bluuebunny/crossref_metadata_2025 huggingface dataset:
Implementing Liquid‐Crystalline Properties in Single‐Stranded Dinuclear Lanthanide Helicates
Authors: Terazzi Emmanuel , Zaïm Amir , Bocquet Bernard , Varin Johan , Guénée Laure , Dutronc Thibault , Lemonnier Jean‐François , Floquet Sébastien , Cadot Emmanuel , Heinrich Benoît , Donnio Bertrand , Piguet Claude
Published: June 2013

Invited for the cover of this issue is the group of Emmanuel Terazzi at the University of Geneva, Switzerland. The cover image shows how single‐stranded dinuclear lanthanide helicates (green) survive immersion into a drop of less polar solvent (e.g. CH2Cl2) and their eventual self‐organization into a liquid‐crystalline material.
Iron‐Catalyzed Direct C–H Arylation of Heterocycles and Quinones with Arylboronic Acids
Authors: Deb Arghya , Manna Srimanta , Maji Arun , Dutta Uttam , Maiti Debabrata
Published: June 2013

The arylation of C–H bonds to generate heteroaryl–aryl (Het–Ar) and arylated quinone (Quin–Ar) compounds has received great attention to achieve sustainable goals in synthetic chemistry. Despite significant advances, arylation of a broad range of Het–Ar and Quin–Ar derivatives remains a challenging task. Herein, a variety of heterocycles are arylated by using arylboronic acids in the presence of catalytic amounts of inexpensive Fe(NO3)3. The C‐arylated quinone compounds can be prepared by reacting arylboronic acids with either quinone or hydroquinone. The present method is operationally simple, scalable, does not require prefunctionalization of the heterocycle or quinone, and can tolerate a wide variety of functional groups in the coupling partners. These qualities are expected to render this method attractive for academic and industrial use.
A critical investigation of smoothed particle hydrodynamics applied to problems with free‐surfaces
Authors: Le Touzé D. , Colagrossi A. , Colicchio G. , Greco M.
Published: June 2013

In this paper, an in‐depth study of SPH method, in its original weakly compressible version, is achieved on dedicated 2D and 3D free‐surface flow test cases. These rather critical prototype problems shall constitute suitable test cases to get through when building a free‐surface SPH model. The present work aims at investigating various numerical aspects of this method, often little mentioned in literature. In particular, a great care is paid to the dynamic part of the solution, which is critical to the local hydrodynamic load prediction. The role of numerical errors in the development of acoustic frequencies in the pressure signals is discussed, as well as the influence of the choice of the sound velocity. On the shown test problems, it is also evidenced that some numerical tools are crucial to ensure the robustness and accuracy of the standard SPH method. The convergence of our model is heuristically proved on these nonlinear prototype tests, showing at the same time the very satisfactory level of accuracy reached. Through these tests, some other numerical specificities of the SPH method are discussed, such as the self‐redistribution of the particles occurring during the Lagrangian evolution. A higher order model is also proposed, and its advantages and drawbacks are discussed. Copyright © 2013 John Wiley & Sons, Ltd.
Dynamic Implied Correlation Modeling and Forecasting in Structured Finance
Authors: Löhr Sebastian , Mursajew Olga , Rösch Daniel , Scheule Harald
Published: June 2013

Correlations are the main drivers for credit portfolio risk and constitute a major element in pricing credit derivatives such as synthetic single‐tranche collateralized debt obligation swaps. This study suggests a dynamic panel regression approach to model and forecast implied correlations. Random effects are introduced to account for unobservable time‐specific effects on implied tranche correlations. The implied‐correlation forecasts of tranche spreads are compared to forecasts using historical correlations from asset returns. The empirical findings support our proposed dynamic mixed‐effects regression correlation model. © 2013 Wiley Periodicals, Inc. Jrl Fut Mark
Microseismicity of the Mid‐Atlantic Ridge at 7°S–8°15′S and at the Logatchev Massif oceanic core complex at 14°40′N–14°50′N
Authors: Grevemeyer Ingo , Reston Timothy J. , Moeller Stefan
Published: June 2013

Lithospheric formation at slow spreading rates is heterogeneous with multiple modalities, favoring symmetric spreading where magmatism dominates or core complex and inside corner high formation where tectonics dominate. We report microseismicity from three deployments of seismic networks at the Mid‐Atlantic Ridge (MAR). Two networks surveyed the MAR near 7°S in the vicinity of the Ascension transform fault. Three inside corner high settings were investigated. However, they remained seismically largely inactive and major seismic activity occurred along the center of the median valley. In contrast, at the Logatchev Massif core complex at 14°45′N seismicity was sparse within the center of the median valley but concentrated along the eastern rift mountains just west of the serpentine hosted Logatchev hydrothermal vent field. To the north and south of the massif, however, seismic activity occurred along the ridge axis, emphasizing the asymmetry of seismicity at the Logatchev segment. Focal mechanisms indicated a large number of reverse faulting events occurring in the vicinity of the vent field at 3–5 km depth, which we interpret to reflect volume expansion accompanying serpentinization. At shallower depth of 2–4 km, some earthquakes in the vicinity of the vent field showed normal faulting behavior, suggesting that normal faults facilitates hydrothermal circulation feeding the vent field. Further, a second set of cross‐cutting faults occurred, indicating that the surface location of the field is controlled by local fault systems.
A 4 kyr stalagmite oxygen isotopic record of the past Indian Summer Monsoon in the Andaman Islands
Authors: Laskar Amzad H. , Yadava M. G. , Ramesh R. , Polyak V. J. , Asmerom Y.
Published: June 2013

