bluuebunny/crossref_metadata_2025_split huggingface dataset:
Migration of atmospheric convection coupled with ocean currents pushes El Niño to extremes
Authors: Kim WonMoo , Cai Wenju , Kug Jong‐Seong 
Published: April 2015

AbstractThe warm phase of El Niño–Southern Oscillation can grow much stronger than the cold phase, but the associated dynamics are not well understood. Here we show that the anomalous zonal advection of warm water is the major process that pushes El Niño to extremes and that this anomalous advection results from the coupling of oceanic currents with eastward migration of the atmospheric convection; a greater zonal advection is associated with a greater extent of the eastward migration. By contrast, there is a limited extent for westward migration during La Niña. Climate models that successfully simulate the amplitude asymmetry display a systematic linkage of a greater longitudinal movement of the convection center with a stronger zonal advection and greater El Niño amplitude. In a warming world, the longitudinal migration of convection response increases, as does the role of zonal advection, increasing the frequency of future extremes of El Niño.
A Further Decrease in the Catalyst Loading for the Palladium‐Catalyzed Direct Intramolecular Arylation of Amides and Sulfonamides
Authors: Conde Nerea , Churruca Fátima , SanMartin Raul , Herrero María Teresa , Domínguez Esther 
Published: April 2015

AbstractThe direct arylation of N‐substituted o‐bromobenzanilides and benzenesulfonamides via CH bond functionalization has been developed using very low catalyst loadings. This novel cost‐effective and more sustainable method relies on a PCN‐type palladium pincer complex as a highly active palladium source, providing a general and efficient access to phenanthridinones, biaryl sultams and related heterocyclic systems. The beneficial effect of water as cosolvent has been observed in this process, which is not seriously influenced by electronic effects at the arene moieties or sterically demanding substituents at the amide or sulfonamide nitrogen. In addition, a number of experiments (kinetic plot, poisoning assays, TEM, ESI) have been performed in order to understand the role of the employed palladium complex in this reaction.magnified image
Phase Behaviors of PU/SPI Green Composites Using SAXS Profiles
Authors: Madhukar B. S. , Bhadre Gowda D. G. , Annadurai V. , Somashekar R. , Siddaramaiah  
Published: April 2015

ABSTRACTA series of polyurethane (PU) green composites have been synthesized with varying amounts, namely 0, 2, 4, 8, and 12 wt% of soya protein isolate (SPI) by two methods. In the first method, castor oil (CO) and toluene‐2,4‐diisocyanate (TDI) molar ratio is CO/TDI : 1/1 with varying amounts of the SPI content. In the second method, the molar ratio of TDI is calculated by considering the –OH groups of both CO and SPI. We made the assumption that, in the first method, SPI acts as a filler and in the second method SPI is one of the coreactants in PU formation. The mechanical properties of the fabricated PU/SPI green composites are evaluated; and it is found that the tensile strength increases up to 8 wt% of SPI, and a further increase in SPI leads to reduction in the tensile strength. The small angle x‐ray scattering profiles have been used to evaluate the arrangement of amorphous (A) and crystalline (C) regions in the PU/SPI green composites in a scale of about 700 Ǻ by considering the variation in scattered intensity with scattering angles ranging from 0.3° to 1.5°. For this purpose, a linear paracrystalline model is used. In this study, the exponential distribution of phase lengths gives a good agreement between the measured and computed data on the basis of a linear paracrystal model. It is observed that there are significant changes in the distribution of phase lengths due to changes in the composition and chemical structure of PU/SPI composites obtained by methods 1 and 2.
Women who deliver twins are more likely to smoke and have high frequencies of specific SNPs: Results from a sample of African–American women who delivered preterm, low birth weight babies
Authors: Huang Hong , Clancy Kathryn B.H. , Burhance Crystal , Zhu Yilliang , Madrigal Lorena 
Published: April 2015

