bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamic Fragmentation of Jointed Rock Blocks During Rockslide‐Avalanches: Insights From Discrete Element Analyses
Authors: Zhao Tao , Crosta Giovanni Battista , Dattola Giuseppe , Utili Stefano 
Published: March 2018

AbstractThe dynamic fragmentation of jointed rock blocks during rockslide avalanches has been investigated by discrete element method simulations for a multiple arrangement of a rock block sliding over a simple slope geometry. The rock blocks are released along an inclined sliding plane and subsequently collide onto a flat horizontal plane at a sharp kink point. The contact force chains generated by the impact appear initially at the bottom frontal corner of the rock block and then propagate radially upward to the top rear part of the block. The jointed rock blocks exhibit evident contact force concentration and discontinuity of force wave propagation near the joint, associating with high energy dissipation of granular dynamics. The corresponding force wave propagation velocity can be less than 200 m/s, which is much smaller than that of an intact rock (1,316 m/s). The concentration of contact forces at the bottom leads to high rock fragmentation intensity and momentum boosts, facilitating the spreading of many fine fragments to the distal ends. However, the upper rock block exhibits very low rock fragmentation intensity but high energy dissipation due to intensive friction and damping, resulting in the deposition of large fragments near the slope toe. The size and shape of large fragments are closely related to the orientation and distribution of the block joints. The cumulative fragment size distribution can be well fitted by the Weibull's distribution function, with very gentle and steep curvatures at the fine and coarse size ranges, respectively. The numerical results of fragment size distribution can match well some experimental and field observations.
Wave Attenuation and Gas Exchange Velocity in Marginal Sea Ice Zone
Authors: Bigdeli A. , Hara T. , Loose B. , Nguyen A. T. 
Published: March 2018

AbstractThe gas transfer velocity in marginal sea ice zones exerts a strong control on the input of anthropogenic gases into the ocean interior. In this study, a sea state‐dependent gas exchange parametric model is developed based on the turbulent kinetic energy dissipation rate. The model is tuned to match the conventional gas exchange parametrization in fetch‐unlimited, fully developed seas. Next, fetch limitation is introduced in the model and results are compared to fetch limited experiments in lakes, showing that the model captures the effects of finite fetch on gas exchange with good fidelity. Having validated the results in fetch limited waters such as lakes, the model is next applied in sea ice zones using an empirical relation between the sea ice cover and the effective fetch, while accounting for the sea ice motion effect that is unique to sea ice zones. The model results compare favorably with the available field measurements. Applying this parametric model to a regional Arctic numerical model, it is shown that, under the present conditions, gas flux into the Arctic Ocean may be overestimated by 10% if a conventional parameterization is used.
The Roles of Convection Parameterization in the Formation of Double ITCZ Syndrome in the NCAR CESM: I. Atmospheric Processes
Authors: Song Xiaoliang , Zhang Guang J. 
Published: March 2018

AbstractSeveral improvements are implemented in the Zhang‐McFarlane (ZM) convection scheme to investigate the roles of convection parameterization in the formation of double intertropical convergence zone (ITCZ) bias in the NCAR CESM1.2.1. It is shown that the prominent double ITCZ biases of precipitation, sea surface temperature (SST), and wind stress in the standard CESM1.2.1 are largely eliminated in all seasons with the use of these improvements in convection scheme. This study for the first time demonstrates that the modifications of convection scheme can eliminate the double ITCZ biases in all seasons, including boreal winter and spring. Further analysis shows that the elimination of the double ITCZ bias is achieved not by improving other possible contributors, such as stratus cloud bias off the west coast of South America and cloud/radiation biases over the Southern Ocean, but by modifying the convection scheme itself. This study demonstrates that convection scheme is the primary contributor to the double ITCZ bias in the CESM1.2.1, and provides a possible solution to the long‐standing double ITCZ problem. The atmospheric model simulations forced by observed SST show that the original ZM convection scheme tends to produce double ITCZ bias in high SST scenario, while the modified convection scheme does not. The impact of changes in each core component of convection scheme on the double ITCZ bias in atmospheric model is identified and further investigated.
Modeling Global Ocean Biogeochemistry With Physical Data Assimilation: A Pragmatic Solution to the Equatorial Instability
Authors: Park Jong‐Yeon , Stock Charles A. , Yang Xiaosong , Dunne John P. , Rosati Anthony , John Jasmin , Zhang Shaoqing 
Published: March 2018

