bluuebunny/crossref_metadata_2025 huggingface dataset:
Protein-responsive assemblies from catechol–metal ion supramolecular coordination
Authors: Yuan C. , Chen J. , Yu S. , Chang Y. , Mao J. , Xu Y. , Luo W. , Zeng B. , Dai L.
Published: January 2015

A synergistic strategy combining the driving forces of both catechol–metal ion coordination and polymer self-assembly can organize polymers into hybrid nanoassemblies with tunable morphologies and protein-triggered disassembly features.
Using intermolecular interactions to crosslink PIM-1 and modify its gas sorption properties
Authors: McDonald Tom O. , Akhtar Riaz , Lau Cher Hon , Ratvijitvech Thanchanok , Cheng Ge , Clowes Rob , Adams Dave J. , Hasell Tom , Cooper Andrew I.
Published: January 2015

The attractive intermolecular interactions between PIM-1 and polycyclic aromatic hydrocarbons were used to produce films with higher CO2/N2 gas sorption selectivity and reduced ageing of permeability.
Ag+-sensitized lanthanide luminescence in Ln3+ post-functionalized metal–organic frameworks and Ag+ sensing
Authors: Hao Ji-Na , Yan Bing
Published: January 2015

A new class of lanthanide luminescent MOFs was constructed by encapsulating Ln3+ into the pores of MIL-121 (Ln3+@MIL-121). Ag+ was found to be able to greatly enhance the weak visible or NIR luminescence of Ln3+@MIL-121 since it can induce more efficient intramolecular energy transfer from the ligand to Ln3+ in Ag–Ln co-doped MOFs.
Low temperature synthesized carbon nanotube superstructures with superior CO2and hydrogen storage capacity
Authors: Adeniran Beatrice , Mokaya Robert
Published: January 2015

Carbon nanotube (CNT) superstructures prepared at 180 °C are activated to highly porous (1479–3802 m2g−1; 0.83–2.98 cm3g−1) carbons with excellent CO2uptake; up to 4.8 and 8.4 mmol g−1at 1 bar and 25 or 0 °C, respectively, and exceptional hydrogen storage; up to 7.5 and 14.9 wt% at −196 °C and 20 or 150 bar, respectively, and 4.4 wt% at 25 °C and 150 bar.
Gold nanoparticle-catalysed photosensitized water reduction for hydrogen generation
Authors: Li Donghua , Wehrung Jean-François , Zhao Yue
Published: January 2015

Gold nanoparticles (AuNPs) can catalyze photosensitized water reduction for hydrogen gas generation by using conventional three-component systems.
Preparation of highly luminescent BaSO4 protected CdTe quantum dots as conversion materials for excellent color-rendering white LEDs
Authors: Chang Yajing , Yao Xudong , Zhang Zhongping , Jiang Danlu , Yu Yalan , Mi Longfei , Wang Hui , Li Guopeng , Yu Dabin , Jiang Yang
Published: January 2015

For the first time, colloidal CdTe quantum dots are incorporated into an inorganic matrix, BaSO4, through a co-precipitation method.
Incident fluence dependent morphologies, photoluminescence and optical oxygen sensing properties of ZnO nanorods grown by pulsed laser deposition
Authors: Liu Xiao , Sun Ye , Yu Miao , Yin Yongqi , Yang Bin , Cao Wenwu , Ashfold Michael N. R.
Published: January 2015

The photoluminescence-based O2 sensing properties of PLD ZnO nanorods at elevated temperatures depend sensitively on their (incident fluence determined) morphology and defect density.
Toxic effect comparison of three typical sterilization nanoparticles on oxidative stress and immune inflammation response in rats
Authors: Liu Huan-Liang , Yang Hong-Lian , Lin Ben-Cheng , Zhang Wei , Tian Lei , Zhang Hua-Shan , Xi Zhu-Ge
Published: January 2015

Three typical sterilization nanoparticles can cause oxidative stress and immune inflammation response to rats, and their toxicities showed significant differences.
Fused polycyclic aromatics incorporating boron in the core: fundamentals and applications
Authors: Escande Aude , Ingleson Michael J.
Published: January 2015

The incorporation of boron into the core structure of fused polycyclic aromatics generates compounds with highly attractive properties. This feature article summarises the recent key developments in this field.
The aldimine effect in bis(imino)pyridine complexes: non-planar nickel(i) complexes of a bis(aldimino)pyridine ligand
Authors: Reed Blake R. , Stoian Sebastian A. , Lord Richard L. , Groysman Stanislav
Published: January 2015

One-electron reduction of bis(aldimino)pyridine nickel(ii) forms a non-planar bis(aldimino)pyridine nickel halide featuring a significant spin density at the Ni center.
Synthesis, structural characterization, electronic spectroscopy, and microfluidic detection of Cu+2 and UO2+2 [di-tert-butyl-salphenazine] complexes
Authors: Maynard B. A. , Brooks J. C. , Hardy E. E. , Easley C. J. , Gorden A. E. V.
Published: January 2015

Oil and organic phases meet at a T-junction in a droplet microchopper design to form droplets. On the left, projection of the UO2[di-tert-butyl salphenazine] complex.
3-Nitro-2-pyridinesulfenyl-mediated solid-phase disulfide ligation in the synthesis of disulfide bond-containing cyclic peptides
Authors: Taguchi Akihiro , Fukumoto Kentarou , Asahina Yuya , Kajiyama Akihiro , Shimura Shunsuke , Hamada Keisuke , Takayama Kentaro , Yakushiji Fumika , Hojo Hironobu , Hayashi Yoshio
Published: January 2015

