bluuebunny/crossref_metadata_2025_split huggingface dataset:
Three‐Component Synthesis of Pyrrole‐Related Nitrogen Heterocycles by a Hantzsch‐Type Process: Comparison between Conventional and High‐Speed Vibration Milling Conditions
Authors: Estévez Verónica , Sridharan Vellaisamy , Sabaté Sònia , Villacampa Mercedes , Menéndez J. Carlos 
Published: February 2016

AbstractThe use of solvent‐free, high‐speed vibration milling conditions has allowed the development of a one‐pot telescoped process for the synthesis of pyrroles starting from ketones, primary amines, and β‐dicarbonyl compounds and comprising an initial α‐iodination followed by an in situ three‐component Hantzsch‐type reaction. This method was compared with a solution‐based protocol from α‐iodoketones, primary amines, and β‐dicarbonyl compounds. Although both protocols were far more general than previous Hantzsch‐type pyrrole syntheses, the mechanochemical method was superior in that it afforded considerably higher yields in spite of comprising an additional step. The stereochemical integrity of the pyrroles obtained from chiral α‐aminoesters was maintained. This solvent‐free method was also used for the efficient preparation of ter‐ and quater‐aryl/heteroaryl frameworks containing two pyrrole units and a variety of fused pyrrole systems, including benzo[g]indoles, indeno[1,2‐b]pyrroles, indoles, and homoindoles.
Comparative analysis of dentognathic pathologies in the Dmanisi mandibles
Authors: Margvelashvili Ann , Zollikofer Christoph P.E. , Lordkipanidze David , Tafforeau Paul , Ponce de León Marcia S. 
Published: February 2016

ABSTRACTObjectivesDue to the scarcity of the fossil record, in vivo changes in the dentognathic system of early Homo are typically documented at the level of individual fossil specimens, and it remains difficult to draw population‐level inferences about dietary habits, diet‐related activities and lifestyle from individual patterns of dentognathic alterations. The Plio‐Pleistocene hominin sample from Dmanisi (Georgia), dated to 1.77 million years ago, offers a unique opportunity to study in vivo changes in the dentognathic system of individuals belonging to a single paleodeme of early Homo.Materials and MethodsWe analyze dentognathic pathologies in the Dmanisi sample, and in comparative samples of modern Australian and Greenlander hunter‐gatherer populations, applying clinical protocols of dentognathic diagnostics.ResultsThe Dmanisi hominins exhibit a similarly wide diversity and similar incidence of dentognathic pathologies as the modern human hunter‐gatherer population samples investigated here. Dmanisi differs from the modern population samples in several respects: At young age tooth wear is already advanced, and pathologies are more prevalent. At old age, hypercementosis is substantial.ConclusionsResults indicate that dentognathic pathologies and disease trajectories are largely similar in early Homo and modern humans, but that the disease load was higher in early Homo, probably as an effect of higher overall stress on the dentognathic system. Am J Phys Anthropol 160:229–253, 2016. © 2016 Wiley Periodicals, Inc.
Mechanical and metabolic interactions in cortical bone development
Authors: Eleazer Courtney D. , Jankauskas Rimantas 
Published: February 2016

ABSTRACTObjectivesAnthropological studies of cortical bone often aim to reconstruct either habitual activities or health of past populations. During development, mechanical loading and metabolism simultaneously shape cortical bone structure; yet, few studies have investigated how these factors interact. Understanding their relative morphological effects is essential for assessing human behavior from skeletal samples, as previous studies have suggested that interaction effects may influence the interpretation from cortical structure of physical activity or metabolic status.Material and MethodsThis study assesses cross‐sectional geometric and histomorphometric features in bones under different loading regimes (femur, humerus, rib) and compares these properties among individuals under different degrees of metabolic stress. The study sample consists of immature humans from a late medieval Lithuanian cemetery (Alytus, 14th–18th centuries AD). Analyses are based on the hypothesis that metabolic bone loss is distributed within the skeleton in a way that optimizes mechanical competency.ResultsResults suggest mechanical compensation for metabolic bone loss in the cross‐sectional properties of all three bones (especially ribs), suggesting a mechanism for conserving adequate bone strength for different loads across the skeleton. Microscopic bone loss is restricted to stronger bones under high loads, which may mitigate fracture risk in areas of the skeleton that are more resistive to loading, although alternative explanations are examined.DiscussionDistributions of metabolic bone loss and subsequent structural adjustments appear to preserve strength. Nevertheless, both mechanics and metabolism have a detectable influence on morphology, and potential implications for behavioral interpretations in bioculturally stressed samples due to this interaction are explored. Am J Phys Anthropol 160:317–333, 2016. © 2016 Wiley Periodicals, Inc.
Connexin gap junction channels and chronic rhinosinusitis
Authors: Kim Raymond , Chang George , Hu Rebecca , Phillips Anthony , Douglas Richard 
Published: February 2016