AbstractReliable estimates of historical and current biogeochemistry are essential for understanding past ecosystem variability and predicting future changes. Efforts to translate improved physical ocean state estimates into improved biogeochemical estimates, however, are hindered by high biogeochemical sensitivity to transient momentum imbalances that arise during physical data assimilation. Most notably, the breakdown of geostrophic constraints on data assimilation in equatorial regions can lead to spurious upwelling, resulting in excessive equatorial productivity and biogeochemical fluxes. This hampers efforts to understand and predict the biogeochemical consequences of El Niño and La Niña. We develop a strategy to robustly integrate an ocean biogeochemical model with an ensemble coupled‐climate data assimilation system used for seasonal to decadal global climate prediction. Addressing spurious vertical velocities requires two steps. First, we find that tightening constraints on atmospheric data assimilation maintains a better equatorial wind stress and pressure gradient balance. This reduces spurious vertical velocities, but those remaining still produce substantial biogeochemical biases. The remainder is addressed by imposing stricter fidelity to model dynamics over data constraints near the equator. We determine an optimal choice of model‐data weights that removed spurious biogeochemical signals while benefitting from off‐equatorial constraints that still substantially improve equatorial physical ocean simulations. Compared to the unconstrained control run, the optimally constrained model reduces equatorial biogeochemical biases and markedly improves the equatorial subsurface nitrate concentrations and hypoxic area. The pragmatic approach described herein offers a means of advancing earth system prediction in parallel with continued data assimilation advances aimed at fully considering equatorial data constraints.
Episodic Reversal of Autumn Ice Advance Caused by Release of Ocean Heat in the Beaufort Sea
Authors: Smith Madison , Stammerjohn Sharon , Persson Ola , Rainville Luc , Liu Guoqiang , Perrie William , Robertson Robin , Jackson Jennifer , Thomson Jim 
Published: March 2018

AbstractHigh‐resolution measurements of the air‐ice‐ocean system during an October 2015 event in the Beaufort Sea demonstrate how stored ocean heat can be released to temporarily reverse seasonal ice advance. Strong on‐ice winds over a vast fetch caused mixing and release of heat from the upper ocean. This heat was sufficient to melt large areas of thin, newly formed pancake ice; an average of 10 MJ/m2 was lost from the upper ocean in the study area, resulting in ∼3–5 cm pancake sea ice melt. Heat and salt budgets create a consistent picture of the evolving air‐ice‐ocean system during this event, in both a fixed and ice‐following (Lagrangian) reference frame. The heat lost from the upper ocean is large compared with prior observations of ocean heat flux under thick, multiyear Arctic sea ice. In contrast to prior studies, where almost all heat lost goes into ice melt, a significant portion of the ocean heat released in this event goes directly to the atmosphere, while the remainder (∼30–40%) goes into melting sea ice. The magnitude of ocean mixing during this event may have been enhanced by large surface waves, reaching nearly 5 m at the peak, which are becoming increasingly common in the autumn Arctic Ocean. The wave effects are explored by comparing the air‐ice‐ocean evolution observed at short and long fetches, and a common scaling for Langmuir turbulence. After the event, the ocean mixed layer was deeper and cooler, and autumn ice formation resumed.
Designer Exosomes for Active Targeted Chemo‐Photothermal Synergistic Tumor Therapy
Authors: Wang Jie , Dong Yue , Li Yiwei , Li Wei , Cheng Kai , Qian Yuan , Xu Guoqiang , Zhang Xiaoshuai , Hu Liang , Chen Peng , Du Wei , Feng Xiaojun , Zhao Yuan‐Di , Zhang Zhihong , Liu Bi‐Feng 
Published: March 2018

AbstractExosomes, naturally derived nanovesicles secreted from various cell types, can serve as an effective platform for the delivery of various cargoes, because of their intrinsic ability such as long blood circulation and immune escapinge. However, unlike conventional synthetic nanoparticles, drug release from exosomes at defined targets is not controllable. Moreover, endowing exosomes with satisfactory cancer‐targeting ability is highly challenging. Here, for the first time, a biological and synthetic hybrid designer exosome is described with photoresponsive functionalities based on a donor cell‐assisted membrane modification strategy. Practically, the designer exosome effectively accumulates at target tumor sites via dual ligand‐mediated endocytosis. Then the localized hyperthermia induced by the conjunct gold nanorods under near‐infrared irradiation impacts the permeability of exosome membrane to enhance drug release from exosomes, thus inhibiting tumor relapse in a programmable manner. The designer exosome combines the merits of both synthetic materials and the natural nanovesicles. It not only preserves the intrinsic functionalities of native exosome, but also gains multiple abilities for efficient tumor targeting, controlled release, and thermal therapy like synthetic nanocarriers. The versatile designer exosome can provide functional platforms by engineering with more multifarious functionalities from synthetic materials to achieve individualized precise cancer therapy in the future.
Electrophoretic Nuclei Assembly for Crystallization of High‐Performance Membranes on Unmodified Supports
Authors: He Guangwei , Dakhchoune Mostapha , Zhao Jing , Huang Shiqi , Agrawal Kumar Varoon 
Published: March 2018