A new solid-phase disulfide ligation method is developed to prepare a disulfide peptide from two types of Cys-containing peptide fragments with minimum purification steps.
Cotton textile enabled, all-solid-state flexible supercapacitors
Authors: Gao Zan , Song Ningning , Zhang Yunya , Li Xiaodong
Published: January 2015

A hierarchical NiCo2O4@NiCo2O4 nanostructure was grown on flexible, cotton activated carbon textiles (ACTs) for flexible asymmetric supercapacitor electrode, which exhibited an exceptional combination of electrochemical and mechanical properties.
Enhanced thermopower wave via nanowire bonding and grain boundary fusion in combustion of fuel/CuO–Cu2O–Cu hybrid composites
Authors: Lee Kang Yeol , Hwang Hayoung , Shin Dongjoon , Choi Wonjoon
Published: January 2015

Understanding the chemical–thermal–electrical energy conversion in micro/nanostructures is crucial for making breakthroughs in new fields related to energy research, as well as in improving the existing energy technologies.
Pushing with actin: from cells to pathogens
Authors: Small J. Victor
Published: January 2015

Actin polymerization is harnessed by cells to generate lamellipodia for movement and by a subclass of pathogens to facilitate invasion of their infected hosts. Using electron tomography (ET), we have shown that lamellipodia are formed via the generation of subsets of actin filaments joined by branch junctions. Image averaging produced a 2.9 nm resolution model of branch junctions in situ and revealed a close fit to the electron density map of the actin-related protein 2/3 (Arp2/3)–actin complex in vitro. Correlated live-cell imaging and ET was also used to determine how actin networks are created and remodelled during the initiation and inhibition of protrusion in lamellipodia. Listeria, Rickettsia and viruses, such as vaccinia virus and baculovirus, exploit the actin machinery of host cells to generate propulsive actin comet tails to disseminate their infection. By applying ET, we have shown that baculovirus generates at its rear a fishbone-like array of subsets of branched actin filaments, with an average of only four filaments engaged in pushing at any one time. In both of these studies, the application of ET of negatively stained cytoskeletons for higher filament resolution and cryo-ET for preserving overall 3D morphology was crucial for obtaining a complete structure–function analysis of actin-driven propulsion.
Functionality of the chromosomal passenger complex in cancer
Authors: Hindriksen Sanne , Meppelink Amanda , Lens Susanne M.A.
Published: January 2015

The evolutionary conserved chromosomal passenger complex (CPC) is essential for faithful transmission of the genome during cell division. Perturbation of this complex in cultured cells gives rise to chromosome segregation errors and cytokinesis failure and as a consequence the ploidy status of the next generation of cells is changed. Aneuploidy and chromosomal instability (CIN) is observed in many human cancers, but whether this may be caused by deregulation of the CPC is unknown. In the present review, we discuss if and how a dysfunctional CPC could contribute to CIN in cancer.
SEC16 in COPII coat dynamics at ER exit sites
Authors: Sprangers Joep , Rabouille Catherine
Published: January 2015

Protein export from the endoplasmic reticulum (ER), the first step in protein transport through the secretory pathway, is mediated by coatomer protein II (COPII)-coated vesicles at ER exit sites. COPII coat assembly on the ER is well understood and the conserved large hydrophilic protein Sec16 clearly has a role to play in COPII coat dynamics. Sec16 localizes to ER exit sites, its loss of function impairs their functional organization in all species where it has been studied, and it interacts with COPII coat subunits. However, its exact function in COPII dynamics is debated, as Sec16 is proposed to act as a scaffold to recruit COPII components and as a device to regulate the Sar1 activity in uncoating, in such a way that the coat is released only when the vesicle is fully formed and loaded with cargo. Furthermore, Sec16 has been shown to respond to nutrient signalling, thus coupling environmental stimuli to secretory capacity.
Retromer and sorting nexins in endosomal sorting
Authors: Gallon Matthew , Cullen Peter J.
Published: January 2015

The evolutionarily conserved endosomal retromer complex rescues transmembrane proteins from the lysosomal degradative pathway and facilitates their recycling to other cellular compartments. Retromer functions in conjunction with numerous associated proteins, including select members of the sorting nexin (SNX) family. In the present article, we review the molecular architecture and cellular roles of retromer and its various functional partners. The endosomal network is a crucial hub in the trafficking of proteins through the cellular endomembrane system. Transmembrane proteins, here termed cargos, enter endosomes by endocytosis from the plasma membrane or by trafficking from the trans-Golgi network (TGN). Endosomal cargo proteins face one of the two fates: retention in the endosome, leading ultimately to lysosomal degradation or export from the endosome for reuse (‘recycling’). The balance of protein degradation and recycling is crucial to cellular homoeostasis; inappropriate sorting of proteins to either fate leads to cellular dysfunction. Retromer is an endosome-membrane-associated protein complex central to the recycling of many cargo proteins from endosomes, both to the TGN and the plasma membrane (and other specialized compartments, e.g. lysosome-related organelles). Retromer function is reliant on a number of proteins from the SNX family. In the present article, we discuss this inter-relationship and how defects in retromer function are increasingly being linked with human disease.
Myosin tails and single α-helical domains
Authors: Batchelor Matthew , Wolny Marcin , Dougan Lorna , Paci Emanuele , Knight Peter J. , Peckham Michelle
Published: January 2015

