bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of a single vial kit formulation of [99mTc]‐labeled doxorubicin for tumor imaging and treatment response assessment‐preclinical evaluation and preliminary human results
Authors: Kumar Pardeep , Singh Baljinder , Ghai Anchal , Hazari Puja P. , Mittal B. R. , Mishra Anil K.
Published: May 2015

The present study describes the successful radiolabeling of [99mTcO−4] with doxorubicin, and the resultant product was formulated in to a ready‐to‐label lyophilized single vial kit preparation for convenient use in a routine clinical setting. The radiolabeled preparation of [99mTc]‐doxorubicin exhibited a high radiolabeling efficiency of more than 95.0%, serum stability for up to 24 h, and shelf‐life of lyophilized cold kits was more than 6 months. Animal imaging data in tumor‐bearing mice demonstrated that [99mTc]‐doxorubicin accumulated in the tumor site with high target (tumor) to non‐target (contra‐lateral thigh) ratio (3.2 ± 0.5). The ratio decreased to 1.2 ± 0.6 indicating a good response on follow up imaging performed after 2 weeks of doxorubicin treatment. [99mTc]‐doxorubicin scintigraphic data in human volunteers supported the hepato‐renal excretion of the radiotracer as reflected by the increased accumulation of the radiotracer as a function of time in intestine, kidneys, and urinary bladder. Further, imaging in patients (very limited number) indicated that the technique may be useful in the detection of active sarcoma and post treatment (surgery/chemotherapy) remission or absence of the disease. The technique, however, needs validation through further preclinical evaluation and imaging in a larger number of patients.
Outcome of vulvar reconstruction by anterolateral thigh flap in patients with advanced and recurrent vulvar malignancy
Authors: Zhang Wei , Zeng Ang , Yang Jiaxin , Cao Dongyan , Huang Huifang , Wang Xiaojun , You Yan , Chen Jie , Lang Jinghe , Shen Keng
Published: May 2015

Background

To evaluate the outcomes of vulvar reconstruction using anterolateral thigh (ALT) flaps in patients with advanced and recurrent vulvar malignancies.

Methods

Totally 24 patients who received ALT‐based vulvar reconstruction were retrospectively reviewed to evaluate the outcome focusing on quality of life and prognosis.

Results

Four patients received vulvar reconstruction at the time of primary surgery due to advanced stage, and 20 patients underwent vulvar reconstruction after recurrence. No patient experienced complete flap loss. Major complications happened in five patients (20.83%). Minor complications occurred in three patients (12.5%). All wounds healed favorable after appropriate treatment. The mean scale of verbal rating scale (VRS‐4) was 1.58 before reconstruction while decreased to 0.13 after surgery (P < 0.0001). Mean performance status was 1.67 before surgery compared to 0.13 after surgery (P < 0.0001). Fourteen patients (58.33%) developed recurrence with a median interval of recurrence of 5 months after vulvar reconstruction. Ten patients (41.67%) are living with disease free in a median follow‐up of 19.5 months. Overall 5 years survival was 56.4%.

Conclusion

ALT flap based vulvar reconstruction method can improve the quality of life and might be considered as an appropriate option for reconstructing the vulvar defects in patients with advanced or recurrent vulvar malignancy. J. Surg. Oncol. 2015 111:985–991. © 2015 Wiley Periodicals, Inc.
Effect of thermal oxidation on electrochemical corrosion behaviour of ZrTi alloys for dental applications
Authors: Mareci D. , Bolat G. , Istrate B. , Munteanu C. , Cailean A.
Published: May 2015

Electrochemical behaviour of Zr5Ti, Zr25Ti and Zr45Ti, with and without surface modification were investigated for dental applications. All untreated and thermal oxidized alloys in Na2CO3 at 890 °C were tested by electrochemical impedance spectroscopy (EIS) performed in 10% carbamide peroxide solution. In addition, scanning electron microscopy (SEM) was employed to observe the surface morphology before and after 8 hours immersion time in carbamide peroxide solution. The electrochemical corrosion parameters obtained from the EIS indicated a typical passive behaviour for untreated and thermal oxidized ZrTi alloys. Higher impedance values were observed for thermal oxidized ZrTi alloys compared to untreated materials. The thermal oxidized Zr45Ti alloy appears to possess superior corrosion resistance than the thermal oxidized Zr25Ti and Zr5Ti alloys in carbamide peroxide solution.
Decoding in the automorphism group of a recursively saturated model of arithmetic
Authors: Nurkhaidarov Ermek
Published: May 2015

The main result of this paper partially answers a question raised in about the existence of countable just recursively saturated models of Peano Arithmetic with non‐isomorphic automorphism groups. We show the existence of infinitely many countable just recursively saturated models of Peano Arithmetic such that their automorphism groups are not topologically isomorphic. We also discuss maximal open subgroups of the automorphism group of a countable arithmetically saturated model of in a very good interstice.
Limitwise monotonic sets of reals
Authors: Faizrahmanov Marat , Kalimullin Iskander
Published: May 2015

We extend the limitwise monotonicity notion to the case of arbitrary computable linear ordering to get a set which is limitwise monotonic precisely in the non‐computable degrees. Also we get a series of connected non‐uniformity results to obtain new examples of non‐uniformly equivalent families of computable sets with the same enumeration degree spectrum.
Kinetic Parameters of the Initiator Decomposition in Microwave and in Conventional Batch Reactors – KPS and V50‐Case Studies
Authors: Costa Cristiane , Alberton André L. , Santos Alexandre F. , Fortuny Montserrat , Araújo Pedro H. H. , Sayer Claudia , Pinto José Carlos
Published: May 2015

