bluuebunny/crossref_metadata_2025 huggingface dataset:
Observed groundwater temperature response to recent climate change
Authors: Menberg K. , Blum P. , Kurylyk B. L. , Bayer P.
Published: March 2014

Abstract. Climate change is known to have a considerable influence on many components of the hydrological cycle. Yet, the implications for groundwater temperature, as an important driver for groundwater quality, thermal use and storage, are not yet comprehensively understood. Furthermore, few studies have examined the implications of climate change-induced groundwater temperature rise for groundwater-dependent ecosystems. Here, we examine the coupling of atmospheric and groundwater warming by employing stochastic and deterministic models. Firstly, several decades of temperature time-series are statistically analyzed with regard to abrupt climate regime shifts (CRS) in the long-term mean. The observed abrupt increases in shallow groundwater temperatures can be associated with preceding positive shifts in regional surface air temperatures, which are in turn linked to global air temperature changes. The temperature data are also analyzed with an analytical solution to the conduction-advection heat transfer equation to investigate how subsurface heat transfer processes control the propagation of the surface temperature signals into the subsurface. In three of the four monitoring wells, the predicted groundwater temperature increases driven by the regime shifts at the surface boundary condition generally concur with the observed groundwater temperature trends. Due to complex interactions at the ground surface and the heat capacity of the unsaturated zone, the thermal signals from distinct changes in air temperature are damped and delayed in the subsurface, causing a more gradual increase in groundwater temperatures. These signals can have a significant impact on large-scale groundwater temperatures in shallow and economically important aquifers. These findings demonstrate that shallow groundwater temperatures have responded rapidly to recent climate change and thus provide insight into the vulnerability of aquifers and groundwater-dependent ecosystems to future climate change.
Contextualizing the Glyphic Texts of Tipan Chen Uitz, Cayo District, Belize
Authors: Andres Christopher R. , Helmke Christophe , Morton Shawn G. , Wrobel Gabriel D. , González Jason J.
Published: March 2014

The 2011 investigations of the Caves Branch Archaeological Survey at the large and recently documented Maya site of Tipan Chen Uitz resulted in the discovery of the site's first monument with a glyphic inscription. Prior to this discovery, the site's glyphic corpus was limited to a small collection of texts rendered on fragmentary ceramics. In this paper, we describe these sherds as well as the monument (Monument 1), report on their archaeological contexts, provide an epigraphic analysis of the texts, and consider these written sources relative to our growing understanding of Tipan and its place in the ancient political landscape. The discovery of Monument 1 is important, for it stands to contribute to sociopolitical reconstructions in this part of the central Maya Lowlands and has significant implications for the possible presence of other, as yet undiscovered, Late Classic period (A.D. 550-830) monuments at Tipan.
Analog-assisted digital low dropout regulator with fast transient response and low output ripple
Authors: Mori Kazuaki , Okuma Yasuyuki , Zhang Xin , Fuketa Hiroshi , Sakurai Takayasu , Takamiya Makoto
Published: March 2014

An analog-assisted digital low dropout regulator (AAD-LDO) is proposed to solve the problems of a slow transient response and a large output ripple in a conventional digital LDO. In the AAD-LDO, a fast-response auxiliary analog LDO is added to the digital LDO in parallel. Compared with the digital LDO, the measured AAD-LDO in 180 nm CMOS reduces the transient response time and the output ripple by 59 and 28%, respectively, at the same current efficiency of 97.1%. The line regulation is 15 mV/V and the load regulation is 0.63 mV/mA.
Eficácia do glyphosate na dessecação de espécies de Urochloa
Authors: Silva Uadson Ramos da , Timossi Paulo César , Almeida Dieimisson Paulo , Lima Suzete Fernandes
Published: March 2014

Na operação de dessecação de plantas de cobertura do solo em áreas sob plantio direto o glyphosate é o herbicida mais utilizado. Com objetivo de determinar a susceptibilidade de plantas de cobertura ao glyphosate em operação de dessecação, três espécies do gênero Urochloa (Urochloa ruziziensis cv. Kennedy, U. decumbens cv. Basilisk e U. brizantha cv. BRS Piatã) e quatro doses de glyphosate (0; 0,72, 1,44 e 2,16 kg ha-1) foram estudadas em esquema de parcelas subdivididas (3x4). As avaliações de eficácia da dessecação foram realizadas aos 7, 14, 21 e 28 dias após a aplicação (DAA), através de notas visuais (0 a 100%). A U ruziziensis foi eficientemente controlada aos 14 DAA de glyphosate na dose de 1,44 kg ha-1, ou até os 28 DAA com 0,72 kg ha-1. Glyphosate aplicado na dose de 2,16 kg ha-1 não foi suficiente para controlar a U. decumbens até os 14 DAA, e assim como para U. brizantha até os 28 DAA. A velocidade de controle da cobertura vegetal formada por U. ruziziensis com glyphosate foi superior a U. decumbens e U. brizantha.
Resolving the fine‐scale density structure of shallow oceanic mantle by Bayesian inversion of localized geoid anomalies
Authors: Cadio C. , Korenaga J.
Published: March 2014

We present a new approach to estimate the density structure of shallow oceanic mantle by inversion of localized geoid anomalies. Our method is based on Bayesian statistics and is implemented by combining forward modeling with Markov Chain Monte Carlo sampling. The inherent nonuniqueness of such inversion is reduced by using spectral localization, reference models, and a priori bounds on the amplitude of density perturbations expected within the convecting mantle. We apply this approach to the geoid anomalies around the Mendocino Fracture Zone that have recently been revealed by wavelet analysis. The depth and vertical extent of density anomalies derived from our inversion indicate that they are intimately related to the structure of the lowermost lithosphere. The amplitude of density perturbations and their spatial organization suggest the occurrence of small‐scale convection induced by a lateral temperature gradient across the fracture zone. As its applicability is not limited to the vicinity of fracture zones, the new inversion method should allow us to resolve the fine‐scale density structure of shallow oceanic mantle beneath the world's oceans.
Evaluations of atmospheric downward longwave radiation from 44 coupled general circulation models of CMIP5
Authors: Ma Qian , Wang Kaicun , Wild Martin
Published: March 2014