AbstractMetal–organic framework (MOF) films have recently emerged as highly permselective membranes yielding orders of magnitude higher gas permeance than that from the conventional membranes. However, synthesis of highly intergrown, ultrathin MOF films on porous supports without complex support‐modification has proven to be a challenge. Moreover, there is an urgent need of a generic crystallization route capable of synthesizing a wide range of MOF structures in an intergrown, thin‐film morphology. Herein, a novel electrophoretic nuclei assembly for crystallization of highly intergrown thin‐films (ENACT) approach, that allows synthesis of ultrathin, defect‐free ZIF‐8 on a wide range of unmodified supports (porous polyacrylonitrile, anodized aluminum oxide, metal foil, porous carbon and graphene), is reported. As a result, a remarkably high H2 permeance of 8.3 × 10−6 mol m−2 s−1 Pa−1 and ideal gas selectivities of 7.3, 15.5, 16.2, and 2655 for H2/CO2, H2/N2, H2/CH4, and H2/C3H8, respectively, are achieved from an ultrathin (500 nm thick) ZIF‐8 membrane. A high C3H6 permeance of 9.9 × 10−8 mol m−2 s−1 Pa−1 and an attractive C3H6/C3H8 selectivity of 31.6 are obtained. The ENACT approach is straightforward, reproducible and can be extended to a wide range of nanoporous crystals, and its application in the fabrication of intergrown ZIF‐7 films is demonstrated.
Metal–Organic Framework as a Simple and General Inert Nanocarrier for Photosensitizers to Implement Activatable Photodynamic Therapy
Authors: Hu Fang , Mao Duo , Kenry  , Wang Yuxiang , Wu Wenbo , Zhao Dan , Kong Deling , Liu Bin 
Published: March 2018

AbstractThere has been a surging interest in the synthesis of activatable photosensitizers (PSs) as they can be selectively activated with minimum nonspecific phototoxic damages for photodynamic therapy (PDT). Conventional strategies to realize activatable PSs are only applicable to a limited number of molecules. Herein, a simple and general strategy to yield activatable PSs by coupling MIL‐100 (Fe) (MIL: Materials Institute Lavoisier) with different kinds of PSs is presented. Specifically, when PSs are encapsulated into MIL‐100 (Fe), the photosensitization capability is suppressed due to their isolation from O2. After the reaction between iron(III) in MIL‐100 (Fe) and H2O2 occurs, the framework of MIL‐100 (Fe) collapses and the encapsulated PSs regain contact with O2, leading to activation of photosensitization. In addition, the decomposition of H2O2 can generate O2 to relieve tumor hypoxia and enhance PDT effect. As O2 is an indispensable factor for PDT, the activation strategy should be generally applicable to different PSs for activatable PDT.
Nanofibered Gelatin‐Based Nonwoven Elasticity Promotes Epithelial Histogenesis
Authors: Jedrusik Nicole , Meyen Christoph , Finkenzeller Günter , Stark G. Björn , Meskath Stephan , Schulz Simon Daniel , Steinberg Thorsten , Eberwein Philipp , Strassburg Sandra , Tomakidi Pascal 
Published: March 2018

AbstractRegarding tissue regeneration, mechanics of biomaterials gains progressive importance. Therefore, this study reports on in situ crosslinked electrospun gelatin nonwoven mats (NWMs) whose distinct modulus of elasticity (ME) promotes epithelial tissue formation in a graded manner. NWMs, comprising fiber diameters in various distributions, yield an ME of about 2.1, 3.2, and 10.9 kPa. A two‐step approach of preclinical in vitro validation identifies the elasticity of 3.2 kPa as superior to the other, regarding the histogenetic epithelial outcome. Hence, this 3.2 kPa candidate NWM is colonized with oral mucosal epithelial keratinocytes in the absence or presence of mesenchymal fibroblasts and/or endothelial cells. Evaluation of epithelial histogenesis at days 1 to 10 occurs by colorimetric and fluorescence‐based immunohistochemistry (IHCH) of specific biomarkers. These include cytokeratins (CK) 14, CK1, and involucrin that indicate different stages of epithelial differentiation, as well as the basement membrane constituent collagen type IV and Ki‐67 as a proliferation marker. Intriguingly, histogenesis and IHCH reveal the best resemblance of the native epithelium by the NWM alone, irrespective of other cell counterparts. These findings prove the gelatin NWM a convenient cell matrix, and evidence that NWM mechanics is important to promote epithelial histogenesis in view of prospective clinical applications.
Sonochemistry‐Assembled Stimuli‐Responsive Polymer Microcapsules for Drug Delivery
Authors: Li Zhanfeng , Wang Zonghua , Du Xiaoyu , Shi Chao , Cui Xuejun 
Published: March 2018