Different values of the kinetic rate constants have been reported for initiator decompositions carried out in microwave and conventional batch reactors. The present work analyzes the confidence regions of kinetic parameters estimated for the thermal decomposition of two initiators, potassium persulfate (KPS) and 2‐2′‐azobis(2‐methylpropionamidine) dihydrochloride (V‐50), which confirm the difference between the parameters obtained in microwave and conventional reactors. Moreover, by assuming no changes in kinetics under microwave heating, the temperature and volume of hot spots required to explain the apparent increase of kinetic rate constants are calculated. The results suggest that formation of hot spots may explain the observed effects without the occurrence of additional phenomena.
Impacts of filler covalent and non‐covalent modification on the network structure and mechanical properties of carbon–silica dual phase filler/natural rubber
Authors: Wang Jingyi , Jia Hongbing , Ding Lifeng , Xiong Xin
Published: May 2015

The carbon–silica dual phase filler (CSDPF) was modified by bis (3‐triethoxy‐silylpropyl) tetrasulphane (Si69) and 1‐allyl‐3‐methyl‐imidazolium chloride (AMI), respectively. The natural rubber (NR) vulcanizates filled with modified CSDPF were fabricated through mechanical mixing followed by a high‐temperature cure process. The impacts of filler surface modification on the curing characters, crosslinked junctions, network structure, and mechanical properties of NR vulcanizates were investigated. The results showed that the Si69 interacted with CSDPF through covalent bond, while the interaction between AMI and CSDPF was hydrogen bond. Both modifications increased the cure rate of CSDPF/NR compounds as well as the crosslinked degree, compared with those of pristine CSDPF/NR compound. The modifications improved the dispersion of CSDPF in NR matrix. The covalent modification by Si69 caused a limited movement of NR chains in the CSDPF surface, which contributed to a greater tensile modulus of Si69‐modified CSDPF/NR. However, the higher content of mono‐sulfidic crosslink and the poorer content of strain‐induced crystallization in the NR matrix led to a slight increase of tensile strength and tear strength of Si69‐modified CSDPF/NR, compared with those of CSDPF/NR. The tensile modulus of AMI‐modified CSDPF/NR had a lower value due to a faster polymer chain motion on the CSDPF surface. However, the tensile and tear strength of AMI‐modified CSDPF/NR increased significantly because of the increase of mono‐sulfidic crosslink, strain‐induced crystallization, and the existed hydrogen bond between CSDPF and NR. Copyright © 2015 John Wiley & Sons, Ltd.
Free‐standing and flexible nano‐ZnO/PVDF composite thin films: impedance spectroscopic studies
Authors: Bhunia Ritamay , Ghosh Barun , Ghosh Dibyendu , Hussain Shamima , Bhar Radhaballabh , Pal Arun Kumar
Published: May 2015

Nanocrystalline ZnO‐impregnated polyvinylidene fluoride (nano‐ZnO/PVDF) composite films were prepared by sol‐gel technique. Free‐standing and flexible films with different nano‐ZnO loadings were synthesized. Addition of ZnO in PVDF host matrix modulated the impedance and dielectric properties. The composite films thus obtained were characterized by microstructural, XPS, and impedance spectroscopic measurements. Copyright © 2015 John Wiley & Sons, Ltd.
Nonspecific yet decisive: Ubiquitination can affect the native‐state dynamics of the modified protein
Authors: Gavrilov Yulian , Hagai Tzachi , Levy Yaakov
Published: May 2015

Ubiquitination is one of the most common post‐translational modifications of proteins, and mediates regulated protein degradation among other cellular processes. A fundamental question regarding the mechanism of protein ubiquitination is whether and how ubiquitin affects the biophysical nature of the modified protein. For some systems, it was shown that the position of ubiquitin within the attachment site is quite flexible and ubiquitin does not specifically interact with its substrate. Nevertheless, it was revealed that polyubiquitination can decrease the thermal stability of the modified protein in a site‐specific manner because of alterations of the thermodynamic properties of the folded and unfolded states. In this study, we used detailed atomistic simulations to focus on the molecular effects of ubiquitination on the native structure of the modified protein. As a model, we used Ubc7, which is an E2 enzyme whose in vivo ubiquitination process is well characterized and known to lead to degradation. We found that, despite the lack of specific direct interactions between the ubiquitin moiety and Ubc7, ubiquitination decreases the conformational flexibility of certain regions of the substrate Ubc7 protein, which reduces its entropy and thus destabilizes it. The strongest destabilizing effect was observed for systems in which Lys48‐linked tetra‐ubiquitin was attached to sites used for in vivo degradation. These results reveal how changes in the configurational entropy of the folded state may modulate the stability of the protein's native state. Overall, our results imply that ubiquitination can modify the biophysical properties of the attached protein in the folded state and that, in some proteins, different ubiquitination sites will lead to different biophysical outcomes. We propose that this destabilizing effect of polyubiquitin on the substrate is linked to the functions carried out by the modification, and in particular, regulatory control of protein half‐life through proteasomal degradation.
ChSeq: A database of chameleon sequences
Authors: Li Wenlin , Kinch Lisa N. , Karplus P. Andrew , Grishin Nick V.
Published: May 2015

