bluuebunny/crossref_metadata_2025 huggingface dataset:
Butterfly pitch angle distribution of relativistic electrons in the outer radiation belt: Evidence of nonadiabatic scattering
Authors: Artemyev A. V. , Agapitov O. V. , Mozer F. S. , Spence H.
Published: May 2015

In this paper we investigate the scattering of relativistic electrons in the nightside outer radiation belt (around the geostationary orbit). We consider the particular case of low geomagnetic activity (|Dst|<20 nT), quiet conditions in the solar wind, and absence of whistler wave emissions. For such conditions we find several events of Van Allen probe observations of butterfly pitch angle distributions of relativistic electrons (energies about 1–3 MeV). Many previous publications have described such pitch angle distributions over a wide energy range as due to the combined effect of outward radial diffusion and magnetopause shadowing. In this paper we discuss another mechanism that produces butterfly distributions over a limited range of electron energies. We suggest that such distributions can be shaped due to relativistic electron scattering in the equatorial plane of magnetic field lines that are locally deformed by currents of hot ions injected into the inner magnetosphere. Analytical estimates, test particle simulations, and observations of the AE index support this scenario. We conclude that even in the rather quiet magnetosphere, small scale (magnetic local time (MLT)‐localized) injection of hot ions from the magnetotail can likely influence the relativistic electron scattering. Thus, observations of butterfly pitch angle distributions can serve as an indicator of magnetic field deformations in the nightside inner magnetosphere. We briefly discuss possible theoretical approaches and problems for modeling such nonadiabatic electron scattering.
Hydrodynamic and sediment transport modeling of New River Inlet (NC) under the interaction of tides and waves
Authors: Chen Jia‐Lin , Hsu Tian‐Jian , Shi Fengyan , Raubenheimer Britt , Elgar Steve
Published: May 2015

The interactions between waves, tidal currents, and bathymetry near New River Inlet, NC, USA are investigated to understand the effects on the resulting hydrodynamics and sediment transport. A quasi‐3‐D nearshore community model, NearCoM‐TVD, is used in this integrated observational and modeling study. The model is validated with observations of waves and currents at 30 locations, including in a recently dredged navigation channel and a shallower channel, and on the ebb tidal delta, for a range of flow and offshore wave conditions during May 2012. In the channels, model skills for flow velocity and wave height are high. Near the ebb tidal delta, the model reproduces the observed rapid onshore (offshore) decay of wave heights (current velocities). Model results reveal that this sharp transition coincides with the location of the breaker zone over the ebb tidal delta, which is modulated by semidiurnal tides and by wave intensity. The modulation of wave heights is primarily owing to depth changes rather than direct wave‐current interaction. The modeled tidally averaged residual flow patterns show that waves play an important role in generating vortices and landward‐directed currents near the inlet entrance. Numerical experiments suggest that these flow patterns are associated with the channel‐shoal bathymetry near the inlet, similar to the generation of rip currents. Consistent with other inlet studies, model results suggest that tidal currents drive sediment fluxes in the channels, but that sediment fluxes on the ebb tidal delta are driven primarily by waves.
Distinct impacts of the Mongolian and Tibetan Plateaus on the evolution of the East Asian monsoon
Authors: Sha Yingying , Shi Zhengguo , Liu Xiaodong , An Zhisheng
Published: May 2015

The Mongolian Plateau (MP), which is relatively lower in altitude and smaller in extent than the Tibetan Plateau (TP), has received little attention about its climate effect. Building upon previous work in which we highlighted the role of the MP on the high‐level westerly jet stream, the response of surface‐level features of the Asian climate is examined in this study. The results show that the Indian and East Asian summer monsoonal and inland precipitation are mainly enhanced by the uplift of the TP. The precipitation during the onset of the summer monsoon is also intensified over India and eastern China. In addition, the East Asian monsoon domain is significantly expanded with the uplift of the TP, while the Indian summer monsoon domain does not change obviously. The MP plays a significant role in the strengthening of the East Asian winter monsoon, which is larger than the TP. With the uplift of the MP, the cold northerly wind in winter intensifies significantly in East Asia from higher latitudes to the South China Sea. The Siberian high is also enhanced and moves remarkably northward to its modern location. The strengthening of the Asian winter monsoon is related to the MP‐induced diversion of westerly wind. The bypassing flows around the plateau modify the temperature advections over middle latitudes and the atmosphere thermal structure in winter, which leads to the strengthening of the East Asian winter monsoon.
Changes to the turbulent kinematics of a volcanic plume inferred from lightning data
Authors: Behnke Sonja A. , Bruning Eric C.
Published: May 2015

The 2009 Redoubt Volcano eruption produced a series of explosive events, the largest of which produced episodes of volcanic lightning similar to thunderstorms. Flash energy spectra were calculated from lightning mapping data collected during the eruption. The spectra were compared to the turbulence characteristics expected from each stage of plume development. Small flash length scales present at early times were associated with the gas thrust and initial convective stages. Increases in flash length scales and flash energy as the explosive events progressed were associated with an increase in volume of the plume. Spectra with a large range in flash length scales (0.2–10 km) and a spectral peak at small flash length scales (< 1 km) were associated with a superposition of spectra from gas thrust, convective, and umbrella/ash cloud regions. An approximate 5/3 power law slope was observed on the order of 10 min after gas thrust forcing had ended and the transition to a drifting ash cloud was underway, which may reflect the dissipating state of the drifting ash cloud.
An experimental investigation into the role of phyllosilicate content on earthquake propagation during seismic slip in carbonate faults
Authors: Bullock Rachael J. , De Paola Nicola , Holdsworth Robert E.
Published: May 2015