Atmospheric downward longwave radiation at the surface (Ld) quantifies the atmospheric greenhouse effect. This study evaluated Ld simulations from 44 general circulation models (GCMs) in the Coupled Model Intercomparison Project Phase 5 (CMIP5) with a comprehensive data set of Ld observations at 156 global‐distributed sites from 1992 to 2005. Compared with the Baseline Surface Radiation Network data that are of the highest quality among the available Ld data sets, CMIP5 GCM Ld has a negligible bias, much better than CMIP3 GCMs, likely because of the improvement of low cloud simulations in CMIP5 models. However, the selection of validation data has an important impact on the evaluation results. The global mean Ld inferred from different bias‐removing methods are nearly the same, approximately 341 W m−2 globally averaged from 1992 to 2005. CMIP5 GCMs showed that global Ld increased at a rate of 1.54 W m−2 per decade (p < 0.01) from 1979 to 2005, which is consistent with available reanalyses. This good agreement in long‐term trends of Ld is likely because both reanalyses and CMIP5 models reproduced the observed warming and the associated increase of water vapor content in the lower atmosphere. However, CMIP5 GCMs are still poor in producing monthly anomalies of Ld.
Many‐objective reservoir policy identification and refinement to reduce policy inertia and myopia in water management
Authors: Giuliani M. , Herman J. D. , Castelletti A. , Reed P.
Published: March 2014

This study contributes a decision analytic framework to overcome policy inertia and myopia in complex river basin management contexts. The framework combines reservoir policy identification, many‐objective optimization under uncertainty, and visual analytics to characterize current operations and discover key trade‐offs between alternative policies for balancing competing demands and system uncertainties. The approach is demonstrated on the Conowingo Dam, located within the Lower Susquehanna River, USA. The Lower Susquehanna River is an interstate water body that has been subject to intensive water management efforts due to competing demands from urban water supply, atomic power plant cooling, hydropower production, and federally regulated environmental flows. We have identified a baseline operating policy for the Conowingo Dam that closely reproduces the dynamics of current releases and flows for the Lower Susquehanna and thus can be used to represent the preferences structure guiding current operations. Starting from this baseline policy, our proposed decision analytic framework then combines evolutionary many‐objective optimization with visual analytics to discover new operating policies that better balance the trade‐offs within the Lower Susquehanna. Our results confirm that the baseline operating policy, which only considers deterministic historical inflows, significantly overestimates the system's reliability in meeting the reservoir's competing demands. Our proposed framework removes this bias by successfully identifying alternative reservoir policies that are more robust to hydroclimatic uncertainties while also better addressing the trade‐offs across the Conowingo Dam's multisector services.
A machine learning approach for the prediction of settling velocity
Authors: Goldstein Evan B. , Coco Giovanni
Published: March 2014

We use a machine learning approach based on genetic programming to predict noncohesive particle settling velocity. The genetic programming routine is coupled to a novel selection algorithm that determines training data from a collected database of published experiments (985 measurements). While varying the training data set size and retaining an invariant validation set we perform multiple iterations of genetic programming to determine the least data needed to train the algorithm. This method retains a maximum quantity of data for testing against published predictors. The machine learning predictor for settling velocity performs better than two common predictors in the literature and indicates that particle settling velocity is a nonlinear function of all the provided independent variables: nominal diameter of the settling particle, kinematic viscosity of the fluid, and submerged specific gravity of the particle.
Microstructure and Properties of Carbon Fiber Reinforced SiC Matrix Composites Containing Ti3SiC2
Authors: Fan Xiaomeng , Yin Xiaowei
Published: March 2014

Carbon fiber reinforced ceramic matrix composites (CFCCs) are promising materials for high‐temperature applications. Due to the unique nanolaminated structure and special properties, the MAX phases are promising reinforcements for CFCCs. As one representative member of the MAX phases, Ti3SiC2 has been in situ formed in C/C‐SiC and C/SiC composites by a joint process of slurry infiltration and liquid silicon infiltration in recent years. The composites containing Ti3SiC2 exhibited improved mechanical properties, tribological performance, and ablation behavior compared with those of unmodified composites. The introduction of MAX phases in CFCCs could extend their application fields effectively, and it is expected to bring more benefits to CFCCs by introducing the MAX phases in the future.
Anodized ITO Thin‐Film Transistors
Authors: Shao Yang , Xiao Xiang , Wang Longyan , Liu Yang , Zhang Shengdong
Published: March 2014

This paper reports that the electrical, optical and structural properties of ITO film can be significantly modulated by an anodization treatment. An ITO TFT technology based on the anodization approach is then proposed and demonstrated, which results in an ideal homo‐junction device structure with the source/drain/pixel electrodes and channel region made of one single ITO layer. A preliminary device fabrication at room temperature shows the resulting TFT has an on/off current ratio exceeding 1 × 108, a saturation mobility of 29.0 cm2 V−1 s−1, and a subthreshold swing of 0.20 V per decade. This technology also allows a feasible VT adjustment and muti‐VT implementation.
A double‐blind, placebo‐controlled phase II study of the efficacy and safety of 2,2‐dimethylbutyrate (HQK‐1001), an oral fetal globin inducer, in sickle cell disease
Authors: Reid Marvin E. , El Beshlawy Amal , Inati Adlette , Kutlar Abdullah , Abboud Miguel R. , Haynes Johnson , Ward Richard , Sharon Bruce , Taher Ali T. , Smith Wally , Manwani Deepa , Ghalie Richard G.
Published: March 2014

