bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling olivine CPO evolution with complex deformation histories: Implications for the interpretation of seismic anisotropy in the mantle
Authors: Boneh Yuval , Morales Luiz F. G. , Kaminski Edouard , Skemer Philip
Published: September 2015

Relating seismic anisotropy to mantle flow requires detailed understanding of the development and evolution of olivine crystallographic preferred orientation (CPO). Recent experimental and field studies have shown that olivine CPO evolution depends strongly on the integrated deformation history, which may lead to differences in how the corresponding seismic anisotropy should be interpreted. In this study, two widely used numerical models for CPO evolution—D‐Rex and VPSC—are evaluated to further examine the effect of deformation history on olivine texture and seismic anisotropy. Building on previous experimental work, models are initiated with several different CPOs to simulate unique deformation histories. Significantly, models initiated with a preexisting CPO evolve differently than the CPOs generated without preexisting texture. Moreover, the CPO in each model evolves differently as a function of strain. Numerical simulations are compared to laboratory experiments by Boneh and Skemer (2014). In general, the D‐Rex and VPSC models are able to reproduce the experimentally observed CPOs, although the models significantly over‐estimate the strength of the CPO and in some instances produce different CPO from what is observed experimentally. Based on comparison with experiments, recommended parameters for D‐Rex are: M* = 10, λ* = 5, and χ = 0.3, and for VPSC: α = 10–100. Numerical modeling confirms that CPO evolution in olivine is highly sensitive to the details of the initial CPO, even at strains greater than 2. These observations imply that there is a long transient interval of CPO realignment which must be considered carefully in the modeling or interpretation of seismic anisotropy in complex tectonic settings.
A new method for calibrating a boron isotope paleo‐pH proxy using massive Porites corals
Authors: Kubota Kaoru , Yokoyama Yusuke , Ishikawa Tsuyoshi , Suzuki Atsushi
Published: September 2015

The boron isotope ratio (δ11B) of marine biogenic carbonates can reconstruct pH and pCO2 of seawater, and potentially CO2 concentration in the atmosphere. To date, δ11B‐pHSW calibration has been proposed via culturing experiments, where calcifying organisms are cultured under artificially acidified seawater. However, in scleractinian corals, reconstructed pH values using culture‐based calibrations do not agree well with actual observations of seawater CO2 chemistry. Thus, another approach is needed to establish a more reliable calibration method. In this study, we established field‐based calibrations for Chichijima and Tahiti, both located in subtropical gyres where surface seawater is close to CO2 equilibrium. We suggest a new approach to calibration of δ11B‐pH in which the long‐term δ11B variation of massive Porites corals is compared with the decreasing pH trend (i.e., ocean acidification) that has occurred since the Industrial Revolution. This calibration will offer a new avenue for studying seawater CO2 chemistry using coral δ11B in diverse settings, such as upwelling regions, coral reefs, and coastal areas.
Vertical kinetic energy and turbulent dissipation in the ocean
Authors: Thurnherr A. M. , Kunze E. , Toole J. M. , St. Laurent L. , Richards K. J. , Ruiz‐Angulo A.
Published: September 2015

Oceanic internal waves are closely linked to turbulence. Here a relationship between vertical wave number (kz) spectra of fine‐scale vertical kinetic energy (VKE) and turbulent dissipation ε is presented using more than 250 joint profiles from five diverse dynamic regimes, spanning latitudes between the equator and 60°. In the majority of the spectra VKE varies as
. Scaling VKE with
collapses the off‐equatorial spectra to within
but underestimates the equatorial spectrum. The simple empirical relationship between VKE and ε fits the data better than a common shear‐and‐strain fine‐scale parameterization, which significantly underestimates ε in the two data sets that are least consistent with the Garrett‐Munk (GM) model. The new relationship between fine‐scale VKE and dissipation rate can be interpreted as an alternative, single‐parameter scaling for turbulent dissipation in terms of fine‐scale internal wave vertical velocity that requires no reference to the GM model spectrum.
Flow visualization of CO2 in tight shale formations at reservoir conditions
Authors: Fernø M. A. , Hauge L. P. , Uno Rognmo A. , Gauteplass J. , Graue A.
Published: September 2015

The flow of CO2 in porous media is fundamental to many engineering applications and geophysical processes. Yet detailed CO2 flow visualization remains challenging. We address this problem via positron emission tomography using 11C nuclides and apply it to tight formations—a difficult but relevant rock type to investigate. The results represent an important technical advancement for visualization and quantification of flow properties in ultratight rocks and allowed us to observe that local rock structure in a layered, reservoir shale (K = 0.74 µdarcy) sample dictated the CO2 flow path by the presence of high‐density layers. Diffusive transport of CO2 in a fractured sample (high‐permeable sandstone) was also visualized, and an effective diffusion coefficient (Di = 2.2 · 10−8 m2/s) was derived directly from the dynamic distribution of CO2. During CO2 injection tests for oil recovery from a reservoir shale sample we observed a recovery factor of RF = 55% of oil in place without fracturing the sample.
Bimodal distribution of free tropospheric ozone over the tropical western Pacific revealed by airborne observations
Authors: Pan L. L. , Honomichl S. B. , Randel W. J. , Apel E. C. , Atlas E. L. , Beaton S. P. , Bresch J. F. , Hornbrook R. , Kinnison D. E. , Lamarque J.‐F. , Saiz‐Lopez A. , Salawitch R. J. , Weinheimer A. J.
Published: September 2015

