bluuebunny/crossref_metadata_2025 huggingface dataset:
Two novel Anderson-type polyoxometalate-based metal–organic complexes with high-efficiency photocatalysis towards degradation of organic dyes under UV and visible light irradiation
Authors: Wang Xiuli , Chang Zhihan , Lin Hongyan , Tian Aixiang , Liu Guocheng , Zhang Juwen , Liu Danna
Published: January 2015

Two novel Anderson-type polyoxometalate-based metal–organic complexes constructed from two bis-pyridyl-bis-amide ligands have been hydrothermally synthesized, showing excellent photocatalytic activities toward the degradation of dyes.
Insights into the catalytic mechanism of chlorophenol 4-monooxygenase: a quantum mechanics/molecular mechanics study
Authors: Li Yanwei , Zhang Ruiming , Du Likai , Zhang Qingzhu , Wang Wenxing
Published: January 2015

The degradation mechanism of chlorophenol 4-monooxygenase toward pollutants 2,4,5-trichlorophenol, 2,4,6-trichlorophenol, and 2,5-dichloro-p-hydroquinone was studied by QM/MM investigations.
Urea formaldehyde (UF) microcapsules loaded with corrosion inhibitor for enhancing the anti-corrosive properties of acrylic-based multi-functional PU coatings
Authors: Marathe Ravindra J. , Chaudhari Ashok B. , Hedaoo Rahul K. , Sohn Daewon , Chaudhari Vijay R. , Gite Vikas V.
Published: January 2015

The present work focuses on enhancing the anti-corrosive performance of multi-functional PU coatings by encapsulation of the commercial inhibitors 2-mercaptobenzimidazole & 2-mercapatobenzothiozole, despite their reaction with diisocyanate.
Free radical-induced grafting from plasma polymers for the synthesis of thin barrier coatings
Authors: Ershov S. , Khelifa F. , Druart M.-E. , Habibi Y. , Olivier M.-G. , Snyders R. , Dubois P.
Published: January 2015

Enhanced barrier properties of Al substrate coated by plasma polymer film grafted with radical-induced polymer.
Synthesis of an amphiphilic hyperbranched polymer as a novel pH-sensitive drug carrier
Authors: Chen Rui , Wang Liqun
Published: January 2015

An amphiphilic hyperbranched polymer containing large amounts of pH sensitive bonds was synthesized. The hydrophobic chains are hyperbranched polyacetals and the hydrophilic chains are polyethylene glycols, attached to the hyperbranched polyacetals by hydrazone bonds.
Bimodal “matrix-free” polymer nanocomposites
Authors: Li Ying , Wang Lei , Natarajan Bharath , Tao Peng , Benicewicz Brian C. , Ullal Chaitanya , Schadler Linda S.
Published: January 2015

“Matrix-free” nanocomposites with a bimodal population of polymer brushes for optimizing filler loading while maintaining controlled dispersion.
4-Cyano-5-(2-thiophenyl)-pyrazoles are high affinity CB1 receptor ligands
Authors: Altomonte Stefano , Baillie Gemma L. , Ross Ruth A. , Zanda Matteo
Published: January 2015

Introduction of a 4-CN group on 5-thiophenyl-pyrazoles afforded high affinity cannabinoid ligands having low nM Ki values and moderate CB1 receptor selectivity. Log P and TPSA values suggest that some of the compounds might be peripherally restricted.
Spontaneous resolution of P and M helical copper(ii) MOFs built from achiral precursors
Authors: Bhattacharyya Anik , Chattopadhyay Shouvik
Published: January 2015

Enantiomorphic P and M helices have been synthesized by the self-assembly of achiral precursors via spontaneous resolution.
Unravelling the correlation between metal induced aggregation and cellular uptake/subcellular localization of Znsalen: an overlooked rule for design of luminescent metal probes
Authors: Tang Juan , Cai Yuan-Bo , Jing Jing , Zhang Jun-Long
Published: January 2015

We demonstrate the importance of speciation of luminescent metal complexes in water on biological behaviours such as cellular uptake and subcellular localization.
Sorting of integral membrane proteins mediated by curvature-dependent protein–lipid bilayer interaction
Authors: Božič Bojan , Das Sovan L. , Svetina Saša
Published: January 2015

The dependence of the sorting ratio (Ŝ) on reduced tether curvature (t/te) for potassium channel KvAP predicted by the model presented (full lines) and obtained experimentally (points) and theoretically (dashed lines) by Aimon et al. (2014).
Nonlinear rheology of entangled polymers at turning point
Authors: Wang Shi-Qing
Published: January 2015

Thanks to extensive observations of strain localization upon startup or after stepwise shear, a conceptual framework for nonlinear rheology of entangled polymers appears to have emerged that has led to discovery of many new phenomena, which were not previously predicted by the standard tube model.
Novelly developed three-dimensional carbon scaffold anodes from polyacrylonitrile for microbial fuel cells
Authors: Wang Ya-Qiong , Huang Han-Xiong , Li Bin , Li Wei-Shan
Published: January 2015

Novel three-dimensional open-celled carbon scaffold anodes for microbial fuel cells were prepared by carbonizing the microcellular polyacrylonitrile (PAN) and PAN/graphite composites.
Carbon-coated α-Fe2O3 nanostructures for efficient anode of Li-ion battery
Authors: Lv Xiaoxin , Deng Jiujun , Wang Jian , Zhong Jun , Sun Xuhui
Published: January 2015