In order to reconstruct the activity of the Indian Summer Monsoon (ISM) during the last ∼4 kyr, two stalagmites from Baratang cave in Andaman Islands have been investigated for their temporal variations in δ18O. The chronology is provided by radiocarbon ages on the stalagmites. During 1800–2100 cal yr BP, we observed a significant increase in stalagmite δ18O that we infer is caused by the amount effect. This increase implies a strong reduction in the strength of the ISM that is correlated with the Roman Warm Period. Other proxy records in the region confirm a reduction in ISM activity during this time. Reduction in the ISM is also observed around 1500 and 400–800 cal yr BP; the latter period is the transition from the Medieval Warm Period to the Little Ice Age. The strongest monsoon in the last ∼4 kyr is observed during 800–1200 cal yr BP, the Medieval Warm Period.
Functionalized DNA Nanostructures for Nanomedicine
Authors: Liu Xiaowei , Liu Yan , Yan Hao
Published: June 2013

DNA nanotechnology utilizes synthetic DNA strands as the building material to construct nanoscale devices, and the field has developed rapidly over the past decade. Recently, the use of DNA nanostructures for various applications, particularly biomedical ones, has drawn great interest. This review focuses on the most recent research directed at utilizing functionalized DNA devices for nanomedical applications and presents representative research progress in disease diagnosis, treatment and prevention. In addition, the safety and future clinical applications of DNA nanostructures are discussed.
Enantioselective Gold(I) Catalysis with Chiral Monodentate Ligands
Authors: Cera Gianpiero , Bandini Marco
Published: June 2013

Enantioselective gold(I) catalysis is receiving a growing level of credit in the field of asymmetric synthesis. After a pioneering work in the mid‐1980s the area remained almost silent for several years, until densely substituted diphosphine chiral ligands were disclosed as competent chiral units for gold‐catalyzed stereoselective manipulation of unactivated unsaturated hydrocarbons. The chemistry of alkynes, allenes and most recently also alkenes received significant benefits from the latter developments. More recently, ad hoc designed chiral monodentate ligands have risen to prominence in producing robust, highly tunable (electronic and steric) and efficient chiral cationic mononuclear gold species for asymmetric transformations. In this scenario, electron‐deficient phosphorus‐based (i.e., phosphoramidites, phosphites) but also axially chiral electron‐rich carbene ligands deserve particular mention and the corresponding applications will be summarized herein.
GPNMB enhances bone regeneration by promoting angiogenesis and osteogenesis: Potential role for tissue engineering bone
Authors: Hu Xuefeng , Zhang Ping , Xu Zhenjie , Chen Hongdong , Xie Xin
Published: June 2013

Bone regeneration is a coordinated process involving the connection between blood vessels and bone cells. Glycoprotein non‐metastatic melanoma protein B (GPNMB) is known to be vital in bone formation. However, the effect of GPNMB on bone regeneration and the underlying molecular mechanism are still undefined. Fibroblast growth factor receptor (FGFR)‐mediating signaling is pivotal in bone formation and angiogenesis. Therefore, we assessed GPNMB function as a communicating molecule between osteoblasts and angiogenesis, and the possible correlation with FGFR‐1 signaling. Recombinant GPNMB dose‐dependently increased the differentiation of human bone marrow stromal cells (hBMSCs) into osteoblasts, as well as the mRNA levels of osteoblasts marker alkaline phosphatase (ALP) and osteocalcin (OCN). Furthermore, these increases depended on the activation of FGFR‐1 signaling, as pretreatment with FGFR‐1 siRNA or its inhibitor SU5402 dramatically dampened GPNMB‐induced osteogenesis. Additionally, GPNMB triggered dose‐dependently the proliferation and migration of human umbilical vein endothelial cells (hUVECs), FGFR‐1 phosphorylation, as well as capillary tube and vessels formation in vitro and in vivo. Blocking FGFR‐1 signaling dampened GPNMB‐induced angiogenic activity. Following construction of a rodent cranial defect model, scaffolds delivering GPNMB resulted in an evident increase in blood vessels and new bone formation; however, combined delivery of GPNMB and SU5402 abated these increase in defect sites. Taken together, these results suggest that GPNMB stimulates bone regeneration by inducing osteogenesis and angiogenesis via regulating FGFR‐1 signaling. Consequently, our findings will clarify a new explanation about how GPNMB induces bone repair, and provide a potential target for bone regeneration therapeutics and bone engineering. J. Cell. Biochem. 114: 2729–2737, 2013. © 2013 Wiley Periodicals, Inc.
Transient Insomnia Versus Chronic Insomnia: A Comparison Study of Sleep‐Related Psychological/Behavioral Characteristics
Authors: Yang Chien‐Ming , Lin Shih‐Chun , Cheng Chung‐Ping
Published: June 2013

Objectives

Vulnerability to transient insomnia is regarded as a predisposing factor for chronic insomnia. However, most individuals with transient insomnia do not develop chronic insomnia. The current study investigated the differential contributing factors for these two conditions to further the understanding of this phenomenon.

Method

Chronic insomnia patients and normal sleepers with high and low vulnerability to transient insomnia completed measures of pre‐sleep arousal, dysfunctional sleep beliefs, and sleep‐related safety behaviors.

