conversion
Authors: Kulys Juozas , Bratkovskaja Irina
Published: January 2012

A Bioelectrode utilizing a synergistic scheme of substrate conversion was built using glucose dehydrogenase from Acinetobacter calcoaceticus immobilized on the surface of a graphite electrode. At saturated glucose concentration the bioelectrode responded to the low reactive substrate hexacyanoferrate(III) with a sensitivity of 0.0035 µA/µM cm2. The response of the bioelectrode increased up to the 3.4×104 fold in the presence of high reactive organic electron acceptors (mediators). The increase of the response depended on the concentration of the mediators and their chemical nature. The sensitivity of the bioelectrode to mediators reached 7.3–77 µA/µM cm2. The comparison of the bioelectrode sensitivity with kinetic parameters of enzyme action in homogeneous solution revealed good correlation between the sensitivity of the bioelectrode and the predicted value from the kinetic scheme of the reactivity of mediators. This confirms a synergistic scheme of bioelectrode action.
The effect of near‐fault directivity on building seismic collapse risk
Authors: Champion Casey , Liel Abbie
Published: January 2012

Forward directivity may cause large velocity pulses in ground motion time histories that are damaging to buildings at sites close to faults, potentially increasing seismic collapse risk. This study quantifies the effects of forward directivity on collapse risk through incremental dynamic analysis of building simulation models that are capable of capturing the key aspects of strength and stiffness degradation associated with structural collapse. The paper also describes a method for incorporating the effects of near‐fault directivity in probabilistic assessment of seismic collapse risk. The analysis is based on a suite of RC frame models that represent both past and present building code provisions, subjected to a database of near‐fault, pulse‐like ground motions with varying pulse periods. Results show that the predicted collapse capacity is strongly influenced by variations in pulse period and building ductility; pulse periods that are longer than the first‐mode elastic building period tend to be the most damaging. A detailed assessment of seismic collapse risk shows that the predicted probability of collapse in 50 years for modern concrete buildings at a representative near‐fault site is approximately 6%, which is significantly higher than the 1% probability in the far‐field region targeted by current seismic design maps in the US. Copyright © 2012 John Wiley & Sons, Ltd.
RISK PERCEPTION, PREVENTION AND DIAGNOSTIC TESTS
Authors: Etner Johanna , Jeleva Meglena
Published: January 2012

The objective of this paper is to study the impact of risk perception and diagnostic information on medical prevention decisions. The intertemporal preferences of individuals are represented by a model of recursive rank dependent utility, which has the advantage of allowing risk perceptions to vary over time and with health status. The main results of the paper are the following. Concerning the impact of risk perception on prevention, two types of pessimists have to be distinguished: the moderate pessimists and the fatalists. Both types overestimate the probability of disease, but the fatalists underestimate the reduction of the disease probability by prevention. Risk perception modification after the occurrence of the disease influences prevention decisions. Indeed, we show that moderate pessimists often choose a high level of primary and tertiary prevention, but a moderate pessimist who becomes fatalist after the occurrence of the disease may choose a high level of primary prevention and a low level of tertiary prevention. Copyright © 2012 John Wiley & Sons, Ltd.
Regulation of myocardial matrix metalloproteinase expression and activity by cardiac fibroblasts
Authors: Turner Neil A. , Porter Karen E.
Published: January 2012

Cardiac fibroblasts (CF) play a key role in orchestrating the structural remodeling of the myocardium in response to injury or stress, in part through direct regulation of extracellular matrix (ECM) turnover. The matrix metalloproteinases (MMPs) are a family of over 25 zinc‐dependent proteases that together have the capacity to degrade all the protein components of the ECM. Fibroblasts are a major source of several MMPs in the heart, thereby representing a viable therapeutic target for regulating ECM turnover in cardiac pathologies characterized by adverse remodeling, such as myocardial infarction, cardiomyopathy, hypertension and heart failure. This review summarizes current knowledge on the identity and regulation of MMPs expressed by CF and discusses future directions for reducing adverse myocardial remodeling by modulating the expression and/or activity of CF‐derived MMPs. © 2012 IUBMB IUBMB Life, 2012.
In situ formation of porous space maintainers in a composite tissue defect
Authors: Spicer Patrick P. , Kretlow James D. , Henslee Allan M. , Shi Meng , Young Simon , Demian Nagi , Jansen John A. , Wong Mark E. , Mikos Antonios G. , Kasper F. Kurtis
Published: January 2012