BackgroundGap junction channels are formed by connexin (Cx) proteins. These channels facilitate communication between adjacent cells, and some have been implicated in acute and chronic inflammation. We investigated whether altered connexin expression could be associated with the inflammatory changes of the sinonasal mucosa that characterize chronic rhinosinusitis (CRS). Our aims were first to screen normal sinus mucosa to determine the expression profile of the connexin family of genes, and second to compare the level of expression of 3 key connexins (Cx26, Cx30, and Cx43) in CRS and normal sinus mucosa. These 3 connexins have been implicated in lower airway epithelial cell repair, as well as chronic and acute cutaneous wounds.MethodsSinus mucosa biopsies were taken from 11 patients with CRS undergoing sinus surgery and from 7 controls with normal sinuses undergoing transnasal pituitary surgery. Gene expression study of the connexin family was performed using polymerase chain reaction (PCR). Subsequent targeted quantitative analyses were done using quantitative real‐time PCR (qPCR) and fluorescent immunohistochemistry (IHC).ResultsA total of 16 different connexin genes were expressed in the normal mucosa including Cx26, Cx30, and Cx43. The qPCR demonstrated increased abundance of Cx26 (p = 0.005), Cx30 (p = 0.07), and Cx43 (p = 0.04) in CRS compared to control mucosa. IHC confirmed significantly higher levels of Cx43 in CRS (p < 0.001).ConclusionThe majority of the connexin family is expressed in normal sinus mucosa. Expression of 3 selected connexins was found elevated in CRS mucosa. Connexin gap junction modulation may offer a novel therapeutic target for CRS.
Mind “De GaPP”: in vitro efficacy of deferiprone and gallium‐protoporphyrin against Staphylococcus aureus biofilms
Authors: Richter Katharina , Ramezanpour Mahnaz , Thomas Nicky , Prestidge Clive A. , Wormald Peter‐John , Vreugde Sarah 
Published: February 2016

BackgroundBiofilms are clusters of bacteria embedded in a protective matrix that frequently cause failure of medical treatments and increase the risk of recurrent infections. In particular, Staphylococcus aureus biofilms are associated with a series of chronic and nosocomial infections that are increasingly resistant to antibiotics. This study proposes a novel intervention strategy targeting the essential iron metabolism for bacterial growth, survival and pathogenesis using the compounds deferiprone (Def) and gallium‐protoporphyrin (GaPP).MethodsS. aureus biofilms were challenged with Def/GaPP as single and dual treatments. In vitro anti‐biofilm efficacy was assessed by the AlamarBlue viability assay and confocal microscopy. In vitro cytotoxicity of the treatments was examined by the lactate dehydrogenase assay on mouse fibroblast (L929) and human bronchial epithelial cells (Nuli‐1).ResultsDef (20 mM) and GaPP (200 μg/mL) monotherapy for 2 hours showed 35% and 74% biofilm removal, respectively, whereas simultaneous Def/GaPP administration showed 55% biofilm removal. In contrast, the consecutive treatment (2 hours Def followed by 2 hours GaPP) achieved 95% biofilm removal. Cytotoxicity studies indicated no cell hazard in all treatments.ConclusionThis study demonstrated the in vitro efficacy of a novel treatment combination against S. aureus biofilms targeting the bacterial iron metabolism. The consecutive Def/GaPP treatment showed significantly enhanced biofilm efficacy than the individual compounds, while being not toxic to 2 cell lines. This novel treatment combination is a promising approach to combat S. aureus–associated biofilm infections having high potential for future clinical application.
Bifunktionale Sauerstoffelektroden durch Einbettung von Co@Co3O4‐Nanopartikeln in CNT‐gekoppelte Stickstoff‐dotierte Kohlenstoffpolyeder
Authors: Aijaz Arshad , Masa Justus , Rösler Christoph , Xia Wei , Weide Philipp , Botz Alexander J. R. , Fischer Roland A. , Schuhmann Wolfgang , Muhler Martin 
Published: February 2016