ObjectivesWe examine if there are genetic and environmental differences between mothers of singleton and multiple pregnancies in a sample of African–American mothers.MethodsWe focus on genomic areas suggested to increase or decrease the odds of multiple pregnancies. We computed the odds ratio (OR) and the 95% confidence interval (CI) for each SNP unadjusted or adjusted with smoking. SNPs' allelic differences between mothers of multiple pregnancies and singletons were also tested using Fisher's exact test. We considered additive terms for the SNPs' genotypes, smoking, and a multiplicative interaction term of two selected SNPs' genotypes.ResultsWe found significant interactions between smoking and SNPs of the CYP19A, MDM4, MTHFR and TP53 genes which correlated with higher odds of twinning. We also found a significant interaction between SNPs at the TP53 (rs8079544) and MTHFR gene (rs4846049), where the interaction between the homozygotes (TT for rs8079544, GG for rs4846049) correlated with lowered odds of multiple pregnancy.ConclusionsWe provide a mechanistic explanation and preliminary evidence for previous reports that mothers of twins are more likely to have smoked, despite seemingly conflicting evidence for the fertility‐reducing effects of nicotine. Nicotine, as an aromatase inhibitor, inhibits estrogen synthesis and may allow for greater production of gonadotropins. While smoking may have deleterious effects on fertility across many genotypes, in women of specific genotypes it may raise their odds of producing twins. TP53 involvement suggests the necessity of future work examining relationships between women who bear multiples and cancer risk. Am. J. Hum. Biol. 27:605–612, 2015. © 2015 Wiley Periodicals, Inc.
Fragmentation of polymer‐bridged silica flocs by high shear impact: experiment and population balance modelling
Authors: Au Pek‐Ing , Leong Yee‐Kwong 
Published: April 2015

AbstractFragmentation of polymer‐bridged flocs is commonly encountered in many areas of suspension processing such as solid–liquid separation, washing and clarification. The effect of high shear impact on the fragmentation of polyelectrolyte‐bridged silica flocs was investigated. The monodisperse silica suspension was first flocculated and then subjected to prolonged breakage in a shear field until a constant size distribution was attained. These flocs were then subjected to high shear impact breakage. The evolution of particle size distribution vs shearing time was monitored. This temporal evolution of size density function was compared with that obtained via population balance modelling converted to logarithmic scale to counter the 6–12 decades in particle size in volume. The Method of Lines (MoL) was employed to solve the equation. At lower breakage speed of 1500 rpm, excellent agreement between experimental and model size density functions was obtained where excellent matching was observed with the first and second moments. However, at the higher speed of 2500 rpm, the agreement is less satisfactory particularly with the variance. Scanning electron microscope images showed physical breakage of particles at this high shear rate. © 2015 Curtin University of Technology and John Wiley & Sons, Ltd.
Chlorination of glycerol with HCl to 1,3‐dichloro‐2‐propanol catalyzed by aliphatic carboxylic acids
Authors: Hou Xiangxiang , Fu Yujun , Zhu Xiaoyan , Yin Hengbo , Wang Aili 
Published: April 2015

AbstractGlycerol oversupplied in biodiesel production can be used as a renewable raw material for producing high‐valued chemicals, such as 1,3‐dichloro‐2‐propanol (1,3‐DCP), propanediol, acrolein, and acrylic acid. Catalytic chlorination of glycerol to 1,3‐DCP is an alternative to propylene chlorination. The catalytic activities of various aliphatic carboxylic acid catalysts for the catalytic chlorination of glycerol with HCl to 1,3‐DCP were investigated. When monocarboxylic acids, such as acetic, propanoic, butyric, and hexylic acids, were used as the catalysts, the monocarboxylic acids with the carbon numbers of 3 and 4 favored the glycerol chlorination to 1,3‐DCP. When dicarboxylic acids, such as oxalic, malonic, succinic, and adipic acids, were used as the catalysts, the dicarboxylic acids with long carbon chain favored the glycerol chlorination to 1,3‐DCP. The highest yield of 1,3‐DCP of 88.6% was obtained over adipic acid catalyst after reacting at 110 °C for 14 h. When hydroxylcarboxylic acids, such as citric, malic, and lactic acids, were used as the catalysts, the 1,3‐DCP yields were approximately half of those over monocarboxylic and dicarboxylic acid catalysts with the same carbon number, respectively. The steric hindrance effect of carboxylic acids played an important role in glycerol chlorination to 1,3‐DCP as compared with their acid strengths. © 2015 Curtin University of Technology and John Wiley & Sons, Ltd.
Electrically conductive polymeric bi‐component fibers containing a high load of low‐structured carbon black
Authors: Nilsson Erik , Rigdahl Mikael , Hagström Bengt 
Published: April 2015

