bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ecosystem CO2/H2O fluxes are explained by hydraulically limited gas exchange during tree mortality from spruce bark beetles
Authors: Frank John M. , Massman William J. , Ewers Brent E. , Huckaby Laurie S. , Negrón José F. 
Published: May 2014

AbstractDisturbances are increasing globally due to anthropogenic changes in land use and climate. This study determines whether a disturbance that affects the physiology of individual trees can be used to predict the response of the ecosystem by weighing two competing hypothesis at annual time scales: (a) changes in ecosystem fluxes are proportional to observable patterns of mortality or (b) to explain ecosystem fluxes the physiology of dying trees must also be incorporated. We evaluate these hypotheses by analyzing 6 years of eddy covariance flux data collected throughout the progression of a spruce beetle (Dendroctonus rufipennis) epidemic in a Wyoming Engelmann spruce (Picea engelmannii)–subalpine fir (Abies lasiocarpa) forest and testing for changes in canopy conductance (gc), evapotranspiration (ET), and net ecosystem exchange (NEE) of CO2. We predict from these hypotheses that (a) gc, ET, and NEE all diminish (decrease in absolute magnitude) as trees die or (b) that (1) gc and ET decline as trees are attacked (hydraulic failure from beetle‐associated blue‐stain fungi) and (2) NEE diminishes both as trees are attacked (restricted gas exchange) and when they die. Ecosystem fluxes declined as the outbreak progressed and the epidemic was best described as two phases: (I) hydraulic failure caused restricted gc, ET (28 ± 4% decline, Bayesian posterior mean ± standard deviation), and gas exchange (NEE diminished 13 ± 6%) and (II) trees died (NEE diminished 51 ± 3% with minimal further change in ET to 36 ± 4%). These results support hypothesis b and suggest that model predictions of ecosystem fluxes following massive disturbances must be modified to account for changes in tree physiological controls and not simply observed mortality.
The two types of El‐Niño and their impacts on the length of day
Authors: de Viron O. , Dickey J. O. 
Published: April 2014

AbstractAt the interannual to decadal time scale, the changes in the Earth rotation rate are linked with the El‐Niño–Southern Oscillation phenomena through changes in the atmospheric angular momentum. As climatic studies demonstrate that there were two types of El‐Niño events, namely, eastern Pacific (EP) and central Pacific (CP) events, we investigate how each of them affects the atmospheric angular momentum. We show in particular that EP events are associated with stronger variations of the atmospheric angular momentum and length of day. We explain this difference by the stronger pressure gradient over the major mountain ranges, due to a stronger and more efficiently localized pressure dipole over the Pacific Ocean in the case of EP events.
Carboxylate‐Directed CH Functionalization
Authors: Shi Guangfa , Zhang Yanghui 
Published: April 2014

AbstractAs a widely existing functional group in organic molecules, the carboxyl group has numerous advantageous characteristics such as great convenience for further transformation, relatively low toxicity and cost, and weak coordination to transition metal catalysts, which render it an attractive directing group in transition metal‐catalyzed CH bond functionalization reactions. This review surveys transition metal‐catalyzed CH bond functionalization reactions directed by carboxylates, including carbon‐carbon, carbon‐oxygen, and other carbon‐heteroatom bond formation reactions. Reactions directed by the acidic N‐arylamides, which are derived from carboxylic acids and have a directing mode similar to that of carboxylates, are also presented here.magnified image
Palladium(0)‐Catalyzed CarbonHydrogen Bond Functionalization for the Synthesis of Indoloquinazolinones
Authors: Tsukano Chihiro , Okuno Masataka , Nishiguchi Hiromi , Takemoto Yoshiji 
Published: April 2014

AbstractThe indoloquinazolinone ring system has attracted considerable attention as a pharmacophore, because it shows various biological activities. The reported synthetic methods for the compound are simple and direct, but are not effective for the direct synthesis of indoloquinazolinone with a methylene group at the C‐6 position. A palladium(0)‐catalyzed cyclization of chloroquinazolinone via CH functionalization was developed for a concise synthesis of indoloquinazolinone derivatives. The presence of a substituent at the C‐6 position is important for obtaining the product in good yield. The conformation of the reaction intermediate, in particular the NCPd bond angle, is important for the regioselectivity of the reaction.magnified image
Tetra‐n‐butylammonium Bromide: A Simple but Efficient Organocatalyst for Alcohol Oxidation under Mild Conditions
Authors: Ma Xinyi , Li Zhongfeng , Liu Feijie , Cao Shengli , Rao Honghua 
Published: April 2014

