bluuebunny/crossref_metadata_2025 huggingface dataset:
Improving snow albedo processes in WRF/SSiB regional climate model to assess impact of dust and black carbon in snow on surface energy balance and hydrology over western U.S.
Authors: Oaida Catalina M. , Xue Yongkang , Flanner Mark G. , Skiles S. McKenzie , De Sales Fernando , Painter Thomas H.
Published: February 2015

Two important factors that control snow albedo are snow grain growth and presence of light‐absorbing impurities (aerosols) in snow. However, current regional climate models do not include such processes in a physically based manner in their land surface models. We improve snow albedo calculations in the Simplified Simple Biosphere (SSiB) land surface model coupled with the Weather Research and Forecasting (WRF) regional climate model (RCM), by incorporating the physically based SNow ICe And Radiative (SNICAR) scheme. SNICAR simulates snow albedo evolution due to snow aging and presence of aerosols in snow. The land surface model is further modified to account for deposition, movement, and removal by meltwater of such impurities in the snowpack. This paper presents model development technique, validation with in situ observations, and preliminary results from RCM simulations investigating the impact of such impurities in snow on surface energy and water budgets. By including snow‐aerosol interactions, the new land surface model is able to realistically simulate observed snow albedo, snow grain size, dust in snow, and surface water and energy balances in offline simulations for a location in western U.S. Preliminary results with the fully coupled RCM show that over western U.S., realistic aerosol deposition in snow induces a springtime average radiative forcing of 16 W/m2 due to a 6% albedo reduction, a regional surface warming of 0.84°C, and a snowpack reduction of 11 mm.
Observed anomalous atmospheric patterns in summers of unusual Arctic sea ice melt
Authors: Knudsen Erlend M. , Orsolini Yvan J. , Furevik Tore , Hodges Kevin I.
Published: February 2015

The Arctic sea ice retreat has accelerated over the last decade. The negative trend is largest in summer, but substantial interannual variability still remains. Here we explore observed atmospheric conditions and feedback mechanisms during summer months of anomalous sea ice melt in the Arctic. Compositing months of anomalous low and high sea ice melt over 1979–2013, we find distinct patterns in atmospheric circulation, precipitation, radiation, and temperature. Compared to summer months of anomalous low sea ice melt, high melt months are characterized by anomalous high sea level pressure in the Arctic (up to 7 hPa), with a corresponding tendency of storms to track on a more zonal path. As a result, the Arctic receives less precipitation overall and 39% less snowfall. This lowers the albedo of the region and reduces the negative feedback the snowfall provides for the sea ice. With an anticyclonic tendency, 12 W/m2 more incoming shortwave radiation reaches the surface in the start of the season. The melting sea ice in turn promotes cloud development in the marginal ice zones and enhances downwelling longwave radiation at the surface toward the end of the season. A positive cloud feedback emerges. In midlatitudes, the more zonally tracking cyclones give stormier, cloudier, wetter, and cooler summers in most of northern Europe and around the Sea of Okhotsk. Farther south, the region from the Mediterranean Sea to East Asia experiences significant surface warming (up to 2.4°C), possibly linked to changes in the jet stream.
Large snowmelt versus rainfall events in the mountains
Authors: Fassnacht Steven R. , Records Rosemary M.
Published: February 2015

While snow is the dominant precipitation type in mountain regions, estimates of rainfall are used for design, even though snowmelt provides most of the runoff. Daily data were used to estimate the 10 and 100 year, 24 h snowmelt, precipitation, and rainfall events at 90 Snow Telemetry stations across the Southern Rocky Mountains. Three probability distributions were compared, and the Pearson type III distribution yielded the most conservative estimates. Precipitation was on average 33% and 28% more than rainfall for the 10 and 100 year events. Snowfall exceeded rainfall at most of the stations and was on average 53% and 38% more for the 10 and 100 year events. On average, snowmelt was 15% and 8.9% more than precipitation. Where snow accumulation is substantial, it is recommended that snowmelt be considered in conjunction with rainfall and precipitation frequencies to develop flood frequencies.
The signature of mesoscale eddies on the air‐sea turbulent heat fluxes in the South Atlantic Ocean
Authors: Villas Bôas A. B. , Sato O. T. , Chaigneau A. , Castelão G. P.
Published: February 2015

By collocating 10 years (1999–2009) of remotely sensed surface turbulent heat fluxes with satellite altimetry data, we investigate the impact of oceanic mesoscale eddies on the latent and sensible heat fluxes in the South Atlantic Ocean. In strongly energetic regions, such as the Brazil–Malvinas confluence and the Agulhas Current Retroflection, eddies explain up to 20% of the total variance in the surface turbulent heat fluxes with averaged anomalies of ± (10–20) W/m2. Cyclonic (anticyclonic, respectively) eddies are associated with negative (positive) heat flux anomalies that tend to cool (warm) the marine atmospheric boundary layer. A composite analysis of the turbulent heat flux anomalies inside the eddies reveals a direct relationship between eddy amplitude and the intensity of such anomalies. In addition, these anomalies are stronger near the eddy center, decaying radially to reach minimum values outside the eddies.
Satellite view of quasi‐equilibrium states in tropical convection and precipitation microphysics
Authors: Matsui Toshi , Tao Wei‐Kuo , Munchak S. Joseph , Grecu Mircea , Huffman George J.
Published: February 2015