ABSTRACTMelt spinning at semi‐industrial conditions of carbon black (CB) containing textiles fibers with enhanced electrical conductivity suitable for heating applications is described. A conductive compound of CB and high density polyethylene (HDPE) was incorporated into the core of bi‐component fibers which had a sheath of polyamide 6 (PA6). The rheological and fiber‐forming properties of a low‐structured and a high‐structured CB/HDPE composite were compared in terms of their conductivity. The low‐structured CB gave the best trade‐off between processability and final conductivity. This was discussed in terms of the strength of the resulting percolated network of carbon particles and its effect on the spin line stability during melt spinning. The conductivity was found to be further enhanced with maintained mechanical properties by an in line thermal annealing of the fibers at temperatures in the vicinity of the melting point of HDPE. By an adequate choice of CB and annealing conditions a conductivity of 1.5 S/cm of the core material was obtained. The usefulness of the fibers for heating applications was demonstrated by means of a woven fabric containing the conductive fibers in the warp direction. By applying a voltage of 48 V the surface temperature of the fabric rose from 20 to 30°C. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42255.
Bio‐based multilayer barrier films by extrusion, dispersion coating and atomic layer deposition
Authors: Vartiainen Jari , Shen Yingfeng , Kaljunen Timo , Malm Tero , Vähä‐Nissi Mika , Putkonen Matti , Harlin Ali 
Published: April 2015

ABSTRACTA single biopolymer film rarely has a competitive edge against synthetic films. One solution is to combine several layers with different properties into multilayer structures. In this way, for example, the barrier properties of bio‐based materials can be improved. In this study, the multilayer films are produced by combining three different techniques/materials: 1) dispersion coating (cellulose nanofibrils, CNF), 2) atomic layer deposition (Al2O3; aluminum oxide), and 3) extrusion coating (polyglycolic acid, PGA). Especially the CNF and PGA‐containing multilayer films show promising oxygen barrier improvements at different humidities. Thin inorganic coatings are brittle and sensitive toward stresses during converting, which may limit their use in such specific multilayer structures. The developed bio‐based films largely fulfill the barrier requirements of fresh food packaging. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42260.
H2A.Z helps genes remember their history so we can remember ours
Authors: Zovkic Iva B. , Walters Brandon J. 
Published: April 2015

Histone variant exchange is a novel epigenetic regulator of cognition. We speculate that H2A.Z, a variant of canonical histone H2A, exerts unique effects on transcription during distinct stages of memory formation, ultimately acting to maintain memory of previous transcriptional states and poise genes for re‐activation. Hippocampus‐dependent memory formation is initiated by transient expression of memory‐related genes, which support the storage of recently acquired memories. Soon after, memories undergo systems consolidation, which transfers memories from the hippocampus to the cortex for long‐term storage, and requires ongoing re‐activation of memory‐related genes. We speculate that learning‐induced H2A.Z eviction from nucleosomes initially contributes to stimulus‐induced transcriptional induction needed for the initial process of memory consolidation. During systems consolidation, we speculate that delayed incorporation of H2A.Z into nucleosomes of memory‐related genes in the cortex is needed to poise genes for rapid re‐activation, thus supporting the long‐term process of memory stabilization.Also watch the Video Abstract
Learning curve for laparoscopic major hepatectomy
Authors: Nomi T , Fuks D , Kawaguchi Y , Mal F , Nakajima Y , Gayet B 
Published: April 2015

Abstract

Background
Laparoscopic major hepatectomy (LMH) is evolving as an important surgical approach in hepatopancreatobiliary surgery. The present study aimed to evaluate the learning curve for LMH at a single centre.

Methods
Data for all patients undergoing LMH between January 1998 and September 2013 were recorded in a prospective database and analysed. The learning curve for operating time (OT) was evaluated using the cumulative sum (CUSUM) method.

Results
Of 173 patients undergoing major hepatectomy, left hepatectomy was performed in 28 (16·2 per cent), left trisectionectomy in nine (5·2 per cent), right hepatectomy in 115 (66·5 per cent), right trisectionectomy in 13 (7·5 per cent) and central hepatectomy in eight (4·6 per cent). Median duration of surgery was 270 (range 100–540) min and median blood loss was 300 (10–4500) ml. There were 20 conversions to an open procedure (11·6 per cent). Vascular clamping was independently associated with conversion on multivariable analysis (hazard ratio 5·95, 95 per cent c.i. 1·24 to 28·56; P = 0·026). The CUSUMOT learning curve was modelled as a parabola (CUSUMOT = 0·2149 × patient number2 − 30·586 × patient number − 1118·3; R2 = 0·7356). The learning curve comprised three phases: phase 1 (45 initial patients), phase 2 (30 intermediate patients) and phase 3 (the subsequent 98 patients). Although right hepatectomy was most common in phase 1, a significant decrease was observed from phase 1 to 3 (P = 0·007) in favour of more complex procedures.

