bluuebunny/crossref_metadata_2025 huggingface dataset:
On the relationship between open cellular convective cloud patterns and the spatial distribution of precipitation
Authors: Yamaguchi T. , Feingold G.
Published: February 2015

Abstract. Precipitation is thought to be a necessary but insufficient condition for the transformation of stratocumulus-topped closed cellular convection to open cellular cumuliform convection. Here we test the hypothesis that the spatial distribution of precipitation is a key element of the closed-to-open cell transition. A series of idealized 3-D simulations are conducted to evaluate the dependency of the transformation on the areal coverage of rain, and to explore the role of interactions between multiple rainy areas in the formation of the open cells. When rain is restricted to a small area, even substantial rain (order few mm day−1) does not result in a transition. With increasing areal coverage of the rain, the transition becomes possible provided that the rain rate is sufficiently large. When multiple small rain regions interact with each other, the transition occurs and spreads over a wider area, provided that the distance between the rain regions is short. When the distance between the rain areas is large, the transition eventually occurs, albeit slowly. For much longer distances between rain regions the system is anticipated to remain in a closed-cell state. These results suggest a connection to the recently hypothesized remote control of open-cell formation. Finally it is shown that this transition occurs along a consistent path in the phase space of the mean vs. coefficient of variation of the liquid water path, droplet number and optical depth. This could be used as a diagnostic tool for global analyses of the statistics of closed- and open-cell occurrence and transitions between them.
Continuous measurements of greenhouse gases and atmospheric oxygen at the Namib Desert Atmospheric Observatory
Authors: Morgan E. J. , Lavrič J. V. , Seifert T. , Chicoine T. , Day A. , Gomez J. , Logan R. , Sack J. , Shuuya T. , Uushona E. G. , Vincent K. , Schultz U. , Brunke E.-G. , Labuschagne C. , Thompson R. L. , Schmidt S. , Manning A. C. , Heimann M.
Published: February 2015

Abstract. A new coastal background site has been established for observations of greenhouse gases (GHGs) in the central Namib Desert at Gobabeb, Namibia. The location of the site was chosen to provide observations for a data-poor region in the global sampling network for GHGs. Semi-automated, continuous measurements of carbon dioxide, methane, nitrous oxide, carbon monoxide, atmospheric oxygen, and basic meteorology are made at a height of 21 m a.g.l., 50 km from the coast at the northern border of the Namib Sand Sea. Atmospheric oxygen is measured with a differential fuel cell analyzer (DFCA). Carbon dioxide and methane are measured with an early-model cavity ring-down spectrometer (CRDS); nitrous oxide and carbon monoxide are measured with an off-axis integrated cavity output spectrometer (OA-ICOS). Instrument-specific water corrections are employed for both the CRDS and OA-ICOS instruments in lieu of drying. The performance and measurement uncertainties are discussed in detail. As the station is located in a remote desert environment, there are some particular challenges, namely fine dust, high diurnal temperature variability, and minimal infrastructure. The gas handling system and calibration scheme were tailored to best fit the conditions of the site. The CRDS and DFCA provide data of acceptable quality when base requirements for operation are met, specifically adequate temperature control in the laboratory and regular supply of electricity. In the case of the OA-ICOS instrument, performance is significantly improved through the implementation of a drift correction through frequent measurements of a working tank.
Technical Note: Cost-efficient approaches to measure carbon dioxide (CO2) fluxes and concentrations in terrestrial and aquatic environments using mini loggers
Authors: Bastviken D. , Sundgren I. , Natchimuthu S. , Reyier H. , Gålfalk M.
Published: February 2015

Abstract. Fluxes of CO2 are important for our understanding of the global carbon cycle and greenhouse gas balances. Several significant CO2 fluxes in nature may still be neglected as illustrated by recent findings of high CO2 emissions from aquatic environments, previously not recognized in global carbon balances. Therefore it is important to develop convenient and affordable ways to measure CO2 in many types of environments. At present, direct measurements of CO2 fluxes from soils or waters, or CO2 concentrations in surface water, are typically labour intensive or require costly equipment. We here present an approach with measurement units based on small inexpensive CO2 loggers, originally made for indoor air quality monitoring, that were tested and adapted for field use. Measurements of soil–atmosphere and lake–atmosphere fluxes, as well as of spatio-temporal dynamics of water CO2 concentrations (expressed as the equivalent partial pressure, pCO2aq) in lakes and a stream network are provided as examples. Results from all these examples indicate that this approach can provide a cost- and labor efficient alternative for direct measurements and monitoring of CO2 flux and pCO2aq in terrestrial and aquatic environments.
Simulating the Greenland ice sheet under present-day and palaeo constraints including a new discharge parameterization
Authors: Calov R. , Robinson A. , Perrette M. , Ganopolski A.
Published: February 2015

Abstract. In this paper, we propose a new sub-grid scale parameterization for the ice discharge into the ocean through outlet glaciers and inspect the role of different observational and palaeo constraints for the choice of an optimal set of model parameters. This parameterization was introduced into the polythermal ice-sheet model SICOPOLIS, which is coupled to the regional climate model of intermediate complexity REMBO. Using the coupled model, we performed large ensemble simulations over the last two glacial cycles by varying two major parameters: a melt parameter in the surface melt scheme of REMBO and a discharge scaling parameter in our parameterization of ice discharge. Our empirical constraints are the present-day Greenland ice sheet surface elevation, the surface mass balance partition (ratio between total ice discharge and total precipitation) and the Eemian interglacial elevation drop relative to present day in the vicinity of the NEEM ice core. We show that the ice discharge parameterization enables us to simulate both the correct ice-sheet shape and mass balance partition at the same time without explicitly resolving the Greenland outlet glaciers. For model verification, we compare the simulated total and sectoral ice discharge with other estimates. For the model versions that are consistent with the range of observational and palaeo constraints, our simulated Greenland ice sheet contribution to Eemian sea-level rise relative to present-day amounts to 1.4 m on average (in the range of 0.6 and 2.5 m).
Prevalence of hypertension and associated factors in Jalalabad City, Nangarhar Province, Afghanistan
Authors: Saeed Khwaja Mir Islam
Published: February 2015