Chameleon sequences (ChSeqs) refer to sequence strings of identical amino acids that can adopt different conformations in protein structures. Researchers have detected and studied ChSeqs to understand the interplay between local and global interactions in protein structure formation. The different secondary structures adopted by one ChSeq challenge sequence‐based secondary structure predictors. With increasing numbers of available Protein Data Bank structures, we here identify a large set of ChSeqs ranging from 6 to 10 residues in length. The homologous ChSeqs discovered highlight the structural plasticity involved in biological function. When compared with previous studies, the set of unrelated ChSeqs found represents an about 20‐fold increase in the number of detected sequences, as well as an increase in the longest ChSeq length from 8 to 10 residues. We applied secondary structure predictors on our ChSeqs and found that methods based on a sequence profile outperformed methods based on a single sequence. For the unrelated ChSeqs, the evolutionary information provided by the sequence profile typically allows successful prediction of the prevailing secondary structure adopted in each protein family. Our dataset will facilitate future studies of ChSeqs, as well as interpretations of the interplay between local and nonlocal interactions. A user‐friendly web interface for this ChSeq database is available at prodata.swmed.edu/chseq.
Chemical ligation of the influenza M2 protein for solid‐state NMR characterization of the cytoplasmic domain
Authors: Kwon Byungsu , Tietze Daniel , White Paul B. , Liao Shu Y. , Hong Mei
Published: May 2015

Solid‐state NMR‐based structure determination of membrane proteins and large protein complexes faces the challenge of limited spectral resolution when the proteins are uniformly 13C‐labeled. A strategy to meet this challenge is chemical ligation combined with site‐specific or segmental labeling. While chemical ligation has been adopted in NMR studies of water‐soluble proteins, it has not been demonstrated for membrane proteins. Here we show chemical ligation of the influenza M2 protein, which contains a transmembrane (TM) domain and two extra‐membrane domains. The cytoplasmic domain, which contains an amphipathic helix (AH) and a cytoplasmic tail, is important for regulating virus assembly, virus budding, and the proton channel activity. A recent study of uniformly 13C‐labeled full‐length M2 by spectral simulation suggested that the cytoplasmic tail is unstructured. To further test this hypothesis, we conducted native chemical ligation of the TM segment and part of the cytoplasmic domain. Solid‐phase peptide synthesis of the two segments allowed several residues to be labeled in each segment. The post‐AH cytoplasmic residues exhibit random‐coil chemical shifts, low bond order parameters, and a surface‐bound location, thus indicating that this domain is a dynamic random coil on the membrane surface. Interestingly, the protein spectra are similar between a model membrane and a virus‐mimetic membrane, indicating that the structure and dynamics of the post‐AH segment is insensitive to the lipid composition. This chemical ligation approach is generally applicable to medium‐sized membrane proteins to provide site‐specific structural constraints, which complement the information obtained from uniformly 13C, 15N‐labeled proteins.
A comparison of pathway‐independent and pathway‐dependent methods in the calculation of conformational free enthalpy differences
Authors: Lin Zhixiong , van Gunsteren Wilfred F.
Published: May 2015

The multistep umbrella sampling method, which belongs to pathway‐dependent methods to calculate conformational free enthalpy differences, is used to calculate the free enthalpy difference between a right‐handed 2.710/12‐helix and a left‐handed 314‐helix of a hexa‐β‐peptide in methanol solution. The same conformational free enthalpy difference was previously investigated using pathway‐independent methods such as direct counting and enveloping distribution sampling. Our results show that the pathway‐dependent simulations are sensitive to the choice of the pathway and its parameter values. A pathway based on restraining distances of hydrogen‐bonding atom pairs shows poor sampling for two different values of the restraining force constant. Another pathway based on restraining backbone dihedral angles did smoothly sample the transition between the two helical conformations, but only with a proper choice of the restraining force constant. The results illustrate that if, and only if, a proper pathway and proper parameters are chosen, the multistep umbrella sampling can be almost 50 times more efficient than the pathway‐independent methods in this case. The analysis illustrates the advantages and pitfalls of the much used multistep umbrella sampling methodology.
Marginally hydrophobic transmembrane α‐helices shaping membrane protein folding
Authors: De Marothy Minttu T. , Elofsson Arne
Published: May 2015

Cells have developed an incredible machinery to facilitate the insertion of membrane proteins into the membrane. While we have a fairly good understanding of the mechanism and determinants of membrane integration, more data is needed to understand the insertion of membrane proteins with more complex insertion and folding pathways. This review will focus on marginally hydrophobic transmembrane helices and their influence on membrane protein folding. These weakly hydrophobic transmembrane segments are by themselves not recognized by the translocon and therefore rely on local sequence context for membrane integration. How can such segments reside within the membrane? We will discuss this in the light of features found in the protein itself as well as the environment it resides in. Several characteristics in proteins have been described to influence the insertion of marginally hydrophobic helices. Additionally, the influence of biological membranes is significant. To begin with, the actual cost for having polar groups within the membrane may not be as high as expected; the presence of proteins in the membrane as well as characteristics of some amino acids may enable a transmembrane helix to harbor a charged residue. The lipid environment has also been shown to directly influence the topology as well as membrane boundaries of transmembrane helices—implying a dynamic relationship between membrane proteins and their environment.
Molecular mechanisms of transcriptional control by Rev‐erbα: An energetic foundation for reconciling structure and binding with biological function
Authors: Vaissière Anaïs , Berger Sylvie , Harrus Deborah , Dacquet Catherine , Le Maire Albane , Boutin Jean A. , Ferry Gilles , Royer Catherine A.
Published: May 2015