Reconstruction of composite defects involving bone and soft tissue presents a significant clinical challenge. In the craniofacial complex, reconstruction of the soft and hard tissues is critical for both functional and aesthetic outcomes. Constructs for space maintenance provide a template for soft tissue regeneration, priming the wound bed for a definitive repair of the bone tissue with greater success. However, materials used clinically for space maintenance are subject to poor soft tissue integration, which can result in wound dehiscence. Porous materials in space maintenance applications have been previously shown to support soft tissue integration and to allow for drug release from the implant to further prepare the wound bed for definitive repair. This study evaluated solid and low porosity (16.9% ± 4.1%) polymethylmethacrylate space maintainers fabricated intraoperatively and implanted in a composite rabbit mandibular defect model for 12 weeks. The data analyses showed no difference in the solid and porous groups both histologically, evaluating the inflammatory response at the interface and within the pores of the implants, and grossly, observing the healing of the soft tissue defect over the implant. These results demonstrate the potential of porous polymethylmethacrylate implants formed in situ for space maintenance in the craniofacial complex, which may have implications in the potential delivery of therapeutic drugs to prime the wound site for a definitive bone repair. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2012.
Collagen–silica xerogel nanohybrid membrane for guided bone regeneration
Authors: Lee Eun‐Jung , Jun Shin‐Hee , Kim Hyoun‐Ee , Koh Young‐Hag
Published: January 2012

A collagen–silica xerogel hybrid membrane was fabricated by a sol–gel process for guided bone regeneration (GBR). The silica xerogel synthesized by the sol–gel method was distributed uniformly within the collagen matrix in the form of nanoparticles. The hybridization of the silica xerogel with collagen improved the biological properties of the membrane significantly. Preosteoblast cells were observed to adhere well and grow much more actively on the hybrid membrane than on the pure collagen membrane. In particular, the hybrid membrane containing 30% of the silica xerogel showed the highest level of osteoblast differentiation. Moreover, the GBR ability, as assessed by the in vivo animal test, was superior to that of the pure collagen membrane. These findings suggest that the collagen–silica xerogel hybrid can be used as a GBR membrane. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2012.
Dual surface modification with PEG and corn trypsin inhibitor: Effect of PEG:CTI ratio on protein resistance and anticoagulant properties
Authors: Alibeik Sara , Zhu Shiping , Yau Jonathan W. , Weitz Jeffrey I. , Brash John L.
Published: January 2012

The objective of this study was to investigate the bioactivity and protein‐resistant properties of dual functioning surfaces modified with PEG for protein resistance and corn trypsin inhibitor (CTI) for anticoagulant effect. Surfaces on gold substrate were prepared with varying ratios of free PEG to CTI‐conjugated PEG. Two methods designated, respectively, “sequential” and “direct” were used. For sequential surfaces, PEG was first immobilized on gold and the surfaces were incubated with CTI at varying concentration. For direct surfaces, a PEG–CTI conjugate was synthesized and gold surfaces were modified using solutions of the conjugate of varying concentration. The CTI density on these surfaces was measured using radiolabeled CTI. Water contact angles were measured and the thickness of PEG–CTI layers was determined by ellipsometry. Fibrinogen adsorption from buffer and human plasma, and adsorption from binary solutions of fibrinogen and α‐lactalbumin were investigated using radiolabeling methods. Bioactivity of the surfaces was evaluated via their effects on FXIIa inhibition and plasma clotting time. It was found that as the ratio of CTI‐conjugated PEG to free PEG increased, bioactivity increased but protein resistance was relatively constant. It is concluded that on these surfaces conjugation of PEG to CTI does not greatly compromise the protein resistance of the PEG but results in improved interactions between the CTI and the “target” protein FXIIa. At the same CTI density, sequential surfaces were more effective in terms of inhibiting FXIIa and prolonging clotting time. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2012.
Intramyocardial hematoma with epicardial rupture following percutaneous coronary intervention
Authors: Ertan Cagatay , Ozeke Ozcan , Demir Ahmet Duran
Published: January 2012