Carbonate faults commonly contain small amounts of phyllosilicate in their slip zones, due to pressure solution and/or clay smear. To assess the effect of phyllosilicate content on earthquake propagation in carbonate faults, friction experiments were performed at 1.3 m/s on end‐members and mixtures of calcite, illite‐smectite, and smectite gouge. Experiments were performed at 9 MPa normal load, under room humidity and water‐saturated conditions. All dry gouges show initial friction values (μi) of 0.51–0.58, followed by slip hardening to peak values of 0.61–0.76. Slip weakening then ensues, with friction decreasing to steady state values (μss) of 0.19–0.33 within 0.17–0.58 m of slip. Contrastingly, wet gouges containing 10–50 wt % phyllosilicate exhibit μi values between 0.07 and 0.52 followed by negligible or no slip hardening; rather, steady state sliding (μss ≪ 0.2) is attained almost immediately. Microstructurally, dry gouges show intense cataclasis and wear within localized principal slip zones, plus evidence for thermal decomposition of calcite. Wet gouges exhibit distributed deformation, less intense cataclasis, and no evidence of thermal decomposition. It is proposed that in wet gouges, slip is distributed across a network of weak phyllosilicate formed during axial loading compaction prior to shear. This explains the (1) subdued cataclasis and associated lack of slip hardening, (2) distributed nature of deformation, and (3) lack of evidence for thermal decomposition, due to low friction and lack of slip localization. These findings imply that just 10% phyllosilicate in the slip zone of fluid‐saturated carbonate faults can (1) dramatically change their frictional behavior, facilitating rupture propagation to the surface, and (2) significantly lower frictional heating, preventing development of microscale seismic markers.
Subannual variability of total alkalinity distributions in the northeastern Gulf of Mexico
Authors: Yang Bo , Byrne Robert H. , Wanninkhof Rik
Published: May 2015

The subannual variability of total alkalinity (TA) distributions in the northeastern Gulf of Mexico was examined through the use of TA data from ship‐based water sampling, historical records of riverine TA, and contemporaneous model output of surface currents and salinity. TA variability was restricted to the upper 150 m of the water column, where relationships between salinity and TA were controlled primarily by subannual variations in the extent of mixing between seawater and river water. A transition in TA distribution patterns between the river‐dominated northern margin (near the Mississippi‐Atchafalaya River System) and the ocean current‐dominated eastern margin (West Florida Shelf) was observed. An index for riverine alkalinity input was formulated to provide insights about riverine alkalinity contributions in the upper water column. Spatial and temporal variations of total alkalinity in the northeastern Gulf of Mexico are primarily controlled by riverine TA inputs and ocean currents.
The Influence of Grain Size Determination Method on Grain Growth Kinetics Analysis
Authors: Hashemi‐Sadraei Leyla , Mousavi S. Ebrahim , Lavernia Enrique J. , Schoenung Julie M.
Published: May 2015

The full‐width at half‐maximum (FWHM), integral width (IntW), and Scherrer methodologies were used jointly with X‐ray diffraction (XRD) peak broadening and transmission electron microscopy (TEM) data to provide insight into the mechanisms that govern grain growth behavior in an Al 5083‐B4C nanocomposite. Grain growth kinetics were studied by fitting the appropriate grain size data from the three XRD‐based methods to the well‐known Burke equation. Variations observed in the absolute grain sizes calculated from different methods were in agreement with previous studies. In spite of these variations, consistent grain growth trends were observed, which resulted in relatively similar Arrhenius plots indicating two grain growth regimes. Consequently, the applicability as well as any relevant uncertainties within each method are described and discussed.
Rational Design of Small Molecular Donor for Solution‐Processed Organic Photovoltaics with 8.1% Efficiency and High Fill Factor via Multiple Fluorine Substituents and Thiophene Bridge
Authors: Wang Jin‐Liang , Yin Qing‐Ru , Miao Jing‐Sheng , Wu Zhuo , Chang Zheng‐Feng , Cao Yue , Zhang Ru‐Bo , Wang Jie‐Yu , Wu Hong‐Bin , Cao Yong
Published: May 2015

A series of tetrafluorine‐substituted small molecules with a D1‐A‐D2‐A‐D1 linear framework based on indacenodithiophene and difluorobenzothiadiazole is designed and synthesized for application as donor materials in solution‐processed small‐molecule organic solar cells. The impacts of thiophene π‐bridge and multiple fluorinated modules on the photophysical properties, the energy levels of the highest occupied molecular orbitals (HOMO) and lowest unoccupied molecular orbitals (LUMO), charge carrier mobility, the morphologies of blend films, and their photovoltaic properties as electron donor material in the photoactive layer are investigated. By incorporating multiple fluorine substituents of benzothiadiazole and inserting two thiophene spacers, the fill factor (FF), open‐circuit voltage, and short‐circuit current density are dramatically improved in comparison with fluorinated‐free materials. With the solvent vapor annealing treatment, further enhancement in charge carrier mobility and power conversion efficiency (PCE) are achieved. Finally, a high PCE of 8.1% with very‐high FF of 0.76 for BIT‐4F‐T/PC71BM is achieved without additional additive, which is among one of the highest reported for small‐molecules‐based solar cells with PCE over 8%. The results reported here clearly indicate that high PCE in solar cells based small molecules can be significantly increased through careful engineering of the molecular structure and optimization on the morphology of blend films by solvent vapor annealing.
A Natural 3D Interconnected Laminated Composite with Enhanced Damage Resistance
Authors: Li Ling , Ortiz Christine
Published: May 2015