This study shows the time series of statistical composites of precipitation‐microphysics signals derived from long‐term Tropical Rainfall Measuring Mission (TRMM) satellite observations aggregated over the entire tropical domain (37°N–37°S). The result shows the nearly time‐invariant monthly signal statistics throughout this time, confirming convection quasi‐equilibrium (CQE) states. Merged precipitation data, with much better temporal and spatial coverage, provide evidence that the equilibrium state occurs on a daily scale. These results further indicate the presence of precipitation microphysics quasi‐equilibrium (MQE) within the CQE environment. A simple analytic microphysics framework illustrates the equilibrium precipitation size distribution, as compared with the TRMM radar‐based as well as preliminary Global Precipitation Measurement combined retrievals. The MQE readily explains the near‐constant tropical precipitation rate, which is roughly balanced with atmospheric radiative cooling rate at the entire tropical scale. Further investigation is required through theoretical, observational, and numerical manners to support the MQE hypothesis.
Development and Manufacture of Polymer‐Based Electrochromic Devices
Authors: Jensen Jacob , Hösel Markus , Dyer Aubrey L. , Krebs Frederik C.
Published: February 2015

The field of organic electrochromics is reviewed here, with particular focus on how the “electrochromic” as a functional material can be brought from the current level of accurate laboratory synthesis and characterization to the device and application level through a number of suited roll‐to‐roll methods compatible with upscaling and manufacture. The successful approaches to operational devices are presented in detail, as well as areas where future research would have a high impact and accelerate the development such as highly conducting and transparent substrates, electrolytes adapted for multilayer application and morphologically stable conjugated polymers.
Interfacing Materials Science and Biology for Drug Carrier Design
Authors: Such Georgina K. , Yan Yan , Johnston Angus P. R. , Gunawan Sylvia T. , Caruso Frank
Published: February 2015

Over the last ten years, there has been considerable research interest in the development of polymeric carriers for biomedicine. Such delivery systems have the potential to significantly reduce side effects and increase the bioavailability of poorly soluble therapeutics. The design of carriers has relied on harnessing specific variations in biological conditions, such as pH or redox potential, and more recently, by incorporating specific peptide cleavage sites for enzymatic hydrolysis. Although much progress has been made in this field, the specificity of polymeric carriers is still limited when compared with their biological counterparts. To synthesize the next generation of carriers, it is important to consider the biological rationale for materials design. This requires a detailed understanding of the cellular microenvironments and how these can be harnessed for specific applications. In this review, several important physiological cues in the cellular microenvironments are outlined, with a focus on changes in pH, redox potential, and the types of enzymes present in specific regions. Furthermore, recent studies that use such biologically inspired triggers to design polymeric carriers are highlighted, focusing on applications in the field of therapeutic delivery.
Elucidating the Excited‐State Properties of CuInS2 Nanocrystals upon Phase Transformation: Quasi‐Quantum Dots Versus Bulk Behavior
Authors: Azimi Hamed , Kuhri Susanne , Stahl Melissa S. , Hou Yi , Guldi Dirk M. , Brabec Christoph J.
Published: February 2015

New insights into the complex relation between the thermal phase transformation and the excited state properties of chalcopyrite CuInS2 nanocrystals (CIS NCs) are presented. An in situ solution processing method via depositing molecular precursors is applied, offering advantages in terms of simplicity, low‐temperature processability, and control over crystallite size, and optical properties. At low annealing temperatures, strong carrier quantum confinement and small crystallite sizes are realized for CIS NC films. CIS crystal growth is found to set in at higher annealing temperatures inducing a complete transformation from quasi‐quantum‐dot (QD) via bulk‐like to bulk behavior. The transition of a near‐infrared localized surface plasmon resonance (LSPR) towards a bulk‐like plasmon resonance documents the crystal growth and further acts as a valuable probe to relate crystallite size with copper‐deficient stoichiometries. In addition, time‐resolved photophysical investigations help to shed light on the dynamics and mechanisms of exciton and charge carrier generation of CIS NC films as a function of annealing temperature. The in situ‐prepared CIS NC films are further passivated by a thin CdS layer, leading to the formation of long‐lived excitons and an effective CIS ground‐state depletion.
Validating skinfold thickness as a proxy to estimate total body fat in wild toque macaques (Macaca sinica) using the mass of dissected adipose tissue
Authors: Dittus Wolfgang P.J. , Gunathilake K.A. Sunil
Published: February 2015

Skinfold thickness (SFT) has been used often in non‐human primates and humans as a proxy to estimate fatness (% body fat). We intended to validate the relation between SFT (in recently deceased specimens) and the mass of adipose tissue as determined from dissection of fresh carcasses of wild toque macaques (Macaca sinica). In adult male and female toque macaques body composition is normally 2% adipose tissue. Calipers for measuring SFT were suitable for measuring only some subcutaneous deposits of adipose tissue but were not suitable for measuring large fat deposits within the body cavity or minor intermuscular ones. The anatomical distribution of 13 different adipose deposits, in different body regions (subcutaneous, intra‐abdominal and intermuscular) and their proportional size differences, were consistent in this species (as in other primates), though varying in total mass among individuals. These consistent allometric relationships were fundamental for estimating fatness of different body regions based on SFT. The best fit statistically significant correlations and regressions with the known masses of dissectible adipose tissue were evident between the SFT means of the seven sites measured, as well as with a single point on the abdomen anterior to the umbilicus. SFT related to total fat mass and intra‐abdominal fat mass in curvilinear regressions and to subcutaneous fat mass in a linear relationship. To adjust for differences in body size among individuals, and to circumvent intangible variations in total body mass allocated, for example to the gastro‐intestinal contents, dissected fat mass was estimated per unit body size (length of crown‐rump)3. SFT had greater coefficients of correlation and regressions with this Fat Mass Index (g/dm3) than with Percent Body Fat. Am. J. Primatol. 77:618–632, 2015. © 2015 Wiley Periodicals, Inc.
Microimaging transienter Konzentrationsprofile von Reaktant‐ und Produktmolekülen während einer katalytischen Umwandlung in nanoporösen Materialien
Authors: Titze Tobias , Chmelik Christian , Kullmann Jens , Prager Lutz , Miersemann Erich , Gläser Roger , Enke Dirk , Weitkamp Jens , Kärger Jörg
Published: February 2015