Background: Hypertension affects an estimated one billion people, worldwide. It is a public health challenge characterized by increased morbidity, mortality, as well as cost to the community and health systems. The goal of this study is to determine the prevalence of hypertension and characterize associated risk factors in an urban setting in Afghanistan.Methods: A cross-sectional study of adults aged 25-65 years was conducted in Jalalabad city from May to June 2013 using the World Health Organization STEPwise approach to surveillance (WHO STEPS). A multistage technique was used to enroll 1,200 participants in the study. Demographic and socio-economic variables were collected via individual interviews using the WHO STEPS survey, after which blood samples were collected using a locally developed standard operating procedure (SOP). Bivariate and multivariable analyses were performed to explore the association between hypertension and associated factors.Results: A total of 1,180 adults (40% males, 60% females) of 25-65 years of age were surveyed. The response rate was 98.5 % and the prevalence of hypertension was 28.4. Independent risk factors of hypertension were found to be: age ≥ 50 (AOR = 3.42, 95% CI: 2.50 – 4.76); sex (AOR = 0.58, 95% CI: 0.38 – 0.88); obesity (AOR = 2.1, 95% CI 1.49 – 2.94); and diabetes (AOR = 1.75, 95% CI: 1.10 – 2.79). Independent protective factors were physically demanding occupations (AOR = 0.55, 95% CI: 0.36 – 0.85); physical activity itself (AOR = 0.69, 95% CI: 0.47 – 0.99) and consuming more vegetables (AOR = 0.59, 95% CI: 0.38 – 0.93).Conclusion: This urban setting in Afghanistan evidenced a high prevalence of hypertension; age, obesity, and diabetes were identified as risk factors and physical activity and consuming more vegetables were protective. These findings have implications for future public health intervention and clinical efforts.
Alcohol and Tobacco Use Among Undergraduate and Postgraduate Medical Students in India: A Multicentric Cross-sectional Study
Authors: Goel Nidhi , Khandelwal Vivek , Pandya Kapil , Kotwal Atul
Published: February 2015

Background: Substance use among medical fraternity is a well-known phenomenon among both undergraduate (UG) and postgraduate (PG) medical students. Yet, there have been very few multi-centric studies to estimate the actual burden of this problem in this important population group in India. This study was conducted to estimate the prevalence of alcohol and tobacco use, assess the knowledge and attitudes towards this issue, and identify factors associated with substance use among UG and PG medical students in India.Methods: A pre-tested, self-report, anonymous questionnaire was administered to medical undergraduates and post graduate medical residents of eight medical colleges across India. This study used a convenience sample of medical colleges with random selection of study participants within each college for each group, UG and PG.Results: Prevalence of alcohol and tobacco use among UG students was 16.6%, 95% CI [14.5, 18.9] and 8.0%, 95% CI [6.4, 9.6], respectively, whereas prevalence was 31.5%, 95% CI [26.3, 37.0] and 14.5%, 95% CI [10.7, 18.9], respectively for PGs. For both substances, males had a higher prevalence of use compared to females in both groups (p < 0.001). Positive family history of substance use (p < 0.001 for both groups) and early age of initiation (p = 0.011 for tobacco; p > 0.05 for alcohol) were associated with a greater difficulty to quit the habit. Over 90% of study participants felt that substance use adversely affected their skills and reported not using substances prior to managing their patients.Conclusions: Since substance use is a relatively common phenomenon among UG and PG medical students in India, future prospective studies and interventions are required to better understand the pattern of substance use and reduce its prevalence.
Reimagining the 10 Megatrends That Will Revolutionize Supply Chain Logistics
Authors: Stank Theodore , Autry Chad , Daugherty Patricia , Closs David
Published: February 2015

Many predictions were made in the growing field of supply chain management at the turn of the twenty-first century to establish the state of key concepts in the field as well as to motivate discussion, help guide resource allocation and implementation initiatives, and spark research to enhance understanding of many revolutionary supply chain management topics. The environment for supply chain activities has changed considerably since 2000, and many experts predict that even more significant change will occur over the next decade. This article will review industry progress on a set of 10 megatrends originally proposed in 2000, as well as extrapolate what the state of these trends may be over the next decade. In addition, new trends are identified that were not yet on the horizon in 2000, but will likely be influential in driving the changing supply chain over the next 10 years.
Autofagia celular em processos patológicos
Authors: Giorgio Selma
Published: February 2015