A recent airborne field campaign over the remote western Pacific obtained the first intensive in situ ozone sampling over the warm pool region from oceanic surface to 15 km altitude (near 360 K potential temperature level). The new data set quantifies ozone in the tropical tropopause layer under significant influence of convective outflow. The analysis further reveals a bimodal distribution of free tropospheric ozone mixing ratio. A primary mode, narrowly distributed around 20 ppbv, dominates the troposphere from the surface to 15 km. A secondary mode, broadly distributed with a 60 ppbv modal value, is prominent between 3 and 8 km (320 K to 340 K potential temperature levels). The latter mode occurs as persistent layers of ozone‐rich drier air and is characterized by relative humidity under 45%. Possible controlling mechanisms are discussed. These findings provide new insight into the physical interpretation of the “S”‐shaped mean ozone profiles in the tropics.
Temporal variability of the South Atlantic Meridional Overturning Circulation between 20°S and 35°S
Authors: Dong Shenfu , Goni Gustavo , Bringas Francis
Published: September 2015

Altimetry‐derived synthetic temperature and salinity profiles between 20°S and 34.5°S are used to estimate the Meridional Overturning Circulation (MOC) and meridional heat transport (MHT), which are assessed against estimates obtained from expendable bathythermograph (XBT) measurements. Consistent with studies from XBTs and Argo data, both the geostrophic and Ekman contributions to the MOC exhibit annual cycles and play an equal role in the MOC seasonal variations. The strongest variations on seasonal and interannual time scales in our study region are found at 34.5°S. The dominance of the geostrophic and Ekman components on the interannual variations in the MOC and MHT varies with time and latitude, with the geostrophic component being dominant during 1993–2006 and the Ekman component dominant between 2006 and 2011 at 34.5°S.
Groundwater recharge and age‐depth profiles of intensively exploited groundwater resources in northwest India
Authors: Lapworth D. J. , MacDonald A. M. , Krishan G. , Rao M. S. , Gooddy D. C. , Darling W. G.
Published: September 2015

Intensive irrigation in northwest India has led to growing concerns over the sustainability of current and future groundwater abstraction. Environmental tracers and measurements of groundwater residence times can help quantify the renewal processes. Results from 16 paired locations show the interquartile ranges for residence times in shallow alluvial groundwater (8–50 m deep) to be 1–50 years and significantly less than those from deeper groundwater (76–160 m deep) at 40–170 years. The widespread occurrence of modern tracers in deep groundwater (>60% of sites had >10% modern recharge) suggests that there is low regional aquifer anisotropy and that deep aquifers are recharged by a significant component of recent recharge via vertical leakage. Stable isotope and noble gas results at all depths conform to modern meteoric sources and annual average temperatures, with no evidence of significant regional recharge from canal leakage in this study area close to the Himalayas.
Production of nongyrotropic and gyrotropic backstreaming ion distributions in the quasi‐perpendicular ion foreshock region
Authors: Savoini Philippe , Lembège Bertrand
Published: September 2015

A curved shock is analyzed in the whole quasi‐perpendicular propagation region (90° ≥ θBn≥45°) in a supercritical regime with the help of a 2‐D particle‐in‐cell code including self‐consistent effects such as the shock front curvature and the time‐of‐flight effects. Two distinct ion populations are observed within the foreshock: a (gyrotropic) field‐aligned beam population, hereafter named “FAB,” and a (nongyrotropic) gyrophase bunched population, hereafter named “GPB.” The origin of these high‐energy particles and their corresponding acceleration mechanisms are analyzed in details in the present paper. Both FAB and GPB populations are shown to be produced by the shock front itself and more important, do have exactly the same origin. At the shock front, the two populations gain a nongyrotropic distribution, but FAB population loses its initial phase coherency after suffering several bounces along the curved front. This result has one main consequence: the time evolution of the two populations does not involve some distinct reflection processes as often claimed in the literature, but results only from the particle time history at the shock front. This important result was not expected and greatly simplifies the question of their origin. More precisely, a new parameter, the injection angle θinj has been defined between the shock normal direction and the ion gyrating velocity vector. We found that the FAB population is formed by ions injected almost along the shock front, while GPB population is formed by ions injected almost along the shock normal.
Frictional characteristics of single and polycrystalline muscovite and influence of fluid chemistry
Authors: Kawai Kenji , Sakuma Hiroshi , Katayama Ikuo , Tamura Kenji
Published: September 2015

Frictional experiments were carried out on powder and single crystal specimens of muscovite. Friction coefficients for powder samples were found to be about twice as large as those for single crystals. We found that whereas in single crystal samples sliding occurs along the (001) plane, the situation is more complicated in powder samples. Experiments under wet conditions showed an ~30% reduction in friction coefficient for both powder and single crystal samples compared with dry conditions. The degree of the reduction depended on the fluid chemistry of NaCl or CsCl solutions, indicating that the presence of adsorbed water reduced the friction coefficients. Surface flatness of gauge particles and high affinity of the surface to water were crucial for realizing the effective lubrication due to adsorbed water.
Dynamic Ridges and Valleys in a Strike‐Slip Environment
Authors: Duvall Alison R. , Tucker Gregory E.
Published: September 2015