Carbon-coated hematite nanostructures were prepared for Li-ion battery with high capacity, and the mechanism was probed by scanning transmission X-ray microscopy.
Probing the initiation of voltage decay in Li-rich layered cathode materials at the atomic scale
Authors: Wu Yan , Ma Cheng , Yang Jihui , Li Zicheng , Allard Lawrence F. , Liang Chengdu , Chi Miaofang
Published: January 2015

Through a correlative investigation of electrochemical characterization and atomic-scale scanning transmission electron microscopy, the voltage decay in Li-rich layered cathode materials is found to originate between 4.4 and 4.8 V, and the most dramatic structural change associated is the layered-to-spinel transition that nucleates in the initial cycle.
Hydrogenation of silicene with tensile strains
Authors: Wu W. C. , Ao Z. M. , Yang C. H. , Li S. , Wang G. X. , Li C. M. , Li S.
Published: January 2015

The energy barrier for hydrogenation of silicene decreases as the strains increase, and the barrier reduces from 1.71 to 0.24 eV when the strain reaches the critical value of 12%. In this way, the reaction time for the hydrogenation of silicene can accelerate significantly from 8.06 × 1016 to 1.68 × 10−8 s.
Effect of sequential morphology adjustment of hematite nanoplates to nanospindles on their properties and applications
Authors: Zhao Jie , Yang Ping , Chen Hsueh-Shih , Li Jia , Che Quande , Zhu Yuanna , Shi Ruixia
Published: January 2015

Marked morphological changes of α-Fe2O3 nanocrystals from nanoplates to nanospindles were achieved using NO3− ions and NH3 molecules as structural guides in an ethylene glycol system.
Reproductive toxicity and meiotic dysfunction following exposure to the pesticides Maneb, Diazinon and Fenarimol
Authors: Daniela A Parodi , Jasmine Sjarif , Yichang Chen , Patrick Allard
Published: January 2015

The comprehensive identification and mechanistic analysis of reproductive toxicants constitutes one of the major hurdles in the toxicological assessment of chemicals.
Tremella-like graphene–Au composites used for amperometric determination of dopamine
Authors: Li Cong , Zhao Jingyu , Yan Xiaoyi , Gu Yue , Liu Weilu , Tang Liu , Zheng Bo , Li Yaru , Chen Ruixue , Zhang Zhiquan
Published: January 2015

Tremella-like graphene–Au composites were synthesized by a one-step hydrothermal method for selective detection of DA.
A modular synthesis of functionalised phenols enabled by controlled boron speciation
Authors: Molloy John J. , Law Robert P. , Fyfe James W. B. , Seath Ciaran P. , Hirst David J. , Watson Allan J. B.
Published: January 2015

Functionalised biaryl phenols can be rapidly accessed via one-pot Suzuki–Miyaura cross-coupling, chemoselective control of boron solution speciation, and oxidation.
Novel reactive PEG for amino group conjugation
Authors: González Marianela , Ceaglio Natalia A. , de los Milagros Bürgi M. , Etcheverrigaray Marina , Kratje Ricardo B. , Vaillard Santiago E.
Published: January 2015

Activated mPEG carbonates are important reagents that have been widely used for the PEGylation of several peptides and proteins by means of stable urethane linkages.
Circulating E3 ligases are novel and sensitive biomarkers for diagnosis of acute myocardial infarction
Authors: Han Qiu-Yue , Wang Hong-Xia , Liu Xiao-Hong , Guo Cai-Xia , Hua Qi , Yu Xiao-Hong , Li Nan , Yang Yan-Zong , Du Jie , Xia Yun-Long , Li Hui-Hua
Published: January 2015

Because of the delayed release of troponins, early diagnosis of acute myocardial infarction (AMI) is a problem. E3 ligase Rnf207 showed higher sensitivity and specificity for diagnosis of AMI. Therefore, We concluded Rnf207 may be a novel biomarkers for AMI.
The impact of cryopreservation on human peripheral blood leucocyte bioenergetics
Authors: Keane Kevin N. , Calton Emily K. , Cruzat Vinicius F. , Soares Mario J. , Newsholme Philip
Published: January 2015

This study has demonstrated for the first time that cryopreservation of primary immune cells modified their metabolism in a time-dependent fashion, indicated by attenuated aerobic respiration and enhanced glycolytic activity. Measurements were recorded using the Seahorse XFe96 extracellular flux analyser.
Hölder continuity of the spectral measures for one-dimensional Schrödinger operator in exponential regime
Authors: Liu Wencai , Yuan Xiaoping
Published: January 2015

Avila and Jitomirskaya prove that the spectral measure μλv,α,xf of quasi-periodic Schrödinger operator is 1/2-Hölder continuous with appropriate initial vector f, if α satisfies Diophantine condition and λ is small. In the present paper, the conclusion is extended to that for all α with β(α) < ∞, the spectral measure μλv,α,xf is 1/2-Hölder continuous with small λ, if v is real analytic in a neighbor of {ℑx≤Cβ}, where C is a large absolute constant. In particular, the spectral measure μλ,α,xf of almost Mathieu operator is 1/2-Hölder continuous if λ<e−Cβ with C a large absolute constant.
Local order of liquid water at metallic electrode surfaces
Authors: Pedroza Luana S. , Poissier Adrien , Fernández-Serra M.-V.
Published: January 2015