Rev‐erbα and β are nuclear receptors that function as transcriptional repressors of genes involved in regulating circadian rhythms, glucose, and cholesterol metabolism and the inflammatory response. Given these key functions, Rev‐erbs are important drug targets for treatment of a number of human pathologies, including cancer, heart disease, and type II diabetes. Transcriptional repression by the Rev‐erbs involves direct competition with transcriptional activators for target sites, but also recruitment by the Rev‐erbs of the NCoR corepressor protein. Interestingly, Rev‐erbs do not appear to interact functionally with a very similar corepressor, Smrt. Transcriptional repression by Rev‐erbs is thought to occur in response to the binding of heme, although structural, and ligand binding studies in vitro show that heme and corepressor binding are antagonistic. We carried out systematic studies of the ligand and corepressor interactions to address the molecular basis for corepressor specificity and the energetic consequences of ligand binding using a variety of biophysical approaches. Highly quantitative fluorescence anisotropy assays in competition mode revealed that the Rev‐erb specificity for the NCoR corepressor lies in the first two residues of the β‐strand in Interaction Domain 1 of NCoR. Our studies confirmed and quantitated the strong antagonism of heme and corepressor binding and significant stabilization of the corepressor complex by a synthetic ligand in vitro. We propose a model which reconciles the contradictory observations concerning the effects of heme binding in vitro and in live cells.
Structures of potent anticancer compounds bound to tubulin
Authors: McNamara Dan E. , Senese Silvia , Yeates Todd O. , Torres Jorge Z.
Published: May 2015

Small molecules that bind to tubulin exert powerful effects on cell division and apoptosis (programmed cell death). Cell‐based high‐throughput screening combined with chemo/bioinformatic and biochemical analyses recently revealed a novel compound MI‐181 as a potent mitotic inhibitor with heightened activity towards melanomas. MI‐181 causes tubulin depolymerization, activates the spindle assembly checkpoint arresting cells in mitosis, and induces apoptotic cell death. C2 is an unrelated compound previously shown to have lethal effects on microtubules in tumorigenic cell lines. We report 2.60 Å and 3.75 Å resolution structures of MI‐181 and C2, respectively, bound to a ternary complex of αβ‐tubulin, the tubulin‐binding protein stathmin, and tubulin tyrosine ligase. In the first of these structures, our crystallographic results reveal a unique binding mode for MI‐181 extending unusually deep into the well‐studied colchicine‐binding site on β‐tubulin. In the second structure the C2 compound occupies the colchicine‐binding site on β‐tubulin with two chemical moieties recapitulating contacts made by colchicine, in combination with another system of atomic contacts. These insights reveal the source of the observed effects of MI‐181 and C2 on microtubules, mitosis, and cultured cancer cell lines. The structural details of the interaction between tubulin and the described compounds may guide the development of improved derivative compounds as therapeutic candidates or molecular probes to study cancer cell division.
Folding thermodynamics of β‐hairpins studied by replica‐exchange molecular dynamics simulations
Authors: Zerze Gül H. , Uz Bilge , Mittal Jeetain
Published: May 2015

We study the differences in folding stability of β‐hairpin peptides, including GB1 hairpin and a point mutant GB1 K10G, as well as tryptophan zippers (TrpZips): TrpZip1, TrpZip2, TrpZip3‐1, and TrpZip4. By performing replica‐exchange molecular dynamics simulations with Amber03* force field (a modified version of Amber ff03) in explicit solvent, we observe ab initio folding of all the peptides except TrpZip3‐1, which is experimentally known to be the least stable among the peptides studied here. By calculating the free energies of unfolding of the peptides at room temperature and folding midpoint temperatures for thermal unfolding of peptides, we find that TrpZip4 and GB1 K10G peptides are the most stable β‐hairpins followed by TrpZip1, GB1, and TrpZip2 in the given order. Hence, the proposed K10G mutation of GB1 peptide results in enhanced stability compared to wild‐type GB1. An important goal of our study is to test whether simulations with Amber 03* model can reproduce experimentally predicted folding stability differences between these peptides. While the stabilities of GB1 and TrpZip1 yield close agreement with experiment, TrpZip2 is found to be less stable than predicted by experiment. However, as heterogenous folding of TrpZip2 may yield divergent thermodynamic parameters by different spectroscopic methods, mismatching of results with previous experimental values are not conclusive of model shortcomings. For most of the cases, molecular simulations with Amber03* can successfully reproduce experimentally known differences between the mutated peptides, further highlighting the predictive capabilities of current state‐of‐the‐art all‐atom protein force fields. Proteins 2015; 83:1307–1315. © 2015 Wiley Periodicals, Inc.
Impact of dopants and silicon structure dimensions on {113}‐defect formation during 2 MeV electron irradiation in an UHVEM
Authors: Vanhellemont J. , Anada S. , Nagase T. , Yasuda H. , Schulze A. , Bender H. , Rooyackers R. , Vandooren A.
Published: May 2015

When processing Si nanowire based Tunnel Field Effect Transistors (TFETS's), a significant reduction of B diffusion with decreasing nanowire diameter is observed and attributed to reduced transient enhanced diffusion close to the nanowire surface caused by the recombination and out‐diffusion of excess self‐interstitials. In this study, Ultra High Voltage Electron Microscopy (UHVEM) is used to study in situ the formation of self‐interstitial clusters in nanowire based TFET containing samples prepared by Focused Ion Beam (FIB) thinning.