The human genome contains 39 myosin genes, divided up into 12 different classes. The structure, cellular function and biochemical properties of many of these isoforms remain poorly characterized and there is still some controversy as to whether some myosin isoforms are monomers or dimers. Myosin isoforms 6 and 10 contain a stable single α-helical (SAH) domain, situated just after the canonical lever. The SAH domain is stiff enough to be able to lengthen the lever allowing the myosin to take a larger step. In addition, atomic force microscopy and atomistic simulations show that SAH domains unfold at relatively low forces and have a high propensity to refold. These properties are likely to be important for protein function, enabling motors to carry cargo in dense actin networks, and other proteins to remain attached to binding partners in the crowded cell.
Therapeutic targeting of aldosterone: a novel approach to the treatment of glomerular disease
Authors: Brem Andrew S. , Gong Rujun
Published: January 2015

Numerous studies have established a role for mineralocorticoids in the development of renal fibrosis. Originally, the research focus for mineralocorticoid-induced fibrosis was on the collecting duct, where ‘classical’ mineralocorticoid receptors (MRs) involved with electrolyte transport are present. Epithelial cells in this segment can, under selected circumstances, also respond to MR activation by initiating pro-fibrotic pathways. More recently, ‘non-classical’ MRs have been described in kidney cells not associated with electrolyte transport, including mesangial cells and podocytes within the glomerulus. Activation of MRs in these cells appears to lead to glomerular sclerosis. Mechanistically, aldosterone induces excess production of reactive oxygen species (ROS) and oxidative stress in glomerular cells through activation of NADPH oxidase. In mesangial cells, aldosterone also has pro-apoptotic, mitogenic and pro-fibrogenic effects, all of which potentially promote active remodelling and expansion of the mesangium. Although mitochondrial dysfunction seems to mediate the aldosterone-induced mesangial apoptosis, the ROS dependent epithelial growth factor receptor (EGFR) transactivation is probably responsible for aldosterone-induced mesangial mitosis and proliferation. In podocytes, mitochondrial dysfunction elicited by oxidative stress is an early event associated with aldosterone-induced podocyte injury. Both the p38 MAPK (p38 mitogen-activated protein kinase) signalling and the redox-sensitive glycogen synthase kinase (GSK)3β pathways are centrally implicated in aldosterone-induced podocyte death. Aldosterone-induced GSK3β over-activity could potentially cause hyperphosphorylation and over-activation of putative GSK3β substrates, including structural components of the mitochondrial permeability transition (MPT) pore, all of which lead to cell injury and death. Clinically, proteinuria significantly decreases when aldosterone inhibitors are included in the treatment of many glomerular diseases further supporting the view that mineralocorticoids are important players in glomerular pathology.
Stereo vision with image‐guided structured‐light pattern matching
Authors: Park Min‐Gyu , Park Jonghee , Shin Yongho , Lim Eul‐Gyoon , Yoon Kuk‐Jin
Published: January 2015

An accurate stereo matching method developed by exploiting the two techniques, discrete‐coded structured‐light projection and image‐guided cost volume filtering, is proposed. The former increases the distinctiveness of pixels by projecting a discrete pattern to the scene, and the latter helps to recover accurate object boundaries. In addition, a previous fast cost volume filtering approach is extended to better preserve slanted surfaces, and a suitable post‐processing algorithm is also suggested for the proposed method. The performance of the proposed method is experimentally verified by comparing the results with those of other algorithms qualitatively and quantitatively in an indoor environment.
Kenntnisstand zu Infektionen mit humanen Papillomaviren und deren Präventionsmöglichkeiten von 13- bis 21-jährigen Schülerinnen und Schülern aus Fulda, Hessen
Authors: Stumm C. , Hahn D. , Heberlein I. , Doherr F. , Hofmann W.
Published: January 2015

Ziel der Studie: Ziel dieser Studie war die Erhebung des Kenntnisstandes von Schülerinnen und Schülern aus Fulda bezüglich HPV und HPV-Impfung. Zudem wurde die Inanspruchnahme der Impfung geprüft.

Methodik: Die Untersuchung von 13- bis 21-jährigen Schülerinnen und Schülern (n=1 515) wurde 2011 mit einem standardisierten Fragebogen durchgeführt.

Ergebnisse: Die Bekanntheit von humanen Papillomaviren (HPV) und das Wissen darüber waren gering. 29% der Stichprobe hatten von HPV gehört. Die Schülerinnen sowie Befragte mit christlicher Religionszugehörigkeit kannten HPV häufiger als die Schüler und Befragte mit muslimischer Religionszugehörigkeit. Von 21 Wissensfragen zu HPV wurden im Mittel 7,8 (SD=3,3) korrekt beantwortetet, wobei keine Unterschiede bezüglich der soziodemografischen Variablen festgestellt wurden. 77% aller Teilnehmenden hatten von der HPV-Impfung gehört. Weibliche Befragte, Personen ohne Migrationshintergrund und mit höherem Bildungsstatus kannten die Impfung häufiger als männliche Befragte, Personen mit Migrationshintergrund und niedrigem Bildungsstatus. Im Mittel beantworteten die Schülerinnen 2,9 (SD=1,3) von 5 Fragen zur HPV-Impfung korrekt. Ältere Befragte verfügten über mehr Wissen als jüngere. 30% der Schülerinnen hatten mindestens eine Impfdosis erhalten, wobei höheres Alter, fehlender Migrationshintergrund und mittlerer bzw. hoher Bildungsstatus als Prädiktoren für die Inanspruchnahme der Impfung festgestellt wurden.

