bluuebunny/crossref_metadata_2025_split huggingface dataset:
Early Main Group Metal Catalysis: How Important is the Metal?
Authors: Penafiel Johanne , Maron Laurent , Harder Sjoerd 
Published: November 2014

AbstractOrganocalcium compounds have been reported as efficient catalysts for various alkene transformations. In contrast to transition metal catalysis, the alkenes are not activated by metal–alkene orbital interactions. Instead it is proposed that alkene activation proceeds through an electrostatic interaction with a Lewis acidic Ca2+. The role of the metal was evaluated by a study using the metal‐free catalysts: [Ph2N−][Me4N+] and [Ph3C−][Me4N+]. These “naked” amides and carbanions can act as catalysts in the conversion of activated double bonds (CO and CN) in the hydroamination of ArNCO and RNCNR (R=alkyl) by Ph2NH. For the intramolecular hydroamination of unactivated CC bonds in H2CCHCH2CPh2CH2NH2 the presence of a metal cation is crucial. A new type of hybrid catalyst consisting of a strong organic Schwesinger base and a simple metal salt can act as catalyst for the intramolecular alkene hydroamination. The influence of the cation in catalysis is further evaluated by a DFT study.
Peptide‐Induced Hierarchical Long‐Range Order and Photocatalytic Activity of Porphyrin Assemblies
Authors: Liu Kai , Xing Ruirui , Chen Chengjun , Shen Guizhi , Yan Linyin , Zou Qianli , Ma Guanghui , Möhwald Helmuth , Yan Xuehai 
Published: November 2014

AbstractLong‐range structural order and alignment over different scales are of key importance for the regulation of structure and functionality in biology. However, it remains a great challenge to engineer and assemble such complex functional synthetic systems with order over different length scales from simple biologically relevant molecules, such as peptides and porphyrins. Herein we describe the successful introduction of hierarchical long‐range order in dipeptide‐adjusted porphyrin self‐assembly by a thermodynamically driven self‐orienting assembly pathway associated with multiple weak interactions. The long‐range order and alignment of fiber bundles induced new properties, including anisotropic birefringence, a large Stokes shift, amplified chirality, and excellent photostability as well as sustainable photocatalytic activity. We also demonstrate that the aligned fiber bundles are able to induce the epitaxially oriented growth of Pt nanowires in a photocatalytic reaction.
Isolation of Functionalized Phenolic Monomers through Selective Oxidation and CO Bond Cleavage of the β‐O‐4 Linkages in Lignin
Authors: Lancefield Christopher S. , Ojo O. Stephen , Tran Fanny , Westwood Nicholas J. 
Published: November 2014

AbstractFunctionalized phenolic monomers have been generated and isolated from an organosolv lignin through a two‐step depolymerization process. Chemoselective catalytic oxidation of β‐O‐4 linkages promoted by the DDQ/tBuONO/O2 system was achieved in model compounds, including polymeric models and in real lignin. The oxidized β‐O‐4 linkages were then cleaved on reaction with zinc. Compared to many existing methods, this protocol, which can be achieved in one pot, is highly selective, giving rise to a simple mixture of products that can be readily purified to give pure compounds. The functionality present in these products makes them potentially valuable building blocks.
ZnO‐Functionalized Upconverting Nanotheranostic Agent: Multi‐Modality Imaging‐Guided Chemotherapy with On‐Demand Drug Release Triggered by pH
Authors: Wang Yinghui , Song Shuyan , Liu Jianhua , Liu Dapeng , Zhang Hongjie 
Published: November 2014

AbstractLimited therapeutic efficiency and severe side effects in patients are two major issues existing in current chemotherapy of cancers in clinic. To design a proper theranostic platform seems thus quite needed to target cancer cells accurately by bioimaging and simultaneously release drugs on demand without premature leakage. A novel ZnO‐functionalized upconverting nanotheranostic platform has been fabricated for clear multi‐modality bioimaging (upconversion luminescence (UCL), computed tomography (CT), and magnetic resonance imaging (MRI)) and specific pH‐triggered on‐demand drug release. In our theranostic platform multi‐modality imaging provides much more detailed and exact information for cancer diagnosis than single‐modality imaging. In addition, ZnO can play the role of a “gatekeeper” to efficiently block the drug in the mesopores of the as‐prepared agents until it is dissolved in the acidic environment around tumors to realize sustained release of the drug. More importantly, the biodegradable ZnO, which is non‐toxic against normal tissues, endows the as‐prepared agents with high therapeutic effectiveness but very low side effects. These findings are of great interests and will inspire us much to develop novel effective imaging‐guided on‐demand chemotherapies in cancer treatment.
Understanding external plasticization of melt extruded PHBV–wheat straw fibers biodegradable composites for food packaging
Authors: Martino Lucrezia , Berthet Marie‐Alix , Angellier‐Coussy Hélène , Gontard Nathalie 
Published: November 2014