Results

Both cognitive and somatic pre‐sleep arousals were identified as significant predictors for transient insomnia. Dysfunctional beliefs regarding worry about insomnia and cognitive arousal were predictors for chronic insomnia. Sleep‐related safety behavior, although correlated with insomnia severity, was not a significant predictor for both conditions.

Conclusions

Dysfunctional beliefs associated with worry and losing control over sleep are the most critical factors in differentiating chronic insomnia from transient insomnia. These factors should be addressed to help prevent individuals with high sleep vulnerability from developing chronic sleep disturbance.
Role of Meaning in the Prediction of Depressive Symptoms Among Trauma‐Exposed and Nontrauma‐Exposed Emerging Adults
Authors: Woo Candice R. S. , Brown Elissa J.
Published: June 2013

Objectives

This study investigated the role of searching for meaning, finding meaning, trauma exposure, and their interaction in the prediction of depressive symptoms among trauma‐exposed and nontrauma‐exposed emerging adults.

Method

Eight thousand seven hundred and eighty‐four college students (73% female; mean age of 19.8 years) completed self‐report measures. Hierarchical regression analysis was conducted to evaluate the three‐way interaction in the prediction of depressive symptoms.

Results

Searching for and finding meaning as well as the three‐way interaction significantly contributed to the prediction of depression. Specifically, searching for meaning was associated with increased symptoms, irrespective of meaning levels among nontrauma‐exposed and low frequency trauma‐exposed emerging adults. Among high frequency trauma‐exposed individuals, an increase in the search‐by‐find meaning interaction predicted fewer symptoms.

Conclusions

The findings suggest that searching for and finding meaning are important mechanisms in the prediction of depression among emerging adults facing daily stressors and traumatic events. Clinical implications are discussed.
Pacific SST influence on spring precipitation in Addis Ababa, Ethiopia
Authors: Eden Jonathan M. , Widmann Martin , Evans Gavin R.
Published: June 2013

Recent periods of drought in Ethiopia and other parts of East Africa have highlighted the growing importance of producing reliable forecasts of seasonal precipitation. Key in deriving such forecasts is a good understanding of the atmospheric and oceanic drivers of different precipitation regimes. In Ethiopia and other parts of East Africa, interannual variability of precipitation depends on variations in sea surface temperature (SST) and atmospheric circulation on both regional and global scales. Links between summer precipitation in Ethiopia and large‐scale modes of climate variability such as El Niño Southern Oscillation (ENSO) have previously been established but the influence of global SST on spring precipitation has not yet been fully explored. Here, we analyse the links between Pacific SST and precipitation in Addis Ababa, Ethiopia for a century‐long period (1900–2004). A tripole correlation pattern between spring precipitation and SST in the Pacific basin is found. We develop regression‐based models to estimate spring precipitation from Pacific SST with a lead time of two to three months. When subject to cross‐validation, models based on principal component multiple linear regression (PC‐MLR) calibrated on Pacific SST during December show substantial skill in reproducing observed temporal variability in Addis Ababa precipitation during February (r = 0.48) and March (r = 0.40), and the period spanning February to April (r = 0.44). Our findings suggest that the inclusion of Pacific SST in predictive models may benefit drought forecasting across Ethiopia.
Melt Spinning of Biodegradable Nanofibrillary Structures from Poly(lactic acid) and Poly(vinyl alcohol) Blends
Authors: An Tran Nguyen Hoai , Brünig Harald , Hinüber Claudia , Heinrich Gert
Published: June 2013

A novel fabrication process for preparing continuous thermoplastic nanofibrillary structures by using the conventional melt spinning method of thermoplastic polymer fibers is developed. Poly(lactic acid) nanofibrils with average diameter of 60 nm are obtained by processing water soluble poly(vinyl alcohol) (PVA) and poly(lactic acid) (PLA) blends at weight ratio of 70/30 and subsequent removal of the PVA matrix. The textile physical properties (tensile and elongation properties) of the PVA/PLA filaments are investigated and interpreted. Produced 2D and 3D PLA textile structures are promising candidates as scaffolds for tissue engineering. Using the conventional melt spinning method and selecting PVA with the properties of “green polymer” as a matrix component, this fabrication process therefore provides an optimal solution to handle important scientific challenges at the present time: the economic and environmental friendly fabrication of highly specialized products for medical purposes.
Sobolev spaces on Riemannian manifolds with bounded geometry: General coordinates and traces
Authors: Große Nadine , Schneider Cornelia
Published: June 2013

We study fractional Sobolev and Besov spaces on noncompact Riemannian manifolds with bounded geometry. Usually, these spaces are defined via geodesic normal coordinates which, depending on the problem at hand, may often not be the best choice. We consider a more general definition subject to different local coordinates and give sufficient conditions on the corresponding coordinates resulting in equivalent norms. Our main application is the computation of traces on submanifolds with the help of Fermi coordinates. Our results also hold for corresponding spaces defined on vector bundles of bounded geometry and, moreover, can be generalized to Triebel‐Lizorkin spaces on manifolds, improving [11].
Usefulness of the Montreal Cognitive Assessment (MoCA) in Huntington's disease
Authors: Gluhm Shea , Goldstein Jody , Brown Daniel , Van Liew Charles , Gilbert Paul E. , Corey‐Bloom Jody
Published: June 2013

Background

The Montreal Cognitive Assessment (MoCA) is a brief screening instrument for dementia that is sensitive to executive dysfunction. This study examined its usefulness for assessing cognitive performance in mild, moderate, and severe Huntington's disease (HD), compared with the use of the Mini–Mental State Examination (MMSE).