Microimaging mittels IR‐Mikroskopie wird verwendet, um die Entwicklung der Konzentrationsprofile von Reaktant‐ und Produktmolekülen während einer katalytischen Reaktion aufzuzeichnen. Beobachtet wird dazu die Hydrierung von Benzol zu Cyclohexan an Nickel‐Nanopartikeln in einem nanoporösen Glas als Trägermaterial. Da der Porennutzungsgrad definiert ist als Quotient aus effektiver Reaktionsgeschwindigkeit und Reaktionsgeschwindigkeit ohne Diffusionslimitierung, wird er herkömmlicherweise bestimmt, indem Reaktionsgeschwindigkeiten für unterschiedlich starke Transportlimitierungen miteinander verglichen werden. Die Variation der “Limitierung” erfolgt dabei durch die Veränderung geeigneter Systemparameter, wie z. B. der Partikelgröße des nanoporösen Katalysatorträgers. Mit den neuen Möglichkeiten des Microimagings kann der Porennutzungsgrad in einer einzigen Messung bestimmt werden, indem lediglich die Verteilung der Reaktant‐ und Produktmoleküle im Katalysator verfolgt wird.
Discrimination Between 8‐Oxo‐2′‐Deoxyguanosine and 2′‐Deoxyguanosine in DNA by the Single Nucleotide Primer Extension Reaction with Adap Triphosphate
Authors: Taniguchi Yosuke , Kikukawa Yoshiya , Sasaki Shigeki
Published: February 2015

The adenosine derivative of 2‐oxo‐1,3‐diazaphenoxazine (Adap) exhibits a superb ability to recognize and form base pairs with 8‐oxo‐2′‐deoxyguanosine (8‐oxo‐dG) in duplex DNA. In this study, the triphosphate of Adap (dAdapTP) was synthesized and tested for single nucleotide incorporation into primer strands using the Klenow Fragment. The efficiency of dAdapTP incorporation into 8‐oxo‐dG‐containing templates was more than 36‐fold higher than with dG‐containing templates, and provides better discrimination than does the incorporation of natural 2′‐deoxyadenosine triphosphate (dATP). The selective incorporation of dAdapTP into 8‐oxo‐dG templates was therefore applied to the detection of 8‐oxo‐dG in human telomeric DNA sequences extracted from H2O2‐treated HeLa cells. The enzymatic incorporation of dAdapTP into 8‐oxo‐dG‐containing templates may provide a novel basis for sequencing oxidative DNA damage in the genome.
The Design of Dual Emitting Cores for Green Thermally Activated Delayed Fluorescent Materials
Authors: Cho Yong Joo , Jeon Sang Kyu , Chin Byung Doo , Yu Eunsun , Lee Jun Yeob
Published: February 2015

Dual emitting cores for thermally activated delayed fluorescent (TADF) emitters were developed. Relative to the corresponding TADF emitter with a single emitting core the TADF emitter with a dual emitting core, 3,3′,5,5′‐tetra(carbazol‐9‐yl)‐[1,1′‐biphenyl]‐2,2′,6,6′‐tetracarbonitrile, showed enhanced light absorption accompanied by a high photoluminescence quantum yield. The quantum and power efficiencies of the TADF devices were enhanced by the dual emitting cores.
Phenanthriporphyrin: An Antiaromatic Aceneporphyrinoid as a Ligand for a Hypervalent Organophosphorus(V) Moiety
Authors: Szyszko Bartosz , Białońska Agata , Szterenberg Ludmiła , Latos‐Grażyński Lechosław
Published: February 2015

The incorporation of a phenanthrene moiety into a porphyrin framework results in the formation of a hybrid macrocycle—phenanthriporphyrin—merging the structural features of polycyclic aromatic hydrocarbons and porphyrins. An antiaromatic aceneporphyrinoid, adopting the trianionic {CCNN} core, is suitable for the incorporation of a phosphorus(V) center to form a hypervalent organophosphorus(V) derivative.
Mild Deoxygenation of Aromatic Ketones and Aldehydes over Pd/C Using Polymethylhydrosiloxane as the Reducing Agent
Authors: Volkov Alexey , Gustafson Karl P. J. , Tai Cheuk‐Wai , Verho Oscar , Bäckvall Jan‐E. , Adolfsson Hans
Published: February 2015

Herein, a practical and mild method for the deoxygenation of a wide range of benzylic aldehydes and ketones is described, which utilizes heterogeneous Pd/C as the catalyst together with the green hydride source, polymethylhydrosiloxane. The developed catalytic protocol is scalable and robust, as exemplified by the deoxygenation of ethyl vanillin, which was performed on a 30 mmol scale in an open‐to‐air setup using only 0.085 mol % Pd/C catalyst to furnish the corresponding deoxygenated product in 93 % yield within 3 hours at room temperature. Furthermore, the Pd/C catalyst was shown to be recyclable up to 6 times without any observable decrease in efficiency and it exhibited low metal leaching under the reaction conditions.
Palladium‐Catalyzed Vicinal Amino Alcohols Synthesis from Allyl Amines by In Situ Tether Formation and Carboetherification
Authors: Orcel Ugo , Waser Jerome
Published: February 2015

Vicinal amino alcohols are important structural motifs of bioactive compounds. Reported herein is an efficient method for their synthesis based on the palladium‐catalyzed oxy‐alkynylation, oxy‐arylation, or oxy‐vinylation of allylic amines. High regio‐ and stereoselectivity were ensured through the in situ formation of a hemiaminal tether using the cheap commercially available trifluoroacetaldehyde in its hemiacetal form. The obtained compounds are important building blocks, which can be orthogonally deprotected to give either free alcohols, amines, or terminal alkynes.
Cobalt Phosphide Nanowires: Efficient Nanostructures for Fluorescence Sensing of Biomolecules and Photocatalytic Evolution of Dihydrogen from Water under Visible Light
Authors: Tian Jingqi , Cheng Ningyan , Liu Qian , Xing Wei , Sun Xuping
Published: February 2015