This placebo‐controlled phase II study evaluated the pharmacodynamics, efficacy and safety of 2,2‐dimethylbutyrate (HQK‐1001), a fetal globin gene‐inducing short‐chain fatty acid derivative, administered orally at 15 mg/kg twice daily for 48 weeks in 76 subjects with sickle cell disease (SCD). The median age was 26 years (range: 12–55 years) and 37 subjects (49%) were treated previously with hydroxycarbamide. Sixty subjects (79%) had Hb SS and 16 (21%) had S/β0 thalassemia. The study was terminated after a planned interim analysis showed no significant increase in fetal hemoglobin (Hb F) and a trend for more pain crises in the HQK‐1001 group. For 54 subjects with Week 24 data, the mean absolute increase in Hb F was 0.9% (95% confidence interval (CI): 0.1–1.6%) with HQK‐1001 and 0.2% (95% CI: −0.7–1.1%) with placebo. Absolute increases in Hb F greater than 3% were noted in 9 of 38 subjects (24%) administered HQK‐1001 and 1 of 38 subjects (3%) administered placebo. The mean changes in hemoglobin at Week 24 were comparable between the two groups. The mean annualized rate of pain crises was 3.5 with HQK‐1001 and 1.7 with placebo. The most common adverse events in the HQK‐1001 group, usually graded as mild or moderate, consisted of nausea, headache, vomiting, abdominal pain, and fatigue. Additional studies of HQK‐1001 at this dose and schedule are not recommended in SCD. Intermittent HQK‐1001 administration, rather than a daily regimen, may be better tolerated and more effective, as shown previously with arginine butyrate, and warrants further evaluation. Am. J. Hematol. 89:709–713, 2014. © 2014 Wiley Periodicals, Inc.
A Bifunctional Perovskite Catalyst for Oxygen Reduction and Evolution
Authors: Jung Jae‐Il , Jeong Hu Young , Lee Jang‐Soo , Kim Min Gyu , Cho Jaephil
Published: March 2014

La0.3(Ba0.5Sr0.5)0.7Co0.8Fe0.2O3−δ is a promising bifunctional perovskite catalyst for the oxygen reduction reaction and the oxygen evolution reaction. This catalyst has circa 10 nm‐scale rhombohedral LaCoO3 cobaltite particles distributed on the surface. The dynamic microstructure phenomena are attributed to the charge imbalance from the replacement of A‐site cations with La3+ and local stress on Co‐site sub‐lattice with the cubic perovskite structure.
Modellierung von Wärmedissipation auf der Nanoskala: ein Einbettungsansatz für chemische Reaktionen auf Metalloberflächen
Authors: Meyer Jörg , Reuter Karsten
Published: March 2014

Wir präsentieren eine Einbettungstechnik für metallische Systeme, die es ermöglicht, Energiedissipation in Substratphononen während chemischer Reaktionen ausgehend von ersten Prinzipien zu modellieren. Die Trennung von chemischen und elastischen Beiträgen zum Wechselwirkungspotential liefert eine quantitative Beschreibung von elektronischer und phononischer Bandstruktur. Eine Anwendung auf O2‐Dissoziation auf Pd(100) sagt in ihren Translationsfreiheitsgraden “heiße” Sauerstoffadatome als eine Folge der dabei freigesetzten Energie (rund 2.6 eV) voraus. Dies stellt die instantane Thermalisierung von Reaktionsenthalpien in Frage, die sonst in der Modellierung von heterogener Katalyse angenommen wird.
High‐Quality Three‐Dimensional Nanoporous Graphene
Authors: Ito Yoshikazu , Tanabe Yoichi , Qiu H.‐J. , Sugawara Katsuaki , Heguri Satoshi , Tu Ngoc Han , Huynh Khuong Kim , Fujita Takeshi , Takahashi Takashi , Tanigaki Katsumi , Chen Mingwei
Published: March 2014

We report three‐dimensional (3D) nanoporous graphene with preserved 2D electronic properties, tunable pore sizes, and high electron mobility for electronic applications. The complex 3D network comprised of interconnected graphene retains a 2D coherent electron system of massless Dirac fermions. The transport properties of the nanoporous graphene show a semiconducting behavior and strong pore‐size dependence, together with unique angular independence. The free‐standing, large‐scale nanoporous graphene with 2D electronic properties and high electron mobility holds great promise for practical applications in 3D electronic devices.
Pigment–Acceptor–Catalyst Triads for Photochemical Hydrogen Evolution
Authors: Kitamoto Kyoji , Sakai Ken
Published: March 2014

In order to solve the problems of global warming and shortage of fossil fuels, researchers have been endeavoring to achieve artificial photosynthesis: splitting water into H2 and O2 under solar light illumination. Our group has recently invented a unique system that drives photoinduced water reduction through “Z‐scheme” photosynthetic pathways. Nevertheless, that system still suffered from a low turnover number (TON) of the photocatalytic cycle (TON=4.1). We have now found and describe herein a new methodology to make significant improvements in the TON, up to around TON=14–27. For the new model systems reported herein, the quantum efficiency of the second photoinduced step in the Z‐scheme photosynthesis is dramatically improved by introducing multiviologen tethers to temporarily collect the high‐energy electron generated in the first photoinduced step. These are unique examples of “pigment–acceptor–catalyst triads”, which demonstrate a new effective type of artificial photosynthesis.
Voltage‐Driven Reversible Insertion into and Leaving from a Lipid Bilayer: Tuning Transmembrane Transport of Artificial Channels
Authors: Si Wen , Li Zhan‐Ting , Hou Jun‐Li
Published: March 2014