Due to their lightweight, high specific stiffness and strength, cost effectiveness, corrosion and fatigue resistance, laminated composites have been widely used in many engineering applications, such as aircraft, automobiles, sporting products, and civil infrastructure. However, delamination damage along in‐plane interfaces has been one of the issues that still remain unsolved. Although many natural load‐bearing materials are also essentially laminated composites composed of mineral and organic phases, the underlying mechanisms for antidelamination are still largely unexplored. Here it is reported that the remarkable resistance to macroscopic indentation damage in the highly mineralized shell of the bivalve Placuna placenta originates from a characteristic nanoscale structural motif, i.e., screw dislocation‐like connection centers, which join adjacent mineral layers together in the laminate structure. This leads to the formation of a complex interconnected network of microcracks surrounding the damage zone, which allows for both efficient energy dissipation and damage localization even when the shell is completely penetrated. Both theoretical analysis and experiment‐based calculations suggest that the interfacial fracture toughness is enhanced by almost two orders of magnitude in comparison to classic laminated composites without connection centers. This design strategy for achieving a 3D integrative laminate architecture can be potentially applied in the design of advanced laminated composite materials.
Radiolabeled Polymeric Nanoconstructs Loaded with Docetaxel and Curcumin for Cancer Combinatorial Therapy and Nuclear Imaging
Authors: Stigliano Cinzia , Key Jaehong , Ramirez Maricela , Aryal Santosh , Decuzzi Paolo
Published: May 2015

Growing evidence suggests that multifaceted diseases as cancer can be effectively tackled by hitting simultaneously different biological targets and monitoring patient‐specific responses. Combinatorial therapies, relying on the administration of two or more molecules with different cytotoxic mechanisms, are rapidly progressing in the clinic. Here, 100 nm spherical polymeric nanoconstructs (SPNs) are proposed for the combinatorial treatment of tumors by codelivering a potent antimitotic drug—docetaxel (DTXL)—and a broad spectrum anti‐inflammatory molecule—curcumin (CURC). In vitro, SPNs loaded with DTXL and CURC induce a threefold decrease in IC50 as compared to DTXL‐loaded SPNs. This synergic antitumor effect is also significant in mouse models of glioblastoma multiforme, where, after 22 d of treatment, the combinatorial approach leads to complete disease regression. At 90 d post‐treatment initiation, mice injected with DTXL + CURC SPNs have a 100% survival, whereas only 50% of the DTXL SPN treated mice survive. SPNs are also labeled with radioactive 64Cu(DOTA) molecules to document, via PET imaging, the progressive tumor mass shrinkage. Sensitization of DTXL by CURC is associated with NF‐κB downregulation and increased apoptosis. These theranostic nanoconstructs could be used for combinatorial treatment and assessment of therapeutic efficacy in other malignancies.
Fast and Reversible Li Ion Insertion in Carbon‐Encapsulated Li3VO4 as Anode for Lithium‐Ion Battery
Authors: Zhang Changkun , Song Huanqiao , Liu Chaofeng , Liu Yaguang , Zhang Cuiping , Nan Xihui , Cao Guozhong
Published: May 2015

Carbon‐encapsulated Li3VO4 is synthesized by a facile environmentally benign solid‐state method with organic metallic precursor VO(C5H7O2)2 being chosen as both V and carbon sources yielding a core–shell nanostructure with lithium introduced in the subsequent annealing process. The Li3VO4 encapsulated with carbon presents exceeding rate capability (a reversible capability of 450, 340, 169, and 106 mAh g−1 at 0.1 C, 10 C, 50 C, and 80 C, respectively) and long cyclic performance (80% capacity retention after 2000 cycles at 10 C) as an anode in lithium‐ion batteries. The superior performance is derived from the structural features of the carbon‐encapsulated Li3VO4 composite with oxygen vacancies in Li3VO4, which increase surface energy and could possibly serve as a nucleation center, thus facilitating phase transitions. The in situ generated carbon shell not only facilitates electron transport, but also suppresses Li3VO4 particle growth during the calcination process. The encouraging results demonstrate the significant potential of carbon encapsulated Li3VO4 for high power batteries. In addition, the simple generic synthesis method is applicable to the fabrication of a variety of electrode materials for batteries and supercapacitors with unique core–shell structure with mesoporous carbon shell.
In Situ Synthesis of Graphene with Telecommunication Lasers for Nonlinear Optical Devices
Authors: Debnath Pulak C. , Park Jaehyun , Scott Austin M. , Lee Junsu , Lee Ju Han , Song Yong‐Won
Published: May 2015

Despite auspicious optical properties of graphene, particularly its ability to absorb light over a broad wavelength range, incorporating presynthesized graphene in optical system by recognized transfer methods has critical drawbacks of introducing impurities and damaging the graphene film which can affect the performance of optical system. Here a transfer‐free, in situ synthesis of multilayered graphene is demonstrated directly onto single‐mode optical fiber end facet and polished surface of D‐shaped fiber by interfacial growth process in ambient condition. Conventional telecommunication lasers operating at ≈1550 nm band are employed to provide the activation energy for carbon atoms to diffuse, precipitate through Ni‐catalyst layer, and form the graphene crystals at the interface of metal catalyst and optical fiber. The in situ grown graphene on optical fiber acts as saturable absorber in the fiber laser ring cavity to generate ultrafast optical pulses by mode‐locking technique. The formation and the quality of the resulting multilayered graphene are confirmed by precision analysis tools. The synthesized graphene has the sp2‐bond shares of 75.8% and it shows nonlinear optical absorption property with the modulation depth of 7%, guaranteeing passive mode‐locking of fiber laser operating in femtosecond scale.
Trinary Layered Double Hydroxides as High‐Performance Bifunctional Materials for Oxygen Electrocatalysis
Authors: Qian Li , Lu Zhiyi , Xu Tianhao , Wu Xiaochao , Tian Yang , Li Yaping , Huo Ziyang , Sun Xiaoming , Duan Xue
Published: May 2015