Strike‐slip faults have long been known for characteristic near‐fault landforms such as offset rivers and strike‐parallel valleys. In this study, we use a landscape evolution model to investigate the longer‐term, catchment‐wide landscape response to horizontal fault motion. Our results show that strike‐slip faulting induces a persistent state of disequilibrium in the modeled landscapes brought about by river lengthening along the fault alternating with abrupt shortening due to stream capture. The models also predict that, in some cases, ridges oriented perpendicular to the fault migrate laterally in conjunction with fault motion. We find that ridge migration happens when slip rate is slow enough and/or soil creep and river incision are efficient enough that the landscape can respond to the disequilibrium brought about by strike‐slip motion. Regional rock uplift relative to baselevel also plays a role, as topographic relief is required for ridge migration. In models with faster horizontal slip rates, stronger rocks, or less efficient hillslope transport, ridge mobility is limited or arrested despite the continuance of river lengthening and capture. In these cases, prominent steep, fault‐facing facets form along well‐developed fault valleys. Comparison of landscapes adjacent to fast‐slipping (>30 mm/yr) and slower‐slipping (≤1 mm/yr or less) strike‐slip faults in California, USA, reveals features that are consistent with model predictions. Our results highlight a potential suite of geomorphic signatures that can be used as indicators of horizontal crustal motion and geomorphic processes in strike‐slip settings even after river capture has diminished or erased apparent offset along the fault.
The role of SANSA's geomagnetic observation network in space weather monitoring: A review
Authors: Kotzé P. B. , Cilliers P. J. , Sutcliffe P. R.
Published: September 2015

Geomagnetic observations play a crucial role in the monitoring of space weather events. In a modern society relying on the efficient functioning of its technology network such observations are important in order to determine the potential hazard for activities and infrastructure. Until recently, it was the perception that geomagnetic storms had no or very little adverse effect on radio communication and electric power infrastructure at middle‐ and low‐latitude regions like southern Africa. The 2003 Halloween storm changed this perception. In this paper we discuss the role of the geomagnetic observation network operated by the South African National Space Agency (SANSA) in space weather monitoring. The primary objective is to describe the geomagnetic data sets available to characterize and monitor the various types of solar‐driven disturbances, with the aim to better understand the physics of these processes in the near‐Earth space environment and to provide relevant space weather monitoring and prediction.
Resolving two‐dimensional flow structure in rivers using large‐scale particle image velocimetry: An example from a stream confluence
Authors: Lewis Quinn W. , Rhoads Bruce L.
Published: September 2015

Large‐scale particle image velocimetry (LSPIV) has emerged as a valuable tool for measuring surface velocity in a variety of fluvial systems. LSPIV has typically been used in the field to obtain velocity or discharge measurements in relatively simple one‐dimensional flow. Detailed two‐dimensional or three‐dimensional characterization of flow structure has been relegated to laboratory settings because of the difficulty in controlling PIV limiting factors such as poor particle seeding, the need for camera rectification, and challenging field conditions. In this study we implement a low‐cost LSPIV setup using a high‐resolution action camera mounted above a stream confluence and water seeded with recycled landscape mulch. Time‐averaged 2‐D velocities derived from LSPIV are compared with those measured with an acoustic Doppler velocimeter (ADV) in the camera's field of view. We also assess the capabilities of this setup to resolve turbulent and time‐averaged flow structures at a stream confluence. Our results reveal that even in challenging field conditions a basic LSPIV setup can yield accurate data on velocity and resolve in detail the temporal evolution of flow structures on the surface of rivers. The resulting dataset contains velocity information at high spatial and temporal resolution, a significant advance in understanding flow processes at stream confluences. Our LSPIV analysis provides support for previous numerical modeling studies that have distinguished between Kelvin‐Helmholtz and wake modes of turbulent behavior within the mixing interface at confluences. This study shows that LSPIV can provide unprecedented levels of resolution of surface velocity patterns on rivers. Detailed velocity data derived from LSPIV can be used to evaluate numerical predictions of flow structure in complex fluvial environments.
The New Science of Form‐Searching
Authors: Carpo Mario
Published: September 2015

New technologies, by definition, change fast, as does our cultural awareness of our use of them. Mario Carpo, Reyner Banham Professor of Architectural History and Theory at the Bartlett School of Architecture, University College London (UCL), explains how in the course of the last few years much of our discourse on new technologies has been driven by an unexpected and, in many ways, inexplicable development: the availability of almost unlimited data storage and data‐processing capabilities at ever‐decreasing ‐ and often almost negligible ‐ costs. As digitally intelligent designers and structural engineers have not failed to notice, this simple, almost banal technical development has the potential to disrupt the way we design and calculate almost everything.
The New Cyber‐Physical Making in Architecture: Computational Construction
Authors: Menges Achim
Published: September 2015

In architectural history, the advent of new fabrication and construction technologies has always been a catalyst for design innovation, and the latent next paradigm shift facilitated by the introduction of cyber‐physical production systems will be no exception. What in other domains is often referred to as the ‘Fourth Industrial Revolution’ will also have a major impact on architecture, making possible a move away from instruction‐based making towards that based on behaviour. In this article, Guest‐Editor Achim Menges, Director of the Institute for Computational Design (ICD) at the University of Stuttgart, argues that these emerging technologies not only challenge our understanding of how buildings are made, but more importantly how we think about the genesis of form, tectonics and space.
ICD/ITKE Research Pavilion 2013‐14: Modular Coreless Filament Winding Based on Beetle Elytra
Authors: Doerstelmann Moritz , Knippers Jan , Menges Achim , Parascho Stefana , Prado Marshall , Schwinn Tobias
Published: September 2015