Conclusion
The learning curve for LMH consisted of three characteristic phases identified by CUSUM analysis. The data suggest that the learning phase of LMH included 45 to 75 patients.
Identification and Biological Evaluation of Secondary Metabolites from the Endolichenic Fungus Aspergillus versicolor
Authors: Li Xiao‐Bin , Zhou Yan‐Hui , Zhu Rong‐Xiu , Chang Wen‐Qiang , Yuan Hui‐Qing , Gao Wei , Zhang Lu‐Lu , Zhao Zun‐Tian , Lou Hong‐Xiang 
Published: April 2015

AbstractA chemical investigation of the endolichenic fungus Aspergillus versicolor (125a), which was found in the lichen Lobaria quercizans, resulted in the isolation of four novel diphenyl ethers, named diorcinols F–H (1–3, resp.) and 3‐methoxyviolaceol‐II (4), eight new bisabolane sesquiterpenoids, named (−)‐(R)‐cyclo‐hydroxysydonic acid (5), (−)‐(7S,8R)‐8‐hydroxysydowic acid (6), (−)‐(7R,10S)‐10‐hydroxysydowic acid (7), (−)‐(7R,10R)‐iso‐10‐hydroxysydowic acid (8), (−)‐12‐acetoxy‐1‐deoxysydonic acid (9), (−)‐12‐acetoxysydonic acid (10), (−)‐12‐hydroxysydonic acid (11), and (−)‐(R)‐11‐dehydrosydonic acid (12), two new tris(pyrogallol ethers), named sydowiols D (13) and E (14), and fifteen known compounds, 15–29. All of the structures were determined by spectroscopic analyses, and a number of them were further identified through chemical transformations and electronic circular dichroism (ECD) calculations. Preliminary bioassays of these isolates for the determination of their inhibitory activities against the fungus Candida albicans, and their cytotoxicities against the human cancer cell lines PC3, A549, A2780, MDA‐MB‐231, and HEPG2 were also evaluated.
Sesquiterpenoids with Anti‐MDR Staphylococcus aureus Activities from Ferula ferulioides
Authors: Liu Tao , Wang Shuangying , Xu Lili , Fu Wei , Gibbons Simon , Mu Qing 
Published: April 2015

AbstractSeven new sesquiterpenoids together with 21 known sesquiterpenoid derivatives were isolated from the medicinal plant Ferula ferulioides (Steud.) Korovin. Their structures were elucidated by comprehensive spectroscopic analyses and chemical transformations. The isolated compounds were evaluated for their antibacterial activities against a panel of bacteria including multidrug‐resistant (MDR) and methicillin‐resistant Staphylococcus aureus (MRSA), displaying minimum inhibitory concentration (MIC) values in the range of 0.5–128 mg/l.
Insecticidal and Repellant Activities of Polyacetylenes and Lactones Derived from Atractylodes lancea Rhizomes
Authors: Chen Hai‐Ping , Zheng Li‐Shi , Yang Kai , Lei Ning , Geng Zhu‐Feng , Ma Ping , Cai Qian , Du Shu‐Shan , Deng Zhi‐Wei 
Published: April 2015

AbstractDuring a screening program for new agrochemicals from Chinese medicinal herbs and local wild plants, the petroleum ether (PE) extract of Atractylodes lancea (Thunb.) rhizomes was found to possess repellent and contact activities against Tribolium castaneum adults. Bioactivity‐directed chromatographic separation of PE extract on repeated silica‐gel columns led to the isolation of two polyacetylenes, atractylodin and atractylodinol (1 and 2, resp.), and two lactones, atractylenolides II and III (3 and 4, resp.). The structures of the compounds were elucidated based on NMR spectra. The four isolated compounds were evaluated for their insecticidal and repellent activities against T. castaneum. Atractylodin exhibited strong contact activity against T. castaneum adults with a LD50 value of 1.83 μg/adult. Atractylodin and atractylenolide II also possessed strong repellenct activities against T. castaneum adults. After 4‐h exposure, >90% repellency was achieved with atractylodin at a low concentration of 0.63 μg/cm2. The results indicated that atractylodin (1) and atractylenolide II (3) have a good potential as a source for natural repellents, and 1 has the potential to be developed as natural insecticide.
The Scope for Using the Volatile Profiles ofPinus caribaeavar.bahamensisas Indicators of Susceptibility to Pine Tortoise Scale and as Predictors of Environmental Stresses
Authors: Green Paul W. C. , Hamilton Martin A. , Sanchez Michele D. , Corcoran Marcella R. , Manco Bryan N. , Malumphy Chris P. 
Published: April 2015