As pesquisas atuais sobre autofagia, um processo catabólico complexo, indicam que é um fenômeno vital para todos os organismos. Sabe-se que a célula se “auto-canabaliza”, englobando porções de seu citoplasma ou até de organelas inteiras, em estruturas denominadas autofagolisossomos, e as macromoléculas, resultantes da degradação por hidrolases lisossomais, são fonte de energia celular em distintas situações. A autofagia é responsável também pela auto-limpeza celular, removendo agregados macromoleculares mal formados. Estudos recentes demonstraram que em situações de estresse como a desnutrição ou a falta de oxigênio, nas doenças neurodegenerativas e no câncer, a autofagia desempenha papel importante. Nesta revisão são abordados aspectos estruturais e moleculares da autofagia, as técnicas atuais de detecção e o envolvimento em processos patológicos, principalmente infecciosos. Bactérias tais como Streptococcus pyogenes, Salmonella entérica, Listeria monocytogenes e os vírus da hepatite C e herpes simplex induzem autofagia nas células infectadas. O parasita Leishmania amazonensis que infecta macrófagos e causa a leishmaniose cutânea em humanos, também induz autofagia nas células infectadas e em tecido cutâneo de modelo experimental, sendo que o tratamento das células com inibidor da autofagia diminui a carga parasitária. Conclui-se, a partir dos resultados aqui revisados e discutidos, que a modulação da autofagia é importante na evolução de várias doenças infecciosas. O caminho está aberto para o desenvolvimento de compostos que modulem o processo autofágico em humanos, e que possam intervir no desenvolvimento de varias doenças.
Evaluation of allowed parameters for nickel in freshwater bodies using the Allium cepa test
Authors: Francisco Annelise , Christofoletti Cintya Aparecida , Fontanetti Carmem Silvia
Published: February 2015

Nickel compounds are disposed in large amounts in the environment, making it an ecotoxicological relevant contaminant, since these can bioaccumulate along the food chain and/or can cause DNA damage to the exposed organisms. In this sense, Brazilian law establishes 0.025 mg/l as the utmost boundary for the total nickel concentration allowed in freshwater bodies that consists in a quarter of the established by United States Environmental Protection Agency (EPA). This study evaluated three nickel concentrations, in nickel chloride (NiCl2) shape, having as reference the limit established by CONAMA (National Environmental Council), using seeds of Allium cepa, in order to measure the cytotoxic, genotoxic and mutagenic potentials of this element. At such concentrations, it was not observed toxicity or cytotoxicity, whereas for all three concentrations employed, there was induction of genotoxic and potentially mutagenic effects, especially cells bearing micronuclei, buds and chromosome stickiness. Thus, it is inferred that nickel chloride has aneugenic and/or clastogenic action. This study is also an alert for the water contamination by metals, since both concentration used, the lowest one and the one permitted by Brazilian law induced damage to the tested organism. The study suggests the necessity of review in the established parameters for such metal in freshwater bodies.
Oxidative stress, NADPH oxidases, and arteries
Authors: Sun Qi-An , Madamanchi Nageswara , Runge Marschall
Published: February 2015

Die Atherosklerose und ihre wichtigsten Komplikationen – Myokardinfarkt und Schlaganfall – sind die Hauptursachen für Tod und Behinderung in den USA und weltweit. Eine dramatische Zunahme bei Adipositas und Diabetes mellitus wird wahrscheinlich auch in Zukunft zu einer hohen Prävalenz kardiovaskulärer Erkrankungen (CVD) und deren Auswirkungen auf das Gesundheitswesen führen. Große Fortschritte gibt es bei der Entwicklung neuer Therapien zur Senkung der Inzidenz von Atherosklerose und CVD, besonders bei der Behandlung der Hypercholesterinämie und Hypertonie. Der gemeinsame mechanistische Nenner bei vielen Risikofaktoren für CVD ist oxidativer Stress. Erst seit kurzem verfügen wir über Methoden, um die Schnittstelle zwischen oxidativem Stress und CVD im Tiermodell zu untersuchen. Die wichtigste Quelle für reaktive Sauerstoffspezies (und damit für oxidativen Stress) in vaskulären Zellen sind die Formen der Nicotin - amidadenindinukleotidphosphat-Oxidase (NADPH-Oxidase). Die jüngsten Studien belegen eindeutig, dass 1. NADPH-Oxidasen im Tiermodell von grundlegender Bedeutung für Atherosklerose und Hypertonie sind und 2. der vaskuläre oxidative Stress, angesichts der gewebespezifischen Expression wichtiger Bestandteile der NADPH-Oxidase, ein Ziel bei der Prävention der CVD sein könnte.
Mathematical Modeling: A Structured Process
Authors: Anhalt Cynthia Oropesa , Cortez Ricardo
Published: February 2015

A task about locating a lost cell phone illustrates the Common Core elements of mathematical modeling. An assessment rubric helps teachers evaluate student work critically.
Thunder and Lightning: Understanding Equidistance
Authors: Colindres Carlos A. Mejía
Published: February 2015

Problems involving thunder and lightning promote high school students' understanding of equidistance, perpendicular bisectors, and the circumcenter of a triangle.
Illuminating Coordinate Geometry with Algebraic Symmetry
Authors: Matsuura Ryota , Sword Sarah
Published: February 2015

An approach using symmetric polynomials to prove that the medians of a triangle intersect at a single point reveals underlying structure and generalization to higher dimensions.
An Authentic Task That Models Quadratics
Authors: Baron Lorraine M.
Published: February 2015

Selling muffins introduced students to quadratic functions. Communicating with tables, graphs, and formulas helped solidify their understanding.
A Blizzard of a Value
Authors: Bostic Jonathan D.
Published: February 2015

To make a Dairy Queen Blizzard problem stand up to scrutiny, look to the Common Core for a recipe.
Fracking: Drilling into Math and Social Justice
Authors: Hendrickson Katie A.
Published: February 2015

A community-focused lesson that allows students to explore and model their findings with mathematics can also produce students who are aware of the environment.
The Story of Kyle
Authors: Dyson Nancy I. , Jordan Nancy C. , Hassinger-Das Brenna L.
Published: February 2015

Positioned for future success: Evidence-based number sense interventions (NSI) can help kindergartners link their nonverbal understanding of quantities to the symbolic representations of number, number relations, and number operations.
Always, Sometimes, Never True
Authors: Muir Tracey
Published: February 2015