AbstractEffiziente und reversible Sauerstoffelektroden für die Sauerstoffreduktion (oxygen reduction reaction, ORR) sowie die Sauerstoffentwicklung (oxygen evolution reaction, OER) sind entscheidend für die Energieumwandlung beispielsweise in regenerativen Brennstoffzellen und Metall‐Luft‐Batterien. Die Realisierung solcher Elektroden wird im Wesentlichen durch unzureichende Aktivität und Stabilität der Elektrokatalysatoren sowohl bei der Wasserspaltung als auch bei der Sauerstoffreduktion erschwert. Wir berichten über hochaktive bifunktionale Elektrokatalysatoren für Sauerstoffelektroden. Die Katalysatoren bestehen aus Co@Co3O4‐Kern‐Schale‐Nanopartikeln, die durch Pyrolyse einer Cobalt‐haltigen Metall‐organischen Gerüstverbindung (MOF; ZIF‐67) in einer reduktiven H2‐Atmosphäre mit anschließender kontrollierter oxidativer Kalzinierung in CNT‐gekoppelte N‐dotierte Kohlenstoffpolyeder eingebettet wurden. Die Katalysatoren liefern eine reversible Gesamtüberspannung von 0.85 V in 0.1 m KOH‐Lösung und übertreffen damit Pt/C, IrO2 und RuO2, sodass sie zu den bislang besten nicht auf Edelmetallen basierenden Elektrokatalysatoren für reversible Sauerstoffelektroden zählen.
Diastereoselective [3+2] Annulation of Aromatic/Vinylic Amides with Bicyclic Alkenes through Cobalt‐Catalyzed C−H Activation and Intramolecular Nucleophilic Addition
Authors: Gandeepan Parthasarathy , Rajamalli Pachaiyappan , Cheng Chien‐Hong 
Published: February 2016

AbstractA highly diastereoselective method for the synthesis of dihydroepoxybenzofluorenone derivatives from aromatic/vinylic amides and bicyclic alkenes is described. This new transformation proceeds through cobalt‐catalyzed C−H activation and intramolecular nucleophilic addition to the amide functional group. Transition‐metal‐catalyzed C−H activation reactions of secondary amides with alkenes usually lead to [4+2] or [4+1] annulation; to the best of our knowledge, this is the first time that a [3+2] cycloaddition is described in this context. The reaction proceeds under mild conditions and tolerates a wide range of functional groups. Mechanistic studies imply that the C−H bond cleavage may be the rate‐limiting step.
Catalytic Enantioselective Assembly of Homoallylic Alcohols from Dienes, Aryldiazonium Salts, and Aldehydes
Authors: Tao Zhong‐Lin , Adili Alafate , Shen Hong‐Cheng , Han Zhi‐Yong , Gong Liu‐Zhu 
Published: February 2016

AbstractA highly selective multicomponent carbonyl allylation reaction of 1,3‐butadienes, aryldiazonium tetrafluoroborates, and aldehydes has been established under the combined catalysis of palladium acetate and chiral anion phase transfer to render the favorable assembly of chiral Z‐configured homoallylic alcohols in high yields and with excellent levels of enantioselectivity.
Dual Genetic Encoding of Acetyl‐lysine and Non‐deacetylatable Thioacetyl‐lysine Mediated by Flexizyme
Authors: Xiong Hai , Reynolds Noah M. , Fan Chenguang , Englert Markus , Hoyer Denton , Miller Scott J. , Söll Dieter 
Published: February 2016

AbstractAcetylation of lysine residues is an important post‐translational protein modification. Lysine acetylation in histones and its crosstalk with other post‐translational modifications in histone and non‐histone proteins are crucial to DNA replication, DNA repair, and transcriptional regulation. We incorporated acetyl‐lysine (AcK) and the non‐hydrolyzable thioacetyl‐lysine (ThioAcK) into full‐length proteins in vitro, mediated by flexizyme. ThioAcK and AcK were site‐specifically incorporated at different lysine positions into human histone H3, either individually or in pairs. We demonstrate that the thioacetyl group in histone H3 could not be removed by the histone deacetylase sirtuin type 1. This method provides a powerful tool to study protein acetylation and its role in crosstalk between post‐translational modifications.
Crystallographic Evidence for Direct Metal–Metal Bonding in a Stable Open‐Shell La2@Ih‐C80 Derivative
Authors: Bao Lipiao , Chen Muqing , Pan Changwang , Yamaguchi Takahisa , Kato Tatsuhisa , Olmstead Marilyn M. , Balch Alan L. , Akasaka Takeshi , Lu Xing 
Published: February 2016