Schlussfolgerung: Der Schulunterricht und ärztliche Untersuchungen wären geeignete Orte der Wissensvermittlung, um soziodemografisch begründeten gesundheitlichen Ungleichheiten entgegenzuwirken.
Experimental triplet and quadruplet fluctuation densities and spatial distribution function integrals for pure liquids
Authors: Ploetz Elizabeth A. , Karunaweera Sadish , Smith Paul E.
Published: January 2015

Fluctuation solution theory has provided an alternative view of many liquid mixture properties in terms of particle number fluctuations. The particle number fluctuations can also be related to integrals of the corresponding two body distribution functions between molecular pairs in order to provide a more physical picture of solution behavior and molecule affinities. Here, we extend this type of approach to provide expressions for higher order triplet and quadruplet fluctuations, and thereby integrals over the corresponding distribution functions, all of which can be obtained from available experimental thermodynamic data. The fluctuations and integrals are then determined using the International Association for the Properties of Water and Steam Formulation 1995 (IAPWS-95) equation of state for the liquid phase of pure water. The results indicate small, but significant, deviations from a Gaussian distribution for the molecules in this system. The pressure and temperature dependence of the fluctuations and integrals, as well as the limiting behavior as one approaches both the triple point and the critical point, are also examined.
Steady state likelihood ratio sensitivity analysis for stiff kinetic Monte Carlo simulations
Authors: Núñez M. , Vlachos D. G.
Published: January 2015

Kinetic Monte Carlo simulation is an integral tool in the study of complex physical phenomena present in applications ranging from heterogeneous catalysis to biological systems to crystal growth and atmospheric sciences. Sensitivity analysis is useful for identifying important parameters and rate-determining steps, but the finite-difference application of sensitivity analysis is computationally demanding. Techniques based on the likelihood ratio method reduce the computational cost of sensitivity analysis by obtaining all gradient information in a single run. However, we show that disparity in time scales of microscopic events, which is ubiquitous in real systems, introduces drastic statistical noise into derivative estimates for parameters affecting the fast events. In this work, the steady-state likelihood ratio sensitivity analysis is extended to singularly perturbed systems by invoking partial equilibration for fast reactions, that is, by working on the fast and slow manifolds of the chemistry. Derivatives on each time scale are computed independently and combined to the desired sensitivity coefficients to considerably reduce the noise in derivative estimates for stiff systems. The approach is demonstrated in an analytically solvable linear system.
Structural fluctuation of proteins induced by thermodynamic perturbation
Authors: Hirata Fumio , Akasaka Kazuyuki
Published: January 2015

A theory to describe structural fluctuations of protein induced by thermodynamic perturbations, pressure, temperature, and denaturant, is proposed. The theory is formulated based on the three methods in the statistical mechanics: the generalized Langevin theory, the linear response theory, and the three dimensional interaction site model (3D-RISM) theory. The theory clarifies how the change in thermodynamic conditions, or a macroscopic perturbation, induces the conformational fluctuation, which is a microscopic property. The theoretical results are applied, on the conceptual basis, to explain the experimental finding by Akasaka et al., concerning the NMR experiment which states that the conformational change induced by pressure corresponds to structural fluctuations occurring in the ambient condition. A method to evaluate the structural fluctuation induced by pressure is also suggested by means of the 3D-RISM and the site-site Kirkwood-Buff theories.
Analysis of pressure perturbation sources on a generic space launcher after-body in supersonic flow using zonal turbulence modeling and dynamic mode decomposition
Authors: Statnikov Vladimir , Sayadi Taraneh , Meinke Matthias , Schmid Peter , Schröder Wolfgang
Published: January 2015

A sparsity promoting dynamic mode decomposition (DMD) combined with a classical data-based statistical analysis is applied to the turbulent wake of a generic axisymmetric configuration of an Ariane 5-like launcher at Ma∞ = 6.0 computed via a zonal Reynolds-averaged Navier-Stokes/large-eddy simulation (RANS/LES) method. The objective of this work is to gain a better understanding of the wake flow dynamics of the generic launcher by clarification and visualization of initially unknown pressure perturbation sources on its after-body in coherent flow patterns. The investigated wake topology is characterized by a subsonic cavity region around the cylindrical nozzle extension which is formed due to the displacement effect of the afterexpanding jet plume emanating from the rocket nozzle (Mae = 2.52, pe/p∞ = 100) and the shear layer shedding from the main body. The cavity region contains two toroidal counter-rotating large-scale vortices which extensively interact with the turbulent shear layer, jet plume, and rocket walls, leading to the shear layer instability process to be amplified. The induced velocity fluctuations in the wake and the ultimately resulting pressure perturbations on the after-body feature three global characteristic frequency ranges, depending on the streamwise position inside the cavity. The most dominant peaks are detected at SrD r3 = 0.85 ± 0.075 near the nozzle exit, while the lower frequency peaks, in the range of SrD r2 = 0.55 ± 0.05 and SrD r1 = 0.25 ± 0.05, are found to be dominant closer to the rocket’s base. A sparse promoting DMD algorithm is applied to the time-resolved velocity field to clarify the origin of the detected peaks. This analysis extracts three low-frequency spatial modes at SrD = 0.27,  0.56,  and  0.85. From the three-dimensional shape of the DMD modes and the reconstructed modulation of the mean flow in time, it is deduced that the detected most dominant peaks of SrD r3 ≈ 0.85 are caused by the radial flapping motion of the shear layer, while the middle-frequency range of SrD r2 ≈ 0.55 is found to be associated with its swinging motion. The less intensive peaks of SrD r1 ≈ 0.25 pronounced on the base wall are caused by the low-frequency longitudinal pumping of the two toroidal large-scale vortices inside the cavity.
A versatile, pulsed anion source utilizing plasma-entrainment: Characterization and applications
Authors: Lu Yu-Ju , Lehman Julia H. , Lineberger W. Carl
Published: January 2015