Three new artificial transmembrane channel molecules have been designed and synthesized by attaching positively charged Arg‐incorporated tripeptide chains to pillar[5]arene. Fluorescent and patch‐clamp experiments revealed that voltage can drive the molecules to insert into and leave from a lipid bilayer and thus switch on and off the transport of K+ions. One of the molecules was found to display antimicrobial activity towardBacillus subtiliswith half maximal inhibitory concentration (IC50) of 10 μMwhich is comparable to that of natural channel‐forming peptide alamethicin.
Bio‐Inspired Photonic‐Crystal Microchip for Fluorescent Ultratrace Detection
Authors: Hou Jue , Zhang Huacheng , Yang Qiang , Li Mingzhu , Song Yanlin , Jiang Lei
Published: March 2014

Ultratrace detection attracts great interest because it is still a challenge to the early diagnosis and drug testing. Enriching the targets from highly diluted solutions to the sensitive area is a promising method. Inspired by the fog‐collecting structure on Stenocara beetle’s back, a photonic‐crystal (PC) microchip with hydrophilic–hydrophobic micropattern was fabricated by inkjet printing. This device was used to realize high‐sensitive ultratrace detection of fluorescence analytes and fluorophore‐based assays. Coupled with the fluorescence enhancement effect of a PC, detection down to 10−16 mol L−1 was achieved. This design can be combined with biophotonic devices for the detection of drugs, diseases, and pollutions of the ecosystem.
The Compressibility of pH‐Sensitive Microgels at the Oil–Water Interface: Higher Charge Leads to Less Repulsion
Authors: Geisel Karen , Isa Lucio , Richtering Walter
Published: March 2014

pH‐responsive microgels are unique stabilizers for stimuli‐sensitive emulsions that can be broken on demand by changing the pH value. However, recent experiments have indicated that electrostatic interactions play a different role to that in conventional Pickering emulsions. The influence of charges on the interactions between microgels at the oil–water interface is now described. Compression isotherms of microgels with different charge density and architecture were determined in a Langmuir trough, and counter‐intuitive results were obtained: Charged microgels can be compressed more easily than uncharged microgels. The compressibility of microgels is thus not determined by direct Coulomb repulsion. Instead, the different swelling of the microgels in the charged and the uncharged states is proposed to be the key parameter.
Controlled Electropolymerization of Ruthenium(II) Vinylbipyridyl Complexes in Mesoporous Nanoparticle Films of TiO2
Authors: Fang Zhen , Keinan Shahar , Alibabaei Leila , Luo Hanlin , Ito Akitaka , Meyer Thomas J.
Published: March 2014

Surface‐initiated, oligomeric assemblies of ruthenium(II) vinylpolypyridyl complexes have been grown within the cavities of mesoporous nanoparticle films of TiO2 by electrochemically controlled radical polymerization. Surface growth was monitored by cyclic voltammetry as well as UV/Vis and X‐ray photoelectron spectroscopy. Polymerization occurs by a radical chain mechanism following cyclic voltammetry scans to negative potentials where reduction occurs at the π* levels of the polypyridyl ligands. Oligomeric growth within the cavities of the TiO2 films occurs until an average of six repeat units are added to the surface‐bound initiator site, which is in agreement with estimates of the internal volumes of the pores in the nanoparticle films.
Mass transfer aspects of 3D cell cultures in tissue engineering
Authors: Mekala Naveen Kumar , Baadhe Rama Raju , Potumarthi Ravichandra
Published: March 2014

Tissue engineering strategies involving in vitro growth of cells over three‐dimensional scaffolds before implantation into the damaged portions represents a significant alternative to current clinical treatment methods. In order to improve this in vitro cell culture system, we need to focus on various engineering aspects, and each aspect has its own advantages and limitations. Undoubtedly, these engineering factors are critical for the successful development of tissues and organ products and the tissue engineering industry as well. These issues include elements of mass transport, biomaterials, biomechanics, and so on. Our focus in this review paper is to discuss the alternative strategies to overcome the mass transfer limitations in the three‐dimensional constructs, which have been widely researched for the tissue engineering purposes. © 2014 Curtin University of Technology and John Wiley & Sons, Ltd.
A convenient crosslinking method for sulfonated poly(ether ether ketone) membranes via friedel–crafts reaction using 1,6‐dibromohexane and aluminum trichloride
Authors: Han Sanghee , Zhang Mei‐Shan , Shin Junhwa , Lee Youn‐Sik
Published: March 2014

In this study, sulfonated poly(ether ether ketone) (SPEEK) was very efficiently crosslinked via a Friedel–Craft reaction using 1,6‐dibromohexane and AlCl3. The resulting crosslinked SPEEK (c‐SPEEK) membranes exhibited improved dimensional stability, thermal and chemical stability, and mechanical strength with slight reduction in the elongation. The methanol permeability was reduced by approximately two orders of magnitude by the crosslinking reaction. The proton conductivities of c‐SPEEK membranes were greater than Nafion‐212 in the temperature range of 30–90°C. Overall, this new crosslinking method can be conveniently and efficiently applicable to most aromatic hydrocarbon polymer membranes. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40695.
Zein‐based micro‐ and nano‐particles for drug and nutrient delivery: A review
Authors: Luo Yangchao , Wang Qin
Published: March 2014