Methods

We compared MoCA and MMSE total scores and the number of correct answers in 5 cognitive‐specific domains in 104 manifest HD patients and 100 matched controls.

Results

For the total HD sample, and for the moderate and severe patients, significant differences between both MoCA and MMSE total scores and almost all cognitive‐specific domains emerged. Even mild HD subjects showed significant differences with regard to total score and several cognitive domains on both instruments.

Conclusions

We conclude that the MoCA, although not necessarily superior to the MMSE, is a useful instrument for assessing cognitive performance over a broad level of functioning in HD. © 2013 International Parkinson and Movement Disorder Society
Global existence of classical solutions to two‐dimensional Navier–Stokes equations with Cauchy data containing vacuum
Authors: Luo Zhen
Published: June 2013

In this paper, the Cauchy problem to the two‐dimensional isentropic compressible Navier–Stokes equations with smooth initial data containing vacuum is investigated. If the initial data are of small energy but possibly large oscillations, we obtain the global well‐posedness of classical solutions in the case of initially nonvacuum far fields. In particular, the smallness of the energy only depends on the norm of the initial velocity, where β can be arbitrary close to 0. In the case of compactly supported initial density, a blow‐up example is given. Copyright © 2013 John Wiley & Sons, Ltd.
Multiscaling analysis of a slowly varying single species population model displaying an Allee effect
Authors: Idlango Majda A. , Shepherd John J. , Gear John A.
Published: June 2013

We consider the growth of a single species population modelled by a logistic equation modified to accommodate an Allee effect, in which the model parameters are slowly varying functions of time. We apply a multitiming technique to construct general approximate expressions for the evolving population in the case where the population survives to a (slowly varying) finite positive limiting state, and that where the population declines to extinction. We show that these expressions give excellent agreement with the results of numerical calculations for particular instances of the changing model parameters. Copyright © 2013 John Wiley & Sons, Ltd.
Systematic assignment of NMR spectra of 5‐substituted‐4‐thiopyrimidine nucleosides
Authors: Zhang Xiaohui , Wang Jian , Xu Yao‐Zhong
Published: June 2013

Unambiguous characterization of 5‐substituted‐4‐thiopyrimidine nucleosides (ribonucleosides and 2'‐deoxynucleosides) was performed using NMR spectroscopy. Assignments of all proton and carbon signals of 5‐bromo‐4‐thiouridine and related nucleosides were systematically carried out and firmly established by COSY and HMQC techniques. The NMR data of various 4‐thiopyrimidine nucleosides are compared, and the key contributing factors discussed. The approach presented here is applicable to other modified nucleosides and nucleotides, as well as nucleobases. Copyright © 2013 John Wiley & Sons, Ltd.
SGEBP, a giant protein from starfish oocytes able to interact with ERK
Authors: Vergé Valérie , Lozano Jean‐Claude , Schatt Philippe , Peaucellier Gérard
Published: June 2013

The mitogen‐activated protein kinase (MAPK) pathway is a key regulator of animal meiotic divisions. It involves cascades of kinases whose specificity has been shown to depend on binding proteins acting as scaffolds. We searched for proteins interacting with starfish extracellular signal‐regulated kinase (ERK) using the yeast two‐hybrid system. An interacting clone was found to encode the 5′ region of a giant 16.7‐kb transcript encoded by an intronless gene. The corresponding 630‐kDa protein could not be detected by Western blot, but the meiotic spindle was labelled by immunolocalization with an antibody against the ERK‐binding domain. A related gene was found in the genome of another starfish species, and similarities were also found to a 42.9‐kb open reading frame in the sea urchin genome. Yet, no conserved protein‐binding domain was detected in the amino acid sequence(s) compared to all the known motifs. Structure prediction software indicated that the encoded proteins are probably disordered while a query of the disordered protein database indicated some similarity with vertebrates microtubule‐associated protein 2 (MAP2). This predicts that SGEBP may function as a space‐filling polymer, having a role in both cytoskeleton organization and ERK targeting. Mol. Reprod. Dev. 80: 816–825, 2013. © 2013 Wiley Periodicals, Inc.
Time domain removal of irrelevant magnetization in chemical exchange saturation transfer Z‐spectra
Authors: Yadav Nirbhay N. , Chan Kannie W. Y. , Jones Craig K. , McMahon Michael T. , van Zijl Peter C. M.
Published: June 2013

Purpose

To evaluate the possibility of processing Z‐spectra using time domain analysis.

Methods

An inverse Fourier transform (IFT) is applied on Z‐spectra, thus transforming the chemical exchange saturation transfer (CEST) data into the time domain. Here, large interfering signals from solvent and semisolid magnetization transfer can be fit and filtered out. The method is demonstrated on a range of phantoms (creatine, a para‐CEST agent, and hen egg white) and also in vivo on a mouse brain.

Results

Using time domain analysis, signal components in Z‐spectra could be fit very well, thus enabling irreverent or nuisance components to be removed. The method worked equally well for samples in a solution or a gel where the large contribution from conventional magnetization transfer contrast (MTC) was easily separated out. Results from egg white and mouse brain in vivo data showed that the large water resonance could easily be removed thus allowing the remaining signal to be analyzed without interference from direct water saturation.