To promote reasoning, mathematical argumentation, and the importance of justifying answers, we can use always, sometimes, never true statements, which can span a range of age groups, abilities, and mathematical topics.
Un perro en cuadrantes de Untikesken
Authors: Cores Uría Gonzalo , Ripollès Alegre Pere Pau
Published: February 2015

Se publica un cuadrante inédito de la ceca de Untikesken con la representación de un perro en reverso. La elección de este animal es singular, ya que no se conocía hasta ahora.
Noves inscripcions ibèriques i romanes de Lesera (la Moleta dels Frares, Forcall-Castelló)
Authors: Arasa Gil Ferran
Published: February 2015

Noves inscripcions en diferents suports.
Credentialing Guidelines for Doctors of Podiatric Medicine Supervising Hyperbaric Oxygen Therapy
Authors: Rogers Lee C. , DellaCorte Michael P. , Stavosky James W. , Millington J. Thomas , Capotorto John V.
Published: February 2015

Hyperbaric oxygen therapy (HBOT) is a useful tool for many conditions within the scope of practice of a Doctor of Podiatric Medicine (DPM). More wound-care clinics are adding HBOT as a service line. The increasing prevalence of DPMs operating inside of these wound-care clinics has raised questions about the licensure and privileging of DPMs to supervise HBOT. This document reviews the safety of outpatient HBOT and provides guidelines for hospitals to credential DPMs to supervise treatments.
In Her Own Eyes: Photovoice as an Innovative Methodology to Reach Disadvantaged Single Mothers
Authors: Valiquette-Tessier Sophie-Claire , Vandette Marie-Pier , Gosselin Julie
Published: February 2015

Photovoice is a photographic technique allowing people to identify, represent, and enhance their community by entrusting cameras to the hands of participants to enable them to capture issues central to their lives. However, few studies have used Photovoice with disadvantaged single mothers, and explicitly studied the impact of using this type of methodology with this population. Hence, the purpose of this study was to assess the impact of Photovoice with disadvantaged single mothers participating in the community-based program Toward Success. Results showed that participants experienced generally positive impacts, such as a sense of accomplishment and increased agency in their lives, and reported no negative impacts.
Electrodynamics of the equatorial evening ionosphere: 1. Importance of winds in different regions
Authors: Richmond A. D. , Fang T.‐W. , Maute A.
Published: February 2015

The importance of winds at different altitudes and latitudes for the electrodynamics of the low‐latitude evening ionosphere is examined with a model of the global coupled ionosphere‐thermosphere system. The model reproduces the main observed features of the evening equatorial plasma vortex and the prereversal enhancement (PRE) of the vertical drift. The electrodynamics is driven primarily by the zonal wind forced by the diurnally varying zonal pressure‐gradient force. The zonal wind lags the zonal pressure‐gradient force owing to inertia. When ion drag is important, the time lag of the wind behind the pressure gradient force is shortened, and the high‐altitude evening wind turns eastward earlier than the wind at lower altitudes, where ion drag is less important. Therefore, a vertical shear of the zonal wind tends to develop at altitudes around the transition between small and large ion drag at the bottom of the F region. This wind shear is closely associated with the vertical shear in the zonal convection velocity that is part of the evening plasma vortex. Unlike previous studies, we find that the winds driving the PRE lie mainly on field lines with apexes above the peak of the equatorial F layer, field lines that extend in magnetic latitude out to nearly 30° and encompass the entire evening equatorial ionization anomaly region. Contrary to previous suggestions, the westward convection in the bottomside of the evening plasma vortex is found to weaken, rather than strengthen, the PRE. Daytime winds have relatively little influence on the low‐latitude evening electrodynamics.
Geodetic imaging of potential seismogenic asperities on the Xianshuihe‐Anninghe‐Zemuhe fault system, southwest China, with a new 3‐D viscoelastic interseismic coupling model
Authors: Jiang Guoyan , Xu Xiwei , Chen Guihua , Liu Yajing , Fukahata Yukitoshi , Wang Hua , Yu Guihua , Tan Xibin , Xu Caijun
Published: February 2015

We use GPS and interferometric synthetic aperture radar (InSAR) measurements to image the spatial variation of interseismic coupling on the Xianshuihe‐Anninghe‐Zemuhe (XAZ) fault system. A new 3‐D viscoelastic interseismic deformation model is developed to infer the rotation and strain rates of blocks, postseismic viscoelastic relaxation, and interseismic slip deficit on the fault surface discretized with triangular dislocation patches. The inversions of synthetic data show that the optimal weight ratio and smoothing factor are both 1. The successive joint inversions of geodetic data with different viscosities reveal six potential fully coupled asperities on the XAZ fault system. Among them, the potential asperity between Shimian and Mianning, which does not exist in the case of 1019 Pa s, is confirmed by the published microearthquake depth profile. Besides, there is another potential partially coupled asperity between Daofu and Kangding with a length scale up to 140 km. All these asperity sizes are larger than the minimum resolvable wavelength. The minimum and maximum slip deficit rates near the Moxi town are 7.0 and 12.7 mm/yr, respectively. Different viscosities have little influence on the roughness of the slip deficit rate distribution and the fitting residuals, which probably suggests that our observations cannot provide a good constraint on the viscosity of the middle lower crust. The calculation of seismic moment accumulation on each segment indicates that the Songlinkou‐Selaha (S4), Shimian‐Mianning (S7), and Mianning‐Xichang (S8) segments are very close to the rupture of characteristic earthquakes. However, the confidence level is confined by sparse near‐fault observations.
Evidence for multidecadal variability in US extreme sea level records
Authors: Wahl Thomas , Chambers Don P.
Published: February 2015