AbstractA simple but efficient organocatalytic system with 5 mol% tetra‐n‐butylammonium bromide (TBAB) as the catalyst has been identified for alcohol oxidation for the first time. This organocatalytic system is compatible with a broad range of benzylic/allylic alcohols with various catalytically reactive groups. Besides, it shows excellent selectivity for secondary benzylic alcohols over aliphatic alcohols, and good selectivity over the primary benzylic alcohol site in 4‐(1‐hydroxyethyl)benzyl alcohol. Thus, the features of simplicity, high efficiency, selectivity and mildness of reaction conditions associated with this TBAB organocatalytic system suggest its potential for widespread use in synthetic chemistry.magnified image
Weakly Coordinating Directing Groups for Ruthenium(II)‐ Catalyzed CH Activation
Authors: De Sarkar Suman , Liu Weiping , Kozhushkov Sergei I. , Ackermann Lutz 
Published: April 2014

AbstractSynthetically useful functional groups, including ketones, amides, carbamates, carboxylic acids, aldehydes or ethers, have been identified as weakly coordinating directing groups in efficient ruthenium(II)‐catalyzed CH functionalizations. This strategy set the stage for versatile CH bond olefinations, oxygenations, nitrogenations and oxidative alkyne annulations among others. Thereby, step‐economical access to diversely decorated arenes and heteroarenes was provided in a sustainable fashion.magnified image
Palladium‐Catalyzed Direct Alkynylation of N‐Vinylacetamides
Authors: Xu Yun‐He , Zhang Qiu‐Chi , He Tao , Meng Fei‐Fan , Loh Teck‐Peng 
Published: April 2014

AbstractA direct ethynylation reaction between N‐vinylacetamides and (bromoethynyl)triisopropylsilane catalyzed by palladium is reported. A broad scope of cyclic N‐vinylacetamide derivatives was tolerated and the corresponding products could be obtained in acceptable yields. This work provides a general tool for the synthesis of conjugated enyne products using palladium(II) acetate as catalyst. The mild reaction conditions and reasonable results should make this method a useful synthetic protocol. Unfortunately, other bromo‐substituted alkynes are found to be unreactive and could not afford the desired products under the current reaction conditions.magnified image
Interrelationships between anthropometric variables and overweight in childhood and adolescence
Authors: Brannsether Bente , Eide Geir Egil , Roelants Mathieu , Bjerknes Robert , Júlíusson Pétur Benedikt 
Published: April 2014

ABSTRACTObjectivesTo answer the questions: how does body mass index (BMI) correlate to five overweight related anthropometric variables during different ages in childhood, and which anthropometric variables contribute most to variation in BMI during childhood?MethodsData on BMI, height (H), sitting height (SH), waist circumference (WC), waist to height ratio (WHtR), waist to sitting height ratio (WSHtR), subscapular skinfold (SSF), and triceps skinfold (TSF), from 4,576 Norwegian children 4.00–15.99 years of age, were transformed to standard deviation scores (SDS) and studied using correlation and multiple regression analyses.ResultsThe correlations between BMI SDS and the standardized anthropometric variables were in general strong and positive. For all variables, the correlations were weakest in the youngest age group and highest between 7 and 12 years. WC SDS and WHtR SDS were most strongly correlated with BMI SDS through all ages and in both sexes. A model with seven anthropometric variables adjusted for age and sex explained 81.4% of the variation in BMI SDS. When adjusted for all other variables, WC SDS contributed most to the variation in BMI SDS (b = 0.467, CI [0.372, 0.562]). Age group, but not sex, contributed significantly to variation in BMI SDS.ConclusionThe interrelationships between BMI SDS and five standardized overweight related anthropometric variables were dependent on age, being weakest in the youngest age group. Independent of sex and age, WC SDS was in this study superior to other anthropometric variables in contributing to variation in BMI SDS during childhood. Am. J. Hum. Biol. 26:502–510, 2014. © 2014 The Authors American Journal of Human Biology Published by Wiley Periodicals, Inc.
A morphological intermediate between eosimiiform and simiiform primates from the late middle Eocene of Tunisia: Macroevolutionary and paleobiogeographic implications of early anthropoids
Authors: Marivaux Laurent , Essid El Mabrouk , Marzougui Wissem , Khayati Ammar Hayet , Adnet Sylvain , Marandat Bernard , Merzeraud Gilles , Ramdarshan Anusha , Tabuce Rodolphe , Vianey‐Liaud Monique , Yans Johan 
Published: April 2014