We study the structure and dynamics of liquid water in contact with Pd and Au (111) surfaces using ab initio molecular dynamics simulations with and without van der Waals interactions. Our results show that the structure of water at the interface of these two metals is very different. For Pd, we observe the formation of two different domains of preferred orientations, with opposite net interfacial dipoles. One of these two domains has a large degree of in-plane hexagonal order. For Au, a single domain exists with no in-plane order. For both metals, the structure of liquid water at the interface is strongly dependent on the use of dispersion forces. The origin of the structural domains observed in Pd is associated to the interplay between water/water and water/metal interactions. This effect is strongly dependent on the charge transfer that occurs at the interface and which is not modeled by current state of the art semi-empirical force fields.
Steady-state heat transport: Ballistic-to-diffusive with Fourier's law
Authors: Maassen Jesse , Lundstrom Mark
Published: January 2015

It is generally understood that Fourier's law does not describe ballistic phonon transport, which is important when the length of a material is similar to the phonon mean-free-path. Using an approach adapted from electron transport, we demonstrate that Fourier's law and the heat equation do capture ballistic effects, including temperature jumps at ideal contacts, and are thus applicable on all length scales. Local thermal equilibrium is not assumed, because allowing the phonon distribution to be out-of-equilibrium is important for ballistic and quasi-ballistic transport. The key to including the non-equilibrium nature of the phonon population is to apply the proper boundary conditions to the heat equation. Simple analytical solutions are derived, showing that (i) the magnitude of the temperature jumps is simply related to the material properties and (ii) the observation of reduced apparent thermal conductivity physically stems from a reduction in the temperature gradient and not from a reduction in actual thermal conductivity. We demonstrate how our approach, equivalent to Fourier's law, easily reproduces results of the Boltzmann transport equation, in all transport regimes, even when using a full phonon dispersion and mean-free-path distribution.
Molecular quantum mechanical gradients within the polarizable embedding approach—Application to the internal vibrational Stark shift of acetophenone
Authors: List Nanna Holmgaard , Beerepoot Maarten T. P. , Olsen Jógvan Magnus Haugaard , Gao Bin , Ruud Kenneth , Jensen Hans Jørgen Aagaard , Kongsted Jacob
Published: January 2015

We present an implementation of analytical quantum mechanical molecular gradients within the polarizable embedding (PE) model to allow for efficient geometry optimizations and vibrational analysis of molecules embedded in large, geometrically frozen environments. We consider a variational ansatz for the quantum region, covering (multiconfigurational) self-consistent-field and Kohn–Sham density functional theory. As the first application of the implementation, we consider the internal vibrational Stark effect of the C=O group of acetophenone in different solvents and derive its vibrational linear Stark tuning rate using harmonic frequencies calculated from analytical gradients and computed local electric fields. Comparisons to PE calculations employing an enlarged quantum region as well as to a non-polarizable embedding scheme show that the inclusion of mutual polarization between acetophenone and water is essential in order to capture the structural modifications and the associated frequency shifts observed in water. For more apolar solvents, a proper description of dispersion and exchange–repulsion becomes increasingly important, and the quality of the optimized structures relies to a larger extent on the quality of the Lennard-Jones parameters.
The effect of anisotropic and isotropic roughness on the convective stability of the rotating disk boundary layer
Authors: Cooper A. J. , Harris J. H. , Garrett S. J. , Özkan M. , Thomas P. J.
Published: January 2015

A theoretical study investigating the effects of both anisotropic and isotropic surface roughness on the convective stability of the boundary-layer flow over a rotating disk is described. Surface roughness is modelled using a partial-slip approach, which yields steady-flow profiles for the relevant velocity components of the boundary-layer flow which are a departure from the classic von Kármán solution for a smooth disk. These are then subjected to a linear stability analysis to reveal how roughness affects the stability characteristics of the inviscid Type I (or cross-flow) instability and the viscous Type II instability that arise in the rotating disk boundary layer. Stationary modes are studied and both anisotropic (concentric grooves and radial grooves) and isotropic (general) roughness are shown to have a stabilizing effect on the Type I instability. For the viscous Type II instability, it was found that a disk with concentric grooves has a strongly destabilizing effect, whereas a disk with radial grooves or general isotropic roughness has a stabilizing effect on this mode. In order to extract possible underlying physical mechanisms behind the effects of roughness, and in order to reconfirm the results of the linear stability analysis, an integral energy equation for three-dimensional disturbances to the undisturbed three-dimensional boundary-layer flow is used. For anisotropic roughness, the stabilizing effect on the Type I mode is brought about by reductions in energy production in the boundary layer, whilst the destabilizing effect of concentric grooves on the Type II mode results from a reduction in energy dissipation. For isotropic roughness, both modes are stabilized by combinations of reduced energy production and increased dissipation.
Air cushioning in droplet impact. I. Dynamics of thin films studied by dual wavelength reflection interference microscopy
Authors: de Ruiter Jolet , Mugele Frieder , van den Ende Dirk
Published: January 2015

When a liquid droplet impacts on a solid surface, it not only deforms substantially but also an air film develops between the droplet and the surface. This thin air film—as well as other transparent films—can be characterized by reflection interference microscopy. Even for weakly reflecting interfaces, relative thickness variations of the order of tens of nanometers are easily detected, yet the absolute thickness is generally known only up to an additive constant which is a multiple of half of the wavelength. Here, we present an optical setup for measuring the absolute film thickness and its spatial and temporal behavior using a combination of a standard Hg lamp, an optical microscope, and three synchronized high-speed cameras to detect conventional side-view images as well as interferometric bottom view images at two different wavelengths. The combination of a dual wavelength approach with the finite coherence length set by the broad bandwidth of the optical filters allows for measuring the absolute thickness of transient air films with a spatial resolution better than 30 nm at 50 μs time resolution with a maximum detectable film thickness of approximately 8 μm. This technique will be exploited in Part II to characterize the air film evolution during low velocity droplet impacts.
Air cushioning in droplet impact. II. Experimental characterization of the air film evolution
Authors: de Ruiter Jolet , van den Ende Dirk , Mugele Frieder
Published: January 2015