A novel pulsed anion source has been developed, using plasma entrainment into a supersonic expansion. A pulsed discharge source perpendicular to the main gas expansion greatly reduces unwanted “heating” of the main expansion, a major setback in many pulsed anion sources in use today. The design principles and construction information are described and several examples demonstrate the range of applicability of this anion source. Large OH−(Ar)n clusters can be generated, with over 40 Ar solvating OH−. The solvation energy of OH−(Ar)n, where n = 1-3, 7, 12, and 18, is derived from photoelectron spectroscopy and shows that by n = 12-18, each Ar is bound by about 10 meV. In addition, cis– and trans– HOCO− are generated through rational anion synthesis (OH− + CO + M → HOCO− + M) and the photoelectron spectra compared with previous results. These results, along with several further proof-of-principle experiments on solvation and transient anion synthesis, demonstrate the ability of this source to efficiently produce cold anions. With modifications to two standard General Valve assemblies and very little maintenance, this anion source provides a versatile and straightforward addition to a wide array of experiments.
First principles study of thermal conductivity cross-over in nanostructured zinc-chalcogenides
Authors: Katre Ankita , Togo Atsushi , Tanaka Isao , Madsen Georg K. H.
Published: January 2015

Systematic first principles studies of zinc-chalcogenides have been performed to understand their thermal transport behaviour. We have applied the Boltzmann transport equation in the relaxation time approximation to calculate the thermal conductivity of ZnS, ZnSe, and ZnTe. We find a thermal conductivity cross-over between ZnS and ZnSe at nanostructure sizes around 0.1–0.2 μm and explain this in terms of the different contributions of phonon modes in these materials. We study the effect of nanostructuring using both the diffusive boundary scattering and confined mean free path limit and discuss the variations in the results. Furthermore, we show the strong influence of isotope scattering on the thermal conductivity. The calculated thermal conductivity is found to be strongly dependent on the volume and we explain the observed differences between local density and generalized gradient approximation calculations. We compare further calculated thermal properties, such as the thermal expansion coefficient, to experiment to validate our approach.
Wavelength-dependent magnetic transitions of self-organized iron–aluminum stripes induced by pulsed laser irradiation
Authors: Yoshida Yutaka , Watanabe Seiichi , Kaiju Hideo , Nishii Junji , Yoshimi Kyosuke
Published: January 2015

We investigate the laser wavelength dependence of structural and magnetic transitions on the surface of an iron–aluminum (FeAl) alloy induced by nanosecond pulsed laser irradiation. The formation of self-organized FeAl stripes with a wavelength-dependent period is observed in a local area on the (111)-oriented plane. Focused magneto-optical Kerr effect measurements reveal that the coercivity reaches up to 1.2 kOe with increasing the magnetic field rotation angle, which is estimated from the stripe direction, in FeAl stripes irradiated at 355 nm, and its magnetization reversal can be explained by the domain-wall motion model. On the other hand, the magnetization reversal agrees with the Stoner–Wohlfarth model in FeAl stripes irradiated at 1064 nm. This magnetic transition originates from the B2-to-A2 phase transition in stripe structures and bulk regions. These results indicate that the magnetic transition from the incoherent to coherent mode as well as the structural transformation of stripe patterns can be controlled by the incident laser wavelength.
10 to 25-fold increase in the transport superconducting critical current density of spark-plasma sintered Bi-2223 superconductors
Authors: Govea-Alcaide E. , Machado I. F. , Jardim R. F.
Published: January 2015

Pre-reacted powders of (Bi-Pb)2Sr2Ca2Cu3O10+δ (Bi-2223) were consolidated by using the spark plasma sintering (SPS) technique under vacuum and at two different temperatures TD: 750 and 830 °C. The results indicate the occurrence of grains with core-shell morphology, where the shell is oxygen deficient. A post-annealing heat treatment (PAHT), performed in air, at 750 °C, and for a brief time interval, is responsible for a 10 to 25-fold increase in the transport superconducting current density at 77 K. The role of the oxygen-deficient shell, before and after the PAHT, was investigated by means of magnetic and transport measurements. We argue that the PAHT is two folds: (i) it is responsible for the decrease of the width of the oxygen-deficient shell, then increasing the oxygen content along the grain boundaries; (ii) it promotes the formation of conduction current paths along the grain boundaries of the SPS material.
Graphene oxide overprints for flexible and transparent electronics
Authors: Rogala M. , Wlasny I. , Dabrowski P. , Kowalczyk P. J. , Busiakiewicz A. , Kozlowski W. , Lipinska L. , Jagiello J. , Aksienionek M. , Strupinski W. , Krajewska A. , Sieradzki Z. , Krucinska I. , Puchalski M. , Skrzetuska E. , Klusek Z.
Published: January 2015

The overprints produced in inkjet technology with graphene oxide dispersion are presented. The graphene oxide ink is developed to be fully compatible with standard industrial printers and polyester substrates. Post-printing chemical reduction procedure is proposed, which leads to the restoration of electrical conductivity without destroying the substrate. The presented results show the outstanding potential of graphene oxide for rapid and cost efficient commercial implementation to production of flexible electronics. Properties of graphene-based electrodes are characterized on the macro- and nano-scale. The observed nano-scale inhomogeneity of overprints' conductivity is found to be essential in the field of future industrial applications.
Mobility enhancement in electric double layer gated n-ZnO ultraviolet photodetector by synergy of gate and illumination: A photo Hall study
Authors: Mondal Shahnewaz , Ghimire Rishi Ram , Raychaudhuri A. K.
Published: January 2015