The detection of specific DNA sequences plays an important role in the identification of disease‐causing pathogens and genetic diseases, and photochemical water splitting offers a promising avenue to sustainable, environmentally friendly hydrogen production. Cobalt–phosphorus nanowires (CoP NWs) show a high fluorescence quenching ability and different affinity toward single‐ versus double‐stranded DNA. Based on this result, the utilization of CoP NWs as fluorescent DNA nanosensors with a detection limit of 100 pM and a selectivity down to single‐base mismatch was demonstrated. The use of a thrombin‐specific DNA aptamer also enabled the selective detection of thrombin. The photoinduced electron transfer from the excited dye that labels the oligonucleotide probe to the CoP semiconductor led to efficient fluorescence quenching, and largely enhanced the photocatalytic evolution of hydrogen from water under visible light.
Polyfunctional macromonomers obtained from 2,2‐bis(hydroxymethyl) propanoic acid and tall oil fatty acids
Authors: Mejía María C. , Murillo Edwin A.
Published: February 2015

Macromonomers (MMs) were obtained with different proportions of dimethylolpropionic acid (DMPA) and tall oil fatty acid (TOFA). The MMs were characterized by their acid value (AV), their hydroxyl value (OHV), IR spectroscopy, NMR, electrospray ionization–mass spectrometry, UV spectroscopy, rheological, differential scanning calorimetry, thermogravimetric analysis, gloss, flexibility, and adherence analyses. The presence of hydroxyl and ester groups and double bonds were confirmed by IR and NMR analyses. IR analysis showed that the intensity of the OH groups decreased with the addition of TOFA. In all cases, the AVs of the MMs were lower than those of DMPA and TOFA. By electrospray ionization–mass spectrometry, the formation of the DMPA homopolymers and structures with molecular weights higher than that of DMPA were observed. All of the MMs were amorphous. The viscosity of the MMs decreased with the addition of TOFA. The gloss values of the MMs at 85° were higher than 100, and the flexibility was good. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42029.
Response of Corynebacterium glutamicum exposed to oscillating cultivation conditions in a two‐ and a novel three‐compartment scale‐down bioreactor
Authors: Lemoine Anja , Maya Martίnez‐Iturralde Nina , Spann Robert , Neubauer Peter , Junne Stefan
Published: February 2015

The oscillatory conditions in substrate and oxygen supply that typically occur on a large (industrial) scale are usually simulated in two‐compartment scale‐down reactors. In this study, the performance of nutrient‐limited fed‐batch cultivations of Corynebacterium glutamicum in a standard two‐compartment reactor (two‐CR) is compared to the performance in a novel three‐compartment reactor (three‐CR). The three‐CR is designed to mimic three distinct zones of an industrial scale bioreactor that occur if the feed addition is installed at the bottom of the fluid phase. Our findings show that lactate and succinate appear in concentrations two‐fold higher in the three‐CR cultivation than in the two‐CR cultivation. Similar results are revealed for the amino acids glycine, threonine, glutamate, and glutamine. In contrast to the two‐CR cultivation, no intracellular accumulation of pyruvate is observed in the three‐CR cultivation, since the carbon fluxes are directed toward lactate. As previously reported, the expression of lactate dehydrogenase (LDH) is increased in the context of oxygen deprivation. Thus, C. glutamicum adapts to the oscillating environment in the three‐CR. This successful adaptation is revealed by a flow cytometric analysis of BOX‐stained cells and a series of electrooptical at line measurements of cell polarisability. Both methods indicate a higher polarisability of cells in the three‐CR cultivation. PI‐staining does not indicate any membrane damage or accelerated cell death in either system. However, although the strain shows robustness, the product yield of lysine is reduced in scale‐down cultivations as compared to cultivations at homogeneous conditions, which underlines the relevance of process optimization. Biotechnol. Bioeng. 2015;112: 1220–1231. © 2015 Wiley Periodicals, Inc.
Concepts and Case Studies in Chemical Biology. Edited by Herbert Waldmann and Petra Janning.
Authors: Kath‐Schorr Stephanie
Published: February 2015

Wiley, Hoboken 2014, 464 pp., softcover, $ 65.00.—ISBN 978‐3‐527‐33611‐1
A Simple Iridicycle Catalyst for Efficient Transfer Hydrogenation of N‐Heterocycles in Water
Authors: Talwar Dinesh , Li Ho Yin , Durham Emma , Xiao Jianliang
Published: February 2015

A cyclometalated iridium complex is shown to catalyse the transfer hydrogenation of various nitrogen heterocycles, including but not limited to quinolines, isoquinolines, indoles and pyridinium salts, in an aqueous solution of HCO2H/HCO2Na under mild conditions. The catalyst shows excellent functional‐group compatibility and high turnover number (up to 7500), with catalyst loadings as low as 0.01 mol % being feasible. Mechanistic investigation of the quinoline reduction suggests that the transfer hydrogenation proceeds via both 1,2‐ and 1,4‐addition pathways, with the catalytic turnover being limited by the step of hydride transfer.
Cobalt‐Catalyzed CH Arylations with Weakly‐Coordinating Amides and Tetrazoles: Expedient Route to Angiotensin‐II‐Receptor Blockers
Authors: Li Jie , Ackermann Lutz
Published: February 2015