The ICD/ITKE Research Pavilion 2013‐14, presented here by Moritz Doerstelmann, Jan Knippers, Achim Menges, Stefana Parascho, Marshall Prado and Tobias Schwinn of the Institute for Computational Design (ICD) and Institute of Building Structures and Structural Design (ITKE) research team at the University of Stuttgart, is based on biological lightweight construction principles. It demonstrates how the development of integrative processes of design computation, simulation and robotic fabrication enable the simultaneous exploration of novel design possibilities, constructional effectiveness and robustness through the expression of material characteristics.
Granular Morphologies: Programming Material Behaviour with Designed Aggregates
Authors: Dierichs Karola , Menges Achim
Published: September 2015

What if designers were to become more than specifiers of materials, and actually defined the composition of the matter they work with? Granular materials, or rather ‘designed aggregates’, as introduced here by Karola Dierichs, architect and researcher at the Institute for Computational Design (ICD), and Guest‐Editor Achim Menges, are one distinct group of materials that can be considered ‘designed matter’. What makes designed granular systems particularly interesting is that they do not obtain a final structure with preset properties. Instead, their elemental constituents remain unfixed, allowing them to continuously and physically recompute structural and spatial characteristics, challenging our very conception of design.
Hacking Science: The ALivE Group's Material Design Methods for Interdisciplinary Environments
Authors: Bechthold Martin , Sayegh Allen
Published: September 2015

Advances in the understanding and processing of materials have historically been one of the foremost drivers of architectural innovation. Today, groundbreaking material developments mainly occur on the nano‐scale, and thus lie outside most designers' working knowledge and expertise. Martin Bechthold, Professor of Architectural Technology at the Harvard Graduate School of Design (GSD), and Allen Sayegh, Associate Professor in Practice of Architectural Technology at the GSD, introduce the work of the Adaptive Living Environments (ALivE) group at Harvard University, which seeks to reconcile fundamental material science with architectural design through new modes of interdisciplinary collaboration drawing from contemporary cultures of computation and hacking.
Probing Local Electronic Transitions in Organic Semiconductors through Energy‐Loss Spectrum Imaging in the Transmission Electron Microscope
Authors: Guo Changhe , Allen Frances I. , Lee Youngmin , Le Thinh P. , Song Chengyu , Ciston Jim , Minor Andrew M. , Gomez Enrique D.
Published: September 2015

Improving the performance of organic electronic devices depends on exploiting the complex nanostructures formed in the active layer. Current imaging methods based on transmission electron microscopy provide limited chemical sensitivity, and thus the application to materials with compositionally similar phases or complicated multicomponent systems is challenging. Here, it is demonstrated that monochromated transmission electron microscopes can generate contrast in organic thin films based on differences in the valence electronic structure at energy losses below 10 eV. In this energy range, electronic fingerprints corresponding to interband excitations in organic semiconductors can be utilized to generate significant spectral contrast between phases. Based on differences in chemical bonding of organic materials, high‐contrast images are thus obtained revealing the phase separation in polymer/fullerene mixtures. By applying principal component analysis to the spectroscopic image series, further details about phase compositions and local electronic transitions in the active layer of organic semiconductor mixtures can be explored.
Inorganic Micelles (Hydrophilic Core@Amphiprotic Shell) for Multiple Applications
Authors: Islam Md. Shahinul , Choi Won San , Kim Sun Ha , Han Oc Hee , Lee Ha‐Jin
Published: September 2015

A facile approach for synthesizing superhydrophobic hollow silica micelles (SHSMs) with hydrophilic cores and amphiprotic (superhydrophobic/hydrophilic) shell structures that act as “all‐in‐one” smart nanomaterials is presented. The particles possess hydrophilic cores consisting of silica and a polyelectrolyte (PE) network and an amphiprotic shell consisting of superhydrophobic long‐chained hydrocarbons and hydrophilic PEs. Due to the unique hydrophilic cores and amphiprotic shells, the particles exhibit extraordinary performance in terms of amphiprotic catalytic reactions in organic and aqueous solutions, oil/water separation and pollutant purification, and an ultrahigh loading capacity of enzymes with significant stability and efficient recyclability. The amphiprotic functionalities of the SHSMs have the potential to allow for a rich range of applications to be explored.
Magnetic Nanoparticles Labeled Mesenchymal Stem Cells: A Pragmatic Solution toward Targeted Cancer Theranostics
Authors: Singh Abhalaxmi , Jain Sumeet , Senapati Shantibhusan , Verma Rama Shanker , Sahoo Sanjeeb K.
Published: September 2015

Mesenchymal stem cells (MSCs) have gained much interest to be used as targeting vehicle in cancer therapy due to the intrinsic tumor‐homing behavior associated with them. In this scenario, superparamagnetic nanoparticles are emerging as an ideal probe for noninvasive cell tracking for different stem cell applications. In the study, it is demonstrated that the formulated aqueous dispersible glyceryl monooleate coated magnetic nanoparticles (MNPs) can act as a better labeling and efficient tracking agent without affecting the inherent properties of MSCs. The MNPs‐MSCs facilitate the stem cell tracking by magnetic resonance imaging at a very low cell number having high T2 relaxivity and potentiates the use of MNPs‐MSCs as a prospective diagnostic tool. Most importantly, the homing of MNPs‐MSCs toward inflammation site, subcutaneous prostate tumor (small as well as large tumor), and in orthotopic prostate tumor suggests the clinical relevance of the system. In addition, intraperitoneal delivery of MNPs‐MSCs shows enhanced tumor accumulation and less sequestration in liver as revealed by in vivo imaging and histological studies. The results here demonstrate that MNPs‐MSCs may prove as a better targeted delivery agent for early diagnosis of tumors even of smaller size.
A Silk Sericin/Silicone Nerve Guidance Conduit Promotes Regeneration of a Transected Sciatic Nerve
Authors: Xie Hongjian , Yang Wen , Chen Jianghai , Zhang Jinxiang , Lu Xiaochen , Zhao Xiaobo , Huang Kun , Li Huili , Chang Panpan , Wang Zheng , Wang Lin
Published: September 2015