ABSTRACTAlthough advanced anthropoid primates (i.e., Simiiformes) are recorded at the end of the Eocene in North Africa (Proteopithecidae, Parapithecidae, and Oligopithecidae), the origin and emergence of this group has so far remained undocumented. The question as to whether these primates are the result of a monophyletic radiation of endemic anthropoids in Africa, or several Asian clades colonizing Africa, is a current focus of paleoprimatology. In this article, we report the discovery of a new anthropoid from Djebel el Kébar in central Tunisia, dating from the late middle Eocene (Bartonian). This taxon, Amamria tunisiensis, new genus and species, currently known by only one isolated upper molar, is among the most ancient anthropoids to be recorded in Africa thus far. Amamria displays a suite of dental features that are primarily observed in Eosimiiformes (stem Anthropoidea). However, it is not allocated to any known family of that group (i.e., Asian Eosimiidae and Afro‐Asian Afrotarsiidae) inasmuch as it develops some dental traits that are unknown among eosimiiforms, but can be found in African simiiform anthropoids such as proteopithecids and oligopithecids. With such a mosaic of dental traits, Amamria appears to be a structural intermediate, and as such it could occupy a key position, close to the root of the African simiiforms. Given its antiquity and its apparent pivotal position, the possibility exists that Amamria could have evolved in Africa from Asian eosimiiform or Asian “proto”‐simiiform ancestors, which would have entered Africa sometime during the middle Eocene. Amamria could then represent one of the earliest offshoots of the African simiiform radiation. This view would then be rather in favor of the hypothesis of a monophyletic radiation of endemic simiiform anthropoids in Africa. Finally, these new data suggest that there must have been at least two Asian anthropoid colonizers of Africa: the afrotarsiids and the ancestor of Amamria. Am J Phys Anthropol 154:387–401, 2014. © 2014 Wiley Periodicals, Inc.
Effectiveness of an improved medical care system for children in a critical care medical center: is it possible to provide an equivalent level of trauma care for children as we do for adults?
Authors: Toida Chiaki , Muguruma Takashi , Matsuoka Tetsuya 
Published: April 2014

AimIn trauma care, most events that result in preventable trauma death tend to occur in the initial phase of treatment, and providing prompt and accurate care affects the outcomes of patients with severe trauma. Developing a system for administering prompt and accurate care and encouraging team coordination is essential for children as well as adults. However, differences in physical size and vital signs specific to children are potential obstacles to carrying out physical assessments, decision‐making, procedures, and treatments in pediatric patients. An improved medical care system for children was designed at the Osaka Prefectural Senshu Critical Care Medical Center. We evaluated the effectiveness of the new system.MethodsWe enrolled all patients with severe trauma admitted to our center. The therapeutic process and outcomes of trauma care before and after the establishment of the improved system was retrospectively compared.ResultsThe results showed a significant decline in the time required to establish an i.v. line and perform tracheal intubation before computed tomography. There were also no statistically significant differences in the timing of craniotomy or trepanation, or the time required to carry out hemostatic procedures, between children and adults. Furthermore, no patients with a probability of survival over 0.5 died following the establishment of the new system.ConclusionOur newly improved medical care system facilitates treatment for children using standards equivalent to those used in adults in critical care centers, regardless of the physical size and vital signs of the patient.
A Designed Amide as an Aldol Donor in the Direct Catalytic Asymmetric Aldol Reaction
Authors: Weidner Karin , Kumagai Naoya , Shibasaki Masakatsu 
Published: April 2014