A liquid drop approaching a solid surface deforms substantially under the influence of the ambient air which needs to be squeezed out before the liquid can actually touch the solid. We use nanometer- and microsecond-resolved dual wavelength interferometry described in Part I (also published in this issue) to reveal the complex spatial and temporal evolution of the squeezed air layer. In low-velocity droplet impact, i.e., We numbers of order unity, the confined air layer below the droplet develops two local minima in thickness. We quantitatively measure the evolution of the droplet bottom interface and find that surface tension determines the air film thickness below the first kink, after which fluid is diverted outward to form a second even sharper kink. Depending on We, one of the two kinks approaches the surface more closely forming liquid-solid contact. The early time spreading of liquid-solid contact is controlled by the capillary driving force and the inertia of the liquid. The cushioned air film geometry, i.e., a flat micrometer-thin gap, induces an increase of the spreading velocity; the contact area first spreads over the cushioned region, only then followed by radial spreading. This spreading mechanism can lead to the entrapment of one or more air bubbles.
Self-assembled two-dimensional nanoporous molecular arrays and photoinduced polymerization of 4-bromo-4′-hydroxybiphenyl on Ag(111)
Authors: Shen Qian , He Jing Hui , Zhang Jia Lin , Wu Kai , Xu Guo Qin , Wee Andrew Thye Shen , Chen Wei
Published: January 2015

Self-assembled two-dimensional molecular arrays and photoinduced polymerization of 4-bromo-4′-hydroxybiphenyl on Ag(111) were studied using low-temperature scanning tunneling microscopy combined with density functional theory calculations. Square-like self-assembled structures of 4-bromo-4′-hydroxybiphenyl stabilized by intermolecular hydrogen and halogen bonds were transformed into hexagonal nanopores of biphenyl biradicals by 266 nm UV laser irradiation at 80 K. The biradicals further coupled to each other and formed covalently linked polyphenylene polymer chains at room temperature.
Adsorption of PTCDA on Si(001) − 2 × 1 surface
Authors: Suzuki Takayuki , Yoshimoto Yoshihide , Yagyu Kazuma , Tochihara Hiroshi
Published: January 2015

Adsorption structures of the 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) molecule on the clean Si(001) − 2 × 1 surface were investigated using scanning tunneling microscopy (STM) experiments in conjunction with first principles theoretical calculations. Four dominant adsorption structures were observed in the STM experiments and their atomic coordinates on the Si(001) surface were determined by comparison between the experimental STM images and the theoretical simulations. Maximizing the number of the Si—O bonds is more crucial than that of the Si—C bonds in the PTCDA adsorption.
Finite size effects in ferroelectric-semiconductor thin films under open-circuit electric boundary conditions
Authors: Eliseev Eugene A. , Kalinin Sergei V. , Morozovska Anna N.
Published: January 2015

General features of finite size effects in the ferroelectric-semiconductor film under open-circuit electric boundary conditions are analyzed using Landau-Ginzburg-Devonshire theory and continuum media electrostatics. The temperature dependence of the film critical thickness, spontaneous polarization, and depolarization field profiles of the open-circuited films are found to be significantly different from the characteristics of short-circuited ones. In particular, we predict the re-entrant type transition boundary between the mono-domain and poly-domain ferroelectric states due to reduced internal screening efficiency and analyzed possible experimental scenarios created by this mechanism. Performed analysis is relevant for the quantitative description of free-standing ferroelectric films phase diagrams and polar properties. Also our results can be useful for the explanation of the scanning-probe microscopy experiments on free ferroelectric surfaces.
Structural features of plastic deformation in bulk metallic glasses
Authors: Scudino S. , Shakur Shahabi H. , Stoica M. , Kaban I. , Escher B. , Kühn U. , Vaughan G. B. M. , Eckert J.
Published: January 2015

Spatially resolved strain maps of a plastically deformed bulk metallic glass (BMG) have been created by using high-energy X-ray diffraction. The results reveal that plastic deformation creates a spatially heterogeneous atomic arrangement, consisting of strong compressive and tensile strain fields. In addition, significant shear strain is introduced in the samples. The analysis of the eigenvalues and eigenvectors of the strain tensor indicates that considerable structural anisotropy occurs in both the magnitude and direction of the strain. These features are in contrast to the behavior observed in elastically deformed BMGs and represent a distinctive structural sign of plastic deformation in metallic glasses.
Perpendicular diffusion of energetic particles in collisionless plasmas
Authors: Shalchi A.
Published: January 2015

A fundamental problem in plasma and astrophysics is the interaction between energetic particles and magnetized plasmas. In the current paper, we focus on particle diffusion across the guide magnetic field. It is shown that the perpendicular diffusion coefficient depends only on the parallel diffusion coefficient and the Kubo number. Therefore, one can find four asymptotic limits depending on the values of these two parameters. These regimes are the quasilinear limit, the Kadomtsev and Pogutse limit, the scaling of Rechester and Rosenbluth, and the scaling found by Zybin and Istomin. In the current article, we focus on the Rechester and Rosenbluth scenario because this was not discovered before in the context of collisionless plasmas. Examples and applications are discussed as well. We show that an energy independent ratio of perpendicular and parallel diffusion coefficients can be found and that this ratio can be very small but also close to unity. This is exactly what one observes in the solar wind.
Time-domain theory of gyrotron traveling wave amplifiers operating at grazing incidence
Authors: Ginzburg N. S. , Sergeev A. S. , Zotova I. V. , Zheleznov I. V.
Published: January 2015