Cobalt‐catalyzed CH arylations enabled the synthesis of biaryl tetrazoles, which are key structural motifs in antihypertensive angiotensin‐II‐receptor blockers. Thus, weakly‐coordinating benzamides were employed for step‐economical CH arylations with ample scope. Further, a low‐valent NHC complex enabled first cobalt‐catalyzed CH functionalization by tetrazole assistance.
A mixture of generalized hyperbolic distributions
Authors: Browne Ryan P. , McNicholas Paul D.
Published: February 2015

We introduce a mixture of generalized hyperbolic distributions as an alternative to the ubiquitous mixture of Gaussian distributions as well as their near relatives within which the mixture of multivariatet‐distributions and the mixture of skew‐tdistributions predominate. The mathematical development of our mixture of generalized hyperbolic distributions model relies on its relationship with the generalized inverse Gaussian distribution. The latter is reviewed before our mixture models are presented along with details of the aforesaid reliance. Parameter estimation is outlined within the expectation–maximization framework before the clustering performance of our mixture models is illustrated via applications on simulated and real data. In particular, the ability of our models to recover parameters for data from underlying Gaussian and skew‐tdistributions is demonstrated. Finally, the role of generalized hyperbolic mixtures within the wider model‐based clustering, classification, and density estimation literature is discussed.The Canadian Journal of Statistics43: 176–198; 2015 © 2015 Statistical Society of Canada
Volatility prediction based on scheduled macroeconomic announcements
Authors: Petralias Athanassios , Dellaportas Petros
Published: February 2015

We investigate the impact of scheduled macroeconomic announcements on the volatility of exchange rates by introducing a flexible model formulation. For each macroeconomic index we estimate cutoff points in the surprise component of the announcement that specify the degree the volatility process is affected. This degree is quantified by jumps of unknown size that occur before and at the time of the announcement and then die out exponentially with unknown rate. We make inferences using a population Markov chain Monte Carlo reversible jump algorithm and illustrate our methodology by predicting exchange rates volatility using 15 U.S. macroeconomic announcements. The Canadian Journal of Statistics 43: 199–223; 2015 © 2015 Statistical Society of Canada
Role of the Polymer Matrix on the Photoluminescence of Embedded CdSe Quantum Dots
Authors: Tselikov Gleb I. , Timoshenko Victor Yu , Golovan Leonid A. , Plenge Jürgen , Shatalova Alina M. , Shandryuk Georgiy A. , Kutergina Irina Yu , Merekalov Alexey S. , Rühl Eckart , Talroze Raisa V.
Published: February 2015

The photoluminescence (PL) of CdSe quantum dots (QDs) that form stable nanocomposites with polymer liquid crystals (LCs) as smectic C hydrogen‐bonded homopolymers from a family of poly[4‐(n‐acryloyloxyalkyloxy)benzoic acids] is reported. The matrix that results from the combination of these units with methoxyphenyl benzoate and cholesterol‐containing units has a cholesteric structure. The exciton PL band of QDs in the smectic matrix is redshifted with respect to QDs in solution, whereas a blueshift is observed with the cholesteric matrix. The PL lifetimes and quantum yield in cholesteric nanocomposites are higher than those in smectic ones. This is interpreted in terms of a higher order of the smectic matrix in comparison to the cholesteric one. CdSe QDs in the ordered smectic matrix demonstrate a splitting of the exciton PL band and an enhancement of the photoinduced differential transmission. These results reveal the effects of the structure of polymer LC matrices on the optical properties of embedded QDs, which offer new possibilities for photonic applications of QD–LC polymer nanocomposites.
Intense Upconversion Luminescence of CaSc2O4:Ho3+/Yb3+ from Large Absorption Cross Section and Energy‐Transfer Rate of Yb3+
Authors: Li Jing , Zhang Jiahua , Hao Zhendong , Chen Li , Zhang Xia , Luo Yongshi
Published: February 2015

Concentration‐optimized CaSc2O4:0.2 % Ho3+/10 % Yb3+ shows stronger upconversion luminescence (UCL) than a typical concentration‐optimized upconverting phosphor Y2O3:0.2 % Ho3+/10 % Yb3+ upon excitation with a 980 nm laser diode pump. The 5F4+5S2→5I8 green UCL around 545 nm and 5F5→5I8 red UCL around 660 nm of Ho3+ are enhanced by factors of 2.6 and 1.6, respectively. On analyzing the emission spectra and decay curves of Yb3+: 2F5/2→2F7/2 and Ho3+: 5I6→5I8, respectively, in the two hosts, we reveal that Yb3+ in CaSc2O4 exhibits a larger absorption cross section at 980 nm and subsequent larger Yb3+: 2F5/2→Ho3+: 5I6 energy‐transfer coefficient (8.55×10−17 cm3 s−1) compared to that (4.63×10−17 cm3 s−1) in Y2O3, indicating that CaSc2O4:Ho3+/Yb3+ is an excellent oxide upconverting material for achieving intense UCL.
Structural Transformation of ZnII‐Dipyridylamide‐Based Coordination Frameworks: Hybrid‐Ligand and Metal Effects
Authors: Tzeng Biing‐Chiau , Chang Tsung‐Yi , Tsai Miao‐Hsin , Lin Yu‐Ting , Lee Shiu‐Feng , Sheu Hwo‐Shuenn
Published: February 2015