Zein is the major storage protein from corn with strong hydrophobicity and unique solubility and has been considered as a versatile food biopolymer. Due to the special tertiary structures, zein can self‐assemble to form micro‐ and nano‐particles through liquid–liquid dispersion or solvent evaporation approaches. Zein‐based delivery systems have been particularly investigated for hydrophobic drugs and nutrients. Recently, increasing attention has been drawn to fabricate zein‐based advanced drug delivery systems for various applications. In this review, the molecular models of zein tertiary structure and possible mechanisms involved in zein self‐assembly micro‐ and nano‐particles are briefly introduced. Then, a state‐of‐the‐art introduction and discussion are given in terms of preparation, characterization, and application of zein‐based particles as delivery systems in the fields of food science, pharmaceutics, and biomedicine. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40696.
Toughening effects of nucleating agent on impact polypropylene copolymer
Authors: Sun Miaomiao , Gao Dali , Zhang Hongbo , Zou Hao , Xu Meng , Zhang Shijun , Li Jie , Liu Jianye
Published: March 2014

In this study, the impact polypropylene copolymer (IPC) blended with the sorbitol‐based nucleating agent (NA) NX8000 was prepared and then characterized using a wide range of instrumentations. The results showed that the NA formed a fibril network which resulted in the increased viscosity of system and the decreased size of ethylene–propylene random copolymer (EPR) phase. The results of mechanical tests revealed “the brittle–ductile transition (BDT)” occurred while the ethylene content was between 3.5 wt % and 6 wt % and indicated that the impact strength of IPC was greatly improved by the addition of NX8000 when the EPR content was right over the critical value of BDT. The investigations provided valuable information for the further development of IPC materials and boarded its potential industrial applications. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40705.
The B(C6F5)3 Boron Lewis Acid Route to Arene‐Annulated Pentalenes
Authors: Chen Chao , Harhausen Marcel , Fukazawa Aiko , Yamaguchi Shigehiro , Fröhlich Roland , Daniliuc Constantin G. , Petersen Jeffrey L. , Kehr Gerald , Erker Gerhard
Published: March 2014

4,5‐Dimethyl‐1,2‐bis(1‐naphthylethynyl)benzene (12) undergoes a rapid multiple ring‐closure reaction upon treatment with the strong boron Lewis acid B(C6F5)3 to yield the multiply annulated, planar conjugated π‐system 13 (50 % yield). In the course of this reaction, a C6F5 group was transferred from boron to carbon. Treatment of 12 with CH3B(C6F5)2 proceeded similarly, giving a mixture of 13 (C6F5‐transfer) and the product 15, which was formed by CH3‐group transfer. 1,2‐Bis(phenylethynyl)benzene (8 a) reacts similarly with CH3B(C6F5)2 to yield a mixture of the respective C6F5‐ and CH3‐substituted dibenzopentalenes 10 a and 16. The reaction is thought to proceed through zwitterionic intermediates that exhibit vinyl cation reactivities. Some B(C6F5)3‐substituted species (26, 27) consequently formed by in situ deprotonation upon treatment of the respective 1,2‐bis(alkynyl)benzene starting materials (24, 8) with the frustrated Lewis pair B(C6F5)3/P(o‐tolyl)3. The overall formation of the C6F5‐substituted products formally require HB(C6F5)2 cleavage in an intermediate dehydroboration step. This was confirmed in the reaction of a thienylethynyl‐containing starting material 21 with B(C6F5)3, which gave the respective annulated pentalene product 23 that had the HB(C6F5)2 moiety 1,4‐added to its thiophene ring. Compounds 12–14, 23, and 26 were characterized by X‐ray diffraction.
An examination of potential seasonal predictability in recent reanalyses
Authors: Feng Xia , Houser Paul
Published: March 2014

This study examined potential seasonal predictability of precipitation and 2‐m temperature in the recent global reanalyses from 1979 to 2012. The reanalyses being investigated are R1, R2, ERA‐40, JRA25, ERA‐I, MERRA, CFSR and 20CR. When compared against Global Precipitation Climatology Project (GPCP) precipitation, ERA‐I and CFSR provide the best estimates of potential predictability, MERRA, R1 and R2 overestimate predictability and ERA‐40 and JRA25 are unrealistic in the tropics. Predictability estimates of 2‐m temperature from 20CR, JRA25, R1, MERRA, CFSR and R2 exhibit better agreement with the reanalysis ensemble mean than ERA‐40 and ERA‐I, which identify less predictability.
Classic versus millennial medical lab anatomy
Authors: Benninger Brion , Matsler Nik , Delamarter Taylor
Published: March 2014

This study investigated the integration, implementation, and use of cadaver dissection, hospital radiology modalities, surgical tools, and AV technology during a 12‐week contemporary anatomy course suggesting a millennial laboratory. The teaching of anatomy has undergone the greatest fluctuation of any of the basic sciences during the past 100 years in order to make room for the meteoric rise in molecular sciences. Classically, anatomy consisted of a 2‐year methodical, horizontal, anatomy course; anatomy has now morphed into a 12‐week accelerated course in a vertical curriculum, at most institutions. Surface and radiological anatomy is the language for all clinicians regardless of specialty. The objective of this study was to investigate whether integration of full‐body dissection anatomy and modern hospital technology, during the anatomy laboratory, could be accomplished in a 12‐week anatomy course. Literature search was conducted on anatomy text, journals, and websites regarding contemporary hospital technology integrating multiple image mediums of 37 embalmed cadavers, surgical suite tools and technology, and audio/visual technology. Surgical and radiology professionals were contracted to teach during the anatomy laboratory. Literature search revealed no contemporary studies integrating full‐body dissection with hospital technology and behavior. About 37 cadavers were successfully imaged with roentograms, CT, and MRI scans. Students were in favor of the dynamic laboratory consisting of multiple activity sessions occurring simultaneously. Objectively, examination scores proved to be a positive outcome and, subjectively, feedback from students was overwhelmingly positive. Despite the surging molecular based sciences consuming much of the curricula, full‐body dissection anatomy is irreplaceable regarding both surface and architectural, radiological anatomy. Radiology should not be a small adjunct to understand full‐body dissection, but rather, full‐body dissection aids the understanding of radiology mediums. The millennial anatomy dissection laboratory should consist of, at least, 50% radiology integration during full‐body dissection. This pilot study is an example of the most comprehensive integration of full‐body dissection, radiology, and hospital technology. Clin. Anat. 27:988–993, 2014. © 2014 Wiley Periodicals, Inc.
Modulation by metformin of molecular and histopathological alterations in the lung of cigarette smoke‐exposed mice
Authors: Izzotti Alberto , Balansky Roumen , D'Agostini Francesco , Longobardi Mariagrazia , Cartiglia Cristina , Micale Rosanna T. , La Maestra Sebastiano , Camoirano Anna , Ganchev Gancho , Iltcheva Marietta , Steele Vernon E. , De Flora Silvio
Published: March 2014