Conclusions

This method successfully filtered out the large nuisance signals from bulk water and MTC in Z‐spectra in a large variety of phantom types and also in vivo. It is expected to be a potentially powerful tool for CEST studies without needing asymmetry analysis. Magn Reson Med 70:547–555, 2013. © 2013 Wiley Periodicals, Inc.
Field emission of MWCNTs/PANi nanocomposites prepared by ex‐situ and in‐situ polymerization methods
Authors: Shumaila Samina Husain , Parveen Shama , Ali Javid , Kumar Avshish , Husain M.
Published: June 2013

The present work describes the field‐emission properties of multiwalled carbon nanotubes (MWCNTs) coated with conducting polymer polyaniline (PANi). MWCNTs/PANi nanocomposites have been prepared by ex‐ situ polymerization methods and inex‐ situ chemical polymerization and are analyzed by SEM and Raman spectroscopy. It is fairly clear from SEM images that PANi is coated on the surface of MWCNT. SEM image of PANi powder also shows that the powder obtained is PANi nanofibers. It is also observed from SEM images that the shell diameter of MWCNTs depends on PANi content in thenanocomposites. The average outer diameter of MWCNTs increases from 7–15 to 50–80 nm upon PANi coating. Field‐emission study shows that although there is decrease in the value of turnex‐on field Eto and increase in the value field enhancement factor β of the nanocomposites as we go from direct solid‐state mixing method to inex‐ situ chemical polymerization method, the parameters obtained by inex‐ situ polymerization chemical method shows superior field emission. The turn‐on field of the nanocomposites are between 2.5 and 4.5 V/μm and the field enhancement factors are significantly high, between 1.2 × 103 and 9.2 × 103 while. PANi nanofibers does not show any field emission. POLYM. COMPOS. 34:1298–1305, 2013. © 2013 Society of Plastics Engineers
Water‐blown polyurethane–clay nanocomposite foams from biopolyol—effect of nanoclay on the properties
Authors: Palanisamy Aruna
Published: June 2013

The present work deals with the development of polyurethane–clay nanocomposite foams by replacing part of the synthetic polyol with castor oil derivative. Hydroxylated castor oil was converted into diethanol amide by transamidation and the resulting polyol was formulated into water‐blown foams. Modified montmorillonite clay was used as nanofiller in different amounts viz. 0.5%, 1.0%, 2.0%, and 5.0% by total weight of the foam formulation. Rheological measurements on the polyol–clay mixtures indicated that up to 1% clay loading there is no significant change in the viscosity with shear rate and beyond 2%, shear thinning occurred. X‐ray diffraction studies further substantiated these results. The effect of the modified clay on the density, mechanical properties such as compression strength, compression modulus, and microstructure of the foams were investigated. The filler thus added had a reinforcing effect on the foam as observed in the density and compression strength measurements. Differential scanning calorimetric studies on Tg and dynamic mechanical analyses on the modulus clearly indicated that 1% clay loading and above led to exfoliation and plasticizing effect. Exfoliated nanocomposites in compositions containing 1% clay and more yielded a much higher nucleation rate than intercalated ones leading to reduced cell size as observed by optical and scanning electron microscopy. Thus, castor oil, which is readily available, relatively inexpensive, and environmentally benign nonedible oil, has been successfully used to prepare filled semirigid foams which can find application in insulation and packing. POLYM. COMPOS. 34:1306–1312, 2013. © 2013 Society of Plastics Engineers
Clinical Laboratory–Based Assay Methodologies May Underestimate and Increase Variability of Vancomycin Protein Binding in Hospitalized Patients
Authors: Crandon Jared L. , MacVane Shawn H. , Nicolau David P.
Published: June 2013

Study Objective

To evaluate and compare the percent protein binding of vancomycin in hospitalized patients by using a clinical or research laboratory–derived assay methodology, and to evaluate potential patient characteristics accounting for alterations in protein binding.

Design

Prospective noninterventional cohort study.

Setting

Single‐center tertiary care medical center.

Patients

A total of 55 hospitalized adults who were receiving vancomycin for a suspected or documented infection between August and November 2011 and required therapeutic drug monitoring.

Measurements and Main Results

Vancomycin protein‐binding studies were conducted by using ultracentrifugation of 63 blood samples collected from the 55 patients for therapeutic drug monitoring as part of clinical practice. Total and free drug concentrations were assayed in the research laboratory by using high‐performance liquid chromatography (HPLC) and in the clinical laboratory by using fluorescence polarization immunoassay (FPIA). Multivariate linear regression analysis was performed to identify patient variables that were predictive of vancomycin protein binding. The average protein binding was statistically significantly lower and more variable when assayed byFPIAcompared withHPLC(mean ± SD47.3 ± 13.0% vs 54.6 ± 9.5%, p<0.001). Multivariate analyses showed that after controlling for days of vancomycin therapy, patients in the intensive care unit (ICU) had a protein binding value that was 8.4% lower than non‐ICUpatients (p=0.005).