ABSTRACTThe objective of this work is to get further knowledge on the external plasticization mechanisms of melt extruded polyhydroxyl‐3‐butyrate‐co−3‐valerate (PHBV) when combined with wheat straw fibers (WSF). Different types of biodegradable substances, all authorized for food contact according to the European regulation, i.e., acetyltributyl citrate (ATBC), glycerol triacetate (GTA) and (PEG) at different molecular weights, were tested at different percentages (5, 10 and 20 wt %). Thermal and mechanical characterization of PHBV/plasticizer blends showed that a significant plasticizing effect was obtained using hydrophobic substances such as ATBC and GTA, with an increase of the elongation at break from 1.8% up to about 6% for an additive content of 10 wt %. However, the incorporation of WSF in plasticized PHBV led to a dramatic decrease in the elongation at break of composites, neutralizing the increase of this parameter by the addition of the plasticizers. The stress at break of plasticized films was also significantly decreased by the introduction of fibers. Such a loss of ductility was mainly explained by the occurrence of microscopic defects in the materials induced by the presence of fibers and to a poor adhesion at the fiber/matrix interface. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41611.
Self‐assembled polypyrrole film by interfacial polymerization for supercapacitor applications
Authors: Yang Qinghao , Hou Zhenzhong , Huang Tianzhu 
Published: November 2014

ABSTRACTA facile interfacial synthesis strategy is proposed to synthesize self‐assembled polypyrrole (PPy) free‐standing films for electrochemical capacitors with the assistance of surfactants. The chemical structure of the obtained samples is characterized by Fourier transform infrared. The morphologies of the samples are studied by scanning electron microscope. The results show that the prepared PPy films own highly porous structures using Tween80 as a surfactant, while the synthesized PPy films have vesicular structures by adding Span80 as a surfactant. Furthermore, lowering polymerization temperature makes PPy films have smaller and more pores or vesicles. The PPy films prepared at 0°C with Tween80 as a surfactant possess a high specific capacitance of 261 F g−1 at 25 mV s−1 as well as retain 75% of the initial specific capacitance value after 1000 cycles. The good electrochemical properties can be attributed to the highly porous structural advantage of the PPy films caused by Tween80. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41615.
Preparation of a poly(phthalazine ether sulfone ketone) membrane with propanedioic acid as an additive and the prediction of its structure
Authors: Qin Peiyong , Liu Anni , Chen Cuixian 
Published: November 2014

ABSTRACTIn this study, propanedioic acid was investigated as a potential additive in poly(phthalazine ether sulfone ketone) (PPESK)/N‐methyl‐2‐pyrrolidone solutions. Compared with poly(ethylene glycol) with a molecular weight of 1000 and Tween 80 as additives, different phenomena were observed: (1) both fingerlike and spongelike structures of asymmetric ultrafiltration membranes were induced by rapid gelation, and (2) a spongelike structure membrane with a high pure water flux was obtained under a high gelation rate. Moreover, the PPESK membrane formation process was recorded with a recently developed optical microscopy (OM)–charge‐coupled device (CCD) camera experimental system. The predicted membrane structure with an OM–CCD system gave good correspondence with the final membrane structure and performance, as detected by scanning electron microscopy. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41621.
Effect of Point Sampling Density in Quantifying Mouse Lung Emphysema
Authors: Limjunyawong Nathachit , Kearson Alexandra , Das Sandhya , Mitzner Wayne 
Published: November 2014