The anti‐diabetic drug metformin is endowed with anti‐cancer properties. Epidemiological and experimental studies, however, did not provide univocal results regarding its role in pulmonary carcinogenesis. We used Swiss H mice of both genders in order to detect early molecular alterations and tumors induced by mainstream cigarette smoke. Based on a subchronic toxicity study, oral metformin was used at a dose of 800 mg/kg diet, which is 3.2 times higher than the therapeutic dose in humans. Exposure of mice to smoke for 4 months, starting at birth, induced a systemic clastogenic damage, formation of DNA adducts, oxidative DNA damage, and extensive downregulation of microRNAs in lung after 10 weeks. Preneoplastic lesions were detectable after 7.5 months in both lung and urinary tract along with lung tumors, both benign and malignant. Modulation by metformin of 42 of 1281 pulmonary microRNAs in smoke‐free mice highlighted a variety of mechanisms, including modulation of AMPK, stress response, inflammation, NFκB, Tlr9, Tgf, p53, cell cycle, apoptosis, antioxidant pathways, Ras, Myc, Dicer, angiogenesis, stem cell recruitment, and angiogenesis. In smoke‐exposed mice, metformin considerably decreased DNA adduct levels and oxidative DNA damage, and normalized the expression of several microRNAs. It did not prevent smoke‐induced lung tumors but inhibited preneoplastic lesions in both lung and kidney. In conclusion, metformin was able to protect the mouse lung from smoke‐induced DNA and microRNA alterations and to inhibit preneoplastic lesions in lung and kidney but failed to prevent lung adenomas and malignant tumors induced by this complex mixture.
CH Bond Activation during and after the Reactions of a Metallacyclic Amide with Silanes: Formation of a μ‐Alkylidene Hydride Complex, Its H–D Exchange, and β‐H Abstraction by a Hydride Ligand
Authors: Wang Li , Hunter Seth C. , Song Zhimin , Steren Carlos A. , Chen Tianniu , Wei Zhenhong , Cai Hu , Xue Zi‐Ling
Published: March 2014

Metallacyclic complex [(Me2N)3Ta(η2‐CH2SiMe2NSiMe3)] (3) undergoes CH activation in its reaction with H3SiPh to afford a Ta/μ‐alkylidene/hydride complex, [(Me2N)2{(Me3Si)2N}Ta(μ‐H)2(μ‐C‐η2‐CHSiMe2NSiMe3)Ta(NMe2)2] (4). Deuterium‐labeling studies with [D3]SiPh show H–D exchange between the TaDTa unit and all methyl groups in [(Me2N)2{(Me3Si)2N}Ta(μ‐D)2(μ‐C‐η2‐CHSiMe2NSiMe3)Ta(NMe2)2] ([D2]‐4) to give the partially deuterated complex [Dn]‐4. In addition, 4 undergoes β‐H abstraction between a hydride and an NMe2 ligand and forms a new complex [(Me2N){(Me3Si)2N}Ta(μ‐H)(μ‐N‐η2‐C,N‐CH2NMe)(μ‐C‐η2‐C,N‐CHSiMe2NSiMe3)Ta(NMe2)2] (5) with a cyclometalated, η2‐imine ligand. These results indicate that there are two simultaneous processes in [Dn]‐4: 1) H–D exchange through σ‐bond metathesis, and 2) HD elimination through β‐H abstraction (to give [Dn]‐5). Both 4 and 5 have been characterized by single‐crystal X‐ray diffraction studies.
The Mechanism of the One‐Step Synthesis of Hollow‐Structured Li3VO4 as an Anode for Lithium‐Ion Batteries
Authors: Shi Yi , Gao Jie , Abruña Héctor D. , Li Hui‐Jun , Liu Hua‐Kun , Wexler David , Wang Jia‐Zhao , Wu Yuping
Published: March 2014

In recent years, the controlled synthesis of inorganic micro‐ and nanostructures with hollow interiors has attracted considerable attention because of their widespread potential applications. A feasible method for synthesizing Li3VO4 by a template‐free, solution synthesis of single‐crystalline microboxes with well‐defined non‐spherical morphologies has been reported. This study provides the useful information to produce other hollow structure materials to the broad audience of readers. The formation of hollow structure and the influence of raw materials have been presented. The thus‐synthesized Li3VO4 exhibited significantly improved conductivity, rate capability, and cycling life compared to commercial graphite, synthesized Li4Ti5O12, and previously reported Li3VO4.
Efficient Palladium‐Catalyzed Aminocarbonylation of Aryl Iodides Using Palladium Nanoparticles Dispersed on Siliceous Mesocellular Foam
Authors: Tinnis Fredrik , Verho Oscar , Gustafson Karl P. J. , Tai Cheuk‐Wai , Bäckvall Jan‐E. , Adolfsson Hans
Published: March 2014