Time-domain theory of the gyrotron traveling wave tube (gyro-TWT) operating at grazing incidence has been developed. The theory is based on a description of wave propagation by a parabolic equation. The results of the simulations are compared with experimental results of the observation of subnanosecond pulse amplification in a gyro-TWT consisting of three gain sections separated by severs. The theory developed can also be used successfully for a description of amplification of monochromatic signals.
Self-normalizing phase measurement in multimode terahertz spectroscopy based on photomixing of three lasers
Authors: Thirunavukkuarasu K. , Langenbach M. , Roggenbuck A. , Vidal E. , Schmitz H. , Hemberger J. , Grüninger M.
Published: January 2015

Photomixing of two near-infrared lasers is well established for continuous-wave terahertz spectroscopy. Photomixing of three lasers allows us to measure at three terahertz frequencies simultaneously. Similar to Fourier spectroscopy, the spectral information is contained in an interferogram, which is equivalent to the waveform in time-domain spectroscopy. We use one fixed terahertz frequency νref to monitor temporal drifts of the setup, i.e., of the optical path-length difference. The other two frequencies are scanned for broadband high-resolution spectroscopy. The frequency dependence of the phase is obtained with high accuracy by normalizing it to the data obtained at νref, which eliminates drifts of the optical path-length difference. We achieve an accuracy of about 1–2 μm or 10−8 of the optical path length. This method is particularly suitable for applications in nonideal environmental conditions outside of an air-conditioned laboratory.
Temperature dependence of the superconducting proximity effect quantified by scanning tunneling spectroscopy
Authors: Stępniak A. , Caminale M. , Leon Vanegas A. A. , Oka H. , Sander D. , Kirschner J.
Published: January 2015

Here, we present the first systematic study on the temperature dependence of the extension of the superconducting proximity effect in a 1–2 atomic layer thin metallic film, surrounding a superconducting Pb island. Scanning tunneling microscopy/spectroscopy (STM/STS) measurements reveal the spatial variation of the local density of state on the film from 0.38 up to 1.8 K. In this temperature range the superconductivity of the island is almost unaffected and shows a constant gap of a 1.20 ± 0.03 meV. Using a superconducting Nb-tip a constant value of the proximity length of 17 ± 3 nm at 0.38 and 1.8 K is found. In contrast, experiments with a normal conductive W-tip indicate an apparent decrease of the proximity length with increasing temperature. This result is ascribed to the thermal broadening of the occupation of states of the tip, and it does not reflect an intrinsic temperature dependence of the proximity length. Our tunneling spectroscopy experiments shed fresh light on the fundamental issue of the temperature dependence of the proximity effect for atomic monolayers, where the intrinsic temperature dependence of the proximity effect is comparably weak.
Synthetic Amino Acids for Applications in Peptide Ligation–Desulfurization Chemistry
Authors: Malins Lara R. , Payne Richard J.
Published: January 2015

Native chemical ligation is a powerful tool for the convergent assembly of homogeneous peptide and protein targets from unprotected peptide fragments. The method involves the chemoselective coupling of a peptide thioester with a peptide bearing an N-terminal cysteine (Cys) residue and is mediated by the nucleophilic Cys thiol functionality. A widely adopted extension of the technique for the disconnection of protein targets at alanine (Ala) ligation junctions has been the application of post-ligation desulfurization protocols for the mild removal of the Cys thiol moiety. Recently, attention has turned to the construction of synthetic amino acid building blocks bearing suitably positioned β-, γ-, or δ-thiol ligation auxiliaries with a view to expanding the scope of the ligation–desulfurization manifold. To date, several thiol-derived amino acids have been prepared, greatly increasing the generality and flexibility of chemoselective ligation technologies for the chemical synthesis of diverse protein targets. This review will highlight the current synthetic approaches to these important amino acid building blocks.
BTB-ZF transcriptional regulator PLZF modifies chromatin to restrain inflammatory signaling programs
Authors: Sadler Anthony J. , Rossello Fernando J. , Yu Liang , Deane James A. , Yuan Xiangliang , Wang Die , Irving Aaron T. , Kaparakis-Liaskos Maria , Gantier Michael P. , Ying Hangjie , Yim Howard C. H. , Hartland Elizabeth L. , Notini Amanda J. , de Boer Suzan , White Stefan J. , Mansell Ashley , Liu Jun-Ping , Watkins D. Neil , Gerondakis Steve , Williams Bryan R. G. , Xu Dakang
Published: January 2015

Significance

Maintaining physiological balance is vital in the primary response to infectious and other stress stimuli to avert damaging inflammation. Delineation of the cell regulatory processes that control inflammatory processes better enable the development of informed strategies to treat associated pathologies. Toward this end, we identify that the promyelocytic leukemia zinc finger (PLZF) transcription factor limits pathogen-induced inflammation. PLZF stabilizes a repressor complex that encompasses histone deacetylase activity, which modifies the state of chromatin. This activity maintains homeostasis by decreasing the scale of induction of select immune response genes. In the absence of PLZF, the chromatin structure is altered, enabling active transcriptional complexes to immediately assemble on gene promoters, resulting in inordinate production of inflammatory cytokines.
Osteocytes mediate the anabolic actions of canonical Wnt/β-catenin signaling in bone
Authors: Tu Xiaolin , Delgado-Calle Jesus , Condon Keith W. , Maycas Marta , Zhang Huajia , Carlesso Nadia , Taketo Makoto M. , Burr David B. , Plotkin Lilian I. , Bellido Teresita
Published: January 2015

