bluuebunny/crossref_metadata_2025_split huggingface dataset:
Silver‐Catalyzed Cyclization of Propargylic Amides to Oxazolines
Authors: Wong Valerie H. L. , White Andrew J. P. , Hor T. S. (Andy) , Hii King Kuok (Mimi) 
Published: November 2015

AbstractA ligand‐accelerated effect is observed in the cyclization of propargylic amides catalyzed by bis(pyridyl)silver(I) complexes, with an unexpected reversal of electronic demand to the analogous NH addition reaction. The catalyst was found to be effective for internal alkyne substrates, offering exclusive selectivity for the 5‐exo‐dig product. Differences in selectivity profile between gold‐ and silver‐catalyzed processes are highlighted and discussed.magnified image
Organocatalytic Radical Involved Oxidative Cross‐Coupling of N‐Hydroxyphthalimide with Benzylic and Allylic Hydrocarbons
Authors: Dian Longyang , Wang Sisi , Zhang‐Negrerie Daisy , Du Yunfei 
Published: November 2015

AbstractThe cross‐coupling reaction between N‐hydroxyphthalimide and various benzylic and allylic hydrocarbons was realized through an organocatalytic radical‐mediated process involving C(sp3)O bond formation using tert‐butyl hydroperoxide (t‐BuOOH) as an oxidant and tetra‐n‐butylammonium iodide [(n‐Bu]4NI] as a catalyst, during which the phthalimide N‐oxyl (PINO) radical and benzylic and allylic radicals were generated in situ and underwent the selective radical/radical cross‐coupling reaction. This novel method provides a convenient metal‐free approach to the synthesis of O‐alkylated hydroxy imides under mild reaction conditions.magnified image
Iridium‐Catalyzed [2+2+2] Cycloaddition of α,ω‐Diynes with Cyanamides
Authors: Hashimoto Toru , Ishii Satoshi , Yano Reiko , Miura Hiroki , Sakata Ken , Takeuchi Ryo 
Published: November 2015

AbstractThe complex [Ir(cod)Cl]2/DPPF or rac‐BINAP is an efficient catalyst for the [2+2+2] cycloaddition of α,ω‐diynes with cyanamides. A wide range of cyanamides derived from secondary amines are good coupling partners for α,ω‐diynes. The reaction of unsymmetrical α,ω‐diynes possessing two different internal alkyne moieties with cyanamides is regioselective. A competitive experiment showed that cyanamide is more reactive than nitrile. This higher reactivity of cyanamide than nitrile was analyzed based on density functional theory (DFT) calculations at the B3LYP level.magnified image
Mitochondrial DNA Depletion in Respiratory Chain–Deficient Parkinson Disease Neurons
Authors: Grünewald Anne , Rygiel Karolina A. , Hepplewhite Philippa D. , Morris Christopher M. , Picard Martin , Turnbull Doug M. 
Published: November 2015

ObjectiveTo determine the extent of respiratory chain abnormalities and investigate the contribution of mtDNA to the loss of respiratory chain complexes (CI–IV) in the substantia nigra (SN) of idiopathic Parkinson disease (IPD) patients at the single‐neuron level.MethodsMultiple‐label immunofluorescence was applied to postmortem sections of 10 IPD patients and 10 controls to quantify the abundance of CI–IV subunits (NDUFB8 or NDUFA13, SDHA, UQCRC2, and COXI) and mitochondrial transcription factors (TFAM and TFB2M) relative to mitochondrial mass (porin and GRP75) in dopaminergic neurons. To assess the involvement of mtDNA in respiratory chain deficiency in IPD, SN neurons, isolated with laser‐capture microdissection, were assayed for mtDNA deletions, copy number, and presence of transcription/replication‐associated 7S DNA employing a triplex real‐time polymerase chain reaction (PCR) assay.ResultsWhereas mitochondrial mass was unchanged in single SN neurons from IPD patients, we observed a significant reduction in the abundances of CI and II subunits. At the single‐cell level, CI and II deficiencies were correlated in patients. The CI deficiency concomitantly occurred with low abundances of the mtDNA transcription factors TFAM and TFB2M, which also initiate transcription‐primed mtDNA replication. Consistent with this, real‐time PCR analysis revealed fewer transcription/replication‐associated mtDNA molecules and an overall reduction in mtDNA copy number in patients. This effect was more pronounced in single IPD neurons with severe CI deficiency.InterpretationRespiratory chain dysfunction in IPD neurons not only involves CI, but also extends to CII. These deficiencies are possibly a consequence of the interplay between nDNA and mtDNA‐encoded factors mechanistically connected via TFAM. ANN NEUROL 2016;79:366–378
Effects of fiber‐surface treatment on the properties of hybrid composites prepared from oil palm empty fruit bunch fibers, glass fibers, and recycled polypropylene
Authors: Islam Muhammad Remanul , Gupta Arun , Rivai Makson , Beg Mohammad Dalour Hossen , Mina Md. Forhad 
Published: November 2015