AbstractStimuli‐responsive polymer microcapsules (PMs) fabricated by the sonochemical method have emerged for developing useful drug delivery systems, and the latest developments are mainly focusing on the synthetic strategies and properties such as structure, size, stability, loading capacity, drug delivery, and release. There, the primary attribution of sonochemistry is to offer a simple and practical approach for the preparation of PMs. Structure, size, stability, and properties of PMs are designed mainly according to synthetic materials, implementation schemes, or specific demands. Numerous functionalities of PMs based on different stimuli are demonstrated: targeting motion in a magnetic field or adhering to the living cells with sensitive sites through molecular recognition, and stimuli‐triggered release including enzymatic catalysis, chemical reaction as well as physical or mechanical process. The current review discusses the basic principles and mechanisms of stimuli effects, and describes the progress in the application such as targeted drug systems and controlled drug systems, and also gives an outlook on the future challenges and opportunities for drug delivery and theranostics.
NanoTRAIL‐Oncology: A Strategic Approach in Cancer Research and Therapy
Authors: Shi Yesi , Pang Xin , Wang Junqing , Liu Gang 
Published: March 2018

AbstractTRAIL is a member of the tumor necrosis factor superfamily that can largely trigger apoptosis in a wide variety of cancer cells, but not in normal cells. However, insufficient exposure to cancer tissues or cells and drug resistance has severely impeded the clinical application of TRAIL. Recently, nanobiotechnology has brought about a revolution in advanced drug delivery for enhanced anticancer therapy using TRAIL. With the help of materials science, immunology, genetic engineering, and protein engineering, substantial progress is made by expressing fusion proteins with TRAIL, engineering TRAIL on biological membranes, and loading TRAIL into functional nanocarriers or conjugating it onto their surfaces. Thus, the nanoparticle‐based TRAIL (nanoTRAIL) opens up intriguing opportunities for efficient and safe bioapplications. In this review, the mechanisms of action and biological function of TRAIL, as well as the current status of TRAIL treatment, are comprehensively discussed. The application of functional nanotechnology combined with TRAIL in cancer therapy is also discussed.
Nanomeshes at Liquid Interfaces: From Free‐Standing Hole Arrays toward Metal–Insulator–Metal Architectures
Authors: Stelling Christian , Retsch Markus 
Published: March 2018

AbstractThe superior optical properties of metamaterials often rely on hierarchical structures in the sub‐wavelength regime comprising stacks of individually patterned layers. For the fabrication of metamaterials in the visible regime, specific top‐down lithographic methods have been developed. These techniques, however, have several inherent drawbacks such the lack of scalability and low production speeds. Here, a simple and modular approach for the construction of multilayer metal–insulator–metal structures based on the transfer of metal nanohole arrays via liquid interfaces is demonstrated. Gold nanohole arrays are used as model systems that are prepared via nanosphere lithography on a zinc oxide sacrificial layer. Exploiting an interface mediated method, the prepared nanohole arrays are subsequently transferred onto arbitrary hydrophilic or hydrophobic substrates without compromising the high quality of the nanomeshes. Two approaches to stack such nanostructured layers with nanometer precision in a rapid way are demonstrated. Finally, the high mechanical stability of only 100 nm thick gold nanohole arrays allows for the preparation of free‐standing nanomeshes in the order of several hundreds of square‐micrometers.
vasQchip: A Novel Microfluidic, Artificial Blood Vessel Scaffold for Vascularized 3D Tissues
Authors: Kappings Vanessa , Grün Christoph , Ivannikov Darja , Hebeiss Isabella , Kattge Saskia , Wendland Ina , Rapp Bastian E. , Hettel Matthias , Deutschmann Olaf , Schepers Ute 
Published: March 2018