Layered double hydroxides (LDHs) are a family of high‐profile layer materials with tunable metal species and interlayer spacing, and herein the LDHs are first investigated as bifunctional electrocatalysts. It is found that trinary LDH containing nickel, cobalt, and iron (NiCoFe‐LDH) shows a reasonable bifunctional performance, while exploiting a preoxidation treatment can significantly enhance both oxygen reduction reaction and oxygen evolution reaction activity. This phenomenon is attributed to the partial conversion of Co2+ to Co3+ state in the preoxidation step, which stimulates the charge transfer to the catalyst surface. The practical application of the optimized material is demonstrated with a small potential hysteresis (800 mV for a reversible current density of 20 mA cm−2) as well as a high stability, exceeding the performances of noble metal catalysts (commercial Pt/C and Ir/C). The combination of the electrochemical metrics and the facile and cost‐effective synthesis endows the trinary LDH as a promising bifunctional catalyst for a variety of applications, such as next‐generation regenerative fuel cells or metal–air batteries.
Surface Mn Oxidation State Controlled Spinel LiMn2O4 as a Cathode Material for High‐Energy Li‐Ion Batteries
Authors: Jeong Minseul , Lee Min‐Joon , Cho Jaephil , Lee Sanghan
Published: May 2015

Spinel lithium manganese oxide (LiMn2O4) has attracted much attention as a promising cathode material for large‐scale lithium ion batteries. However, its continuous capacity fading at elevated temperature is an obstacle to extended cycling in large‐scale applications. Here, surface Mn oxidation state controlled LiMn2O4 is synthesized by coating stoichiometric LiMn2O4 with a cobalt‐substituted spinel, for which stoichiometric LiMn2O4 is used as the starting material and onto which a LixMnyCozO4 layer is coated from an acetate‐based precursor solution. In the coated material, the concentrations of both cobalt and Mn4+ ions vary from the surface to the core. the former without any lattice mismatch between the coating layer and host material. Cycle tests are performed under severe conditions, namely, high temperature and intermittent high current load. During the first discharge cycle at 7 C and 60 °C, a high energy and power density are measured for the coated material, 419 and 3.16 Wh kg−1, respectively, compared with 343 and 3.03 Wh kg−1, respectively, for the bare material. After 65 cycles under severe conditions, the coated material retains 82% and ≈100% of the initial energy and power density, respectively, whereas the bare material retains only ≈68% and ≈97% thereof.
A numerical‐indicator‐based method for design of distributed wastewater treatment systems with multiple contaminants
Authors: Li Ai‐Hong , Yang Yu‐Zhen , Liu Zhi‐Yong
Published: May 2015

In the design of distributed wastewater treatment systems with multiple contaminants, it is very important to minimize unnecessary stream mixing to reduce total treatment flow rate as much as possible. A new numerical indicator, total mixing influence potential (TMIP), to reflect the influence of the stream mixing caused by performing a process on the total treatment flow rate of a distributed wastewater system is introduced. In design procedure, the TMIP value is calculated based on pinch principle. The process with the smallest TMIP value will be performed first. The results of a few literature examples show that designs with very low (even minimum) total treatment flow rates can be obtained with the method proposed. In addition, the method proposed is simple and of clear engineering insight. The calculation effort does not increase significantly when the number of streams, contaminants, and/or treatment units increases. © 2015 American Institute of Chemical Engineers AIChE J, 61: 3223–3231, 2015
Individual and occupational characteristics associated with respiratory symptoms among latino horse farm workers
Authors: Swanberg Jennifer E. , Clouser Jessica Miller , Gan Wenqi , Mannino David M. , Flunker John C.
Published: May 2015

Background

Latino workers are likely exposed to a variety of respiratory hazards in the horse barn, yet the potential impact of these exposures on respiratory health has not been investigated.

Methods

Using a community‐based sample of 225 Latino horse farmworkers we investigated the prevalence of upper and lower respiratory symptoms and occupational characteristics associated with them. Multivariable logistic regression was used to identify factors associated with respiratory symptomology.

Results

Upper respiratory symptoms prevalence ranged from 24% to 45%. Half of workers reported lower respiratory symptoms. Workers with symptoms were more likely to be female and have lower levels of English understanding. Workers who never/rarely used dust masks while working in the barn experienced over two times the odds of reporting upper respiratory symptoms.

Conclusions

Many Latino horse workers experienced upper and lower respiratory symptoms. Dust mask use may protect workers in this and other enclosed livestock operations from respiratory symptoms. Am. J. Ind. Med. 58:679–687, 2015. © 2015 Wiley Periodicals, Inc.
Contrasting patterns of care for musculoskeletal disorders and injuries of the upper extremity and knee through workers' compensation and private health care insurance among union carpenters in Washington State, 1989 to 2008
Authors: Lipscomb Hester J. , Schoenfisch Ashley L. , Cameron Wilfrid , Kucera Kristen L. , Adams Darrin , Silverstein Barbara A.
Published: May 2015

Background

Musculoskeletal symptoms and disorders (MSDIs) are common reasons for visits to medical providers in the general population and they are common work‐related complaints. Prior reports raise concerns as to whether declines in workers' compensation (WC) rates represent true improvement in occupational health and safety or shifting of care to other payment systems.