A series of one‐dimensional (1D) double‐zigzag ({[Zn(papx)2(H2O)2](ClO4)2}n (x=so 1, sc 3, oc 5, and soc 7) and 2D polyrotaxane ([Zn(papx)2(ClO4)2]n (x=so 2, sc 4, oc 6, and soc 8) frameworks are synthesized by the reactions of Zn(ClO4)2 with equimolar amounts of papx (i.e., papso=1/2paps+1/2papo, papsc=1/2paps+1/2papc, papoc=1/2papo+1/2papc, and papsoc=1/3paps+1/3papo+1/3papc; paps=N,N′‐bis(pyridylcarbonyl)‐4,4′‐diaminodiphenyl thioether, papo=N,N′‐bis(pyridylcarbonyl)‐4,4′‐diaminodiphenyl ether, papc=N,N′‐(methylenedi‐p‐phenylene)bispyridine‐4‐carboxamide). The new frameworks are isolated and characterized by single‐crystal and powder X‐ray diffraction studies, elemental analysis, and 1H NMR spectroscopy. In addition, synthesis and structural characterization of 2D polyrotaxane frameworks of [Cu(papx)2(ClO4)2]n (x=s 9, o 10, and c 11) by the reaction of Cu(ClO4)2 with the respective dipyridylamide ligands are carried out. Based on the PXRD experiments, upon heating, the double‐zigzag frameworks of 1, 3, 5, and 7 undergo structural transformation to give the respective polyrotaxane frameworks of 2, 4, 6, and 8. Moreover, grinding the solid samples of 2, 4, 6, and 8 in the presence of moisture also result in the total conversion back into the double‐zigzag frameworks of 1, 3, 5, and 7, respectively. Remarkably, grinding the solid samples of polyrotaxane frameworks of 9 and 10 in the presence of moisture fails to induce a structural transformation process.
A first study comparing preservation of a ready‐to‐eat soup under pressure (hyperbaric storage) at 25°C and 30°C with refrigeration
Authors: Moreira Sílvia A. , Fernandes Pedro A. R. , Duarte Ricardo , Santos Diana I. , Fidalgo Liliana G. , Santos Mauro D. , Queirós Rui P. , Delgadillo Ivonne , Saraiva Jorge A.
Published: February 2015

Hyperbaric storage (HS), storage under pressure at 25°C and 30°C, of a ready‐to‐eat (RTE) soup was studied and compared with refrigeration. Soup was stored at different time (4 and 8 h), temperature (4°C, 25°C, and 30°C), and pressure (0.1, 100, and 150 MPa) conditions, to compare microbial loads and physicochemical parameters. HS resulted in similar (microbial growth inhibition) to better (microbial inactivation) results compared to refrigeration, leading to equal and lower microbial loads, respectively, at the end of storage. Lower/higher pressure (100 vs. 150 MPa) and shorter/longer storage times (4 vs. 8 h) resulted in more pronounced microbial growth inhibition/microbial inactivation. Aerobic mesophiles showed less susceptibility to HS, compared to Enterobacteriaceae and yeast and molds. HS maintained generally the physicochemical parameters at values similar to refrigeration. Thus, HS with no need for temperature control throughout storage and so basically energetically costless, is a potential alternative to refrigeration.
Cooperative genetic changes in pediatric B‐cell precursor acute lymphoblastic leukemia with deletions or mutations of IKZF1
Authors: Olsson Linda , Albitar Ferras , Castor Anders , Behrendtz Mikael , Biloglav Andrea , Paulsson Kajsa , Johansson Bertil
Published: February 2015

In contrast to IKZF1 deletions (ΔIKZF1), IKZF1 sequence mutations (mutIKZF1) have been reported to be rare in B‐cell precursor acute lymphoblastic leukemia and their clinical implications are unknown. We performed targeted deep sequencing of all exons of IKZF1 in 140 pediatric cases, eight (5.7%) of which harbored a mutIKZF1. The probabilities of relapse (pRel) and event‐free survival (pEFS) did not differ between cases with or without mutIKZF1, whereas pEFS was decreased and pRel increased in ΔIKZF1‐positive case. Coexisting microdeletions, mutations (FLT3, JAK2, SH2B3, and SPRED1), and rearrangements (ABL1, CRLF2, JAK2, and PDGFRB) in 35 ΔIKZF1 and/or mutIKZF1‐positive cases were ascertained using fluorescence in situ hybridization, single nucleotide polymorphism array, Sanger, and targeted deep sequencing analyses. The overall frequencies of copy number alterations did not differ between cases with our without ΔIKZF1/mutIKZF1. Deletions of HIST1, SH2B3, and the pseudoautosomal region (PAR1), associated with deregulation of CRLF2, were more common in ΔIKZF1‐positive cases, whereas PAR1 deletions and JAK2 mutations were overrepresented in the combined ΔIKZF1/mutIKZF1 group. There was no significant impact on pRel of the deletions in ΔIKZF1‐positive cases or of JAK2 mutations in cases with ΔIKZF1/mutIKZF1. In contrast, the pRel was higher (P = 0.005) in ΔIKZF1/mutIKZF1‐positive cases with PAR1 deletions. © 2015 Wiley Periodicals, Inc.
Preferential flow mechanisms identified from staining experiments in forested hillslopes
Authors: Gerke Kirill M. , Sidle Roy C. , Mallants Dirk
Published: February 2015