Intramyocardial (or subepicardial) hematomas are uncommon conditions that occur mostly after myocardial infarction, percutaneous coronary intervention (PCI), coronary artery bypass surgery, cardiac surgery, or chest trauma. Coronary perforation is a rare complication of PCI and the subset of patients developing an intramyocardial hematoma, usually considered a catastrophic event, is even rarer. We describe here the case of 63‐year‐old man in whom an intramyocardial hematoma with epicardial rupture occurred after PCI. The patient was treated conservatively with a successful outcome. © 2012 Wiley Periodicals, Inc. J Clin Ultrasound, 2013.
Effect of surface roughness on magneto‐hydrodynamic couple‐stress squeeze film lubrication between circular stepped plates
Authors: Naduvinamani N. B. , Hanumagowda B. N. , Siddangouda A.
Published: January 2012

In this paper, a theoretical analysis of the problem of magneto‐hydrodynamic couple‐stress squeeze film lubrication between rough circular stepped plates is presented. The modified averaged Reynolds equation is derived for the two types of one‐dimensional roughness structures, namely the radial roughness pattern and the azimuthal roughness pattern. The closed‐form expressions are obtained for the mean squeeze film pressure, load‐carrying capacity and squeeze film time. The results are presented for different operating parameters. It is observed that the effect of azimuthal (radial) roughness pattern on the bearing surface is to increase (decrease) the mean load‐carrying capacity and squeeze film time. The applied magnetic field increases the load‐carrying capacity and lengthens the squeezing time. Copyright © 2012 John Wiley & Sons, Ltd.
Pressure viscosity coefficients and traction properties of synthetic lubricants for wind turbine gear systems
Authors: Greaves Martin
Published: January 2012

Synthetic lubricants are increasingly used to provide equipment reliability for wind turbine gear boxes. The majority of synthetic lubricants used today are based on polyalphaolefins. In gear systems where contact pressures are high, the pressure viscosity coefficient and traction values of the lubricant are important fundamental properties. A comparison of these properties for a wind turbine lubricant based on a polyalphaolefin and two lubricants based on polyalkylene glycols has been undertaken. Pressure viscosity coefficients were calculated from viscosity measurements made using an ultra‐high pressure falling needle viscometer at pressures up to 50 000 psi. Significant differences in properties were observed with both polyalkylene glycol lubricants showing lower pressure viscosity coefficients and much lower traction values. A calculation of the film thickness values in the Hertzian contact zone suggests that polyalkylene glycol lubricants may provide elastohydrodynamic films that are approximately 25% thicker than polyalphaolefin lubricants. Copyright © 2012 John Wiley & Sons, Ltd.
Optimal wavelengths for vein‐selective photothermolysis
Authors: Rubin Iris K. , Farinelli William A. , Doukas Apostolos , Anderson R. Rox
Published: January 2012

Background and Objective

Oxyhemoglobin (HbO2) has been regarded as the primary target chromophore for selective photothermolysis of vascular malformations. In theory, venous lesions might be better treated with wavelengths preferentially absorbed by deoxyhemoglobin (Hb).