A highly dispersed nanopalladium catalyst supported on mesocellular foam (MCF), was successfully used in the heterogeneous catalysis of aminocarbonylation reactions. During the preliminary evaluation of this catalyst it was discovered that the supported palladium nanoparticles exhibited a “release and catch” effect, meaning that a minor amount of the heterogeneous palladium became soluble and catalyzed the reaction, after which it re‐deposited onto the support.
Hypoiodite‐Mediated Cyclopropanation of Alkenes
Authors: Yoshimura Akira , Koski Steven R. , Kastern Brent J. , Fuchs Jonathan M. , Jones T. Nicholas , Yusubova Roza Y. , Nemykin Victor N. , Zhdankin Viktor V.
Published: March 2014

An efficient, transition metal‐free procedure for the cyclopropanation of alkenes using malononitrile and the LiI‐tBuOCl combination under mild reaction conditions is described. The reaction mechanism most likely involves tBuOI generated in situ from LiI and tBuOCl. The utility of this new methodology has been demonstrated by the synthesis of a potential HIV‐1 RT inhibitor.
Study of the shade tabs of the toothguide 3D master through cluster analysis
Authors: Gómez‐Polo Cristina , Gómez‐Polo Miguel , Vázquez De Parga Juan Antonio Martínez , Celemín‐Viñuela Alicia
Published: March 2014

To find out whether the 26 shade tabs of the Toothguide 3D Master can be grouped according to the five groups of lightness proposed by the manufacturer (Vita‐Zahnfabrik) the three color coordinates L*, C*, and h were studied. Upper central incisor color was measured through the Easyshade Compact spectrophotometer using 1361 participants aged between 16 and 89. The color of the middle third was registered in the Toothguide 3D Master nomenclature and in the CIELCh‐system. Principal Component Analysis and Cluster analysis, were applied for data processing. The statistical analysis reveals the existence of five cluster groups. Cluster 1 comprises samples 1M1 ‐ 2L1.5 ‐ 2M1 ‐ 2R1.5 ‐ 3L1.5 ‐ 3M1. Cluster 2 comprises 1M2 ‐ 2L2.5 ‐ 2M2 ‐ 2M3 ‐ 2R2.5 −3M2 ‐ 3L2.5. Cluster 3 comprises 3R1.5 ‐ 4L1.5 ‐ 4L2.5 ‐ 4M1 ‐ 4M2 ‐ 4R1.5 ‐ 5M1. Cluster 4 comprises 3M3 ‐ 3R2.5 ‐ 4M3 ‐ 4R2.5. And, finally, Cluster 5 comprises: 5M2 ‐ 5M3. The 26 shade tabs in the Toothguide 3D Master can be grouped into five clusters following coordinates L*, C*, and h resulting from the dental spectrophotometer Vita Easyshade compact. The shade tabs that compose each cluster do not belong to the same lightness group. © 2014 Wiley Periodicals, Inc. Col Res Appl, 40, 194–200, 2015
Phosphate Monoester Hydrolysis by Trinuclear Alkaline Phosphatase; DFT Study of Transition States and Reaction Mechanism
Authors: Chen Shi‐Lu , Liao Rong‐Zhen
Published: March 2014

Alkaline phosphatase (AP) is a trinuclear metalloenzyme that catalyzes the hydrolysis of a broad range of phosphate monoesters to form inorganic phosphate and alcohol (or phenol). In this paper, by using density functional theory with a model based on a crystal structure, the AP‐catalyzed hydrolysis of phosphate monoesters is investigated by calculating two substrates, that is, methyl and p‐nitrophenyl phosphates, which represent alkyl and aryl phosphates, respectively. The calculations confirm that the AP reaction employs a “ping‐pong” mechanism involving two chemical displacement steps, that is, the displacement of the substrate leaving group by a Ser102 alkoxide and the hydrolysis of the phosphoseryl intermediate by a Zn2‐bound hydroxide. Both displacement steps proceed via a concerted associative pathway no matter which substrate is used. Other mechanistic aspects are also studied. Comparison of our calculations with linear free energy relationships experiments shows good agreement.
Indium phosphide nanofibers prepared by electrospinning method: Synthesis and characterization
Authors: Evcin Atilla , Bezir Nalan Çiçek , Kayalı Refik , Arı Mehmet , Kepekçi Deniz Belkıs
Published: March 2014

Nine sets of (3 × 3) InP nanofiber samples have been successfully prepared at three different voltages (20, 25, 30 kV) and at three separate heights (5, 7, 10 cm) by electrospinning with a constant precursor flow rate of 0.3 mLh−1. The crystalline structure, thermal, morphologies and nanostructure, electrical, and optical properties of the samples are characterized by X‐ray powder diffractometer (XRD) and thermal gravity‐differential scanning calorimeter (TG‐DSC), scanning electron microscopy (SEM), by Four‐Point Probe Technique (FPPT,) and ultraviolet/visible spectrometry (UV/VIS), respectively. From these measurements, we have found the formation of stoichiometric nanostructured InP with zinc‐blende structure and having lattice parameter of a = 5.874 Å, weight loss of 64.59% and crystallization temperature of 500°C, average fiber diameter of 65.82 nm, the activation energies, Ea, of the samples, and band gap energy, Eg, of the nanofibers developed at constant applied voltage 30 kV. The band gap energies determined at different distances 5, 7, and 10 cm are found to be as 1.29, 1.37, and 1.30 eV, respectively.
Secondary diabetic ketoacidosis and severe hypoglycaemia in patients with established type 1 diabetes mellitus in China: a multicentre registration study
Authors: Li Jin , Yang Daizhi , Yan Jinhua , Huang Bin , Zhang Yan , Weng Jianping ,   For the Guangdong Type 1 Diabetes Translational Study Group
Published: March 2014

Background

Diabetic ketoacidosis (DKA) and severe hypoglycaemia are common acute complications of type 1 diabetes mellitus (T1DM). This study aimed to determine the incidence of, and risk factors for, these complications in Chinese patients with established T1DM.