Field staining experiments in five different plots at two sites in Japan (Okaya in Nagano Prefecture and Konohara in Mie Prefecture) were undertaken to improve understanding of subsurface stormflow runoff within organic layers of natural forested hillslopes. This type of shallow lateral subsurface flow, specifically referred to as biomat flow, was observed only at the Okaya site based on staining experiments conducted under controlled water application rates. When the same irrigation rate (50–100 mm h−1) was applied to the Konohara site, overland flow without a significant shallow subsurface component was the dominant flow mechanism. Even in gently sloping (15–20°) forest soils at the Okaya site, biomat flow was responsible for lateral dye transport over much longer distances than subsurface flow in the matrix of mineral soil layers. Based on analysis of staining pattern images observed in the Okaya site, we conclude that (i) the organic biomat layer could be divided into two sub‐layers of different structure, (ii) biomat flow transported the dye tracer longer distances than subsurface flow in the matrix and (iii) the biomat layer topography affected biomat flow by generating preferential flowpaths and subsequent percolation into the deeper soil. Based on field experimental results and pore‐scale consideration of water infiltration into pores of soils with varying wettability properties, we hypothesized and developed a conceptual model for two key biomat flow mechanisms. The first mechanism considers lateral subsurface flow because of a permeability contrast between the much more porous and hence permeable biomat layer and the underlying mineral soil. The second mechanism involves a hydrophobic soil layer between the biomat and the underlying mineral soil. Flow across the hydrophobic layer is believed to occur when a threshold pore pressure is exceeded, i.e. as a result of a perched water table within the biomat layer. Lower pore pressures are needed to initiate flow when preferential flow paths exist, which are less hydrophobic than the surrounding organic layers. Numerical models of catchment hydrology should include lateral biomat flow when such layers are present in hillslope soils, in addition to typical subsurface flow within the soil matrix. Copyright © 2015 John Wiley & Sons, Ltd.
“Nomadic Knowledge”
Authors: Guzzetti Barbara J. , Foley Leslie M. , Lesley Mellinee
Published: February 2015

Adult men create zines (self‐publications written as alternative to commercial magazines) that advance content learning and knowledge. We describe three of these zine writers who created five zines on topics related to the disciplines of science, social studies, and English/language arts. We collected their zines, interviewed the authors, and analyzed their zines’ supporting social media. These men wrote to author their lives, share their passions for a discipline, and motivate their readers to explore topics on their own through alternative textual forms and forums. These zinesters used multi‐textual forms, fiction, and humor as tactical strategies to engage readers and in doing so, they provide models for incorporating the ethos of zines in content instruction. Recommendations are provided for appropriate and inappropriate uses of zines for content and disciplinary literacy teaching and learning.
Label‐free, zeptomole cancer biomarker detection by surface‐enhanced fluorescence on nanoporous gold disk plasmonic nanoparticles
Authors: Santos Greggy M. , Zhao Fusheng , Zeng Jianbo , Li Ming , Shih Wei‐Chuan
Published: February 2015

We experimentally demonstrate a label‐free biosensor for the ERBB2 cancer gene DNA target based on the distance‐dependent detection of surface‐enhanced fluorescence (SEF) on nanoporous gold disk (NPGD) plasmonic nanoparticles. We achieve detection of 2.4 zeptomole of DNA target on the NPGD substrate with an upper concentration detection limit of 1 nM. Without the use of molecular spacers, the NPGD substrate as an SEF platform was shown to provide higher net fluorescence for visible and NIR fluorophores compared to glass and non‐porous gold substrates. The enhanced fluorescence signals in patterned nanoporous gold nanoparticles make NPGD a viable material for further reducing detection limits for biomolecular targets used in clinical assays.

With patterned nanoporous gold disk (NPGD) plasmonic nanoparticles, a label‐free biosensor that makes use of distance‐dependent detection of surface‐enhanced fluorescence (SEF) is constructed and tested for zeptomole detection of ERBB2 cancer gene DNA targets.

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With patterned nanoporous gold disk (NPGD) plasmonic nanoparticles, a label‐free biosensor that makes use of distance‐dependent detection of surface‐enhanced fluorescence (SEF) is constructed and tested for zeptomole detection of ERBB2 cancer gene DNA targets.
Fe–Au and Fe–Ag composites as candidates for biodegradable stent materials
Authors: Huang Tao , Cheng Jian , Bian Dong , Zheng Yufeng
Published: February 2015

In this study, Fe–Ag and Fe–Au composites were fabricated by powder metallurgy using spark plasma sintering. Their microstructures, mechanical properties, and biocorrosion behavior were investigated by using optical microscopy, X‐ray diffraction, environment scanning electronic microscopy, compressive test, electrochemical measurements, and immersion tests. Microstructure characterization indicated that the as‐sintered iron‐based materials obtained much finer grains than that of as‐cast pure iron. Phase analysis showed that the Fe–Ag composites were composed of α‐Fe and pure Ag phases, and Fe–Au composites consisted of α‐Fe and Au phases. Compressive test showed that the improved mechanical strengths were obtained in as‐sintered iron‐based materials, among which the Fe‐5 wt %Ag exhibited the best mechanical properties. The electrochemical and immersion tests revealed that the addition of Ag and Au could increase the corrosion rate of the iron matrix and change the corrosion mode into more uniform one. Based on the results of cytotoxicity evaluation, it was found that all the experimental material extracts performed no significant toxicity on the L‐929 cells and EA. hy‐926 cells, whereas a considerable inhibition on the proliferation of vascular smooth muscle cells was observed. The hemocompatibility tests showed that the hemolysis of all the experimental materials was within the range of 5%, which is the criteria value of biomaterials with good hemocomaptibility. The amount of platelet adhered on the surface of as‐sintered iron‐based materials was lower than that of as‐cast pure iron, and the morphology of platelets kept smoothly spherical on the surface of all the experimental materials. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 225–240, 2016.
Quercetin Metabolites Up‐Regulate the Antioxidant Response in Osteoblasts Isolated From Fetal Rat Calvaria
Authors: Messer Jonathan G. , Hopkins Robin G. , Kipp Deborah E.
Published: February 2015