We analyze a set of 20 tide gauge records covering the contiguous United States (US) coastline and the period from 1929 to 2013 to identify long‐term trends and multidecadal variations in extreme sea levels (ESLs) relative to changes in mean sea level (MSL). Different data sampling and analysis techniques are applied to test the robustness of the results against the selected methodology. Significant but small long‐term trends in ESLs above/below MSL are found at individual sites along most coastline stretches, but are mostly confined to the southeast coast and the winter season when storm surges are primarily driven by extratropical cyclones. We identify six regions with broadly coherent and considerable multidecadal ESL variations unrelated to MSL changes. Using a quasi‐nonstationary extreme value analysis, we show that the latter would have caused variations in design relevant return water levels (50–200 year return periods) ranging from ∼10 cm to as much as 110 cm across the six regions. The results raise questions as to the applicability of the “MSL offset method,” assuming that ESL changes are primarily driven by changes in MSL without allowing for distinct long‐term trends or low‐frequency variations. Identifying the coherent multidecadal ESL variability is crucial in order to understand the physical driving factors. Ultimately, this information must be included into coastal design and adaptation processes.
Relating reactive solute transport to hierarchical and multiscale sedimentary architecture in a Lagrangian‐based transport model: 2. Particle displacement variance
Authors: Soltanian Mohamad Reza , Ritzi Robert W. , Huang Chao Cheng , Dai Zhenxue
Published: February 2015

This series of papers addresses the transport of sorbing solutes in groundwater. In part 2, plume dispersion, as quantified by the particle displacement variance,
, is linked to hierarchical sedimentary architecture using a Lagrangian‐based transport model. This allows for a fundamental understanding of how dispersion arises from the hierarchical architecture of sedimentary facies, and allows for a quantitative decomposition of dispersion into facies‐related contributions at different scales within the hierarchy. As in part 1, the plume behavior is assumed to be controlled by linear‐equilibrium sorption and the heterogeneity in both the log permeability,
, and the log distribution coefficient,
. Heterogeneity in
and
arises from sedimentary processes and is structured by the consequent sedimentary architecture. Our goal is to understand the basic science of the dispersion process at this very fundamental level. The spatial auto and cross covariances for the relevant attributes are linear sums of terms corresponding to the probability of transitioning across stratal facies types defined at different scales. Unlike previous studies that used empirical relationships for the spatial covariances, here the model parameters are developed from independent measurements of physically quantifiable attributes of the stratal architecture (i.e., proportions and lengths of facies types, and univariate statistics for
and
). Nothing is assumed about Y‐
point correlation; it is allowed to differ by facies type. However, it is assumed that Y and
variance is small but meaningful, and that pore‐scale dispersion is negligible. The time‐dependent spreading rate is a function of the effective ranges of the cross‐transition probability structures (i.e., the ranges of indicator correlation structures) for each relevant scale of stratal hierarchy. As in part 1, the well‐documented perchloroethene (PCE) tracer test at the Borden research site is used to illustrate the model. The model was parameterized with univariate statistics for
,
of (PCE), and proportions and lengths of lithologic facies types defined at two scales within a two‐level hierarchical classification, as given by Ritzi et al. (). The model gives a viable explanation for the observed PCE plume dispersion, and thus
can be explained by the process of linear equilibrium sorption and the heterogeneity in k and
. The results quantitatively show that the
‐
cross correlation, though small, and varied by facies type, can significantly impact the particle displacement variance. Furthermore, by quantitatively decomposing the dispersion into facies‐related contributions, we gain the fundamental insight that that the time‐dependent rate of spreading is mostly defined by the cross‐transition probability correlation structure imparted by the proportions and sizes of the larger‐scale facies types.
Emerging In Situ and Operando Nanoscale X‐Ray Imaging Techniques for Energy Storage Materials
Authors: Nelson Weker Johanna , Toney Michael F.
Published: February 2015

Electrical vehicles (EVs) are an attractive option for moving towards a CO2 neutral transportation sector, but in order for widespread commercial use of EVs, the cost of electrical energy storage (i.e., batteries) must be reduced and the energy storage capacity must be increased. New, higher performing but Earth abundant electrodes are needed to accomplish this goal. To aid the development of these materials, in situ characterization to understand battery operation and failure is essential. Since electrodes are inherently heterogeneous, with a range of relevant length scales, imaging is a necessary component of the suite of characterization methods. In this Feature Article, the rapidly growing and developing field of X‐ray based microscopy (XM) techniques is described and reviewed focusing on in situ and operando adaptations. Further, in situ transmission electron microscopy (TEM) is briefly discussed in this context and its complement to XM is emphasized. Finally, a perspective is given on some emerging X‐ray based imaging approaches for energy storage materials.
Room‐Temperature Copper‐Catalyzed Arylation of Dimethylamine and Methylamine in Neat Water
Authors: Wang Deping , Kuang Daizhi , Zhang Fuxing , Yang Chunlin , Zhu Xiaoming
Published: February 2015

The first room‐temperature copper‐catalyzed arylations of dimethylamine and methylamine in neat water have been developed. Using a combination of CuI and 6,7‐dihydroquinolin‐8(5 H)‐one oxime as catalyst, dimethylamine is arylated with various aryl halides to give the corresponding products in good to excellent yields. Further, this catalysis enables the selective arylation of methylamine to afford the high yields of monoarylated methylamines as the sole products.