Methods

This cross‐sectional study recruited patients with established T1DM from 16 centres in Guangdong Province, China. Incidence rates were expressed as episodes/100 patient–years. Regression models identified risk factors for the occurrence and recurrence of secondary DKA and severe hypoglycaemia.

Results

A total of 611 patients with established T1DM (53.7% women) were recruited. The incidence of secondary DKA and severe hypoglycaemia was 26.4 (22.4, 31.0) and 68.8 (62.2, 76.0)/100 patient–years, respectively. Significant risk factors for secondary DKA were female gender [relative risk (RR) = 2.12], medical reimbursement rate <50% (RR = 1.84), uncontrolled diet (RR = 1.76), smoking (RR = 2.18) and poor glycaemic control [glycated haemoglobin A1c (HbA1c)/1.0% increase; RR = 1.15]. Overweight/obesity was a protective factor (RR = 0.57). Significant risk factors for severe hypoglycaemia included male gender (RR = 1.71), medical reimbursement rate < 50% (RR = 1.36), longer duration of T1DM (per 5‐year increase, RR = 1.22), underweight (RR = 1.44), uncontrolled diet (‘never controlled’ or ‘sometimes controlled’ vs. ‘usually controlled’, RR = 2.09 or 2.02, respectively), exercise <150 min/week (RR = 1.66), presence of neuropathy (RR = 1.89), smoking (RR = 1.48) and lower HbA1c values (per 1.0% decrease, RR = 1.46). Overweight/obesity was a protective factor (RR = 0.62). Additionally, 34.4% of secondary DKA and 81.1% of severe hypoglycaemia episodes occurred in 3.8% and 16.2% patients with recurrent events (≥two episodes), respectively.

Conclusions

The results indicate that secondary DKA and severe hypoglycaemia occur at high rates in Chinese patients with established T1DM and that recurrence is likely to occur in high‐risk patients. Comprehensive management of T1DM should include recommendations to control modifiable risk factors. Copyright © 2014 John Wiley & Sons, Ltd.
Genetic variation in UGT genes modify the associations of NSAIDs with risk of colorectal cancer: Colon cancer family registry
Authors: Scherer Dominique , Koepl Lisel M. , Poole Elizabeth M. , Balavarca Yesilda , Xiao Liren , Baron John A. , Hsu Li , Coghill Anna E. , Campbell Peter T. , Kleinstein Sarah E. , Figueiredo Jane C. , Lampe Johanna W. , Buck Katharina , Potter John D. , Kulmacz Richard J. , Jenkins Mark A. , Hopper John L. , Win Aung K. , Newcomb Polly A. , Ulrich Cornelia M. , Makar Karen W.
Published: March 2014

The use of non‐steroidal anti‐inflammatory drugs (NSAIDs) is associated with reduced risk of colorectal neoplasia. Previous studies have reported that polymorphisms in NSAID‐metabolizing enzymes central to NSAID metabolism including UDP‐glucuronosyltransferases (UGT) and cytochrome P450 (CYP) 2C9 may modify this protective effect. We investigated whether 35 functionally relevant polymorphisms within CYP2C9 and UGT genes were associated with colorectal cancer risk or modified the protective effect of NSAIDs on colorectal cancer susceptibility, using 1,584 colorectal cancer cases and 2,516 unaffected sibling controls from the Colon Cancer Family Registry. A three‐SNP genotype in UGT1A6 (G–A–A; Ala7–Thr181–Arg184) and the Asp85 variant in UGT2B15 increased the risk of colorectal cancer (OR 3.87; 95% CI 1.04–14.45 and OR 1.34; 95% CI 1.10–1.63, respectively). We observed interactions between UGT1A3 Thr78Thr (A>G) and NSAID use (P‐interaction = 0.02), a three‐SNP genotype within UGT2B4 and ibuprofen use (P‐interaction = 0.0018), as well as UGT2B15 Tyr85Asp (T>G) and aspirin use (P‐interaction = 0.01). The interaction with the UGT2B4 and the UGT2B15 polymorphisms were noteworthy at the 25% FDR level. This study highlights the need for further pharmacogenetic studies to identify individuals who might benefit from NSAID use as part of developing effective strategies for prevention of colorectal neoplasia. © 2014 Wiley Periodicals, Inc.
Usefulness of optical coherence tomography to detect central serous chorioretinopathy in monkeys
Authors: Park Hyun‐Kyu , Jo Woori , Choi Hyun‐Ji , Kim Bongcheol , Lee Gilnam , Seo Jeongbeob , Cho Suk Young , Kim Choung‐Soo , Choi Eun Kyung , Hwang Jung Jin , Lee Joo Yong , Yoon Young Hee , Son Woo‐Chan
Published: March 2014

Many systemic drugs can induce ocular toxicity and several ocular side‐effects have been identified in clinical studies. However, it is difficult to detect ocular toxicity in preclinical studies because of the lack of appropriate evaluation methods. Optical coherence tomography (OCT) is useful because it can provide real‐time images throughout a study period, whereas histopathology only provides images of sacrificed animals. Using OCT alongside histopathology, attempts were made to find effective approaches for screening of drug‐induced ocular toxicity in monkeys. Such approaches could be used in preclinical studies prior to human trials. Six male cynomolgus monkeys (Macaca fascicularis Raffles) were orally administered one of six candidate MAPK/ERK kinase (MEK) inhibitors. Central serous chorioretinopathy, a known side‐effect of such inhibitors, was identified in four monkeys by OCT. Artifacts generated during tissue processing meant that histopathology could not detect edematous changes. Thus, OCT is a useful tool to detect ocular toxicity which cannot be detected by histopathology in preclinical studies. Copyright © 2014 John Wiley & Sons, Ltd.