Peripheral nerve gap defects lead to significant loss of sensory or motor function. Tissue engineering has become an important alternative to nerve repair. Sericin, a major component of silk, is a natural protein whose value in tissue engineering has just begun to be explored. Here, the first time use of sericin in vivo is reported as a long‐term implant for peripheral nerve regeneration. A sericin nerve guidance conduit is designed and fabricated. This conduit is highly porous with mechanical strength matching peripheral nerve tissue. It supports Schwann cell proliferation and is capable of up‐regulating the transcription of glial cell derived neurotrophic factor and nerve growth factor in Schwann cells. The sericin conduit wrapped with a silicone conduit (sericin/silicone double conduits) is used for bridging repair of a 5 mm gap in a rat sciatic nerve transection model. The sericin/silicone double conduits achieve functional recovery comparable to that of autologous nerve grafting as evidenced by drastically improved nerve function and morphology. Importantly, this improvement is mainly attributed to the sericin conduit as the silicone conduit alone only produces marginal functional recovery. This sericin/silicone‐double‐conduit strategy offers an efficient and valuable alternative to autologous nerve grafting for repairing damaged peripheral nerve.
89Zr‐ and Fe‐Labeled Polymeric Micelles for Dual Modality PET and T1‐Weighted MR Imaging
Authors: Starmans Lucas W. E. , Hummelink Marcus A. P. M. , Rossin Raffaella , Kneepkens Esther C. M. , Lamerichs Rolf , Donato Katia , Nicolay Klaas , Grüll Holger
Published: September 2015

In this study, a new 89Zr‐ and Fe3+‐labeled micelle nanoplatform (89Zr/Fe‐DFO‐micelles) for dual modality position emission tomography/magnetic resonance (PET/MR) imaging is investigated. The nanoplatform consists of self‐assembling amphiphilic diblock copolymers that are functionalized with 89Zr‐deferoxamine (89Zr‐DFO) and Fe3+‐deferoxamine (Fe‐DFO) for PET and MR purposes, respectively. 89Zr displays favorable PET imaging characteristics with a 3.3 d half‐life suitable for imaging long circulating nanoparticles. The nanoparticles are modified with Fe‐DFO as MR T1‐contrast label instead of commonly used Gd3+‐based chelates. As these micelles are cleared by liver and spleen, any long term Gd‐ related toxicity such as nephrogenic systemic fibrosis is avoided. As a proof of concept, an in vivo PET/MR study in mice is presented showing tumor targeting of 89Zr/Fe‐DFO‐micelles through the enhanced permeability and retention (EPR) effect of tumors, yielding high tumor‐to‐blood (10.3 ± 3.6) and tumor‐to‐muscle (15.3 ± 8.1) ratios at 48 h post injection. In vivo PET images clearly delineate the tumor tissue and show good correspondence with ex vivo biodistribution results. In vivo magnetic resonance imaging (MRI) allows visualization of the intratumoral distribution of the 89Zr/Fe‐DFO‐micelles at high resolution. In summary, the 89Zr/Fe‐DFO‐micelle nanoparticulate platform allows EPR‐based tumor PET/MRI, and, furthermore, holds great potential for PET/MR image guided drug delivery.
Biodegradable Antimicrobial Polycarbonates with In Vivo Efficacy against Multidrug‐Resistant MRSA Systemic Infection
Authors: Cheng Junchi , Chin Willy , Dong Huihui , Xu Liang , Zhong Guansheng , Huang Yuan , Li Lanjuan , Xu Kaijin , Wu Min , Hedrick James L. , Yang Yi Yan , Fan Weimin
Published: September 2015

The threat of multidrug resistance requires development of new medicines to treat methicillin‐resistant Staphylococcus aureus (MRSA) infection. The biodegradable polycarbonates that have broad‐spectrum antibacterial activity and show the highest selectivity toward S. aureus are studied for their antibacterial properties against clinically isolated MRSA and toxicity both in vitro and in vivo. Minimum inhibitory concentrations of the polymers are demonstrated to be much lower than those of cefoxitin (a commonly used antibiotic) against all 31 isolates but slightly higher than those of vancomycin, a last resort medication for treating severe Gram‐positive drug‐resistant bacterial infections. Both polymers show low hemolytic activity toward human red blood cells, making them highly selective toward MRSA in vitro. A time‐kill study reveals that these polymers have high bactericidal efficiency and eradicate MRSA more rapidly than vancomycin. Results from a resistance development study also attests to the polymers low tendency toward resistance. Furthermore, the in vivo study shows that one of the polymers is highly efficacious in a mouse systemic infection model, and reduced MRSA counts in the blood more promptly than vancomycin. The administration of the polymer to mice further indicates that it did not cause any dysfunctions of liver and kidney as well as blood electrolytes. This is the first example of a polymeric therapeutics for treating systemic MRSA infection. Taken together, the biodegradable antimicrobial polycarbonate may be a better candidate for treating MRSA infection.
Water Affinity to Epitaxial Graphene: The Impact of Layer Thickness
Authors: Giusca Cristina E. , Panchal Vishal , Munz Martin , Wheeler Virginia D. , Nyakiti Luke O. , Myers‐Ward Rachael L. , Gaskill D. Kurt , Kazakova Olga
Published: September 2015