ABSTRACTIn the official joint policy document of the American Thoracic Society and European Respiratory Society (Hsia et al., Am J Respir Crit Care Med 181:394‐418), the need for proper stereologic assessment of lungs was emphasized. In this document it was emphasized that for the quantitative analysis of lung histologic sections, one of the most robust and reliable methods is point and intercept counting (Knudsen et al., J Appl Physiol 108:412‐421). One of the practical aspects of this method is how many points or intercepts are needed. The answer to this question has been considered from a theoretical perspective, and it depends on the relative magnitudes of the methodological and biologic variabilities. Although it is generally accepted that in a normal lung, one needs only 100–200 points to sufficiently lower the methodological variability, given the increased variability often seen in experimental emphysematous lung injury, the requisite number of points of intercepts has not been evaluated. In this study, we examined this question by focusing on some of the relevant sampling levels in mice with extensive elastase‐induced emphysema. Using fixed samples of tissue blocks, we varied the number of sampling points or intercepts from about 25 to 1,000 in control and emphysematous lungs. Our results show that, at the sampling levels investigated, even with the increased heterogeneity in the lung tissue damage caused by elastase, the number of sampling points needed to detect changes is similar to what is needed for control mice. Anat Rec, 298:531–537, 2015. © 2014 Wiley Periodicals, Inc.
The Distinct Distributions of Immunocompetent Cells in Rat Dentin Pulp After Pulpotomy
Authors: Zhang Min , Kokabu Shoichiro , Nakatomi Chihiro , Sugiyama Goro , Matsuo Kou , Jimi Eijiro 
Published: November 2014

ABSTRACTPulpotomy involves the removal of the coronal portion of pulp, including the diseased tissue, with the intent of maintaining the vitality of the remaining pulpal tissue via a therapeutic dressing. Once odontoblasts suffer injuries, the differentiation of mesenchymal cells is induced from the precursor cell population in the dental pulp, and these cells are recruited to the injured site to differentiate into odontoblasts. However, the involvement of immunocompetent cells during pulpal regeneration remains unclear. Thus, the purpose of this study was to investigate the properties of macrophages that infiltrated wound healing sites in rats between 1 and 28 days after pulpotomy (dap). During the inflammatory phase, ED1+ (CD68+) macrophages significantly increased throughout root pulp, especially apical to the demarcation zone, and this population persisted until 3 dap before decreasing gradually until 28 dap. OX6+ macrophages expressing class II MHC also increased in the apical pulp at 1 dap and declined thereafter. However, OX6+ cells appeared prior to dentin bridge formation at 3 dap and appeared again apical to the dentin bridge during the healing stage at 14 dap. The shift from ED1+ cells in the inflammation phase to OX6+ cells during dentin bridge formation might contribute to wound healing. Anat Rec, 298:741–749, 2015. © 2014 Wiley Periodicals, Inc.
Expedient Construction of the [5‐6‐7] Tricyclic Core of Calyciphylline A‐Type Alkaloids
Authors: Guo Jing‐Jing , Li Yun , Cheng Bin , Xu Tingting , Tao Cheng , Yang Xinkan , Zhang Denghong , Yan Guangqi , Zhai Hongbin 
Published: November 2014

AbstractAn efficient synthetic route toward the highly congested [5‐6‐7] tricyclic core of calyciphylline A‐type alkaloids has been developed. This approach features a highly efficient intramolecular Diels–Alder cycloaddition to establish the aza‐five‐membered C ring as well as the C1 all‐carbon quaternary center, and a subsequent cyclopropanation together with a ring‐expansion reaction of the resulted adduct to construct the seven‐membered D ring.
Population pharmacokinetics of etomidate in neonates and infants with congenital heart disease
Authors: Su Felice , El‐Komy Mohammed H. , Hammer Gregory B. , Frymoyer Adam , Cohane Carol A. , Drover David R. 
Published: November 2014

AbstractBackgroundEtomidate is a rapid‐onset, short‐acting hypnotic medication administered for the induction of anesthesia. It is currently approved by the Food and Drug Administration for use in older children and adults. Pharmacokinetic data to help guide dosing in neonates and infants are lacking.ObjectiveThe aim of this study was to determine the pharmacokinetics of etomidate in neonates and infants with congenital heart disease undergoing cardiac surgery.MethodsFour neonates and 16 infants, postnatal age 0.3–11.7 months, requiring open‐heart surgery received 0.3 mg/kg of etomidate administered as a single intravenous dose prior to surgery. Blood sampling for plasma etomidate concentration occurred immediately following etomidate administration until the initiation of cardiopulmonary bypass. A population pharmacokinetic approach using nonlinear mixed‐effects modeling was applied to characterize etomidate pharmacokinetics.ResultsThe pharmacokinetics of etomidate was described by a two‐compartment model with first‐order elimination. An allometric weight‐based model was applied to scale results to a 70 kg adult. Covariates including age and cardiac physiology were not found significantly to impact etomidate pharmacokinetics. The study population was found to have a central and intercompartmental clearance of 0.624 l/min/70 kg and 0.44 l/min/70 kg, respectively; central and peripheral distribution volume of 9.47 l/70 kgand 22.8 l/70 kg, respectively. Inter‐individual variability was 94–142% for all parameters and the residual variability was 29%.ConclusionsThe clearance of etomidate is lower in neonates and infants with congenital heart disease compared with published values for older children without congenital heart disease. In addition, etomidate pharmacokinetics is highly variable in this pediatric cardiac population. Copyright © 2014 John Wiley & Sons, Ltd.
Association between maternal single nucleotide polymorphisms in genes regulating glucose metabolism and risk for neural tube defects in offspring
Authors: Fu Yunting , Wang Lin‐lin , Yi Deqing , Jin Lei , Liu Jufen , Zhang Yali , Ren Aiguo 
Published: November 2014