Si nanowires with diameters ranging from 40 to 500 nm are irradiated in an UHVEM using different fluxes of 2 MeV electrons at temperatures between room temperature and 375 °C. A strong dependence of defect formation on nanowire radius and on dopant concentration and type is observed. The UHVEM observations are compared with simulations based on quasi‐chemical reaction rate theory and with two dimensional dopant concentration distributions determined with high‐vacuum Scanning Spreading Resistance Microscopy (SSRM). (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigation of the kinetics of the chemical vapor deposition of aluminum from dimethylethylamine alane: experiments and computations
Authors: Aviziotis Ioannis G. , Duguet Thomas , Soussi Khaled , Kokkoris George , Cheimarios Nikolaos , Vahlas Constantin , Boudouvis Andreas G.
Published: May 2015

Experiments and computations are performed for the metalorganic chemical vapor deposition (MOCVD) of aluminum (Al) from dimethylethylamine alane (DMEAA). The deposition rate as a function of the substrate temperature and the evolution of the deposition rate along the radius of the susceptor are experimentally determined, in a vertical, warm wall MOCVD reactor operating at 10 Torr, in the temperature range 139 °C‐240 °C. Following previously published mechanism for the decomposition of DMEAA, a predictive 3D model of the process is built, based on the mass, momentum, energy and species transport equations with the aim to simulate the process. Taking into account experimental results it is demonstrated that a volumetric and a surface reaction are responsible for the deposition of Al from DMEAA. For both reactions, first order Arrhenius kinetics are implemented and the kinetic parameters are determined through fitting to the experimental data. The results show satisfactory agreement between experiments and computations for almost the whole temperature range examined. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Intermolecular interaction between rare earth and manganese precursors in metalorganic chemical vapor deposition of perovskite manganite films
Authors: Nakamura Toshihiro
Published: May 2015

The gas‐phase reaction mechanism was investigated in liquid delivery metalorganic chemical vapor deposition (MOCVD) of praseodymium and lanthanum manganite films. We studied the gas‐phase behavior of praseodymium, lanthanum, and manganese precursors under actual CVD conditions by in situ infrared absorption spectroscopy. The rate of the decrease of the infrared absorbance due to Pr(DPM)3 was almost constant even if Mn(DPM)3 was added, indicating that the intermolecular interaction between Pr and Mn precursors in the gas phase is relatively weak in MOCVD of praseodymium manganite films. On the other hand, the temperature dependence of the infrared absorption indicates that the thermal decomposition of La(DPM)3 was promoted in the presence of Mn(DPM)3. The significant intermolecular interaction occurs between La and Mn precursors in the gas phase in MOCVD of lanthanum manganite films. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth mechanism of planar or nanorod structured tungsten oxide thin films deposited via aerosol assisted chemical vapour deposition (AACVD)
Authors: Ling Min , Blackman Chris
Published: May 2015

Aerosol assisted chemical vapour deposition (AACVD) is used to deposit tungsten oxide thin films from tungsten hexacarbonyl (W(CO)6) at 339 to 358 °C on quartz substrate. The morphologies of as‐deposited thin films, which are comprised of two phases (W25O73 and W17O47), vary from planar to nanorod (NR) structures as the distance from the inlet towards the outlet of the reactor is traversed. This is related to variation of the actual temperature on the substrate surface (ΔT = 19 °C), which result in a change in growth mode due to competition between growth rate (perpendicular to substrate) and nucleation rate (parallel to substrate). When the ratio of perpendicular growth rate to growth rate contributed by nucleation is higher than 7.1, the as‐deposited tungsten oxide thin film forms as NR. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effects of calcium complexation on heparin‐like disaccharides. A combined theoretical, tandem mass spectrometry and ultraviolet experiment
Authors: Ortiz Daniel , Enjalbert Quentin , MacAleese Luke , Dugourd Philippe , Salpin Jean‐Yves
Published: May 2015

Rationale

In order to shed light on the influence of the Ca2+ metal cation on the structure of heparin‐like (Hp) disaccharides, we have explored the gas‐phase structures of both [Hp, −2H]2− and [Ca(Hp), −3H]− ions by coupling experimental and theoretical methods.

Methods

The goal of this work was to (i) provide new evidence of the metal influence on the Hp structure, which can have important biological consequences, and (ii) to study the usefulness of metal complexation for the analytical distinction of Hp isomers. Collision‐induced dissociation (CID) and ultraviolet photodissociation (UVPD) fragments, as well as optical spectra recorded in the gas phase for both [Hp, −2H]2− and [Ca(Hp), −3H]− complexes were compared for I‐H, II‐S and III‐S isomers of Hp.

Results

In the case of CID fragmentation, a change in the fragmentation pattern was observed upon calcium complexation, with respect to deprotonated Hp.