Methods

By linking administrative records, we compared patterns of WC claims and private health care utilization for disorders of the upper extremity (UE) and knee among a large cohort of union carpenters over a 20‐year period.

Results

As WC claim rates declined, private health care utilization increased. The increase was muted somewhat but sustained when adjusting for other patterns of health care utilization.

Conclusions

Findings suggest the decline of WC claim rates do not solely represent improved occupational safety in this population, but also a considerable shifting of care to their private insurance coverage over time. Am. J. Ind. Med. 58:955–963, 2015. © 2015 Wiley Periodicals, Inc.
Extensively Reversible Thermal Transformations of a Bistable, Fluorescence‐Switchable Molecular Solid: Entry into Functional Molecular Phase‐Change Materials
Authors: Srujana P. , Radhakrishnan T. P.
Published: May 2015

Functional phase‐change materials (PCMs) are conspicuously absent among molecular materials in which the various attributes of inorganic solids have been realized. While organic PCMs are primarily limited to thermal storage systems, the amorphous–crystalline transformation of materials like Ge‐Sb‐Te find use in advanced applications such as information storage. Reversible amorphous–crystalline transformations in molecular solids require a subtle balance between robust supramolecular assembly and flexible structural elements. We report novel diaminodicyanoquinodimethanes that achieve this transformation by interlinked helical assemblies coupled with conformationally flexible alkoxyalkyl chains. They exhibit highly reversible thermal transformations between bistable (crystalline/amorphous) forms, along with a prominent switching of the fluorescence emission energy and intensity.
Reliable Quantitative SERS Analysis Facilitated by Core–Shell Nanoparticles with Embedded Internal Standards
Authors: Shen Wei , Lin Xuan , Jiang Chaoyang , Li Chaoyu , Lin Haixin , Huang Jingtao , Wang Shuo , Liu Guokun , Yan Xiaomei , Zhong Qiling , Ren Bin
Published: May 2015

Quantitative analysis is a great challenge in surface‐enhanced Raman scattering (SERS). Core‐molecule‐shell nanoparticles with two components in the molecular layer, a framework molecule to form the shell, and a probe molecule as a Raman internal standard, were rationally designed for quantitative SERS analysis. The signal of the embedded Raman probe provides effective feedback to correct the fluctuation of samples and measuring conditions. Meanwhile, target molecules with different affinities can be adsorbed onto the shell. The quantitative analysis of target molecules over a large concentration range has been demonstrated with a linear response of the relative SERS intensity versus the surface coverage, which has not been achieved by conventional SERS methods.
Kohlenhydrat‐basierte Nanocarrier mit spezifischem Zell‐Targeting und minimalem Einfluss durch die Proteinkorona
Authors: Kang Biao , Okwieka Patricia , Schöttler Susanne , Winzen Svenja , Langhanki Jens , Mohr Kristin , Opatz Till , Mailänder Volker , Landfester Katharina , Wurm Frederik R.
Published: May 2015

Sobald Nanopartikel mit biologischen Flüssigkeiten wie Blut in Kontakt kommen, adsorbieren Proteine auf ihrer Oberfläche, welche die sogenannte Proteinkorona ausbilden. Die Wichtigkeit dieser Proteinhülle ist weitgehend anerkannt, jedoch untersuchen nur wenige Studien den Einfluss von Oberflächenfunktionalisierung der Nanocarrier auf die Proteinkorona. Vor allem die Variation der Proteinkorona von PEGylierten und zusätzlich mit Targeting‐Molekülen versehenen Nanoträgern und der Einfluss auf das Targeting sind nicht bekannt. Hydroxyethylstärke‐Nanocarrier (HES‐NCs) wurden synthetisiert, anschließend PEGyliert und zusätzlich (“on top”) mit Mannose funktionalisiert, um dendritische Zellen (DCs) spezifisch anzusteuern. Die Wechselwirkungen mit menschlichem Plasma wurden untersucht: Niedrige Gesamtproteinabsorption mit einem ähnlichen Proteinmuster und eine hohe spezifische Bindungsaffinität zu DCs zeigen eine leistungsfähige Kombination von “Stealth”‐ und Targeting‐Verhalten.
A Crystalline Mesoporous Germanate with 48‐Ring Channels for CO2 Separation
Authors: Liang Jie , Su Jie , Luo Xiaodan , Wang Yingxia , Zheng Haoquan , Chen Hong , Zou Xiaodong , Lin Jianhua , Sun Junliang
Published: May 2015

One of the challenges in materials science has been to prepare crystalline inorganic compounds with mesopores. Although several design strategies have been developed to address the challenge, expansion of pore sizes in inorganic materials is more difficult compared to that for metal–organic frameworks. Herein, we designed a novel mesoporous germanate PKU‐17 with 3D 48×16×16‐ring channels by introducing two large building units (Ge10 and Ge7 clusters) into the same framework. The key for this design strategy is the selection of 2‐propanolamine (MIPA), which serves as the terminal species to promote the crystallization of Ge7 clusters. Moreover, it is responsible for the coexistence of Ge10 and Ge7 clusters. To our knowledge, the discovery of PKU‐17 sets a new record in pore sizes among germanates. It is also the first germanate that exhibits a good selectivity toward CO2 over N2 and CH4.
Asymmetric Synthesis of 1,3‐Butadienyl‐2‐carbinols by the Homoallenylboration of Aldehydes with a Chiral Phosphoric Acid Catalyst
Authors: Huang Yiyong , Yang Xing , Lv Zongchao , Cai Chen , Kai Cheng , Pei Yong , Feng Yu
Published: May 2015