The sensitivity to water vapour of one‐, two‐, and three‐layer epitaxial graphene (1, 2, and 3LG) is examined in this study. It is unambiguously shown that graphene's response to water, as measured by changes in work function and carrier density, is dependent on its thickness, with 1LG being the most sensitive to water adsorption and environmental concentration changes. This is furthermore substantiated by surface adhesion measurements, which bring evidence that 1LG is less hydrophobic than 2LG. Yet, surprisingly, it is found that other contaminants commonly present in ambient air have a greater impact on graphene response than water vapor alone. This study indicates that graphene sensor design and calibration to minimize or discriminate the effect of the ambient, in which it is intended to operate, are necessary to insure the desired sensitivity and reliability of sensors. The present work will aid in developing models for realistic graphene sensors and establishing protocols for molecular sensor design and development.
Mid‐infrared Plasmonic Resonances in 2D VO2 Nanosquare Arrays
Authors: Matsui Hiroaki , Ho Ya‐Lun , Kanki Teruo , Tanaka Hidekazu , Delaunay Jean‐Jacques , Tabata Hitoshi
Published: September 2015

Plasmon resonances on 2D nanosquare arrays and their temperature‐dependent modulations are demonstrated using the insulator‐to‐metal transition (IMT) of VO2. A comparison between observed experimental trends and electromagnetic simulations reveals that the plasmon coupling is effective in the periodic 2D alignment of metallic VO2 nanosquares and results in a collective plasmon excitation. This plasmon excitation affects the optical responses of VO2 nanosquares in the mid‐infrared (IR) range through reduction of plasmon damping in relation to the specific band structure of VO2. This preliminary understanding is important for the elucidation of temperature‐dependent plasmon resonances. The IMT of VO2 produces temperature‐dependent plasmon resonances with respect to spectral features. The electrodynamic simulations reveal that these phenomena are based on plasmon coupling in the nanosquare array when each nanosquare acts as a single metallic domain. The hysteretic plasmon resonances are derived from resonant coupling between metallic VO2 nanosquares via the IMT nature of VO2, which results in temperature‐dependent changes in collective plasmon excitations in the nanosquare array.
A General Strategy to Fabricate Carbon‐Coated 3D Porous Interconnected Metal Sulfides: Case Study of SnS/C Nanocomposite for High‐Performance Lithium and Sodium Ion Batteries
Authors: Zhu Changbao , Kopold Peter , Li Weihan , van Aken Peter A. , Maier Joachim , Yu Yan
Published: September 2015

Transition metal sulfides have a great potential for energy storage due to the pronouncedly higher capacity (owing to conversion to metal or even alloy) than traditional insertion electrode materials. However, the poor cycling stability still limits the development and application in lithium and sodium ion batteries. Here, taking SnS as a model material, a novel general strategy is proposed to fabricate a 3D porous interconnected metal sulfide/carbon nanocomposite by the electrostatic spray deposition technique without adding any expensive carbonaceous materials such as graphene or carbon nanotube. In this way, small nanorods of SnS are generated with sizes of ≈10–20 nm embedded in amorphous carbon and self‐assembled into a 3D porous interconnected nanocomposite. The SnS:C is directly deposited on the Ti foil as a current collector and neither conductive additives nor binder are needed for battery assembly. Such electrodes exhibit a high reversible capacity, high rate capability, and long cycling stability for both lithium and sodium storage.
National machine guarding program: Part 1. Machine safeguarding practices in small metal fabrication businesses
Authors: Parker David L. , Yamin Samuel C. , Brosseau Lisa M. , Xi Min , Gordon Robert , Most Ivan G. , Stanley Rodney
Published: September 2015

Background

Metal fabrication workers experience high rates of traumatic occupational injuries. Machine operators in particular face high risks, often stemming from the absence or improper use of machine safeguarding or the failure to implement lockout procedures.

Methods

The National Machine Guarding Program (NMGP) was a translational research initiative implemented in conjunction with two workers' compensation insures. Insurance safety consultants trained in machine guarding used standardized checklists to conduct a baseline inspection of machine‐related hazards in 221 business.

Results

Safeguards at the point of operation were missing or inadequate on 33% of machines. Safeguards for other mechanical hazards were missing on 28% of machines. Older machines were both widely used and less likely than newer machines to be properly guarded. Lockout/tagout procedures were posted at only 9% of machine workstations.