AbstractTo date, tissue engineering and organ‐on‐a‐chip devices become more powerful as replacements for animal testings in high throughput drug screenings. However, the majority of the devices are either based on static 2D or 3D cell cultures or on microfluidic channel systems that are usually rectangular and do not fit to the geometry of natural blood vessels. Therefore, a semicircular microfluidic blood vessel scaffold (vasQchip) with a surrounding microfluidic compartment for vascularized 3D cell culture was developed, which resembles the curvature of natural blood vessels. vasQchip is composed of a porous microchannel which is produced by micro‐thermoforming of polycarbonate membranes. The pores generated by ion track technology allow for the support of nutrients and gases as well as for the exchange of growth factors or immune cells with the surrounding compartment. Eventually the surrounding compartment can be used for the establishment of 3D cell cultures in order to reconstruct vascularized tissues. Here, the vasQchip for its biocompatibility is characterized to somatic primary cells, the diffusion of molecules through the artificial blood vessels and its suitability for 3D cell culture. In addition, shear stress and flow regimes are simulated in order to mimic the natural environment of vascularized tissues.
Tailoring Surface Frustrated Lewis Pairs of In2O3−x(OH)y for Gas‐Phase Heterogeneous Photocatalytic Reduction of CO2 by Isomorphous Substitution of In3+ with Bi3+
Authors: Dong Yuchan , Ghuman Kulbir Kaur , Popescu Radian , Duchesne Paul N. , Zhou Wenjie , Loh Joel Y. Y. , Ali Feysal M. , Jia Jia , Wang Di , Mu Xiaoke , Kübel Christian , Wang Lu , He Le , Ghoussoub Mireille , Wang Qiang , Wood Thomas E. , Reyes Laura M. , Zhang Peng , Kherani Nazir P. , Singh Chandra Veer , Ozin Geoffrey A. 
Published: March 2018

AbstractFrustrated Lewis pairs (FLPs) created by sterically hindered Lewis acids and Lewis bases have shown their capacity for capturing and reacting with a variety of small molecules, including H2 and CO2, and thereby creating a new strategy for CO2 reduction. Here, the photocatalytic CO2 reduction behavior of defect‐laden indium oxide (In2O3−x(OH)y) is greatly enhanced through isomorphous substitution of In3+ with Bi3+, providing fundamental insights into the catalytically active surface FLPs (i.e., InOH···In) and the experimentally observed “volcano” relationship between the CO production rate and Bi3+ substitution level. According to density functional theory calculations at the optimal Bi3+ substitution level, the 6s2 electron pair of Bi3+ hybridizes with the oxygen in the neighboring InOH Lewis base site, leading to mildly increased Lewis basicity without influencing the Lewis acidity of the nearby In Lewis acid site. Meanwhile, Bi3+ can act as an extra acid site, serving to maximize the heterolytic splitting of reactant H2, and results in a more hydridic hydride for more efficient CO2 reduction. This study demonstrates that isomorphous substitution can effectively optimize the reactivity of surface catalytic active sites in addition to influencing optoelectronic properties, affording a better understanding of the photocatalytic CO2 reduction mechanism.
Reduction of Parasitic Capacitance in Indium‐Gallium‐Zinc Oxide (a‐IGZO) Thin‐Film Transistors (TFTs) without Scarifying Drain Currents by Using Stripe‐Patterned Source/Drain Electrodes
Authors: Lee Suhui , Chen Yuanfeng , Jeon Jaekwon , Park Chanju , Jang Jin 
Published: March 2018

AbstractA new device structure of oxide thin‐film transistor (TFT) having lower overlap capacitance without scarifying the drain current is proposed. This can be used for high‐speed circuits and high frame rate displays using the conventional TFT manufacturing process. The existence of spreading currents in amorphous indium‐gallium‐zinc oxide (a‐IGZO) TFTs with stripe‐patterned source/drain (S/D) electrodes is demonstrated. The device performances of the a‐IGZO TFTs with various widths of stripe‐patterned S/D electrodes and open spaces between them are compared. The drain currents of the a‐IGZO TFTs are almost same when the width of open space changes from 0 to 10 µm because of the existence of spreading currents. The overlap capacitance between gate and S/D of the a‐IGZO TFTs can be significantly reduced without scarifying drain currents by using stripe‐patterned S/D electrodes. The operation frequency of the ring oscillator made of the TFTs with stripe S/D electrodes with 10 µm open space width is 2.5 times that made of the conventional a‐IGZO TFTs. This spreading current concept can be widely used for the design of oxide TFT array with low RC (resistance capacitance product) delay for high‐speed circuits.