BackgroundMaternal pregestational hyperglycemia, diabetes, and obesity are well‐established risk factors for neural tube defects (NTDs). As a common underlying mechanism, the imbalance of glucose homeostasis is directly related to the development of NTDs. Polymorphisms in genes regulating glucose metabolism in women may impact their chance of having an NTD‐affected pregnancy.MethodsWe conducted a two‐stage case‐control study to investigate the association between maternal genetic variants in genes regulating glucose metabolism and risk for NTDs. The cases were 547 women who gave birth to a child with an NTD (anencephaly, spina bifida, or encephalocele); the controls were 543 women who gave birth to a full‐term healthy infant. In the first stage, 12 single nucleotide polymorphisms were genotyped in 160 cases and 162 controls. In the second stage, five single nucleotide polymorphisms found in the first stage and potentially associated with NTD risk were genotyped for validation, in an additional 387 cases and 381 controls.ResultsCombined analysis of data from the two stages showed an association between maternal AA genotype of GCKR rs780094 and increased risk for total NTDs [odds ratio, 1.73; 95% confidence interval, 1.16–2.59) and spina bifida subtype [odds ratio, 1.83; 95% confidence interval, 1.16–2.88). No association was found between the other four single nucleotide polymorphisms (LEPR rs1137100, HK1 rs748235, HHEX rs5015480, KCNQ1 rs2237892) and NTD risk.ConclusionThe AA genotype in maternal GCKR rs780094 is associated with an increased risk for NTDs and spina bifida in the Chinese population. Birth Defects Research (Part A) 103:471–478, 2015. © 2014 Wiley Periodicals, Inc.
Simulation Studies on Growth and Death of Microorganisms Using the Oil‐Degrading Bacteria Petrotoga sp.
Authors: Daryasafar Amin , Azad Ehsan Ganji , Ghahfarokhi Ali Khorram , Mousavi Seyyedeh Fatemeh 
Published: November 2014

AbstractThree models were developed to estimate the potential of the selected bacteria Petrotoga sp., a thermophilic anaerobic oil‐degrading microorganism. Fourteen data sets of these bacteria were simulated by a multilayer feed‐forward neural network and an adaptive neuro‐fuzzy interference system. Twelve data sets served for training and two for testing these models. A simplified numerical model was performed assuming two phases in the growth process of oil‐degrading microorganisms, the logarithmic growth phase and the death phase. Comparison between these models in predicting bacterial cell concentration for different data sets indicates little difference between the overall average relative errors of the three methods and that all can be applied for prediction. Effects of salinity concentration, amount of yeast extract, and temperature on bacterial cell concentration were simulated by numerical and neural network models.
Mathematical Modeling of Ocimum basilicum L. Supercritical CO2 Extraction
Authors: Zeković Zoran , Filip Snežana , Vidović Senka , Jokić Stela , Svilović Sandra 
Published: November 2014

AbstractThe effects of pressure and temperature on supercritical extraction of Ocimum basilicum L. in terms of extraction yield and aromatic compounds were investigated. Linalool, eugenol, and δ‐cadinene were indentified as three main compounds of the prepared extracts. The dominant compound in all investigated supercritical basil extracts was linalool. Within the experimental range the extraction parameters had a significant influence on the extraction yield. The obtained results for the sweet basil total extract, cadinene, and linalool best matched with the Gordillo et al. model, therefore, the solubility of total extract, linalool, and cadinene in supercritical CO2 at investigated temperatures is described as a function of pressure.
Relationship between Pyrite in the Precursor and the Pore Structure of High‐Surface Area Activated Carbon Preparations
Authors: Zhang Huaihao , Jiang Yuanyuan , Chen Kai , Hu Yongfeng , Wang Hui , Zhao Jing , Zhang Xiaoxing , Wang Chengyin 
Published: November 2014