Conclusions

Remarkably, when optical spectra are compared in the UV range, the metal effect on the carboxylic group absorption can be detected by an unambiguous blue‐shift (~20 nm). Copyright © 2015 John Wiley & Sons, Ltd.
On invariant sets and closed‐loop boundedness of Lure‐type nonlinear systems by LPV‐embedding
Authors: Seron Maria M. , De Doná José A.
Published: May 2015

We address the problem of achieving trajectory boundedness and computing ultimate bounds and invariant sets for Lure‐type nonlinear systems with a sector‐bounded nonlinearity. Our first contribution is to compare two systematic methods to compute invariant sets for Lure systems. In the first method, a linear‐like bound is considered for the nonlinearity, and this bound is used to compute an invariant set by regarding the nonlinear system as a linear system with a nonlinear perturbation. In the second method, the sector‐bounded nonlinearity is treated as a time‐varying parameterised linear function with bounded parameter variations, and then invariant sets are computed by embedding the nonlinear system into a convex polytopic linear parameter varying (LPV) system. We show that under some conditions on the system matrices, these approaches give identical invariant sets, the LPV‐embedding method being less conservative in the general case. The second contribution of the paper is to characterise a class of Lure systems, for which an appropriately designed linear state feedback achieves bounded trajectories of the closed‐loop nonlinear system and allows for the computation of an invariant set via a simple, closed‐form expression. The third contribution is to show that, for disturbances that are ‘aligned’ with the control input, arbitrarily small ultimate bounds on the system states can be achieved by assigning the eigenvalues of the linear part of the system with ‘large enough’ negative real part. We illustrate the results via examples of a pendulum system, a Josephson junction circuit and the well‐known Chua circuit. Copyright © 2015 John Wiley & Sons, Ltd.
Downstream Swimming Behaviour of Catadromous and Potamodromous Fish Over Spillways
Authors: Silva A. T. , Katopodis C. , Tachie M. F. , Santos J. M. , Ferreira M. T.
Published: May 2015

Flow characteristics associated with spillways are important to restore ecological connectivity because spillways can either constrain or offer safe routes for downstream passage of fish. We studied the hydrodynamics of flow and downstream movement behaviour of the catadromous European eel (Anguilla anguilla) and the potamodromous Iberian barbel (Luciobarbus bocagei) in spillways with upstream face inclinations of θ = 90° (standard) 45° and 30° (modified). The standard spillway was tested for two water depths (H = 32 and 42 cm). Modified spillways facilitated downstream passage and reduced delay times of passage of the European eel. Upstream of the 90° spillway, distinct recirculation areas were observed, and associated turbulence strongly hampered downstream passage of fish. Both species were found to avoid turbulence, but barbel displayed stronger avoidance for areas of rapid changes in flow velocity when comparing to eels. Overall, eels were faster in passing the spillway and had a higher downstream passage success (80%) than barbel (32%). Eels were predominantly thigmotactic in contrast to barbel, which showed limited contact with structures. The results suggest that modified spillways may enhance passage survival. Copyright © 2015 John Wiley & Sons, Ltd.
From the Source to the Outlet: understanding the Distribution of Invasive Knotweeds along a North American River
Authors: Duquette M.‐C. , Compérot A. , Hayes L. F. , Pagola C. , Belzile F. , Dubé J. , Lavoie C.
Published: May 2015

Understanding the drivers of exotic plant invasions along waterways is crucial for helping environmental managers devise effective control strategies. We combined a field survey, molecular data and a logistic regression model to further our understanding of the spatial distribution of Japanese (Fallopia japonica) and Bohemian (Fallopia × bohemica) knotweeds along the entire course (185 km) of a river located in Québec (Canada). Both knotweeds were abundant along the river, but each had a distinct spatial distribution pattern. Only one genotype for each knotweed species or hybrid was found, suggesting that the individuals established along the Chaudière River resulted from the propagation of rhizome or stem fragments. The distance from the nearest town or village was the only explanatory variable significantly correlated to the spatial distribution of knotweeds. However, spatial autoregressive coefficients were significant, indicating that knotweeds were more likely to occur close to other knotweeds. In summary, the invasion was probably initiated by the introduction, in riverside towns and villages, of a few individuals of the same genotype. The clones then spread vegetatively, probably during spring floods. The rhizome and stem fragments spread over short distances, dispersing downstream from urban centres. The introduction of just two knotweed genotypes along the Chaudière River was sufficient to initiate a massive riverside colonization, as few riparian vegetation types were apparently able to resist knotweed invasion. Copyright © 2015 John Wiley & Sons, Ltd.
Growth, characterization and interfacial reaction of magnetron sputtered Pt/CeO2 thin films on Si and Si3N4 substrates
Authors: Anandan Chinnasamy , Bera Parthasarathi
Published: May 2015

Growth of magnetron sputtered Pt/CeO2 thin films on Si and Si3N4 were characterized by X‐ray diffraction (XRD), field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM) and X‐ray photoelectron spectroscopy (XPS). Interaction of Pt/CeO2 films with Si on Si and Si3N4 substrates was extensively investigated by XPS. XRD studies show that films are oriented preferentially to (200) direction of CeO2. XPS results show that Pt is mainly present in +2 oxidation state in Pt/CeO2/Si film, whereas Pt4+ predominates in Pt/CeO2/Si3N4 film. Concentration of Pt4+ species is more than four times on Si3N4 substrate as compared with that on Si. Ce is present as both +4 and +3 oxidation states in Pt/CeO2 films deposited on Si and Si3N4 substrates, but concentration of Ce3+ species is more in Pt/CeO2/Si film. Interfacial reaction between CeO2 and Si substrate is controlled in the presence of Pt. Pt/Ce concentration ratio decreases in Pt/CeO2/Si3N4 film upon successive sputtering, whereas this ratio decreases initially and then increases in Pt/CeO2/Si film. Copyright © 2015 John Wiley & Sons, Ltd.
Knowledge problems in climate change and security research
Authors: Lewis Kirsty H. , Lenton Timothy M.
Published: May 2015