Asymmetric C(sp)C(sp2) bond formation to give enantiomerically enriched 1,3‐butadienyl‐2‐carbinols occurred through a homoallenylboration reaction between a 2,3‐dienylboronic ester and aldehydes under the catalysis of a chiral phosphoric acid (CPA). A diverse range of enantiomerically enriched butadiene‐substituted secondary alcohols with aryl, heterocyclic, and aliphatic substituents were synthesized in very high yield with high enantioselectivity. Preliminary density functional theory (DFT) calculations suggest that the reaction proceeds via a cyclic six‐membered chairlike transition state with essential hydrogen‐bond activation in the allene reagent. The catalytic reaction was amenable to the gram‐scale synthesis of a chiral alkyl butadienyl adduct, which was converted into an interesting optically pure compound bearing a benzo‐fused spirocyclic cyclopentenone framework.
Palladium‐Assisted “Aromatic Metamorphosis” of Dibenzothiophenes into Triphenylenes
Authors: Vasu Dhananjayan , Yorimitsu Hideki , Osuka Atsuhiro
Published: May 2015

Two new palladium‐catalyzed reactions of aromatic sulfur compounds enabled the conversion of dibenzothiophenes into triphenylenes in four steps. This transformation of one aromatic framework into another consists of 1) 4‐chlorobutylation of the dibenzothiophene to form the corresponding sulfonium salt, 2) palladium‐catalyzed arylative ring opening of the sulfonium salt with a sodium tetraarylborate, 3) an intramolecular SN2 reaction to form a teraryl sulfonium salt, and 4) palladium‐catalyzed intramolecular CS/CH coupling through electrophilic palladation. Symmetrical as well as unsymmetrical triphenylenes of interest were synthesized in a tailor‐made fashion in satisfactory overall yields.
Carbohydrate‐Based Nanocarriers Exhibiting Specific Cell Targeting with Minimum Influence from the Protein Corona
Authors: Kang Biao , Okwieka Patricia , Schöttler Susanne , Winzen Svenja , Langhanki Jens , Mohr Kristin , Opatz Till , Mailänder Volker , Landfester Katharina , Wurm Frederik R.
Published: May 2015

Whenever nanoparticles encounter biological fluids like blood, proteins adsorb on their surface and form a so‐called protein corona. Although its importance is widely accepted, information on the influence of surface functionalization of nanocarriers on the protein corona is still sparse, especially concerning how the functionalization of PEGylated nanocarriers with targeting agents will affect protein corona formation and how the protein corona may in turn influence the targeting effect. Herein, hydroxyethyl starch nanocarriers (HES‐NCs) were prepared, PEGylated, and modified on the outer PEG layer with mannose to target dendritic cells (DCs). Their interaction with human plasma was then studied. Low overall protein adsorption with a distinct protein pattern and high specific affinity for DC binding were observed, thus indicating an efficient combination of “stealth” and targeting behavior.
Gold nanoparticles supported on three‐dimensional nitrogen‐doped graphene: an efficient catalyst for selective aerobic oxidation of hydrocarbons under mild conditions
Authors: Mahyari Mojtaba , Laeini Mohammad Sadegh , Shaabani Ahmad , Kazerooni Hanif
Published: May 2015

The development of efficient and selective aerobic oxidation of alkylarenes to form more functional compounds by heterogeneously catalysed routes still presents a great challenge in the fine chemical industry and is a major research topic. In this work, gold nanoparticles supported on three‐dimensional nitrogen‐doped graphene‐based frameworks (Au NPs@3D‐(N)GFs) were successfully synthesized and found to have an impressive performance as bifunctional catalysts (nitrogen dopant as base and gold nanoparticles as active site) in the controlled oxidation of alkylarenes. The catalyst was found to be a simple bench top, stable, recyclable and selective catalytic system for the aerobic oxidation of various types of alkylarenes into their corresponding ketones at room temperature under environmentally friendly conditions with good yields and high selectivity. Copyright © 2015 John Wiley & Sons, Ltd.
Study on properties of natural rubber reinforced by poly(sodium‐4‐styrenesulfonate)‐decorated carbon black with a latex compounding technique
Authors: Jin Shenbo , Mao Yapeng , Li Qiuying , Wu Chifei
Published: May 2015

Natural rubber filled with poly(sodium‐4‐styrenesulfonate) (PSS)‐decorated carbon black (CB) by employing a latex compounding technique was prepared. The result of scanning electron microscope demonstrated that CB was uniformly dispersed in the matrix. Comparing to traditional dry compounding, an improvement in physical and mechanical properties was observed in the composites attributed to the homogeneous distribution of CB in matrix and an augment of bound rubber. Owing to the changes of the physical properties of CB surface, vulcanizate filled with oxidized CB via latex way exhibited higher mechanical properties. The resulting vulcanizates displayed a diminished interaction between fillers based on the consequence of strain dependence of storage modulus. Furthermore, a splendid wet‐skid resistance was obtained in vulcanizates fabricated by latex compounding technique in comparison with vulcanizates prepared by traditional dry compounding. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42346.
Rational Modification of the Biological Profile of GPCR Ligands through Combination with Other Biologically Active Moieties
Authors: Huang Guozheng , Nimczick Martin , Decker Michael
Published: May 2015