AbstractHigh‐surface area activated carbons (HAC) were prepared from analogous sulfur‐containing precursors by using KOH chemical activation. The relationship between pyrite (FeS2) in the precursor and the pore structure of the as‐prepared HAC was investigated comprehensively. The results suggest that FeS2 in the precursor reacts with KOH, producing K2SO4, K2S2O3, K2S, thioether (R‐S‐R'), and Fe3O4, which reduce the actual amount of KOH used to develop the porosity. As a result, the existence of the by‐product Fe3O4 further clarifies that FeS2 in the precursor can consume some amount of KOH, which leads to the decrease in the specific surface area and pore volume of HAC. Interestingly, part of the inorganic sulfur from FeS2 in the precursor can be transformed into organic sulfide R‐S‐R'.
Gold‐Nanoparticle‐Based Multifunctional Amyloid‐β Inhibitor against Alzheimer’s Disease
Authors: Gao Nan , Sun Hanjun , Dong Kai , Ren Jinsong , Qu Xiaogang 
Published: November 2014

AbstractTargeting amyloid‐β (Aβ)‐induced complex neurotoxicity has received considerable attention in the therapeutic and preventive treatment of Alzheimer’s disease (AD). The complex pathogenesis of AD suggests that it requires comprehensive treatment, and drugs with multiple functions against AD are more desirable. Herein, AuNPs@POMD‐pep (AuNPs: gold nanoparticles, POMD: polyoxometalate with Wells–Dawson structure, pep: peptide) were designed as a novel multifunctional Aβ inhibitor. AuNPs@POMD‐pep shows synergistic effects in inhibiting Aβ aggregation, dissociating Aβ fibrils and decreasing Aβ‐mediated peroxidase activity and Aβ‐induced cytotoxicity. By taking advantage of AuNPs as vehicles that can cross the blood–brain barrier (BBB), AuNPs@POMD‐pep can cross the BBB and thus overcome the drawbacks of small‐molecule anti‐AD drugs. Thus, this work provides new insights into the design and synthesis of inorganic nanoparticles as multifunctional therapeutic agents for treatment of AD.
Metal–Carbonyl Units for Vibrational and Luminescence Imaging: Towards Multimodality
Authors: Clède Sylvain , Policar Clotilde 
Published: November 2014

AbstractMetal–carbonyl complexes are attractive structures for bio‐imaging. In addition to unique vibrational properties due to the CO moieties enabling IR and Raman cell imaging, the appropriate choice of ancillary ligands opens up the opportunity for luminescence detection. Through a classification by techniques, past and recent developments in the application of metal–carbonyl complexes for vibrational and luminescence bio‐imaging are reviewed. Finally, their potential as bimodal IR and luminescent probes is addressed.
Supramolecular Water Oxidation with Ru–bda‐Based Catalysts
Authors: Richmond Craig J. , Matheu Roc , Poater Albert , Falivene Laura , Benet‐Buchholz Jordi , Sala Xavier , Cavallo Luigi , Llobet Antoni 
Published: November 2014

AbstractExtremely slow and extremely fast new water oxidation catalysts based on the Ru–bda (bda=2,2′‐bipyridine‐6,6′‐dicarboxylate) systems are reported with turnover frequencies in the range of 1 and 900 cycles s−1, respectively. Detailed analyses of the main factors involved in the water oxidation reaction have been carried out and are based on a combination of reactivity tests, electrochemical experiments, and DFT calculations. These analyses give a convergent interpretation that generates a solid understanding of the main factors involved in the water oxidation reaction, which in turn allows the design of catalysts with very low energy barriers in all the steps involved in the water oxidation catalytic cycle. We show that for this type of system π‐stacking interactions are the key factors that influence reactivity and by adequately controlling them we can generate exceptionally fast water oxidation catalysts.
Chitosan‐Templated Synthesis of Few‐Layers Boron Nitride and its Unforeseen Activity as a Fenton Catalyst
Authors: Primo Ana , Navalón Sergio , Asiri Abdullah M. , García Hermenegildo 
Published: November 2014

AbstractA novel procedure for the preparation of few‐layers boron nitride (BN), either as films or as suspended BN platelets, is presented, based on the pyrolysis of chitosan, which serves both as a matrix to embed ammonium borate and as a template for BN synthesis. The resulting BN samples are characterized by XRD, Raman and X‐ray photoelectron spectroscopy, and by TEM and AFM imaging. The samples exhibit deep UV emission, which is characteristic of high quality BN. This template synthesis and the easy exfoliation of BN platelets facilitate the use of BN as an extremely high‐efficiency Fenton catalyst for the generation of highly aggressive hydroxyl radicals in water.