We report a large enhancement of the Hall mobility of a ZnO film (channel) by simultaneously application of an ultraviolet illumination along with a gate bias in an electric double layer field effect transistor configuration. The effect arises from a synergy between the illumination and the field effect (FE), leading to large enhancement of the channel conductivity and the photo response. We propose that large carrier density created by the simultaneous presence of the illumination and the FE leads to neutralization of some of the oxygen charged vacancies which in turn reduce potential scattering leading to the enhanced mobility.
Noncontact broadband all-optical photoacoustic microscopy based on a low-coherence interferometer
Authors: Chen Zhongjiang , Yang Sihua , Wang Yi , Xing Da
Published: January 2015

We developed and fabricated a noncontact broadband all-optical photoacoustic microscopy (BD-AO-PAM) with a microchip laser and an all-fiber low coherence interferometer. Currently, the available detection bandwidth of the BD-AO-PAM is 67 MHz, and the lateral resolution measured by carbon fibers reaches 11 μm. Furthermore, the imaging capability of the BD-AO-PAM was testified by imaging hairs embedded in scattering gel and in vivo blood vessels of a mouse ear. The experimental results demonstrate that the BD-AO-PAM can image the tissues with high spatial resolution in vivo, which can be used as portable noncontact PAM for biomedical applications.
Enhancement of critical current density in YBa2Cu3O7 films using a semiconductor ion implanter
Authors: Matsui H. , Ootsuka T. , Ogiso H. , Yamasaki H. , Sohma M. , Yamaguchi I. , Kumagai T. , Manabe T.
Published: January 2015

An up-to-11-fold enhancement was observed in the in-magnetic-field critical current density (Jc) in epitaxial YBa2Cu3O7 films on CeO2-buffered SrTiO3 substrates by irradiation with 200- to 750-keV Si and 200-keV B ions. This enhancement indicates that ion beams in the range of 100 to 1000 keV, which are widely used for modifying the conductive properties of semiconducting materials, can significantly improve the vortex-pinning properties in second-generation superconducting wires. Also observed was a scaling relation between Jc and the density of the vacancies (i.e., of Frenkel pairs) produced by the nuclear collisions between incident ions and target atoms, suggesting that this density is a key parameter in determining the magnitude of the Jc enhancement. Also observed was an additional Jc enhancement by a modification of the depth distribution of the vacancies, thus demonstrating the flexibility in controlling artificial pinning center (APC) properties in physical APC introduction.
Monolithically integrated mid-infrared sensor using narrow mode operation and temperature feedback
Authors: Ristanic Daniela , Schwarz Benedikt , Reininger Peter , Detz Hermann , Zederbauer Tobias , Andrews Aaron Maxwell , Schrenk Werner , Strasser Gottfried
Published: January 2015

A method to improve the sensitivity and selectivity of a monolithically integrated mid-infrared sensor using a distributed feedback laser (DFB) is presented in this paper. The sensor is based on a quantum cascade laser/detector system built from the same epitaxial structure and with the same fabrication approach. The devices are connected via a dielectric-loaded surface plasmon polariton waveguide with a twofold function: it provides high light coupling efficiency and a strong interaction of the light with the environment (e.g., a surrounding fluid). The weakly coupled DFB quantum cascade laser emits narrow mode light with a FWHM of 2 cm−1 at 1586 cm−1. The room temperature laser threshold current density is 3 kA∕cm2 and a pulsed output power of around 200 mW was measured. With the superior laser noise performance, due to narrow mode emission and the compensation of thermal fluctuations, the lower limit of detection was expanded by one order of magnitude to the 10 ppm range.
Fabrication of high-performance ultra-thin-body SnO2 thin-film transistors using microwave-irradiation post-deposition annealing
Authors: Jo Kwang-Won , Moon Sung-Wan , Cho Won-Ju
Published: January 2015

We report on the fabrication of high-performance ultra-thin-body (UTB) SnO2 thin-film transistors (TFTs) using microwave-irradiation post-deposition annealing (PDA) at a low process temperature (<100 °C). We confirm that the electrical characteristics of SnO2 TFTs become drastically enhanced below a body thickness of 10 nm. The microwave-annealed UTB SnO2 TFTs with a thickness of 5 nm exhibited increased optical transmittance, as well as remarkable transfer characteristics: a high mobility of 35.4 cm2 V−1 s−1, a drain current on/off ratio of 4.5 × 107, a steep subthreshold gate voltage swing of 623 mV/dec, and a clear enhancement-mode behavior. Additionally, the microwave-annealed SnO2 TFTs exhibited a better positive gate-bias stress/negative gate-bias stress immunity than thermally annealed SnO2 TFTs. Therefore, the thickness of the UTB SnO2 TFTs, as well as the microwave-annealing process, are both shown to be essential for transparent and flexible display technology.
TiO2 hierarchical nanostructures: Hydrothermal fabrication and application in dye-sensitized solar cells
Authors: Liang Jia , Zhang Gengmin , Yang Jin , Sun Wentao , Shi Mingji
Published: January 2015

Arrays of TiO2 hierarchical nanostructures that consisted of rutile nanorods and anatase branches were hydrothermally fabricated and employed as photoanodes in dye-sensitized solar cells (DSSCs). Each hierarchical nanostructure array was attained in two steps. First, a primary nanorod array was synthesized in aqueous solutions of hydrochloric acid (HCl) and tetrabutyl titanate (C16H36O4Ti); subsequently, secondary branches were grown on the nanorods in aqueous solutions of ammonium hexafluorotitanate ((NH4)2TiF6) and boric acid (H3BO3). The secondary anatase branches filled part of the space among the primary rutile nanorods and gave rise to a larger surface area. Light-harvesting capability of the DSSCs with TiO2 hierarchical nanostructures as photoanodes was appreciably improved because more dye molecules could be loaded on the photoanodes and more light could be scattered inside the DSSCs. Therefore, the conversion efficiencies of the DSSCs were doubled by replacing the photoanode of primary TiO2 nanorod array with the photoanodes of TiO2 hierarchical nanostructure arrays. Furthermore, in order to reach a compromise between the photoanode surface area and the inter-nanorod space volume, the growth time of the secondary TiO2 anatase branches was optimized.
A Facile Synthesis of Ion Imprinted Mesoporous Silica Adsorbents by a Co-Condensation Pathway and Application in a Fixed-Bed Column Study for Lead Removal
Authors: Gao Yanmin , Hu Zhaoyong , Liu Yan , Liu Zhanchao , Chen Rui , Meng Xiangguo , Meng Mingjia , Zhou Chao
Published: January 2015