AbstractClimate change, unseasonal fire and urbanization are contributing to the decline ofPinus caribaeavar.bahamensispopulations in the Turks and Caicos Islands (TCI). Infestation of pines with the invasive pine tortoise scale (PTS,Toumeyella parvicornis) is accelerating this decline. Pine trees in the Bahamas are larger and healthier and are not infested with PTS although they are subject to some of the same environmental pressures as the trees in TCI. Volatile compounds were collected from wild and nursery‐rearedP. caribaeavar.bahamensisfrom TCI and the Bahamas and characterized using GC/MS analysis, to look for differences between the compounds detected in insect‐infested pines of TCI and the healthy pines of the Bahamas. Ten compounds contributing at least 1% of the total detected peak areas in any one of the samples were selected for further study. Eight of these compounds were identified using authentic standards and mass spectral libraries. The main constituents in the samples wereα‐ andβ‐pinene as well asβ‐phellandrene, and, together withβ‐myrcene, their contents varied the most between samples collected at different locations. Principal‐component analysis showed that the two structural isomers of pinene, together withβ‐myrcene andβ‐phellandrene, contributed 98.4% of the variance between samples. There was a positive relationship between the concentrations of the two structural isomers of pinene and between levels ofβ‐myrcene andβ‐phellandrene. The results are discussed in relation to the biology and adaptations of invasive scale insects, the importance of monoterpenes in pine as a defense against insect predation, whether these compounds can be used as indicators of tree health, and future directions for research into conserving the Caicos pine.
Novel Daidzein Analogs and Their in Vitro Anti‐Influenza Activities
Authors: Chung Shu‐Ting , Huang Yi‐Ting , Hsiung Hsin‐Yi , Huang Wen‐Hsin , Yao Chen‐Wen , Lee An‐Rong 
Published: April 2015

AbstractA series of novel isoflavonoids were synthesized based on structural modifications of daidzein, an active ingredient of traditional Chinese medicine (TCM) and evaluated for their anti‐influenza activity, in vitro, against H1N1 Tamiflu‐resistant (H1N1 TR) virus in the MDCK cell line. Among them, 4‐oxo‐4H‐1‐benzopyran‐8‐carbaldehydes 11a–11g were most promising, and they demonstrated better activities and selectivities comparable to those the reference ribarivin, a nucleoside antiviral agent. 3‐(4‐Bromophenyl)‐7‐hydroxy‐4‐oxo‐4H‐1‐benzopyran‐8‐carboxaldehyde (11c) displayed the best inhibitory activity (EC50, 29.0 μM) and selectivity index (SI>10.3). Analysis of the structureactivity relationships (SAR) indicated that both the non‐naturally‐occurring Br‐substituted B‐ring and appropriate CHO and OH groups on the A‐ring might be critical for the activity and selectivity against H1N1 TR influenza viruses.
Modulation of Aggregation‐Induced Emission and Electroluminescence of Silole Derivatives by a Covalent Bonding Pattern
Authors: Nie Han , Chen Bin , Quan Changyun , Zhou Jian , Qiu Huayu , Hu Rongrong , Su Shi‐Jian , Qin Anjun , Zhao Zujin , Tang Ben Zhong 
Published: April 2015

AbstractThe deciphering of structure–property relationships is of high importance to rational design of functional molecules and to explore their potential applications. In this work, a series of silole derivatives substituted with benzo[b]thiophene (BT) at the 2,5‐positions of the silole ring are synthesized and characterized. The experimental investigation reveals that the covalent bonding through the 2‐position of BT (2‐BT) with silole ring allows a better conjugation of the backbone than that achieved though the 5‐position of BT (5‐BT), and results in totally different emission behaviors. The silole derivatives with 5‐BT groups are weakly fluorescent in solutions, but are induced to emit intensely in aggregates, presenting excellent aggregation‐induced emission (AIE) characteristics. Those with 2‐BT groups can fluoresce more strongly in solutions, but no obvious emission enhancements are found in aggregates, suggesting they are not AIE‐active. Theoretical calculations disclose that the good conjugation lowers the rotational motions of BT groups, which enables the molecules to emit more efficiently in solutions. But the well‐conjugated planar backbone is prone to form strong intermoelcular interactions in aggregates, which decreases the emission efficiency. Non‐doped organic light‐emitting diodes (OLEDs) are fabricated by using these siloles as emitters. AIE‐active silole derivatives show much better elecroluminescence properties than those without the AIE characterisic, demonstrating the advantage of AIE‐active emitters in OLED applications.