AbstractThe direct catalytic asymmetric aldol reaction offers efficient access to β‐hydroxy carbonyl entities. Described is a robust direct catalytic asymmetric aldol reaction of α‐sulfanyl 7‐azaindolinylamide, thus affording both aromatic and aliphatic β‐hydroxy amides with high ee values. The design of this transformation features a cooperative interplay of a soft and a hard Lewis acid, which together facilitate the challenging chemoselective enolization by a hard Brønsted base.
Magnetobiosensors Based on Viral Protein p19 for MicroRNA Determination in Cancer Cells and Tissues
Authors: Campuzano Susana , Torrente‐Rodríguez Rebeca M. , López‐Hernández Eva , Conzuelo Felipe , Granados Rosario , Sánchez‐Puelles José M. , Pingarrón José M. 
Published: April 2014

AbstractMicroRNAs (miRs) have emerged as important clinical biomarkers with both diagnostic and prognostic value for relevant diseases, such as cancer. MiRs pose unique challenges for detection and are currently detected by northern blotting, real‐time PCR, and microarray techniques. These expensive, complicated, and time‐consuming techniques are not feasible for on‐site miR determination. In this study, amperometric magnetobiosensors involving RNA‐binding viral protein p19 as a selective biorecognition element were developed for miR quantification. The p19‐based magnetosensors were able to detect 0.4 fmol of a synthetic target and endogenous miR‐21 (selected as a model for its role in a wide variety of cancers) in only 2 h in total RNA extracted from cancer cells and human breast‐tumor specimens without PCR amplification and sample preprocessing. These results open up formidable perspectives for the diagnosis and prognosis of human cancers and for drug‐discovery programs.
Excited‐State Dynamics of Pentacene Derivatives with Stable Radical Substituents
Authors: Ito Akitaka , Shimizu Akihiro , Kishida Noriaki , Kawanaka Yusuke , Kosumi Daisuke , Hashimoto Hideki , Teki Yoshio 
Published: April 2014

AbstractThe excited‐state dynamics of pentacene derivatives with stable radical substituents were evaluated in detail through transient absorption measurements. The derivatives showed ultrafast formation of triplet excited state(s) in the pentacene moiety from a photoexcited singlet state through the contributions of enhanced intersystem crossing and singlet fission. Detailed kinetic analyses for the transient absorption data were conducted to quantify the excited‐state characteristics of the derivatives.
Significance of Branching for Transfection: Synthesis of Highly Branched Degradable Functional Poly(dimethylaminoethyl methacrylate) by Vinyl Oligomer Combination
Authors: Zhao Tianyu , Zhang Hong , Newland Ben , Aied Ahmed , Zhou Dezhong , Wang Wenxin 
Published: April 2014

AbstractA series of degradable branched PDMAEMA copolymers were investigated with the linear PDMAEMA counterpart as gene‐delivery vectors. The branched PDMAEMA copolymers were synthesized by controlled radical cross‐linking copolymerization based on the “vinyl oligomer combination” approach. Efficient degradation properties were observed for all of the copolymers. The degree of branching was found to have a big impact on performance in transfection when tested on different cell types. The product with the highest degree of branching and highest degree of functionality had a superior transfection profile in terms of both transfection capability and the preservation of cell viability. These branched PDMAEMA copolymers show high potential for gene‐delivery applications through a combination of the simplicity of their synthesis, their low toxicity, and their high performance.
Wearable Solar Cells by Stacking Textile Electrodes
Authors: Pan Shaowu , Yang Zhibin , Chen Peining , Deng Jue , Li Houpu , Peng Huisheng 
Published: April 2014