Significance

Bone anabolic stimuli activate canonical Wnt/β-catenin signaling and human mutations of this pathway underscore its essential role in bone accrual. However, the cell responsible for orchestrating these actions has remained elusive. This study identifies osteocytes as mediators of the anabolic effect of canonical Wnt/β-catenin signaling in bone; further, it dissects desired (bone gain) from undesired (decreased resorption and leukemia) outcomes by selective activation of canonical Wnt/β-catenin signaling in osteocytes versus osteoblasts. Long-lived osteocytes constitute more than 90% of bone cells, thus representing more logical and effective target cells to induce bone anabolism than scarce, short-lived osteoblasts. These findings pave the way toward the development of better treatments for osteoporosis and other bone-related disorders targeting osteocytic Wnt/β-catenin signaling.
Cross-evaluation of metrics to estimate the significance of creative works
Authors: Wasserman Max , Zeng Xiao Han T. , Amaral Luís A. Nunes
Published: January 2015

Significance

Whether it is Hollywood movies or research papers, identifying works of great significance is imperative in a modern society overflowing with information. Through analysis of a network constructed from citations between films as referenced in the Internet Movie Database, we obtain several automated metrics for significance. We find that the best automated method can identify significant films, represented by selection to the US National Film Registry, at least as well as the aggregate rating of many experts and far better than the rating of a single expert. We hypothesize that these results may hold for other creative works.
Reductions in emissions from deforestation from Indonesia’s moratorium on new oil palm, timber, and logging concessions
Authors: Busch Jonah , Ferretti-Gallon Kalifi , Engelmann Jens , Wright Max , Austin Kemen G. , Stolle Fred , Turubanova Svetlana , Potapov Peter V. , Margono Belinda , Hansen Matthew C. , Baccini Alessandro
Published: January 2015

Significance

Our paper is significant in a number of respects. First, we expand the literature on quasi-experimental evaluation of the causal impact of conservation measures to include agricultural concessions. Second, our report is rare in that we use panel data and techniques in a literature on spatially explicit land-use change econometrics that has necessarily relied upon cross-sectional analyses because of data-availability constraints. Third, our report is rare among land-use change scenario analyses in that we calibrate the effect of land-use designations empirically, rather than assuming idealized perfect effectiveness of conservation measures or complete conversion without such measures. Finally, we compare the effectiveness of place-based policies with alternative price-based instruments for climate-change mitigation within a globally significant landscape.
Combating pertussis resurgence: One booster vaccination schedule does not fit all
Authors: Riolo Maria A. , Rohani Pejman
Published: January 2015

Significance

Pertussis has reemerged as a major public health concern in many countries where vaccine uptake remains high and pertussis has been considered well controlled until recently. In our paper, we address the important scientific and practical problem of developing optimal booster vaccination schedules by using a genetic algorithm. Our results argue that booster vaccination schedules developed based on misdiagnosis of the problem are likely to be epidemiologically ineffective and economically costly.
TFIIH-dependent
MMP-1
overexpression in trichothiodystrophy leads to extracellular matrix alterations in patient skin
Authors: Arseni Lavinia , Lanzafame Manuela , Compe Emmanuel , Fortugno Paola , Afonso-Barroso António , Peverali Fiorenzo A. , Lehmann Alan R. , Zambruno Giovanna , Egly Jean-Marc , Stefanini Miria , Orioli Donata
Published: January 2015

Significance

Despite exhibiting different phenotypes, the UV-sensitive syndromes trichothiodystrophy (TTD) and xeroderma pigmentosum (XP) result from the same mutated genes encoding specific subunits of the DNA-repair/transcription factor TFIIH. The widely accepted notion is that XP cancer proneness results from mutations interfering with DNA repair, whereas TTD clinical hallmarks (namely, hair anomalies, physical and mental retardation, and premature aging) are because of transcriptional alterations. The present study identifies a TTD-specific overexpression of
matrix metalloproteinase 1
, leading to collagen I degradation in patient skin. This finding explains the clinical features distinguishing TTD from XP (i.e. bone alterations, pregnancy abnormalities and likely lack of skin cancer despite the accumulation of unrepaired DNA lesions) and the features that TTD shares with osteogenesis imperfecta caused by
COL1
mutations.
Jagged–Delta asymmetry in Notch signaling can give rise to a Sender/Receiver hybrid phenotype
Authors: Boareto Marcelo , Jolly Mohit Kumar , Lu Mingyang , Onuchic José N. , Clementi Cecilia , Ben-Jacob Eshel
Published: January 2015

Significance

Notch signaling pathway plays crucial roles in cell-fate determination during embryonic development and cancer progression. According to the current paradigm, the Notch–Delta signaling leads to complementary cell-fate selection between two neighboring cells where one acts as Sender or Receiver. However, this picture is not complete because an additional ligand, Jagged, is involved in the Notch signaling. We devise a specific theoretical framework to decipher the functional role of Jagged. We find that the asymmetry between the modulations of Delta and Jagged leads to the existence of the previously unexplored possibility of a Sender–Receiver phenotype enabling two interacting cells to share a similar fate. This realization can provide important clues regarding embryonic development, wound healing, and how to target tumor–stroma signaling.
Belief about nicotine selectively modulates value and reward prediction error signals in smokers
Authors: Gu Xiaosi , Lohrenz Terry , Salas Ramiro , Baldwin Philip R. , Soltani Alireza , Kirk Ulrich , Cinciripini Paul M. , Montague P. Read
Published: January 2015