AbstractEndohedral metallofullerenes (EMFs) have novel structures and properties that are closely associated with the internal metallic species. Benzyl radical additions have been previously shown to form closed‐shell adducts by attaching an odd number of addends to open‐shell EMFs (such as Sc3C2@Ih‐C80) whereas an even number of groups are added to closed‐shell EMFs (for example Sc3N@Ih‐C80). Herein we report that benzyl radical addition to the closed‐shell La2@Ih‐C80 forms a stable, open‐shell monoadduct instead of the anticipated closed‐shell bisadduct. Single‐crystal X‐ray diffraction results show the formation of a stable radical species. In this species, the La−La distance is comparable to the theoretical value of a La−La covalent bond and is shorter than reported values for other La2@Ih‐C80 derivatives, providing unambiguous evidence for the formation of direct La−La bond.
High‐Throughput Measurement of Binding Kinetics by mRNA Display and Next‐Generation Sequencing
Authors: Jalali‐Yazdi Farzad , Huong Lai Lan , Takahashi Terry T. , Roberts Richard W. 
Published: February 2016

AbstractThere is great demand for high‐throughput methods to characterize ligand affinity. By combining mRNA display with next‐generation sequencing, we determined the kinetic on‐ and off‐rates for over twenty thousand ligands without the need for synthesis or purification of individual members. Our results are reproducible and as accurate as those obtained with other methods of affinity measurement.
Experimental investigation of the rheological behaviors of polypropylene in a capillary flow
Authors: Meng Limin , Wu Daming , Kelly Adrian , Woodhead Mike , Liu Ying 
Published: February 2016

ABSTRACTThe rheological characterization of polymer melts is strongly related to their material properties. In this study, we focused on the rheological behaviors of a polypropylene (PP) melt through a capillary die. With an advanced twin‐bore capillary rheometer with dies measuring 1.0, 0.5, and 0.25 mm in diameter, experiments were performed over a shear‐rate range of 3 × 102 to 5 × 103 s−1 at three temperatures, 210, 220, and 230 °C. The results demonstrate that the geometry dependence of the PP viscosity relied on the die diameter and the temperature of the PP melt. The viscosity values of the PP melt in the 0.25‐mm diameter die were higher than were those in the 0.5‐ and 1.0‐mm dies at 220 and 230 °C. However, the viscosity values in all of the tested dies were similar at 210 °C. The tendency for the viscosity to decrease as the temperature of the polymer melt increased weakened in the 0.25‐mm diameter die. As a result, the pressure applied to the PP melt in the 0.25‐mm diameter die increased; this caused a decrease in the free volume between molecules. On the basis of the Barus equation, the contribution of pressure to the changed viscosity in each die at each of the tested temperatures was calculated and was found to be as high as 32.86% in the 0.25‐mm die at 230 °C. Additionally, the effect of the wall slip on the geometry dependence of the PP viscosity in the tested dies was investigated with a modified Mooney method. The values of the slip velocity revealed that wall slip occurred only in the 0.25‐mm die at 210 °C. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43459.
Polythiophene nanoparticles in aqueous media
Authors: Kadac Kornelia , Nowaczyk Jacek 
Published: February 2016

ABSTRACTThe article presents the data concerning the synthesis of polythiophene (PTh) nanoparticles in aqueous medium applying emulsion polymerization. The synthetic method was studied in variety of combinations of initiator and surfactant. It was found that application of potassium peroxydisulfate (KPS) as initiator and sodium dodecyl sulfate (SDS) as the surfactant gives the best product yields. The structure, morphology, and physicochemical properties have been analyzed showing that the resulting latex have conducting film forming properties. Resulting polymers were characterized via fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), thermogravimetry‐differential thermal analysis (TG‐DTA), differential scanning calorimetry (DSC), and electrochemical methods [e.g. current–voltage characteristics (I–V), activation energy of electric conductivity, and doping processes]. A mechanism of the polymerization reaction is also discussed. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2016,133, 43495.
Electron beam sterilization of cyclo olefin polymer leads to polymer degradation and production of alkyl radicals
Authors: Kiminami Hideaki , Imae Yasufumi , Takahashi Eiji , Wei Hong , Oomura Satoshi , Abe Yoshihiko 
Published: February 2016