Conclusions

The NMGP demonstrates a need for improvement in many aspects of machine safety and lockout in small metal fabrication businesses. Am. J. Ind. Med. 58:1174–1183, 2015. © 2015 The Authors. American Journal of Industrial Medicine published by Wiley Periodicals, Inc.
Thyroid nodules on chest CT of patients with tuberous sclerosis complex
Authors: Auladell Maria , Boronat Susana , Barber Ignasi , Thiele Elizabeth A.
Published: September 2015

A few cases of thyroid disease have been reported in tuberous sclerosis complex (TSC); however, studies on prevalence and characterization of lesions have not been done. Patients with TSC are routinely screened using chest CT for assessment of lung disease. Incidental thyroid findings on chest CT have been reported in large studies of the general population. The purpose of this study is to evaluate the frequency and type of thyroid anomalies in a cohort of TSC patients. We performed a retrospective review of 93 patients with a definite diagnosis of TSC, who had a chest CT. Images of the thyroid gland and final radiological report were reviewed. Reports of additional thyroid studies performed in some patients were also reviewed. Thyroid abnormalities were present in 19 of 93 (20.4%) patients. They consisted mainly of hypodense lesions categorized as nodules. Multiple nodules were found in 10 patients (52.6%). There was one papillary carcinoma. Thyroid gland lesions may be part of the clinical spectrum of TSC. They are usually asymptomatic. As some cases of thyroid carcinoma have been described in TSC, ultrasound exams are recommended, given that CT is not the gold standard technique for thyroid evaluation. © 2015 Wiley Periodicals, Inc.
Design, Synthesis, and Applications of Highly Phosphorescent Cyclometalated Platinum Complexes
Authors: Huo Shouquan , Carroll Jeffrey , Vezzu Dileep A. K.
Published: September 2015

Phosphorescent cyclometalated platinum complexes are highly attractive compounds for a variety of applications, including organic‐light emitting diodes (OLEDs), chemical and biological sensing and imaging, and photocatalysis. This review deals with the progress made in the last five years in the development of highly luminescent platinum complexes based on bidentate, tridentate, and tetradentate cyclometalating ligands. The ligand design and synthesis, general methods for the formation of cycloplatinated complexes, and their photophysical properties, in particular, the emission energy and photoluminescent quantum efficiency of the complexes, are discussed. The applications of the complexes in OLEDs, chemical sensing, biological imaging, and other fields are briefly covered.
Monks on the move: Evaluating pilgrimage to byzantine St. Stephen's monastery using strontium isotopes
Authors: Sheridan Susan Guise , Gregoricka Lesley A.
Published: September 2015

Objectives

Written and archaeological evidence indicates that migration, in the form of pilgrimage to Byzantine Palestine, was a major social phenomenon between the 5th and 7th centuries CE. Monasteries saw record growth at this time as pilgrims chose to stay in the region and take up religious life. A major influx of people to the region, with a corresponding growth in monastic vocations that led travelers to stay in the area, is not in question; however, the distant origins of pilgrims reflected in surviving texts may be an artifact of preservation, biased towards an elite minority. The Byzantine monastery of St. Stephen's provides an opportunity to study this question from a bioarchaeological perspective, given the excellent preservation of the human skeletal assemblage, a wealth of written works about the community as well as daily life in Byzantine Palestine, and a rich archaeological record for the site and region. Materials and Methods: An analysis of radiogenic strontium isotope values from the third molars of 22 individuals recovered from the St. Stephen's crypt complex was conducted to test whether those interred at the monastery were of local origin. Results: Of those examined (
= 0.7084 ± 0.0007, 1σ), 8 out of 22 (36%) exhibited 87Sr/86Sr ratios that fell outside of local ranges. Discussion: These results confirmed the sizeable presence of nonlocals at St. Stephen's Monastery. While most of these migrants likely traveled to Jerusalem from different areas of the Levant as pilgrims, others may have hailed from further afield, including Europe. Am J Phys Anthropol, 2015. © 2015 Wiley Periodicals, Inc. Am J Phys Anthropol 158:581–591, 2015. © 2015 Wiley Periodicals, Inc.
Effect of nitrogen dioxide and sulfur dioxide on viability and morphology of oak pollen
Authors: Ouyang Yuhui , Xu Zhaojun , Fan Erzhong , Li Ying , Zhang Luo
Published: September 2015

Background

Nitrogen dioxide (NO2) and sulfur dioxide (SO2) generated by excessive coal combustion and motor vehicle emissions are major air pollutants in the large cities of China. The objective of our study was to determine the effects of the exposure of oak pollens (Quercusmongolica) to several concentrations of NO2 or SO2.

Methods

Pollen grains were exposed to 0.5 ppm to 5.0 ppm NO2 or SO2 for 4 hours and assessed for morphological damage by field emission scanning electron microscopy and for viability using the trypan blue stain. Morphological changes in pollen grains were also examined after contact with acid solutions at pH 4.0 to pH 7.0.

Results

Exposure to NO2 or SO2 significantly damaged pollen grains at all concentrations investigated, compared to exposure to air; with exposure to concentrations of 0.5 ppm to 2 ppm resulting in fissures or complete breaks in the exine and a concentration of 5 ppm resulting in complete breakdown and release of pollen cytoplasmic granules. Significantly greater amounts of pollen grain were damaged after exposure to SO2 (15.5–20.4%) than after exposure to NO2 (7.1–14.7%). Similarly, exposure to NO2 or SO2 significantly decreased the viability of pollen grains, compared with exposure to air; with SO2 being slightly more detrimental than NO2. Exposure to acid solutions also induced pollen damage, which appeared to be pH‐dependent (from 24.6% at pH 6.0 to 55.8% at pH 4.0; compared to 3.8% at pH 7.0).