AbstractA new and general method to produce flexible, wearable dye‐sensitized solar cell (DSC) textiles by the stacking of two textile electrodes has been developed. A metal–textile electrode that was made from micrometer‐sized metal wires was used as a working electrode, while the textile counter electrode was woven from highly aligned carbon nanotube fibers with high mechanical strengths and electrical conductivities. The resulting DSC textile exhibited a high energy conversion efficiency that was well maintained under bending. Compared with the woven DSC textiles that are based on wire‐shaped devices, this stacked DSC textile unexpectedly exhibited a unique deformation from a rectangle to a parallelogram, which is highly desired in portable electronics. This lightweight and wearable stacked DSC textile is superior to conventional planar DSCs because the energy conversion efficiency of the stacked DSC textile was independent of the angle of incident light.
Drug release behavior of polyurethane/clay nanocomposite: Film vs. nanofibrous web
Authors: Saha Kasturi , Butola B. S. , Joshi Mangala 
Published: May 2014

ABSTRACTIn the present study, polyurethane/clay nanocomposite films have been prepared by solvent casting method. Antiseptic drug chlorhexidine acetate was intercalated into montmorillonite clay and then incorporated into the polyurethane film. For comparison, the drug was also added directly into the polymeric dope used for film casting. In addition to that, nanofibrous web containing neat drug and drug loaded clay were fabricated using electrospinning technique. The emphasis of the study was on investigating the effect of drug intercalated into nanoclay vis‐à‐vis direct drug loading in the polymer on the drug release behaviour of polyurethane nanocomposite films as well as nanofibrous webs. The effect of morphology (film vs. nanofibrous web) on the drug release kinetics has also been discussed. It is observed that the nanoclay is acting as a sustained release carrier of drug, and nanofibrous web exhibits higher drug release rate as compared to the film. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2014,131, 40824.
Extraction of fibers from saccharum munja grass and its application in composites
Authors: Singh Girendra Pal , Madiwale Pallavi Vishwas , Jagtap Ramanand N , Adivarekar Ravindra V 
Published: May 2014

ABSTRACTWith growing environmental awareness, ecological concerns and new legislations, natural fiber‐reinforced plastic composites have received increasing attention during the recent decades. The natural fiber composites have many advantages over traditional glass fiber composites, including lower cost, lighter weight, environmental friendliness, and recyclability. This article reports the findings of the studies done on a new fiber, hitherto unexplored, extracted from Saccharum munja grass. The extracted fibers were further treated using sodium hydroxide to improve its performance in composites. Both treated and untreated fiber‐reinforced composites were prepared by hand lay‐up process using unsaturated polyester resin. Mechanical properties and thermal behavior of the composites were evaluated. The improvement in properties was found for alkali‐treated fiber composites. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40829.
Surface imprinted core‐shell nanorod with ultrathin water‐compatible polymer brushes for specific recognition and adsorption of sulfamethazine in water medium
Authors: Dai Jiangdong , Zhou Zhiping , Zou Yongli , Wei Xiao , Dai Xiaohui , Li Chunxiang , Yan Yongsheng 
Published: May 2014

ABSTRACTA surface imprinted core‐shell nanorod with water‐compatible property was first prepared, using a two‐step “living” polymerization technique, with magnetic attapulgite (MATP) as core, and it was applicable in the enhanced selective removal of sulfamethazine residue from pure water environments. MATP was synthesized by an impregnation and pyrolysis method, and polymerable group was subsequently attached onto the surface. The imprinted polymer nanoshell (13 nm) with the “living” fragments was formed via a reverse atom transfer radical precipitation polymerization, avoiding the tedious graft of initiator and providing the easy‐accessible imprinted sites. Ultrathin hydrophilic polymer brushes (2.0 nm) were surface‐grafted to improve their water‐compatibility. The nanoadsorbent exhibited good thermal stability, magnetism, and hydrophilicity through characterization. The nanoadsorbent showed large adsorption capacity toward sulfamethazine from water, which increased with the increase of contact temperature. Langmuir isotherm fitted the equilibrium data better, and the kinetic data (within 45 min) were well‐analyzed by the pseudo‐second‐order kinetic model. Also, the specific adsorption property of the nanoadsorbent was greatly improved through the surface‐grafting, which exhibited excellent selectivity to sulfamethazine compared with other reference antibiotics. Efficient magnetic separation and good reuse of the nanoadsorbent provided the potential possibility for selective recognition and fast removal of antibiotic pollutions from water environments. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40854.