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Rhodium(III)‐Catalyzed in situ Oxidizing Directing Group‐ Assisted CH Bond Activation and Olefination: A Route to 2‐Vinylanilines
Authors: Muralirajan Krishnamoorthy , Haridharan Radhakrishnan , Prakash Sekar , Cheng Chien‐Hong
Published: February 2015

A new and efficient method for the synthesis of 2‐vinylanilines from the reaction of arylhydrazine hydrochlorides with alkenes and diethyl ketone via a rhodium‐catalyzed CH activation is described. The oxidant‐free olefination reaction involves the in situ generation of an NNCR1R2 moiety as the oxidizing directing group thus providing an easy access to 2‐vinylanilines.

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Multicomponent Syntheses based upon Copper‐Catalyzed Alkyne‐Azide Cycloaddition
Authors: Hassan Sidra , Müller Thomas J. J.
Published: February 2015

The copper‐catalyzed alkyne‐azide cycloaddition (CuAAC) is a highly versatile, regioselective synthesis of 1,4‐disubstituted 1,2,3‐triazoles under mild reaction conditions and has found numerous applications in medicinal, bioorganic, and materials chemistry in the past one and a half decades. By virtue of the enormous tolerance for functional groups and the mild reaction conditions, CuAAC has become increasingly important in combination with multicomponent reactions (MCR), either in a domino or in a consecutive fashion. While the majority of CuAAC‐based MCR are founded on the in situ or en route generation of azides, one‐pot generation of alkynes and the concatenation with other MCR are rapidly catching up and novel sequences for efficient one‐pot syntheses of triazole‐based structures in a multicomponent fashion are constantly evolving. This review summarizes important contributions of CuAAC‐based MCR including MCR‐type applications in polymer science.

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Palladium‐Catalyzed Construction of Spirooxindoles by Arylative Cyclization of 3‐(γ,δ‐Disubstituted)allylidene‐2‐Oxindoles
Authors: Kim Ko Hoon , Moon Hye Ran , Lee Junseong , Kim Jae Nyoung
Published: February 2015

The palladium‐catalyzed, one‐pot arylative cyclization of 3‐(γ,δ‐disubstituted)allylidene‐2‐oxindoles afforded spirodihydronaphthalene‐2‐oxindole frameworks via an oxidative Heck arylation (Fujiwara–Moritani reaction), an allylic palladium migration, and an aryl CH bond functionalization/arylation cascade of reactions. This is a first example of the palladium‐catalyzed oxidative arylation and an aryl CH bond functionalization/arylation cascade reaction which involves an electrophilic arylative quenching of a π‐allylpalladium intermediate and a regio‐controlled aryl CH bond activation assisted by a weak palladium‐arene interaction.

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Sodium Iodide‐Catalyzed Direct α‐Alkoxylation of Ketones with Alcohols via Oxidation of α‐Iodo Ketone Intermediates
Authors: Zhu Cuiju , Zhang Yuanfei , Zhao Huaiqing , Huang Shijun , Zhang Min , Su Weiping
Published: February 2015

The direct α‐alkoxylation of ketones with alcohols via a sodium iodide‐catalyzed oxidative cross‐coupling has been developed. This protocol enables a range of alkyl aryl ketones to cross‐couple with an array of alcohols in synthetically useful yields. The mechanistic studies provided solid evidence supporting that an α‐iodo ketone was a key reaction intermediate, being converted into an α‐alkoxylated ketone via further oxidation to a hypervalent iodine species rather than a common nucleophilic substitution, and was generated from the ketone starting material via a radical intermediate. These new mechanism insights should have an effect on the design of iodide‐catalyzed oxidative cross‐coupling reactions between nucleophiles.

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Presence of isocitrate dehydrogenase mutations may predict clinical response to hypomethylating agents in patients with acute myeloid leukemia
Authors: Emadi Ashkan , Faramand Rawan , Carter‐Cooper Brandon , Tolu Seda , Ford Laurie A. , Lapidus Rena G. , Wetzler Meir , Wang Eunice S. , Etemadi Arash , Griffiths Elizabeth A.
Published: February 2015

Mutations in IDH1 and IDH2 occur in 15–20% of AML cases, resulting in the production of 2‐hydroxyglutarate, which promotes aberrant hypermethylation of DNA in leukemic cells. Although these mutations have been shown to have prognostic implications for patients with AML, optimal treatment strategies have yet to be defined. We retrospectively identified forty‐two patients with AML treated with DNA methyltransferase inhibitors (DNMTIs) decitabine (n = 36) or azacitidine (n = 6) and performed analysis of stored samples for the presence of IDH1 and IDH2 mutations. Of the forty‐two samples analyzed, seven (16.7%) had IDH mutations. Thirteen patients (31%) achieved remission [(complete remission (CR)/complete remission with incomplete count recovery (CRi)/partial response (PR)] after treatment with a DNMTI, five of seven (71.4%) with IDH mutations and eight of thirty‐five (22.9%) without IDH mutations (P = 0.01). When adjusted for age at diagnosis, sex, bone marrow blast percentage and cytogenetic, the odds of achieving response after administration of a DNMTI among patients with an IDH mutation was 14.2 when compared to patients without an IDH mutation (95%CI: 1.3–150.4). IDH1 and IDH2 mutations may predict a favorable response to DNMTI in patients with AML. Am. J. Hematol. 90:E77–E79, 2015. © 2015 Wiley Periodicals, Inc.
Metal‐Free, Room‐Temperature, Radical Alkoxycarbonylation of Aryldiazonium Salts through Visible‐Light Photoredox Catalysis
Authors: Guo Wei , Lu Liang‐Qiu , Wang Yue , Wang Ya‐Ni , Chen Jia‐Rong , Xiao Wen‐Jing
Published: February 2015