Conclusion

Short‐term exposure of oak pollen to high concentrations of SO2 or NO2 significantly increases their fragility and disruption, leading to subsequent release of pollen cytoplasmic granules into the atmosphere. These results suggest that heightened air pollution during the oak pollen season may possibly increase the incidence of allergic airway disease in sensitized individuals by facilitating the bioavailability of airborne pollen allergens.
Will There Be a Vast Worldwide Expansion Of Mediation for International Disputes?
Authors: Kaster Laura A.
Published: September 2015

From February at Turtle Bay in Manhattan, the site of the United Nations, to July in Vienna, Austria, the United Nations Commission on International Trade Law has been considering a tectonic shift in the treatment of mediated and conciliated settlements for international or cross‐border commercial disputes.
Precisely Size‐Tunable Magnetic/Plasmonic Core/Shell Nanoparticles with Controlled Optical Properties
Authors: Yang Di , Pang Xinchang , He Yanjie , Wang Yiquan , Chen Genxiang , Wang Wenzhong , Lin Zhiqun
Published: September 2015

Star‐like amphiphilic triblock copolymers were rationally designed and synthesized by combining two sequential atom‐transfer radical polymerization reactions with a click reaction. Subsequently, a family of uniform magnetic/plasmonic core/shell nanoparticles was crafted by capitalizing on these triblock copolymers as nanoreactors. The diameter of the magnetic core and the thickness of the plasmonic shell could be independently and accurately controlled by varying the molecular weights (i.e., the chain lengths) of the inner and intermediate blocks of the star‐like triblock copolymers, respectively. The surface plasmonic absorption of core/shell nanoparticles with different core diameters and shell thicknesses was systematically studied and theoretically modeled. This robust strategy provides easy access to a large variety of multifunctional nanoparticles with large lattice mismatches for use in optics, optoelectronics, catalysis, or bioimaging.
Kontrollierte lichtvermittelte Synthese von Gold‐Nanopartikeln über Norrish‐Typ‐I‐Reaktion in photoaktiven Polymeren
Authors: Mäsing Florian , Mardyukov Artur , Doerenkamp Carsten , Eckert Hellmut , Malkus Ursula , Nüsse Harald , Klingauf Jürgen , Studer Armido
Published: September 2015

Gold‐Nanopartikel (AuNPs) erfahren zurzeit aufgrund ihrer interessanten physikochemischen Eigenschaften große wissenschaftliche Beachtung. Wir stellen hier eine einfache und kontrollierte lichtvermittelte Synthese von Gold‐Nanopartikeln über Norrish‐Typ‐I‐Reaktion in photoaktiven Polymeren vor. Diese funktionell konzipierten Polymere agieren sowohl als Reagentien zur photochemischen Reduktion von Goldionen als auch zur Stabilisierung der in situ hergestellten AuNPs. Durch geschickte Variation der Länge und der Zusammensetzung der photoaktiven Polymere kann die Größe der Gold‐Nanopartikel in einem Bereich zwischen 1.5 nm und 9.6 nm gezielt eingestellt werden.
Readily Removable Directing Group Assisted Chemo‐ and Regioselective C(sp3)H Activation by Palladium Catalysis
Authors: Zhang Yun‐Fei , Zhao Hong‐Wei , Wang Hui , Wei Jiang‐Bo , Shi Zhang‐Jie
Published: September 2015

Currently used directing groups for selective aliphatic β‐functionalization of carbonyl compounds show excellent reactivity and selectivity with an amide as a linker. Described herein is 2‐piconimide, used for the first time with commercially available 2‐picolinamide/2‐picolic acid as precursors, to direct CH arylation/alkenylation by palladium catalysis. The directing group is essential for promoting the sequnetial primary and secondary C(sp3)H arylation with different aryl iodides in one substrate. The directing group was easily removed under simple reaction conditions at room temperature.
Highly Regioselective Radical Amination of Allenes: Direct Synthesis of Allenamides and Tetrasubstituted Alkenes
Authors: Zhang Ge , Xiong Tao , Wang Zining , Xu Guoxing , Wang Xuedan , Zhang Qian
Published: September 2015

The first controllable, regioselective radical amination of allenes with N‐fluoroarylsulfonimide is described to proceed under very mild reaction conditions. With this methodology, a general and straightforward route for the synthesis of both allenamides and fluorinated tetrasubstituted alkenes was realized from a wide range of terminal and internal allenes.
Rhodium‐Catalyzed Dehydrogenative Borylation of Aliphatic Terminal Alkenes with Pinacolborane
Authors: Morimoto Masao , Miura Tomoya , Murakami Masahiro
Published: September 2015

Aliphatic terminal alkenes react with pinacolborane at ambient temperature to afford dehydrogenative borylation compounds as the major product when iPr‐Foxap is used as the ligand with cationic rhodium(I) in the presence of norbornene, which acts as the sacrificial hydrogen acceptor. The reaction is applied to the one‐pot syntheses of aldehydes and homoallylic alcohols from aliphatic terminal alkenes.
Palladium‐Catalyzed Catellani ortho‐Acylation Reaction: An Efficient and Regiospecific Synthesis of Diaryl Ketones
Authors: Huang Yunze , Zhu Rui , Zhao Kun , Gu Zhenhua
Published: September 2015

A palladium‐catalyzed, norbornene‐mediated Catellani ortho‐acylation reaction was developed by the use of either acyl chlorides or acid anhydrides as acylation reagents. The addition of more than a stoichiometric amount of H2O is crucial for this transformation when acid chlorides are used, and kinetic studies indicate that the active acylation reagent is possibly an acid anhydride.