Significance

Nicotine is the primary addictive substance in tobacco, which stimulates neural pathways mediating reward processing. However, pure biochemical explanations are not sufficient to account for the difficulty in quitting and remaining smoke-free among smokers, and in fact cognitive factors are now considered to contribute critically to addiction. Using model-based functional neuroimaging, we show that smokers’ prior beliefs about nicotine specifically impact learning signals defined by principled computational models of mesolimbic dopamine systems. We further demonstrate that these specific changes in neural signaling are accompanied by measurable changes in smokers’ choice behavior. Our findings suggest that subjective beliefs can override the physical presence of a powerful drug like nicotine by modulating learning signals processed in the brain’s reward system.
Mitochondrial alarmins released by degenerating motor axon terminals activate perisynaptic Schwann cells
Authors: Duregotti Elisa , Negro Samuele , Scorzeto Michele , Zornetta Irene , Dickinson Bryan C. , Chang Christopher J. , Montecucco Cesare , Rigoni Michela
Published: January 2015

Significance

The neuromuscular junction is the site of transmission of the nerve impulse to the muscle. This finely tuned synapse relies on at least three components: the motor neuron, the muscle fiber, and the Schwann cells, which assist nerve recovery after injury. Using animal neurotoxins to induce an acute and reversible nerve degeneration, we have identified several mitochondrial molecules through which the damaged nerve terminal communicates with nearby cells, activating signaling pathways in Schwann cells involved in nerve regeneration. Among these messengers, hydrogen peroxide appears to be crucial at the initial stages of regeneration, because its inactivation delays the functional recovery of the damaged neuromuscular junction in vivo. These findings provide important indications about the pharmacological treatment of traumatized patients.
Ventral striatal dopamine reflects behavioral and neural signatures of model-based control during sequential decision making
Authors: Deserno Lorenz , Huys Quentin J. M. , Boehme Rebecca , Buchert Ralph , Heinze Hans-Jochen , Grace Anthony A. , Dolan Raymond J. , Heinz Andreas , Schlagenhauf Florian
Published: January 2015

Significance

Whether humans make choices based on a deliberative “model-based” or a reflexive “model-free” system of behavioral control remains an ongoing topic of research. Dopamine is implicated in motivational drive as well as in planning future actions. Here, we demonstrate that higher presynaptic dopamine in human ventral striatum is associated with more pronounced model-based behavioral control, as well as an enhanced coding of model-based signatures in lateral prefrontal cortex and diminished coding of model-free learning signals in ventral striatum. Our study links ventral striatal presynaptic dopamine to a balance between two distinct modes of behavioral control in humans. The findings have implications for neuropsychiatric diseases associated with alterations of dopamine neurotransmission and a disrupted balance of behavioral control.
Cyclic AMP concentrations in dendritic cells induce and regulate Th2 immunity and allergic asthma
Authors: Lee Jihyung , Kim Tae Hoon , Murray Fiona , Li Xiangli , Choi Sara S. , Broide David H. , Corr Maripat , Lee Jongdae , Webster Nicholas J. G. , Insel Paul A. , Raz Eyal
Published: January 2015

Significance

Allergic asthma is characterized by Th2 type inflammation, leading to airway hyperresponsiveness and remodeling. However, the mechanisms by which DC promote Th2 differentiation remain unclear. Herein we demonstrate that low cAMP levels in DC induce Th2-biased responses in vitro and in vivo. Furthermore, mice with conditional deletion of
Gnas
in DC (
Gnas
ΔCD11c
mice) develop spontaneous bronchial asthma that shares multiple similarities with human asthma. In contrast, increasing cAMP levels inhibit these responses. Thus, regulators of cAMP levels in DC such as G-protein-coupled receptors are non-pattern recognition receptors that play a significant role in CD4 T cell differentiation.
Rapid deposition of oxidized biogenic compounds to a temperate forest
Authors: Nguyen Tran B. , Crounse John D. , Teng Alex P. , St. Clair Jason M. , Paulot Fabien , Wolfe Glenn M. , Wennberg Paul O.
Published: January 2015

Significance

Dry deposition is an important removal mechanism for oxidized atmospheric compounds. This process remains, however, poorly understood due to the scarcity of direct flux observations for all but small, inorganic molecules in the atmosphere. The chemically speciated fluxes presented here comprise a unique and novel dataset that quantifies the dry deposition velocities for a variety of trace gases in a typical forested ecosystem. The data illustrate the key role of molecular diffusion in the atmosphere−biosphere exchange of water-soluble species. Furthermore, this work enabled evaluation of the dry deposition parameterization in a global chemical transport model. The results aid in resolving key discrepancies within the global model, resulting in more-accurate predictions of trace gas lifetimes and surface concentrations.
Persistence of deeply sourced iron in the Pacific Ocean
Authors: Horner Tristan J. , Williams Helen M. , Hein James R. , Saito Mak A. , Burton Kevin W. , Halliday Alex N. , Nielsen Sune G.
Published: January 2015