Conclusion

Using research laboratory–basedHPLCmethodology, we identified an average vancomycin protein binding of 54.6% with considerably less variability than reported in the literature using clinical‐based assay methodologies. Further, we identified patient factors that may likewise have an impact on this value. Future studies of vancomycin protein binding should consider use of a nonclinical assay to minimize methodological‐induced variability.
Mechanistic aspects of reactions of triphenylphosphine with electron‐deficient alkenes in acetic acid solution
Authors: Salin Alexey V. , Fatkhutdinov Albert R. , Il'in Anton V. , Sotov Evgeniy I. , Sobanov Alexandr A. , Galkin Vladimir I. , James Brian R.
Published: June 2013

Kinetic data provide evidence that proton transfer to the carbanion centre of a phosphonium zwitterion is the rate‐determining step in quarternization reactions of triphenylphosphine with electron‐deficient alkenes in acetic acid solution. This conclusion is based on the third‐order rate equation, the reactivity of the alkenes, and solvent isotope effects in deuteroacetic acid. Copyright © 2013 John Wiley & Sons, Ltd.
Four‐component relativistic chemical shift calculations of halogenated organic compounds
Authors: Demissie Taye B. , Repisky Michal , Komorovsky Stanislav , Isaksson Johan , Svendsen John S. , Dodziuk Helena , Ruud Kenneth
Published: June 2013

The calculation of nuclear magnetic resonance (NMR) properties of organic compounds with heavy elements has been a computational challenge due to the importance of relativistic effects and the cost of relativistic calculations capable of capturing these effects. The heavy‐atom effect on the chemical shift of light atoms also challenges the interpretation of NMR spectra of organic compounds, since relativistic effects can affect the predicted values of protons bonded to heavy atoms by as much as 20 ppm. Here, we investigate the chemical shifts of six organic compounds with/without halogen atoms using non‐relativistic and state‐of‐the‐art four‐component relativistic methods, comparing the results to available experimental data. Our study confirms the importance of relativistic effects in modeling NMR properties of organic compounds involving heavy atoms and shows that these effects cannot be properly described by non‐relativistic methods. We also demonstrate that relativistic four‐component calculations of NMR chemical shifts now have reached a level of maturity that allows these methods to be used routinely in theoretical studies of NMR properties of large organic compounds containing heavy elements. The accuracy of these calculations is high enough to allow them to be used in assisting in the structural characterization of natural compounds. Comparison of the GGA functionals used in the four‐component relativistic density functional theory calculations shows that the PBE functional seems to be well suited for such studies. Copyright © 2013 John Wiley & Sons, Ltd.
EFFECTS OF THE ELECTRONIC SPIN TRANSITIONS OF IRON IN LOWER MANTLE MINERALS: IMPLICATIONS FOR DEEP MANTLE GEOPHYSICS AND GEOCHEMISTRY
Authors: Lin Jung‐Fu , Speziale Sergio , Mao Zhu , Marquardt Hauke
Published: June 2013

We have critically reviewed and discussed currently available information regarding the spin and valence states of iron in lower mantle minerals and the associated effects of the spin transitions on physical, chemical, and transport properties of the deep Earth. A high‐spin to low‐spin crossover of Fe2+ in ferropericlase has been observed to occur at pressure‐temperature conditions corresponding to the middle part of the lower mantle. In contrast, recent studies consistently show that Fe2+ predominantly exhibits extremely high quadrupole splitting values in the pseudo‐dodecahedral site (A site) of perovskite and post‐perovskite, indicative of a strong lattice distortion. Fe3+ in the A site of these structures likely remains in the high‐spin state, while a high‐spin to low‐spin transition of Fe3+ in the octahedral site of perovskite occurs at pressures of 15–50 GPa. In post‐perovskite, the octahedral‐site Fe3+ remains in the low‐spin state at the pressure conditions of the lowermost mantle. These changes in the spin and valence states of iron as a function of pressure and temperature have been reported to affect physical, chemical, rheological, and transport properties of the lower mantle minerals. The spin crossover of Fe2+ in ferropericlase has been documented to affect these properties and is discussed in depth here, whereas the effects of the spin transition of iron in perovskite and post‐perovskite are much more complex and remain debated. The consequences of the transitions are evaluated in terms of their implications to deep Earth geophysics, geochemistry, and geodynamics including elasticity, element partitioning, fractionation and diffusion, and rheological and transport properties.
Counting Fluorescent Dye Molecules on DNA Origami by Means of Photon Statistics
Authors: Kurz Anton , Schmied Jürgen J. , Grußmayer Kristin S. , Holzmeister Phil , Tinnefeld Philip , Herten Dirk‐Peter
Published: June 2013

Obtaining quantitative information about molecular assemblies with high spatial and temporal resolution is a challenging task in fluorescence microscopy. Single‐molecule techniques build on the ability to count molecules one by one. Here, a method is presented that extends recent approaches to analyze the statistics of coincidently emitted photons to enable reliable counting of molecules in the range of 1–20. This method does not require photochemistry such as blinking or bleaching. DNA origami structures are labeled with up to 36 dye molecules as a new evaluation tool to characterize this counting by a photon statistics approach. Labeled DNA origami has a well‐defined labeling stoichiometry and ensures equal brightness for all dyes incorporated. Bias and precision of the estimating algorithm are determined, along with the minimal acquisition time required for robust estimation. Complexes containing up to 18 molecules can be investigated non‐invasively within 150 ms. The method might become a quantifying add‐on for confocal microscopes and could be especially powerful in combination with STED/RESOLFT‐type microscopy.
The Influence on Cell Cycle and Cell Division by Various Cadmium‐Containing Quantum Dots
Authors: Liu Yuexian , Wang Peng , Wang Yue , Zhu Zhening , Lao Fang , Liu Xuefeng , Cong Wenshu , Chen Chunying , Gao Yan , Liu Ying
Published: June 2013