The demand for policy‐relevant information on climate change has never been higher, but there remains a gap between the type of information climate projections provide and an understanding of the consequences for human well‐being. This review explores the knowledge available to support assessments of climate change and security for a wide range of policy stakeholders. Both the climate science and social science communities undertake valuable research toward understanding climate change and the interaction of environment and security, but address different aspects of the problem. Differences in the types of knowledge produced include analytical methods, language, and scale issues. This makes research conclusions difficult to reconcile and provides a barrier to knowledge sharing. It is largely left to policy and security analysts to bring these two very different types of information together in accessible, policy‐relevant assessments. Often this is done by considering the potential implications of existing climate change projections, with little or no input from social scientists on the complexities of the relationship between environment and security. An alternative approach to climate change and security assessments is to consider the problem from a systems perspective. This approach has the potential to offer new insight across disciplines and improve the utility of research outcomes to inform action on climate change and security. WIREs Clim Change 2015, 6:383–399. doi: 10.1002/wcc.346

This article is categorized under:

Integrated Assessment of Climate Change > Methods of Integrated Assessment of Climate Change
ECDGP: extended cluster‐based data gathering protocol for vehicular networks
Authors: Brik Bouziane , Lagraa Nasreddine , Lakas Abderrahmane , Cherroun Hadda , Cheddad Abbas
Published: May 2015

An important application in wireless networks is data collection. It aims to gather and deliver specific data for concerned authorities. Many researchers invest in vehicular ad hoc networks for that purpose to acquire data from different sources on the roads as from its vicinity. A vehicle is considered as a mobile data collector, it gathers real‐time or delay‐tolerant data such as road traffic, environmental information, and event advertisements. In a previous work, we have proposed a novel clustered data gathering protocol (CDGP) for vehicular ad hoc network, which improves the collection performance by implementing a new space division multiple access technique called dynamic space division multiple access and a retransmission mechanism in case of errors. However, CDGP supports only delay‐tolerant data as it does not use any aggregation technique. In this paper, we propose an enhancement of this protocol by extending it to support: (i) both real‐time and delay‐tolerant applications; (ii) multiple types of data; and (iii) aggregation of collected data prior to sending them to the initiator. We present the plausible analytical complexity of the extended CDGP, as we illustrate the superiority of its performance throughout the results obtained from simulation experiments, using a Freeway mobility model. Copyright © 2015 John Wiley & Sons, Ltd.
Proposed Minimum Rates of Surgery to Support Desirable Health Outcomes: An Observational Study Based on Three Strategies
Authors: Esquivel Micaela M. , Molina George , Uribe‐Leitz Tarsicio , Lipsitz Stuart R. , Rose John , Bickler Stephen , Gawande Atul A. , Haynes Alex B. , Weiser Thomas G.
Published: May 2015

Background

The global volume of surgery is estimated at 312.9 million operations annually, but rates of surgery vary dramatically. Identifying surgical rates associated with improved health outcomes would be useful for benchmarking and targeted health system strengthening.

Methods

We identified rates of surgery associated with a life expectancy (LE) of 74–75 years, a maternal mortality ratio (MMR) of less than or equal to 100 per 100,000 live births, and the estimated need for surgery in the seven global burden of disease (GBD) super‐regions based on the prevalence of surgical conditions. We compared our findings to surgical rates from Chile, China, Costa Rica, and Cuba (“4C”), countries with moderate resources but high health outcomes.

Results

The median surgical rates associated with LE of 74–75 years (N = 17) and MMR below 100 (N = 109) are 4392 (IQR 2897–4873) and 5028 (IQR 4139–6778) operations per 100,000 people annually, respectively. The mean surgical rate estimated for the seven super‐regions was 4723 (95 % CI 3967–5478) operations per 100,000 people annually. The “4C” countries had a mean surgical rate of 4344 (95 % CI 2620–6068) operations per 100,000 people annually. Thirteen of the twenty‐one GBD regions, accounting for 78 % of the world’s population, do not achieve rates of surgery at the lowest end of this range.

Conclusions

We identified a narrow range of surgical rates associated with important health indicators. This target range can be used for benchmarking of surgical services, and as part of a policy aimed at strengthening health care systems and surgical capacity.
Use of Cardiac Magnetic Resonance Imaging Based Measurements of Inferior Vena Cava Cross-Sectional Area in the Diagnosis of Pericardial Constriction
Authors: Hanneman Kate , Thavendiranathan Paaladinesh , Nguyen Elsie T. , Moshonov Hadas , Wald Rachel , Connelly Kim A. , Paul Narinder S. , Wintersperger Bernd J. , Crean Andrew M.
Published: May 2015

Purpose

To evaluate the value of cardiac magnetic resonance imaging (MRI)–based measurements of inferior vena cava (IVC) cross-sectional area in the diagnosis of pericardial constriction.