The first radical alkoxycarboxylation of aryldiazonium salts using CO gas through visible‐light‐induced photoredox catalysis (16 W blue LEDs) has been developed. This reaction is entirely metal‐free, is carried out at room temperature with a low loading of an organic dye as a photocatalyst (0.5 mol %), and provides a wide range of arylcarboxylic acid esters in high yields. Importantly, this photocatalytic system can be successfully extended to other carboxylation reactions.
Selektive Kontrolle der Bildung von Calciumsulfat‐Polymorphen bei Raumtemperatur
Authors: Tritschler Ulrich , Van Driessche Alexander E. S. , Kempter Andreas , Kellermeier Matthias , Cölfen Helmut
Published: February 2015

Calciumsulfat ist ein in der Natur weit verbreitetes und technologisch wichtiges Mineral mit breitem Anwendungsspektrum. Allerdings stellte die Kontrolle der CaSO4‐Polymorphie und damit der Materialeigenschaften nach wie vor eine beträchtliche Herausforderung dar, und bis jetzt gibt es keine universelle Methode für die selektive Herstellung der verschiedenen hydratisierten und wasserfreien Formen unter milden Bedingungen. Hier berichten wir über die erste erfolgreiche Synthese von reinem Anhydrit aus einer Lösung bei Raumtemperatur. Erreicht wurde dies durch Ausfällen von Calciumsulfat in alkoholischen Medien mit niedrigen Wassergehalten. Durch Variieren der Wassermenge gelang es uns außerdem, zwischen einzelnen Polymorphen zu schalten und das Ergebnis der Reaktion fein abzustimmen, um entweder eine gewünschte CaSO4‐Phase in reiner Form oder binäre Mischungen mit festgelegten Zusammensetzungen herzustellen. Das Konzept bietet die volle Kontrolle über die Auswahl der Phasen in der CaSO4‐Mineralisation und könnte die gezielte Herstellung entsprechender Materialien für diverse Anwendungsgebiete ermöglichen.
Natriumionenbatterien für die elektrochemische Energiespeicherung
Authors: Kundu Dipan , Talaie Elahe , Duffort Victor , Nazar Linda F.
Published: February 2015

Fortschrittliche Energiespeichertechnologien sind von immenser Bedeutung für tragbare elektronische Geräte, Elektrofahrzeuge, die Stromspeicherung in Kraftwerken und den Lastausgleich von Stromnetzen auf der Basis erneuerbarer Energien wie Solarenergie und Windkraft. Für die ersten zwei dieser Anwendungen haben sich Lithiumionenbatterien erfolgreich bewährt. Für die zwei letzteren Fälle scheint es jedoch sinnvoll, einen Schritt weiterzugehen – hin zum nächsten Alkalimetall im Periodensystem, dem Natrium. Eine flächendeckende Einführung von Natriumionenbatterien erfordert deren intensive Erforschung, einschließlich der Entdeckung neuer Materialien und ihrer Elektrochemie. Dieser Aufsatz fasst den aktuellen Stand der Forschung auf dem Gebiet der Natriumionenbatterien zusammen.
Excimers Beyond Pyrene: A Far‐Red Optical Proximity Reporter and its Application to the Label‐Free Detection of DNA
Authors: Han Garam , Kim Dongwook , Park Younbong , Bouffard Jean , Kim Youngmi
Published: February 2015

A family of organic chromophores that, like pyrene, forms emissive excimers is reported. Their chemical and photophysical properties are superior to pyrene for the design of chemo‐ and biosensors. Unlike hydrophobic pyrene, which requires excitation by cell‐damaging UV irradiation, these polar dyes absorb strongly in the visible range, and their excimers emit brightly in the red to far‐red region of the electromagnetic spectrum. The intensity of the emission signal is greatly increased upon formation of a preassociated dimer that is triggered upon aggregation or crystallization. In demonstration of the potential of this new family of excimer‐forming dyes, a probe that is capable of detecting label‐free DNA in water down to 10 pM and also doubles as a visualization agent for DNA in gel electrophoresis is reported.
Perfekte Raumfüllung – Fullerengäste in sternförmigen Oligophenylenvinylen‐Mesogenen
Authors: Lehmann Matthias , Hügel Markus
Published: February 2015

Sternförmige Oligophenylenvinylen(OPV)‐Mesogene sind formtreu und weisen formal zwischen ihren Armen große Freiräume auf. Ein Mesogen mit Armen aus drei Phenylenethenylen‐Wiederholungseinheiten packt dicht in einer kolumnar‐helikalen Anordnung. Das Anbringen eines Fullerens über einen kurzen Abstandhalter (Spacer) führt zu einer außergewöhnlichen Erhöhung der Mesophasenstabilität. Röntgenstreuung und Modellierung bestätigen die Selbstorganisation zur Tripelhelix, in der Fullerene den Freiraum zwischen den Armen der Sternmesogene perfekt ausfüllen.
Formale anti‐Carbopalladierungen nicht‐aktivierter Alkine: Voraussetzungen, mechanistische Untersuchungen und Anwendungen
Authors: Pawliczek Martin , Schneider Tobias F. , Maaß Christian , Stalke Dietmar , Werz Daniel B.
Published: February 2015

Formale anti‐Carbopalladierungsreaktionen von C‐C‐Dreifachbindungen sind ungewöhnliche, aber äußerst nützliche Transformationen. Alkine, die gezielt anti‐Carbopalladierungsprodukte ergeben, werden vorgestellt. Voraussetzung ist der Ausschluss anderer Reaktionswege, um eine cis‐trans‐Isomerisierung der entstehenden Doppelbindung zu ermöglichen. Der entscheidende mechanistische Schritt wurde sowohl experimentell als auch theoretisch untersucht. Eine intramolekulare Version der Reaktion ermöglicht die einfache Herstellung sowohl von oligocyclischen Produkten als auch von Dibenzofuranen.
The Kinetic Isotope Effect as a Probe of Spin Crossover in the CH Activation of Methane by the FeO+ Cation
Authors: Mai Binh Khanh , Kim Yongho
Published: February 2015