Quantum dots (QDs) have attracted great attention because of their favorable optical properties and have been widely applied in biomedical fields. However, in recent years, there have been an increasing number of reports about the cytotoxicity of QDs, especially cadmium‐containing QDs, which may release cadmium ions to induce cytotoxicity. Importantly, the chemical composition and surface modifications of cadmium‐based QDs determine the amount of Cd2+ released inside the cell. Thus, there is an urgent need for more systematic work to study the relationship between cytotoxicity and the surface properties of QDs. In this article, the cytotoxicity of seven cadmium‐containing QDs with different constituent elements and surface chemistries are compared. The results show that the cytotoxicity of QDs is closely related to their constituent elements and surface properties: First, CdTe@ZnS core–shell QDs show much lower cytotoxicity than naked ones when they have similar surface modifications; second, the positively charged QDs are more toxic than the negatively charged ones. Moreover, both positively and negatively charged QDs without ZnS coatings lead to multipolar spindles, misaligned chromosomes, and G2/M checkpoint failures. Interestingly, although CdSe QDs with a PEG coating cause no apparent cytotoxicity in any of the cell lines studied, they can localize near the contractile ring during cytokinesis and then block contractile ring disassembly. The cellular effect of CdTe QDs comes not only from the release of cadmium ions but also the intracellular distribution of QD nanoparticles in cells and the associated nanoscale effects. It is also found that QD‐caused cytokinesis failure is closely related to the decreased expression of Cyclin A and Cyclin B. Taken together, the above findings provide new insight into the dynamic fate of QDs during cell mitosis, and are important for understanding the intracellular effects of QDs on the mitotic spindle and chromosomes during cell division. Furthermore, this kind of cytotoxicity evaluation method should be applicable to studies of the biological effects and health impacts of other nanomaterials.
On the Control Parameters of the Quasi‐One Dimensional Superconductivity in Sc3CoC4
Authors: Eickerling Georg , Hauf Christoph , Scheidt Ernst‐Wilhelm , Reichardt Lena , Schneider Christian , Muñoz Alfonso , Lopez‐Moreno Sinhué , Humberto Romero Aldo , Porcher Florence , André Gilles , Pöttgen Rainer , Scherer Wolfgang
Published: June 2013

Within the series of ternary rare‐earth transition metal carbides Sc3TC4 (T = Fe, Co, Ni) only the Co congener displays a structural phase transition at 72 K and an onset of bulk superconductivity at 4.5 K. In this paper we present the results of a detailed analysis of the structural, electronic, and vibrational properties of the low‐temperature phase of Sc3CoC4 that represents one of the few well‐documented examples of a quasi one‐dimensional (1D) superconductor. Variable temperature neutron powder diffraction and low temperature X‐ray diffraction experiments were performed in order to confirm the subtle structural distortions during the phase transition. The results of periodic electronic structure calculations indicate, that the structural transition can clearly be identified as a Peierls‐type distortion and by a comparison with the isostructural carbide Sc3FeC4 we are able to identify the chemical, electronic, and the vibrational control parameters of the transition. Topological analyses of the electron density distribution and of the valence shell charge concentrations at the cobalt atom finally allow us to directly correlate the changes in the electronic structure due to the Peierls transition in reciprocal space with the according subtle changes in the real space properties of Sc3CoC4.
Longitudinal changes in total body creatine pool size and skeletal muscle mass using the D3‐creatine dilution method
Authors: Stimpson Stephen A. , Leonard Michael S. , Clifton Lisa G. , Poole James C. , Turner Scott M. , Shearer Todd W. , Remlinger Katja S. , Clark Richard V. , Hellerstein Marc K. , Evans William J.
Published: June 2013

Background

We recently validated in cross‐sectional studies a new method to determine total body creatine pool size and skeletal muscle mass based on D3‐creatine dilution from an oral dose and detection of urinary creatinine enrichment by isotope ratio mass spectrometry (IRMS). Routine clinical use of the method in aging and disease will require repeated application of the method, with a more widely available technology than IRMS, to enable determination of change in skeletal muscle mass in longitudinal studies. We therefore adapted the method to liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) technology, and sought to establish proof of concept for the repeated application of the method in a longitudinal study. Because the turnover of creatine is slow, it was also critical to determine the impact of background enrichment from an initial dose of oral D3‐creatine on subsequent, longitudinal measurements of change in muscle mass.

Methods

Rats were given an oral tracer dose of D3‐creatine (1.0 mg/kg body weight) at 10 and 17 weeks of age. LC‐MS/MS was used to determine urinary D3‐creatine, and urinary D3‐creatinine enrichment, at time intervals after D3‐creatine administration. Total body creatine pool size was calculated from urinary D3‐creatinine enrichment at isotopic steady state 72 h after administration of D3‐creatine tracer.

Results

At 10 weeks of age, rat lean body mass (LBM) measured by quantitative magnetic resonance correlated with creatine pool size (r = 0.92, P = 0.0002). Over the next 7 weeks, the decline in urinary D3‐creatinine enrichment was slow and linear, with a rate constant of 2.73 ± 0.06 %/day. Subtracting background urinary D3‐creatinine enrichment from the elevated enrichment following a second dose of D3‐creatine at 17 weeks permitted repeat calculations of creatine pool size. As at 10 weeks, 17‐week LBM correlated with creatine pool size (r = 0.98, P <0.0001). In addition, the change in creatine pool size was correlated with the change in LBM during the 7 weeks of rat growth between measurements (r = 0.96, P <0.0001).