Significance

The vertical supply of dissolved Fe (iron) is insufficient compared with the physiological needs of marine phytoplankton in vast swathes of the open ocean. However, the relative importance of the main sources of “new” Fe to the ocean—continental mineral dust, hydrothermal exhalations, and sediment dissolution—and their temporal evolution are poorly constrained. By analyzing the isotopic composition of Fe in marine sediments, we find that much of the dissolved Fe in the central Pacific Ocean originated from hydrothermal and sedimentary sources thousands of meters below the sea surface. As such, these data underscore the vital role of the oceans’ physical mixing in determining if any deeply sourced Fe ever reaches the Fe-starved surface-dwelling biota.
Quantum dot/antibody conjugates for in vivo cytometric imaging in mice
Authors: Han Hee-Sun , Niemeyer Elisabeth , Huang Yuhui , Kamoun Walid S. , Martin John D. , Bhaumik Jayeeta , Chen Yunching , Roberge Sylvie , Cui Jian , Martin Margaret R. , Fukumura Dai , Jain Rakesh K. , Bawendi Moungi G. , Duda Dan G.
Published: January 2015

Significance

One of the key questions in biology is understanding how cells move, interact, and evolve in living organisms. Tremendous efforts have been made to answer these questions in vitro, which have yielded a molecular-level understanding of cellular events. However, an increasing number of studies indicate that cellular activities need to be understood in the context of their natural environments. Single-cell labeling methods in use currently involve immunohistochemistry, genetic manipulation, or irradiation of mice, none of which reflect the native microenvironments. Here, we report quantum dot immunoconstructs that can be used for intravital imaging of single cells in unmanipulated mice and multiplexed in vivo cytometric analysis of rare cell populations.
Oldest known euarchontan tarsals and affinities of Paleocene
Purgatorius
to Primates
Authors: Chester Stephen G. B. , Bloch Jonathan I. , Boyer Doug M. , Clemens William A.
Published: January 2015

Significance

Purgatorius
has been considered a plausible ancestor for primates since it was discovered, but this fossil mammal has been known only from teeth and jaw fragments. We attribute to
Purgatorius
the first (to our knowledge) nondental remains (ankle bones) which were discovered in the same ∼65-million-year-old deposits as dentitions of this putative primate. This attribution is based mainly on size and unique anatomical specializations known among living euarchontan mammals (primates, treeshrews, colugos) and fossil plesiadapiforms. Results of phylogenetic analyses that incorporate new data from these fossils support
Purgatorius
as the geologically oldest known primate. These recently discovered tarsals have specialized features for mobility and provide the oldest fossil evidence that suggests arboreality played a key role in earliest primate evolution.
Intracellular and extracellular forces drive primary cilia movement
Authors: Battle Christopher , Ott Carolyn M. , Burnette Dylan T. , Lippincott-Schwartz Jennifer , Schmidt Christoph F.
Published: January 2015

Significance

A single primary cilium extends from the surface of many mammalian cells—often into an aqueous lumen, such as a kidney duct. In kidney epithelial cells, primary cilia are believed to sense fluid flow. This mechanosensory function is critical for proper organ function. Fluid flow is assumed to deflect cilia, leading to activation of transmembrane ion channels. This study defines the mechanical contributions of both bending and pivoting at the base to ciliary deflection. In addition, we report that active intracellular forces drive ciliary pivoting. This cell-directed cilia movement may be important for tuning ciliary mechanosensitivity.
PSB27: A thylakoid protein enabling
Arabidopsis
to adapt to changing light intensity
Authors: Hou Xin , Fu Aigen , Garcia Veder J. , Buchanan Bob B. , Luan Sheng
Published: January 2015

Significance

Our results provide evidence that PSB27, a soluble protein of the chloroplast thylakoid lumen, is essential for enabling plants to adapt to changes in light intensity. Adaptation takes place independently of photosystem II supercomplexes and, based on work of others, of state transitions for the redistribution of light harvesting proteins. This finding opens the door to pursue the question of how photosynthesis adjusts to fluctuating sunlight and enables plants to grow under ever-changing environmental conditions.
Kinetics of sickle cell biorheology and implications for painful vasoocclusive crisis
Authors: Du E , Diez-Silva Monica , Kato Gregory J. , Dao Ming , Suresh Subra
Published: January 2015

Significance

A major challenge with in vitro investigations of the pathophysiological processes in sickle cell disease (SCD) has been the lack of a well-controlled microenvironment to mimic in vivo circulating conditions. The microfluidic platform developed here provides a quantitative assay of the kinetics of cell sickling, unsickling, and single-cell rheology. The ensuing alterations in the biorheological characteristics of sickle cells under hypoxic conditions show strong correlation with sickle hemoglobin level, hydroxyurea (HU) therapy, and cell density. These analyses provide cell-level perspectives of the clinical manifestations in SCD patients and offer unique diagnostic indicators of vasoocclusion and disease severity. These results could also provide alternative pathways to supplement current clinical practices to evaluate HU therapy.
Fitness tradeoffs between spores and nonaggregating cells can explain the coexistence of diverse genotypes in cellular slime molds
Authors: Tarnita Corina E. , Washburne Alex , Martinez-Garcia Ricardo , Sgro Allyson E. , Levin Simon A.
Published: January 2015

Significance

Cellular slime molds, including
Dictyostelium discoideum
, are amoebae whose life cycle includes both single-cellular and multicellular stages, the latter achieved when individual amoebae aggregate upon starvation. In the (not necessarily clonal) aggregate, there is strong selection to be represented in the reproductive spores. This would lead to a reduction in overall genotypic diversity inconsistent with the great diversity found in nature. We suggest that cells that fail to aggregate provide an additional fitness component that can resolve the inconsistency: Strong selection for aggregation only occurs in environments where food is slow to replenish. Otherwise, there is strong selection for unicellularity. These tradeoffs allow a multitude of genotypes to coexist when many environments with different food-recovery characteristics are connected via weak-to-moderate dispersal.