Two‐state reactivity (TSR) is often used to explain the reaction of transition‐metal–oxo reagents in the bare form or in the complex form. The evidence of the TSR model typically comes from quantum‐mechanical calculations for energy profiles with a spin crossover in the rate‐limiting step. To prove the TSR concept, kinetic profiles for CH activation by the FeO+ cation were explored. A direct dynamics approach was used to generate potential energy surfaces of the sextet and quartet H‐transfers and rate constants and kinetic isotope effects (KIEs) were calculated using variational transition‐state theory including multidimensional tunneling. The minimum energy crossing point with very large spin–orbit coupling matrix element was very close to the intrinsic reaction paths of both sextet and quartet H‐transfers. Excellent agreement with experiments were obtained when the sextet reactant and quartet transition state were used with a spin crossover, which strongly support the TSR model.
Fragment Screening and Druggability Assessment for the CBP/p300 KIX Domain through Protein‐Observed 19F NMR Spectroscopy
Authors: Gee Clifford T. , Koleski Edward J. , Pomerantz William C. K.
Published: February 2015

19F NMR spectroscopy of labeled proteins is a sensitive method for characterizing structure, conformational dynamics, higher‐order assembly, and ligand binding. Fluorination of aromatic side chains has been suggested as a labeling strategy for small‐molecule ligand discovery for protein–protein interaction interfaces. Using a model transcription factor binding domain of the CREB binding protein (CBP)/p300, KIX, we report the first full small‐molecule screen using protein‐observed 19F NMR spectroscopy. Screening of 508 compounds and validation by 1H–15N HSQC NMR spectroscopy led to the identification of a minimal pharmacaphore for the MLL‐KIX interaction site. Hit rate analysis for the CREB‐KIX and MLL‐KIX sites provided a metric to assess the ligandability or “druggability” of each interface informing future medicinal chemistry efforts. The structural information from the simplified spectra and data collection speed, affords a new screening tool for analysis of protein interfaces and discovery of small molecules.
A Nuclear Singlet Lifetime of More than One Hour in Room‐Temperature Solution
Authors: Stevanato Gabriele , Hill‐Cousins Joseph T. , Håkansson Pär , Roy Soumya Singha , Brown Lynda J. , Brown Richard C. D. , Pileio Giuseppe , Levitt Malcolm H.
Published: February 2015

Nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) are supremely important techniques with numerous applications in almost all branches of science. However, until recently, NMR methodology was limited by the time constant T1 for the decay of nuclear spin magnetization through contact with the thermal molecular environment. Long‐lived states, which are correlated quantum states of multiple nuclei, have decay time constants that may exceed T1 by large factors. Here we demonstrate a nuclear long‐lived state comprising two 13C nuclei with a lifetime exceeding one hour in room‐temperature solution, which is around 50 times longer than T1. This behavior is well‐predicted by a combination of quantum theory, molecular dynamics, and quantum chemistry. Such ultra‐long‐lived states are expected to be useful for the transport and application of nuclear hyperpolarization, which leads to NMR and MRI signals enhanced by up to five orders of magnitude.
Graphene Liquid Marbles as Photothermal Miniature Reactors for Reaction Kinetics Modulation
Authors: Gao Wei , Lee Hiang Kwee , Hobley Jonathan , Liu Tianxi , Phang In Yee , Ling Xing Yi
Published: February 2015

We demonstrate the fabrication of graphene liquid marbles as photothermal miniature reactors with precise temperature control for reaction kinetics modulation. Graphene liquid marbles show rapid and highly reproducible photothermal behavior while maintaining their excellent mechanical robustness. By tuning the applied laser power, swift regulation of graphene liquid marble’s surface temperature between 21–135 °C and its encapsulated water temperature between 21–74 °C are demonstrated. The temperature regulation modulates the reaction kinetics in our graphene liquid marble, achieving a 12‐fold superior reaction rate constant for methylene blue degradation than at room temperature.
Noncanonical Amino Acids to Improve the pH Response of pHLIP Insertion at Tumor Acidity
Authors: Onyango Joab O. , Chung Michael S. , Eng Chee‐Huat , Klees Lukas M. , Langenbacher Rachel , Yao Lan , An Ming
Published: February 2015

The pH low insertion peptide (pHLIP) offers the potential to deliver drugs selectively to the cytoplasm of cancer cells based on tumor acidosis. The WT pHLIP inserts into membranes with a pH50 of 6.1, while most solid tumors have extracellular pH (pHe) of 6.5–7.0. To close this gap, a SAR study was carried out to search for pHLIP variants with improved pH response. Replacing Asp25 with α‐aminoadipic acid (Aad) adjusts the pH50 to 6.74, matching average tumor acidity, and replacing Asp14 with γ‐carboxyglutamic acid (Gla) increases the sharpness of pH response (transition over 0.5 instead of 1 pH unit). These effects are additive: the Asp14Gla/Asp25Aad double variant shows a pH50 of 6.79, with sharper transition than Asp25Aad. Furthermore, the advantage of the double variant over WT pHLIP in terms of cargo delivery was demonstrated in turn‐on fluorescence assays and anti‐proliferation studies (using paclitaxel as cargo) in A549 lung cancer cells at pH 6.6.