Highly selective lead ion imprinted mesoporous silica adsorbents (PbII-IMS) were prepared through a co-condensation pathway with 3-(γ-aminoethylamino)propyltrimethoxysilane (AAPTS) (PbII-IMS-NN) and 3-aminepropyltriethoxysilyl (APTES) (PbII-IMS-N) as monomers. The prepared adsorbents were characterised by FT-IR spectroscopy, X-ray photoelectron spectroscopy, power X-ray diffraction, transmission electron microscopy, scanning electron microscopy, thermogravimetric analysis, and nitrogen adsorption–desorption techniques. The results showed that the synthesised adsorbents presented a highly ordered mesoporous structure. In comparison with PbII-IMS-N, PbII-IMS-NN demonstrated a higher adsorption capacity in a series of static and dynamic adsorption experiments, and was further applied to a continuous fixed-bed column study under different conditions. It was found that the breakthrough time of the fixed-bed increased with an increase in bed depth, but decreased with increased flow rate and initial PbII concentration, and the dynamic adsorption data was more consistent with the Thomas model than the Adams–Bohart model. Furthermore, the PbII-IMS-NN showed a greater recognition and binding affinity towards the target lead ions than PbII-IMS-N.
Synthesis and DNA-Binding Studies of a Dinuclear Gadolinium(III)–Platinum(II) Complex
Authors: Fenton Jacob M. , Busse Madleen , Rendina Louis M.
Published: January 2015

The synthesis and characterisation of a new dinuclear GdIII–PtII complex (1·PF6) containing a functionalised macrocyclic 1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid derivative linked to a PtII-terpy (terpy = 2,2′ : 6′,2″-terpyridine) unit by means of a short thiolato linker are reported. The complex was synthesised in six steps from cyclen by means of a modular synthetic strategy. A preliminary DNA-binding study with calf-thymus DNA (ct-DNA) was performed on 1·PF6 by means of linear dichroism (LD). The observed changes in the DNA LD signal in the presence of the metal complex are fully consistent with an intercalative binding mode. Furthermore, an induced negative LD signal in the ultraviolet absorption region of the complex provides strong evidence of a strong DNA-binding interaction. The in vitro cytotoxicity of 1·PF6 towards a human glioblastoma cell line (T98G) was also determined.
The Conversion of Levoglucosenone into Isolevoglucosenone
Authors: Ma Xinghua , Anderson Natasha , White Lorenzo V. , Bae Song , Raverty Warwick , Willis Anthony C. , Banwell Martin G.
Published: January 2015

Levoglucosenone (1), a compound that will soon be available in tonne quantities through the pyrolysis of acid-treated lignocellulosic biomass, has been converted into isolevoglucosenone (2) using Wharton rearrangement chemistry. Treatment of compound 1 with alkaline hydrogen peroxide gave the γ-lactones 5 and 6 rather than the required epoxy-ketones 3 and/or 4. However, the latter pair of compounds could be obtained by an initial Luche reduction of compound 1, electrophilic epoxidation of the resulting allylic alcohol 8 and oxidation of the product oxiranes 9 and 10. Independent treatment of compounds 3 and 4 with hydrazine then acetic acid followed by oxidation of the ensuing allylic alcohols finally afforded isolevoglucosenone (2). Details of the single-crystal X-ray analyses of epoxy-alcohols 9 and 10 are reported.
Management of syphilis in HIV-positive individuals
Authors: Cresswell Fiona V. , Fisher Martin
Published: January 2015

Since the turn of the millennium a sustained outbreak of syphilis among men who have sex with men continues, approximately 20–50% of whom have concurrent HIV infection. In this paper we aim to explore the controversies that exist around the management of syphilis in HIV-positive individuals. Not only do HIV-positive people have different clinical manifestations of syphilis they have higher rates of asymptomatic neurological involvement, slower serological response to treatment and higher serological failure than HIV-negative individuals in most studies. Whether long-term clinical outcomes are different or affected by the antibiotic regimen selected remains to be established. The optimal antimicrobial regimen to treat syphilis in HIV is unknown due to a dearth of randomised controlled trial data. International guidelines state that the antibiotic management of syphilis is the same regardless of HIV status, with early syphilis treated with a single dose of benzathine penicillin G 2.4mU intrmuscularly. In practice, however, the majority of surveyed clinicians do treat HIV-positive people with more intensive antibiotics suggesting a lack of faith in guidelines. Factors which appear to affect the likelihood of developing neurological disease include CD4+ count of <350 cells/μL, absence of antiretroviral therapy, rapid plasma regain (RPR) or venereal diseases reference laboratory titre (VDRL) >1 : 32, late-latent disease or lack of response to standard antibiotic treatment. We recommend a low-threshold for offering antibiotic treatment effective against neurosyphilis in HIV-positive people with syphilis, especially if they exhibit any of the above factors.
Post-fire seeding with ryegrass: implications for understorey plant communities and overall effectiveness
Authors: McMaster Melissa A. , Thode Andrea , Kearsley Michael
Published: January 2015