Oxidative stress contributes to osteoporosis by suppressing differentiation of osteoblasts, suggesting the osteoblast antioxidant response may be a viable strategy for osteoporosis prevention. Quercetin, an antioxidant flavonol, up‐regulates the antioxidant response in many cell types, but studies are needed to understand the effects of quercetin plasma metabolites on the osteoblast antioxidant response. The first specific aim was to examine antioxidant response genes and proteins in osteoblasts exposed to plasma quercetin metabolites. The second specific aim was to identify potential signaling pathways in the osteoblast antioxidant response that mediate the effect of quercetin, specifically Nrf2, ERK1/2, and NFκB p65. Osteoblasts isolated from fetal rat calvaria were treated with doses up to 20 μM of three different quercetin metabolites found in blood plasma after consumption of quercetin‐rich foods or supplements: quercetin aglycone (QRC), isorhamnetin (ISO), or quercetin 3‐O‐glucuronide (Q3G). Alternatively, some cells received a 2:1:1 mixture of all three metabolites (10 μM Q3G: 5 μM ISO: 5 μM QRC) to evaluate synergistic effects. Antioxidant response genes and proteins known to be up‐regulated by quercetin were analyzed along with Nrf2, ERK1/2, and NFκB proteins. Both QRC and ISO, but not Q3G, up‐regulated heme oxygenase‐1 (HO‐1) and γ‐glutamate cysteine ligase catalytic subunit (GCLC) at the mRNA and protein level. Synergistic effects of metabolites were not observed. Up‐regulation of HO‐1 and GCLC was associated with suppression of phosphorylated ERK1/2 and NFκB, but no alterations in Nrf2 protein levels were observed. This study shows that the antioxidant response of osteoblasts is differentially stimulated by quercetin metabolites. J. Cell. Biochem. 116: 1857–1866, 2015. © 2015 Wiley Periodicals, Inc.
Fep1d: A script for the analysis of reaction coordinates
Authors: Banushkina Polina V. , Krivov Sergei V.
Published: February 2015

The dynamics of complex systems with many degrees of freedom can be analyzed by projecting it onto one or few coordinates (collective variables). The dynamics is often described then as diffusion on a free energy landscape associated with the coordinates. Fep1d is a script for the analysis of such one‐dimensional coordinates. The script allows one to construct conventional and cut‐based free energy profiles, to assess the optimality of a reaction coordinate, to inspect whether the dynamics projected on the coordinate is diffusive, to transform (rescale) the reaction coordinate to more convenient ones, and to compute such quantities as the mean first passage time, the transition path times, the coordinate dependent diffusion coefficient, and so forth. Here, we describe the implemented functionality together with the underlying theoretical framework. © 2015 Wiley Periodicals, Inc.
Solution structure and DNA binding of the catalytic domain of the large serine resolvase TnpX
Authors: Headey Stephen J. , Sivakumaran Andrew , Adams Vicki , Lyras Dena , Rood Julian I. , Scanlon Martin J. , Wilce Matthew C. J.
Published: February 2015

The transfer of antibiotic resistance between bacteria is mediated by mobile genetic elements such as plasmids and transposons. TnpX is a member of the large serine recombinase subgroup of site‐specific recombinases and is responsible for the excision and insertion of mobile genetic elements that encode chloramphenicol resistance in the pathogens Clostridium perfringens and Clostridium difficile. TnpX consists of three structural domains: domain I contains the catalytic site, whereas domains II and III contain DNA‐binding motifs. We have solved the solution structure of residues 1–120 of the catalytic domain I of TnpX. The TnpX catalytic domain shares the same overall fold as other serine recombinases; however, differences are evident in the identity of the proposed hydrogen donor and in the size, amino acid composition, conformation, and dynamics of the TnpX active site loops. To obtain the interaction surface of TnpX1–120, we titrated a DNA oligonucleotide containing the circular intermediate joint attCI recombination site into 15N‐labeled TnpX1–120 and observed progressive nuclear magnetic resonance chemical shift perturbations using 15N HSQC spectra. Perturbations were largely confined to a region surrounding the catalytic serine and encompassed residues of the active site loops. Utilizing the perturbation map and the data‐driven docking program, HADDOCK, we have generated a model of the DNA interaction complex for the TnpX catalytic domain. Copyright © 2015 John Wiley & Sons, Ltd.
Screening of l‐histidine‐based ligands to modify monolithic supports and selectively purify the supercoiled plasmid DNA isoform
Authors: Amorim Lúcia F. A. , Sousa Fani , Queiroz João A. , Cruz Carla , Sousa Ângela
Published: February 2015

The growing demand of pharmaceutical‐grade plasmid DNA (pDNA) suitable for biotherapeutic applications fostered the development of new purification strategies. The surface plasmon resonance technique was employed for a fast binding screening of l‐histidine and its derivatives, 1‐benzyl‐l‐histidine and 1‐methyl‐l‐histidine, as potential ligands for the biorecognition of three plasmids with different sizes (6.05, 8.70, and 14 kbp). The binding analysis was performed with different isoforms of each plasmid (supercoiled, open circular, and linear) separately. The results revealed that the overall affinity of plasmids to l‐histidine and its derivatives was high (KD > 10−8 M), and the highest affinity was found for human papillomavirus 16 E6/E7 (KD = 1.1 × 10−10 M and KD = 3.34 × 10−10 M for open circular and linear plasmid isoforms, respectively). l‐Histidine and 1‐benzyl‐l‐histidine were immobilized on monolithic matrices. Chromatographic studies of l‐histidine and 1‐benzyl‐l‐histidine monoliths were also performed with the aforementioned samples. In general, the supercoiled isoform had strong interactions with both supports. The separation of plasmid isoforms was achieved by decreasing the ammonium sulfate concentration in the eluent, in both supports, but a lower salt concentration was required in the 1‐benzyl‐l‐histidine monolith because of stronger interactions promoted with pDNA. The efficiency of plasmid isoforms separation remained unchanged with flow rate variations. The binding capacity for pDNA achieved with the l‐histidine monolith was 29‐fold higher than that obtained with conventional l‐histidine agarose. Overall, the combination of either l‐histidine or its derivatives with monolithic supports can be a promising strategy to purify the supercoiled isoform from different plasmids with suitable purity degree for pharmaceutical applications. Copyright © 2015 John Wiley & Sons, Ltd.