Study Design/Materials and Methods

Wavelength‐dependent fluence thresholds for photocoagulation of whole human blood were determined in glass capillary samples with measured oxygen saturation levels. Pulsed dye lasers at 585, 590, 595, 600, 633 nm, a 694 nm ruby laser, a 755 nm alexandrite laser, and a 1,064 nm Nd:Yag laser were used, all with 1.5–3 milliseconds pulse width and similar exposure spot size.

Results

Selectivity (a lower fluence threshold) for venous blood was maximal at 694 nm, and significant at 595, 600, 633, and 755 nm. At 633 nm, a wavelength with strong relative absorption by metHb, selectivity for venous blood was much less than expected. The Nd:YAG laser at 1,064 nm showed significant selectivity for arterial blood.

Conclusion

Preferential photocoagulation of venous blood is possible at wavelengths with a high Hb/HbO2 absorption coefficient ratio. Laser‐induced metHb may also affect wavelength‐dependent selective photothermolysis. Venular malformations such as port wine stains could potentially be treated more selectively with ∼630–780 nm sources. Nd:YAG laser pulses at 1,064 nm tend to affect arterial more than venous blood. Lasers Surg. Med. 44:152–157, 2012. © 2012 Wiley Periodicals, Inc.
Huntington's disease: Objective assessment of posture—A link between motor and functional deficits
Authors: Reilmann Ralf , Rumpf Silke , Beckmann Heike , Koch Raphael , Ringelstein Erich B. , Lange Herwig W.
Published: January 2012

Background:

Postural deficits in Huntington's disease are linked to functional impairment. We investigated whether assessment of center‐of‐mass variability using posturography provides objective and quantitative measures that correlate to the severity of motor phenotype, functional measures, and genotype as assessed by a disease burden score (based on repeat length and age). In addition, we investigated whether withdrawing visual feedback facilitates the detection of postural deficits.

Methods:

Using a force plate, the ability of symptomatic Huntington's disease patients (n = 34) and controls (n = 20) to stand as stably as possible was assessed in eyes‐open and eyes‐closed conditions.

Results:

All posturographic measures (DISTANCE, VELOCITY, and SURFACE of centre‐of‐mass mobility) were increased in patients and correlated to (1) the UHDRS Total Motor Score, (2) the UHDRS Total Functional Capacity, (3) the UHDRS Functional Assessment Score, and (4) the disease burden score. Correlations to motor and functional measures were stronger when visual feedback was provided.

Conclusions:

Posturography may provide useful objective and quantitative measures of postural motor dysfunction in Huntington's disease. © 2012 Movement Disorder Society
Optimization of iron oxide nanoparticle detection using ultrashort echo time pulse sequences: Comparison of T1, T2*, and synergistic T1 − T2* contrast mechanisms
Authors: Girard O. M. , Du J. , Agemy L. , Sugahara K. N. , Kotamraju V. R. , Ruoslahti E. , Bydder G. M. , Mattrey R. F.
Published: January 2012

Iron oxide nanoparticles (IONPs) are used in various MRI applications as negative contrast agents. A major challenge is to distinguish regions of signal void due to IONPs from those due to low signal tissues or susceptibility artifacts. To overcome this limitation, several positive contrast strategies have been proposed. Relying on IONP T1 shortening effects to generate positive contrast is a particularly appealing strategy because it should provide additional specificity when associated with the usual negative contrast from effective transverse relaxation time (T2*) effects. In this article, ultrashort echo time imaging is shown to be a powerful technique which can take full advantage of both contrast mechanisms. Methods of comparing T1 and T2* contrast efficiency are described and general rules that allow optimizing IONP detection sensitivity are derived. Contrary to conventional wisdom, optimizing T1 contrast is often a good strategy for imaging IONPs. Under certain conditions, subtraction of a later echo signal from the ultrashort echo time signal not only improves IONP specificity by providing long T2* background suppression but also increases detection sensitivity, as it enables a synergistic combination of usually antagonist T1 and T2* contrasts. In vitro experiments support our theory, and a molecular imaging application is demonstrated using tumor‐targeted IONPs in vivo. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.