ABSTRACTWe investigated the effects of electron‐beam (EB) sterilization on syringe barrels manufactured from cyclo olefin polymer (COP). The chemical structure of the polymer was determined by interpreting the 13C NMR and DEPT‐135 spectra of the COP resin. The antioxidants in the resin were identified by analyzing the liquid chromatography‐photo diode array‐mass spectrometry (LC‐PDA‐MS) data for the methanol extract of the resin and the gas chromatography‐mass spectrometry (GC‐MS) data for the supercritical methanol degradation products of the extract. NMR and LC‐PDA‐MS analyses revealed that EB sterilization produces degradation products in the COP main chain and reduces the quantity of the antioxidants in the COP resin. ESR spectra of the EB‐sterilized syringe barrels indicated the presence and location of alkyl radicals, which were generated in the COP main chain by EB sterilization. ESR analyses also indicated that the quantity of alkyl radicals decreased over time. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43498.
Stable isotope analyses reveal predation on amphibians by a globally invasive fish (Gambusia holbrooki)
Authors: Remon Jonathan , Bower Deborah S. , Gaston Troy F. , Clulow John , Mahony Michael J. 
Published: February 2016

Abstract

Biodiversity loss caused by invasive species is particularly problematic in freshwater ecosystems, which are among the world's most threatened habitats. Invasive fish such as the eastern mosquitofish, Gambusia holbrooki, have been implicated in the decline of amphibians, which suffer high extinction rates globally. Although G. holbrooki is one of the most studied freshwater fish, its diet shows wide geographic variation and its impact on amphibian populations remains unclear.
Stable isotopes 13C and 15N were used in 10 urban ponds in Sydney, Australia to compare the diet of G. holbrooki in January, April and May 2013 using a stable isotope mixing model.
Gambusia holbrooki was carnivorous and fed on invertebrates (24–39%), tadpoles (25–32%) and conspecifics (20–45%). In contrast to previous studies, primary producers were a negligible part of Gambusia holbrooki diet (<10%). Its diet in late autumn comprised a high proportion of conspecifics (up to 45%) owing to the depletion of other food sources before winter (metamorphosis of larvae).
This study provides evidence of high rates of predation on native tadpoles and invertebrates by a highly invasive fish. This knowledge should be incorporated into amphibian releases through head‐starting tadpoles or using soft releases where tadpoles are placed in predator‐free enclosures until larvae are large enough to avoid predation. Considering the dire conservation status of amphibians globally and the growing interest for invertebrates, it is suggested that stable isotopes are valuable to identify threats from predation in order to target conservation practice toward suitable priorities.
Copyright © 2016 John Wiley & Sons, Ltd.
Epigallocatechin‐3‐Gallate Inhibits Ethanol‐Induced Apoptosis Through Neurod1 Regulating CHOP Expression in Pancreatic β‐Cells
Authors: Wu Tijun , Xiang Jie , Shan Wei , Li Mengxiao , Zhou Wenbo , Han Xiao , Chen Fang 
Published: February 2016

ABSTRACTEpiga‐llocatechin‐3‐gallate (EGCG) is one kind of polyphenol abundant extracted from green tea which has a potent antidiabetic activity. However, the molecular mechanisms mediating the protection procession of EGCG are still unclear. The aim of this study was to investigate the protective effect of EGCG on pancreatic β‐cells exposed to ethanol and the possible underlying mechanisms. To observe the effect of EGCG, we assessed apoptosis in βTC‐6 and INS‐1 cells, which were in complete medium containing 60 mM ethanol, or coincubation with different concentration of EGCG. We also evaluated the roles of Neurod1 in CHOP expression and ethanol‐mediated damage through plasmid overexpression. Treatment with EGCG decreased CHOP expression and apoptosis, whereas its treatment increased Neurod1 expression in ethanol‐treated βTC‐6 and INS‐1 cells. Overexpression of Neurod1 caused the decrease of CHOP expression and apoptosis in ethanol‐treated cells. Furthermore, Neurod1 inhibited CHOP expression by deacetylation of Histone H4 at the CHOP gene promoter. In addition, EGCG partially restores the activity of Neurod1 binding to CHOP promoter in ethanol‐treated cells. In conclusion, EGCG protected β‐cell against ethanol‐induced β‐cell apoptosis by Neurod1 regulating CHOP expression. Anat Rec, 299:573–582, 2016. © 2016 Wiley Periodicals, Inc.