In recent years, G protein‐coupled receptor (GPCR) ligands have not only been modified by conducting structure–activity relationship studies of leads and known ligands, but several new approaches have emerged in which GPCR ligands were connected or merged with other biologically active molecules. Identical or related ligands were combined to bivalent ones. Orthosteric ligands were combined with allosteric ligands, sometimes leading to dualsteric ones, and also chemical structures were merged to dual‐acting or multifunctional compounds. In this article, we want to present some representative examples for these approaches at different GPCRs, showing the versatility of this approach, with a focus on our own work and references to related articles and reviews.
What Comes First? Multitissue Involvement Leading to Radiographic Osteoarthritis: Magnetic Resonance Imaging–Based Trajectory Analysis Over Four Years in the Osteoarthritis Initiative
Authors: Roemer Frank W. , Kwoh C. Kent , Hannon Michael J. , Hunter David J. , Eckstein Felix , Fujii Tomoko , Boudreau Robert M. , Guermazi Ali
Published: May 2015

Objective

To assess whether the presence of structural osteoarthritis (OA) features over as many as 4 years prior to incident radiographic OA increases the risk of radiographic OA in a nested, case–control design.

Methods

We studied 355 knees from the Osteoarthritis Initiative cohort that developed radiographic OA before the 48‐month visit. They were matched one‐to‐one by sex, age, and contralateral knee radiographic status with a control knee. Magnetic resonance images (MRIs) were read for bone marrow lesions (BMLs), cartilage damage, meniscal damage (including tears and extrusion), Hoffa synovitis, and effusion synovitis. Conditional logistic regression was applied to assess the risk of radiographic OA with regard to the presence of BMLs (score ≥2), cartilage lesions (score ≥1.1), meniscal damage (any) and extrusion of ≥3 mm ± (score ≥2), and Hoffa and effusion synovitis (any). Time points were defined as incident radiographic OA visit (P0), 1 year prior to the detection of radiographic OA (P −1), 2 years prior to the detection of radiographic OA (P −2), etc.

Results

The presence of Hoffa synovitis (hazard ratio [HR] 1.76 [95% confidence interval (95% CI) 1.18–2.64]), effusion synovitis (HR 1.81 [95% CI 1.18–2.78]), and medial meniscal damage (HR 1.83 [95% CI 1.17–2.89]) at P −2 predicted radiographic OA incidence. At P −1, all features but meniscal extrusion predicted radiographic OA, with highest odds for medial BMLs (HR 6.50 [95% CI 2.27–18.62]) and effusion synovitis (HR 2.50 [95% CI 1.76–3.54]). The findings at P −3 and P −4 did not reach statistical significance.

Conclusion

Our findings indicate that the presence of specific structural features of MRI‐detected joint damage 2 years prior to incident radiographic OA increases the risk of incident radiographic OA. However, 1 year prior to radiographic OA, the presence of almost any abnormal morphologic feature increases the risk of radiographic OA in the subsequent year.
Genome‐Wide Mapping of DNA Hydroxymethylation in Osteoarthritic Chondrocytes
Authors: Taylor Sarah E. B. , Li Ye Henry , Wong Wing H. , Bhutani Nidhi
Published: May 2015

Objective

To examine the genome‐wide distribution of hydroxymethylated cytosine (5hmC) in osteoarthritic (OA) and normal chondrocytes in order to investigate the effect on OA‐specific gene expression.

Methods

Cartilage was obtained from OA patients undergoing total knee arthroplasty or from control patients undergoing anterior cruciate ligament reconstruction. Genome‐wide sequencing of 5hmC‐enriched DNA was performed in a small cohort of normal and OA chondrocytes to identify differentially hydroxymethylated regions (DhMRs) in OA chondrocytes. Data from the genome‐wide sequencing of 5hmC‐enriched DNA were intersected with global OA gene expression data to define subsets of genes and pathways potentially affected by increased 5hmC levels in OA chondrocytes.

Results

A total of 70,591 DhMRs were identified in OA chondrocytes as compared to normal chondrocytes, 44,288 (63%) of which were increased in OA chondrocytes. The majority of DhMRs (66%) were gained in gene bodies. Increased DhMRs were observed in ∼50% of genes previously implicated in OA pathology including MMP3, LRP5, GDF5, and COL11A1. Furthermore, analyses of gene expression data revealed gene body gain of 5hmC appears to be preferentially associated with activated, but not repressed, genes in OA chondrocytes.

Conclusion

This study provides the first genome‐wide profiling of 5hmC distribution in OA chondrocytes. We had previously reported a global increase in 5hmC levels in OA chondrocytes. Gain of 5hmC in the gene body is found to be characteristic of activated genes in OA chondrocytes, highlighting the influence of 5hmC as an epigenetic mark in OA. In addition, this study identifies multiple OA‐associated genes that are potentially regulated either singularly by gain of DNA hydroxymethylation or in combination with loss of DNA methylation.
Mitochondrial Biogenesis Is Impaired in Osteoarthritis Chondrocytes but Reversible via Peroxisome Proliferator–Activated Receptor γ Coactivator 1α
Authors: Wang Yun , Zhao Xianling , Lotz Martin , Terkeltaub Robert , Liu‐Bryan Ru
Published: May 2015

Objective

The etiology of chondrocyte mitochondrial dysfunction in osteoarthritis (OA) is not completely understood. OA chondrocytes are deficient in the metabolic biosensors active AMP‐activated protein kinase (AMPK) and sirtuin 1 (SIRT‐1), which modulate the mitochondrial biogenesis “master regulator” peroxisome proliferator–activated receptor γ coactivator 1α (PGC‐1α). Moreover, PGC‐1α critically mediates AMPK anticatabolic activity in chondrocytes. The aim of this study was to test the hypothesis that mitochondrial biogenesis is deficient in human OA chondrocytes and that this deficiency functionally increases chondrocyte procatabolic responses, which are reversed by activation of the AMPK/SIRT‐1/PGC‐1α pathway.