Methods

Patients who had undergone cardiac MRI for evaluation of clinically suspected pericardial constriction were identified retrospectively. The diagnosis of pericardial constriction was established by clinical history, echocardiography, cardiac catheterization, intraoperative findings, and/or histopathology. Cross-sectional areas of the suprahepatic IVC and descending aorta were measured on a single axial steady-state free-precession (SSFP) image at the level of the esophageal hiatus in end-systole. Logistic regression and receiver-operating curve (ROC) analyses were performed.

Results

Thirty-six patients were included; 50% (n = 18) had pericardial constriction. Mean age was 53.9 ± 15.3 years, and 72% (n = 26) were male. IVC area, ratio of IVC to aortic area, pericardial thickness, and presence of respirophasic septal shift were all significantly different between patients with constriction and those without ( P < .001 for all). IVC to aortic area ratio had the highest odds ratio for the prediction of constriction (1070, 95% confidence interval [8.0-143051], P = .005). ROC analysis illustrated that IVC to aortic area ratio discriminated between those with and without constriction with an area under the curve of 0.96 (95% confidence interval [0.91-1.00]).

Conclusions

In patients referred for cardiac MRI assessment of suspected pericardial constriction, measurement of suprahepatic IVC cross-sectional area may be useful in confirming the diagnosis of constriction when used in combination with other imaging findings, including pericardial thickness and respirophasic septal shift.
G‐quadruplexes: Emerging roles in neurodegenerative diseases and the non‐coding transcriptome
Authors: Simone Roberto , Fratta Pietro , Neidle Stephen , Parkinson Gary N. , Isaacs Adrian M.
Published: May 2015

G‐rich sequences in DNA and RNA have a propensity to fold into stable secondary structures termed G‐quadruplexes. G‐quadruplex forming sequences are widespread throughout the human genome, within both, protein coding and non‐coding genes, and regulatory regions. G‐quadruplexes have been implicated in multiple cellular functions including chromatin epigenetic regulation, DNA recombination, transcriptional regulation of gene promoters and enhancers, and translation. Here we will review the evidence for the occurrence of G‐quadruplexes both in vitro and in vivo; their role in neurological diseases including G‐quadruplex‐forming repeat expansions in the C9orf72 gene in frontotemporal dementia and amyotrophic lateral sclerosis and loss of the G‐quadruplex binding protein FMRP in the intellectual disability fragile X syndrome. We also review mounting evidence that supports a role for G‐quadruplexes in regulating the processing or function of a range of non‐coding RNAs. Finally we will highlight current perspectives for therapeutic interventions that target G‐quadruplexes.
The sleeper framing effect: The influence of frame valence on immediate and retrospective judgments
Authors: Isaac Mathew S. , Poor Morgan
Published: May 2015

Prior research on attribute framing has documented a robust valence‐consistent shift whereby positively valenced options (e.g., 75% lean beef) are preferred over equivalent negatively valenced options (e.g., 25% fat beef). However, this research has typically explored how labels influence judgments of prospective or hypothetical consumption. In contrast, we examine how frames interact with actual consumption experiences to influence both immediate and retrospective judgments. We find evidence of a sleeper framing effect wherein a valence‐consistent shift emerges for retrospective judgments even when absent immediately after consumption. We attribute this effect to differences in how consumers integrate the more cognitive information of the frame with the more affective information acquired during consumption. Specifically, three experiments show that consumers attend to and rely relatively more on affective information from experience when making immediate judgments, but relatively more on cognitive information from the frame when making retrospective judgments. In addition, we identify the valence of the experience as an important boundary condition, such that the sleeper framing effect is most pronounced when the experience is relatively neutral in valence.
Autophagy induction impairs migration and invasion by reversing EMT in glioblastoma cells
Authors: Catalano Myriam , D'Alessandro Giuseppina , Lepore Francesca , Corazzari Marco , Caldarola Sara , Valacca Cristina , Faienza Fiorella , Esposito Vincenzo , Limatola Cristina , Cecconi Francesco , Di Bartolomeo Sabrina
Published: May 2015

Cell migration and invasion are highly regulated processes involved in both physiological and pathological conditions. Here we show that autophagy modulation regulates the migration and invasion capabilities of glioblastoma (GBM) cells. We observed that during autophagy occurrence, obtained by nutrient deprivation or by pharmacological inhibition of the mTOR complexes, GBM migration and chemokine‐mediated invasion were both impaired. We also observed that SNAIL and SLUG, two master regulators of the epithelial–mesenchymal transition (EMT process), were down‐regulated upon autophagy stimulation and, as a consequence, we found a transcriptional and translational up‐regulation of N‐ and R‐cadherins. Conversely, in BECLIN 1‐silenced GBM cells, an increased migration capability and an up‐regulation of SNAIL and SLUG was observed, with a resulting decrease in N‐ and R‐cadherin mRNAs. ATG5 and ATG7 down‐regulation also resulted in an increased migration and invasion of GBM cells combined to an up‐regulation of the two EMT regulators. Finally, experiments performed in primary GBM cells from patients largely confirmed the results obtained in established cell cultures.

Overall, our results indicate that autophagy modulation triggers a molecular switch from a mesenchymal phenotype to an epithelial‐like one in GBM cellular models. Since the aggressiveness and lethality of GBM is defined by local invasion and resistance to chemotherapy, we believe that our evidence provides a further rationale for including autophagy/mTOR‐based targets in the current therapeutical regimen of GBM patients.