Seeding following high-severity wildfires is motivated by the goals of increasing vegetative cover and decreasing bare soil in order to minimise soil erosion and exotic plant invasions. We compared the ground cover and vegetation response of seeded versus non-seeded areas located in the Warm Fire in northern Arizona, where post-fire seeding treatments with Italian ryegrass (Lolium perenne spp. multiflorum (L.)) were conducted in 4000 ha of high-severity burned areas. Over the course of the study, we observed no significant difference between seeded and non-seeded plots in percentage of bare soil, total vegetative cover or exotic plant cover. However, there were significant differences in plant community composition as revealed by PERMANOVA and Indicator Species Analysis. Two years post-fire there were significantly fewer ponderosa pine seedlings, and the cover of annual and biennial forbs was significantly lower in plots that were seeded with Italian ryegrass. In the third year, the cover of native bunch grasses was significantly lower in seeded plots. The differences we observed may be due to differences in pre-existing vegetation composition because of the geographic separation of the plots across the landscape. Our results illustrate the ineffectiveness of post-fire seeding in achieving the goals of increasing vegetative cover and decreasing the invasion of non-native plants, and we suggest that alternative post-fire remediation should be considered in the future.
Heterogeneity for IGF-II production maintained by public goods dynamics in neuroendocrine pancreatic cancer
Authors: Archetti Marco , Ferraro Daniela A. , Christofori Gerhard
Published: January 2015

Significance

Cancer cells compete for space and nutrients against healthy cells and other cancer cells but also cooperate by secreting growth factors. Clones that do not produce growth factors, however, have a proliferation advantage because they can use the factors produced by neighboring cells without the cost of producing them. Therefore, the cooperative production of growth factors by tumor cells should collapse. What maintains cooperation within the tumor? Here, we use evolutionary game theory to explain how heterogeneity can persist, and we use experiments with pancreatic cancer cells to test the predictions of the theory. Cancer is a process of clonal selection, and studying cancer cell populations using methods and concepts from evolutionary biology can reveal potential evolutionarily stable therapies.
Protein folding and binding can emerge as evolutionary spandrels through structural coupling
Authors: Manhart Michael , Morozov Alexandre V.
Published: January 2015

Significance

Most proteins must be folded to perform their function, which typically involves binding another molecule. This property enables protein traits of stable folding and strong binding to emerge through adaptation even when the trait itself does not increase the organism’s fitness. Such traits, known as evolutionary “spandrels,” have been investigated across many organisms and scales of biology. Here we show that proteins can spontaneously evolve strong but nonfunctional binding interactions. Moreover, evolution of such interactions can be highly unpredictable, with chance mutation events determining the outcome. In contrast, evolution of functional interactions follows a more predictable pattern of first gaining folding stability and then losing it as the new binding function improves.
Ocean fronts drive marine fishery production and biogeochemical cycling
Authors: Woodson C. Brock , Litvin Steven Y.
Published: January 2015

Significance

Fronts in the ocean act as oases in a fluid desert that are not fully accounted for in climate or fisheries model projections. Fronts act to increase production by channeling nutrients through multiple trophic levels, including commercially important fishes and marine mammals, and enhance carbon export to the deep ocean. Fronts consequently have immense effects on the ocean, from base of the food chain up through the dinner table and mediation of global climate change. Here we show how fronts can be incorporated into current models, using a technique from fluid dynamics to improve both climate and fisheries models.
Immune-mediated antitumor effect by type 2 diabetes drug, metformin
Authors: Eikawa Shingo , Nishida Mikako , Mizukami Shusaku , Yamazaki Chihiro , Nakayama Eiichi , Udono Heiichiro
Published: January 2015

Significance

The multifunctional ability of CTLs is downregulated by interaction between immune-checkpoint molecules expressed on CTLs and their ligands expressed on cancer cells, referred to as immune exhaustion. The antibody-mediated, immune-checkpoint blockade turned out to a promising method for immunotherapy against advanced melanoma. Metformin, a drug prescribed for patients with type 2 diabetes, has been recognized to have anti-cancer effect. We found that CD8
+
tumor infiltrating lymphocytes (TILs) is a target of metformin. CD8
+
TILs inevitably undergo immune exhaustion, characterized by diminished production of multiple cytokines such as IL-2, TNFα, and IFNγ, followed by elimination with apoptosis. Metformin is able to counter the state. Along with conventional therapy, treatment of cancer patients with metformin may have a great advantage for cancer therapy.
BRAF inhibitor resistance mediated by the AKT pathway in an oncogenic BRAF mouse melanoma model
Authors: Perna Daniele , Karreth Florian A. , Rust Alistair G. , Perez-Mancera Pedro A. , Rashid Mamunur , Iorio Francesco , Alifrangis Constantine , Arends Mark J. , Bosenberg Marcus W. , Bollag Gideon , Tuveson David A. , Adams David J.
Published: January 2015

Significance

Using
Sleeping Beauty
transposon mutagenesis in a melanoma model driven by oncogenic BRAF (B-Raf proto-oncogene, serine/threonine kinase), we identified both known and novel candidate genes that mediate resistance to the BRAF inhibitor PLX4720. We validate ES-cell expressed Ras as a novel promoter of BRAF inhibitor resistance and propose that AKT (v-akt murine thymoma viral oncogene homolog 1)-mediated inactivation of BAD (BCL2-associated agonist of cell death) constitutes a pathway that may contribute to hepatocyte growth factor-mediated therapy resistance. Our work establishes
Sleeping Beauty
mutagenesis as a powerful tool for the identification of novel resistance genes and mechanisms in genetically modified mouse models.