Methods

We assessed the expression and activity (phosphorylation) of AMPKα, SIRT‐1, and PGC‐1α in human knee chondrocytes and human and mouse knee cartilage, and we defined and compared the content and function of mitochondria, including oxidative phosphorylation and expression of mitochondrial biogenesis factors (mitochondrial transcriptional factor A [TFAM] and nuclear respiratory factors [NRFs]).

Results

Human knee OA chondrocytes had a decreased mitochondrial biogenesis capacity, which was linked to reduced AMPKα activity and decreased expression of SIRT‐1, PGC‐1α, TFAM, NRF‐1, and NRF‐2. Human knee OA and aging mouse knee cartilage had decreased expression of TFAM and ubiquinol–cytochrome c reductase core protein, a subunit of mitochondrial complex III, in situ. Chondrocyte TFAM knockdown inhibited mitochondrial biogenesis and enhanced procatabolic responses to interleukin‐1β. Finally, activation of AMPK by A‐769662 increased PGC‐1α expression via SIRT‐1 and reversed impairments in mitochondrial biogenesis, oxidative phosphorylation, and intracellular ATP in human knee OA chondrocytes.

Conclusion

Mitochondrial biogenesis is deficient in human OA chondrocytes, and this deficiency promotes chondrocyte procatabolic responses. TFAM‐mediated activation of the AMPK/SIRT‐1/PGC‐1α pathway reverses these effects, suggesting translational potential of pharmacologic AMPK activators to limit OA progression.
Clinical Characterization of Antiphospholipid Syndrome by Detection of IgG Antibodies Against β2‐Glycoprotein I Domain 1 and Domain 4/5: Ratio of Anti–Domain 1 to Anti–Domain 4/5 As a Useful New Biomarker for Antiphospholipid Syndrome
Authors: Andreoli Laura , Chighizola Cecilia B. , Nalli Cecilia , Gerosa Maria , Borghi M. Orietta , Pregnolato Francesca , Grossi Claudia , Zanola Alessandra , Allegri Flavio , Norman Gary L. , Mahler Michael , Meroni Pier Luigi , Tincani Angela
Published: May 2015

Objective

It has been suggested that only antibodies against domain 1 (D1) of β2‐glycoprotein I (β2GPI) are pathogenic and diagnostic. The role of antibodies against other β2GPI domains is still debated. This study was undertaken to evaluate the clinical relevance of domain specificity profiling of anti‐β2GPI IgG antibodies in antiphospholipid syndrome (APS) patients and in control groups of patients with systemic autoimmune rheumatic diseases and in asymptomatic antiphospholipid antibody (aPL) carriers.

Methods

We evaluated 159 subjects with persistently positive, medium or high‐titer anti‐β2GPI IgG, including 56 patients with thrombotic (obstetric or nonobstetric) primary APS, 31 women with obstetric primary APS, 42 aPL‐positive patients with systemic autoimmune rheumatic diseases, and 30 asymptomatic aPL carriers. One hundred healthy donors were included. Anti‐β2GPI D1 and D4/5 IgG were tested on research enzyme‐linked immunosorbent assays containing recombinant β2GPI domains.

Results

As compared to other groups, aPL carriers displayed higher frequency/titer of anti‐D4/5 IgG. Unlike anti‐D4/5, anti‐D1 IgG antibodies were more frequent and at higher titer in triple than in single or double aPL‐positive subjects. An anti‐D1 to anti‐D4/5 ratio of ≥1.5 was predictive of systemic autoimmunity (odds ratio 3.25 [95% confidence interval 1.45–7.49], P = 0.005). Neither anti‐D1 nor anti‐D4/5 antibodies were associated with APS clinical criteria.

Conclusion

Anti‐D1 IgG is the preferential specificity not only in vascular and obstetric primary APS, but also in patients with systemic autoimmune rheumatic disease with no clinical features of APS. Conversely, aPL carriers do not have a polarized profile toward D1. Combined testing for anti‐β2GPI IgG with different domain specificity allows a more accurate aPL profiling, with polarization toward anti‐D1 IgG as a possible fingerprint of systemic autoimmunity.
Observations of fire‐induced turbulence regimes during low‐intensity wildland fires in forested environments: implications for smoke dispersion
Authors: Heilman Warren E. , Clements Craig B. , Seto Daisuke , Bian Xindi , Clark Kenneth L. , Skowronski Nicholas S. , Hom John L.
Published: May 2015

Low‐intensity wildland fires occurring beneath forest canopies can result in particularly adverse local air‐quality conditions. Ambient and fire‐induced turbulent circulations play a substantial role in the transport and dispersion of smoke during these fire events. Recent in situ measurements of fire–atmosphere interactions during low‐intensity wildland fires have provided new insight into the structure of fire‐induced turbulence regimes and how forest overstory vegetation can affect the horizontal and vertical dispersion of smoke. In this paper, we provide a summary of the key turbulence observations made during two low‐intensity wildland fire events that occurred in the New Jersey Pine Barrens.