Conclusion

The LC‐MS/MS‐based D3‐creatine dilution method can be applied repeatedly to measure total body creatine skeletal muscle mass change in longitudinal study.
Refining the dual‐system theory of choice
Authors: Martin Justin W. , Sloman Steven A.
Published: June 2013

We are highly sympathetic to Dhar and Gorlin's goal of developing a dual system theory of choice. But we do feel that the proposal could be changed and clarified in a few ways. Specifically, we believe that the evidence suggests that the systems operate in parallel, not sequentially. In addition, the relation between intuitive/associative processing and affect remains unresolved, a vagueness that is especially troublesome for the problem of choice. Relatedly, the description of System I as perceptual requires further explanation and refinement. Finally, we reconsider the attribution of the compromise effect to deliberative processing and propose an alternative explanation, one that reveals one aspect of the interaction between intuitive and deliberative processes. While further specification and testing of predictions are necessary, the proposal by Dhar and Gorlin makes a substantive contribution toward understanding how choices are made.
The response of a continuously stratified fluid to an oscillating flow past an obstacle
Authors: Winters Kraig B. , Armi Laurence
Published: June 2013

An oscillating continuously stratified flow past an isolated obstacle is investigated using scaling arguments and two-dimensional non-hydrostatic numerical experiments. A new dynamic scaling is introduced that incorporates the blocking of fluid with insufficient energy to overcome the background stratification and crest the obstacle. This clarifies the distinction between linear and nonlinear flow regimes near the crest of the obstacle. The flow is decomposed into propagating and non-propagating components. In the linear limit, the non-propagating component is related to the unstratified potential flow past the obstacle and the radiating component exhibits narrow wave beams that are tangent to the obstacle at critical points. When the flow is nonlinear, the near crest flow oscillates between states that include asymmetric, crest-controlled flows. Thin, fast, supercritical layers plunge in the lee, separate from the obstacle and undergo shear instability in the fluid interior. These flow features are localized to the neighbourhood of the crest where the flow transitions from subcriticality to supercriticality and are non-propagating. The nonlinear excitation of energetic non-propagating components reduces the efficiency of topographic radiation in comparison with linear dynamics.
PendulousUsneaspecies (Parmeliaceae, lichenized Ascomycota) in tropical South America and the Galapagos
Authors: TRUONG Camille , RODRIGUEZ Juan Manuel , CLERC Philippe
Published: June 2013

The diversity of pendulousUsneaspecies in tropical South America (Bolivia, Brazil, Colombia, Ecuador, Paraguay, Peru and Venezuela) and the Galapagos Islands is discussed with reference to 23 species.Usnea crenulataTruong & Clerc is newly described.Usnea articulata,U. deformis,U. dimorpha,U. geissleriana,U. merrillii,U. perhispidella,U. sanctaeritae,U. subflammeaandU. transitoriaare newly reported for South America. Modern descriptions are provided forUsnea amabilis,U. arthroclada,U. dodgei,U. humboldtiiandU. regia. We propose to reject the synonymy ofU. hesperinawithU. schadenbergiana, and the valid name forU. hesperinais thereforeU. subgracilis. Distinct patterns of unidentified triterpenoids have been detected by thin-layer chromatography and are used to characterize several species within this group. The morphology, branch anatomy, chemistry, ecology and distribution of each species are given, together with an identification key.
New species ofPolymeridiumfrom Brazil expand the range of known morphological variation within the genus
Authors: APTROOT André , MENEZES Aline Anjos , de LIMA Edvaneide Leandro , XAVIER-LEITE Amanda Barreto , CÁCERES Marcela Eugenia da Silva
Published: June 2013

Five new species of the genusPolymeridiumare described from Brazil. All exhibit at least one character that was previously unknown in the genus:P. corticatumhas a corticate thallus and 2 ascospores per ascus,P. immersumhas the ascomata deeply immersed in the bark under the thallus,P. isohypocrellinumhas a red, KOH+ green pigment (iso-hypocrellin) in the ostiole,P. julelloideshas short and broad muriform (Julella-like) ascospores, andP. paraproponenshas ascomata in groups of two to three. Brazil is clearly the centre of diversity of the genus. Iso-hypocrellin is a new substance for the genus.
Ethnicity as a predictor of detention under the Mental Health Act
Authors: Singh S. P. , Burns T. , Tyrer P. , Islam Z. , Parsons H. , Crawford M. J.
Published: June 2013

Background

There has been major concern about the ‘over-representation’ of Black and ethnic minority groups amongst people detained under the Mental Health Act (MHA). We explored the effect of patient ethnicity on detention following an MHA assessment, once confounding variables were controlled for.

Method

Prospective data were collected for all MHA assessments over 4-month periods in the years 2008, 2009, 2010 and 2011 each in three regions in England: Birmingham, West London and Oxfordshire. Logistic regression modelling was conducted to predict the outcome of MHA assessments – either resulting in ‘detention’ or ‘no detention’.

Results

Of the 4423 MHA assessments, 2841 (66%) resulted in a detention. A diagnosis of psychosis, the presence of risk, female gender, level of social support and London as the site of assessment predicted detention under the MHA. Ethnicity was not an independent predictor of detention.

Conclusions

There is no evidence for that amongst those assessed under the MHA, ethnicity has an independent effect on the odds of being detained.