ABSTRACTIn this article, we report the effects of hybridization and fiber‐surface modification on the properties of hybrid composites prepared from recycled polypropylene (RPP), coupling agents, oil palm empty fruit bunch (EFB), and glass fibers through a twin‐screw extruder and an injection‐molding machine. The surface of the EFB fibers was modified with different concentrations (10–15 wt %) and temperatures (60–90°C) of alkali solutions. The structure and morphology of the fibers were observed with the help of Fourier transform infrared spectroscopy and scanning electron microscopy. Different types of composites were fabricated with untreated, alkali‐treated, and heat‐alkali‐treated fibers. Comparative analysis of the mechanical, structural, morphological, and thermal properties of the composites was carried out to reveal the effects of treatment and hybridization. The analysis results reveal that composites prepared from the alkali‐treated (in the presence of heat) fibers show improved mechanical, thermal, and morphological properties with a remarkably reduced water absorption. Additionally, the crystallinity of RPP also increased with the development of biaxial crystals. The improvement of various properties in relation to the structures and morphologies of the composites is discussed. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43049.
Genome‐Wide Association Study in an Amerindian Ancestry Population Reveals Novel Systemic Lupus Erythematosus Risk Loci and the Role of European Admixture
Authors: Alarcón‐Riquelme Marta E. , Ziegler Julie T. , Molineros Julio , Howard Timothy D. , Moreno‐Estrada Andrés , Sánchez‐Rodríguez Elena , Ainsworth Hannah C. , Ortiz‐Tello Patricia , Comeau Mary E. , Rasmussen Astrid , Kelly Jennifer A. , Adler Adam , Acevedo‐Vázquez Eduardo M. , Mariano Cucho-Venegas Jorge , García‐De la Torre Ignacio , Cardiel Mario H. , Miranda Pedro , Catoggio Luis J. , Maradiaga‐Ceceña Marco , Gaffney Patrick M. , Vyse Timothy J. , Criswell Lindsey A. , Tsao Betty P. , Sivils Kathy L. , Bae Sang‐Cheol , James Judith A. , Kimberly Robert P. , Kaufman Kenneth M. , Harley John B. , Esquivel‐Valerio Jorge A. , Moctezuma José F. , García Mercedes A. , Berbotto Guillermo A. , Babini Alejandra M. , Scherbarth Hugo , Toloza Sergio , Baca Vicente , Nath Swapan K. , Aguilar Salinas Carlos , Orozco Lorena , Tusié‐Luna Teresa , Zidovetzki Raphael , Pons‐Estel Bernardo A. , Langefeld Carl D. , Jacob Chaim O. 
Published: November 2015

ObjectiveSystemic lupus erythematosus (SLE) is a chronic autoimmune disease with a strong genetic component. We undertook the present work to perform the first genome‐wide association study on individuals from the Americas who are enriched for Native American heritage.MethodsWe analyzed 3,710 individuals from the US and 4 countries of Latin America who were diagnosed as having SLE, and healthy controls. Samples were genotyped with HumanOmni1 BeadChip. Data on out‐of‐study controls genotyped with HumanOmni2.5 were also included. Statistical analyses were performed using SNPtest and SNPGWA. Data were adjusted for genomic control and false discovery rate. Imputation was performed using Impute2 and, for classic HLA alleles, HiBag. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated.ResultsThe IRF5–TNPO3 region showed the strongest association and largest OR for SLE (rs10488631: genomic control–adjusted P [Pgcadj] = 2.61 × 10−29, OR 2.12 [95% CI 1.88–2.39]), followed by HLA class II on the DQA2–DQB1 loci (rs9275572: Pgcadj = 1.11 × 10−16, OR 1.62 [95% CI 1.46–1.80] and rs9271366: Pgcadj = 6.46 × 10−12, OR 2.06 [95% CI 1.71–2.50]). Other known SLE loci found to be associated in this population were ITGAM, STAT4, TNIP1, NCF2, and IRAK1. We identified a novel locus on 10q24.33 (rs4917385: Pgcadj = 1.39 × 10−8) with an expression quantitative trait locus (eQTL) effect (Peqtl = 8.0 × 10−37 at USMG5/miR1307), and several new suggestive loci. SLE risk loci previously identified in Europeans and Asians were corroborated. Local ancestry estimation showed that the HLA allele risk contribution is of European ancestral origin. Imputation of HLA alleles suggested that autochthonous Native American haplotypes provide protection against development of SLE.ConclusionOur results demonstrate that studying admixed populations provides new insights in the delineation of the genetic architecture that underlies autoimmune and complex diseases.
Brief Report: Menopause and Primary Ovarian Insufficiency in Women Treated for Antineutrophil Cytoplasmic Antibody–Associated Vasculitides
Authors: Tuin Janneke , Sanders Jan‐Stephan F. , van Beek André P. , Hoek Annemieke , Stegeman Coen A. 
Published: November 2015

ObjectiveOne of the side effects of cyclophosphamide is earlier menopause and primary ovarian insufficiency. This study was undertaken to investigate the onset of menopause and the incidence of primary ovarian insufficiency in women with antineutrophil cytoplasmic antibody–associated vasculitis (AAV), especially after treatment with orally administered cyclophosphamide.MethodsWe retrospectively studied the onset of menopause and the influence of cyclophosphamide in women diagnosed as having AAV in our center between 1970 and 2012.ResultsNinety‐four premenopausal women diagnosed as having AAV were included. Sixty‐seven patients received cyclophosphamide, and 27 received other, mostly immunosuppressive, medication. Forty‐six cyclophosphamide‐treated women developed menopause, 22 of whom were considered to have primary ovarian insufficiency. None of the patients who were not treated with cyclophosphamide developed primary ovarian insufficiency. There was a significant association between a cumulative cyclophosphamide dose of >16.6 gm, versus a cumulative dose of <16.6 gm, and menopause (χ2 = 8.72, P = 0.003; odds ratio [OR] 2.60 [95% confidence interval 1.38–4.90]). In addition, there was a significant association between a cumulative cyclophosphamide dose of <16.6 gm, versus no cyclophosphamide exposure, and menopause (χ2 = 16.37, P < 0.001; OR 7.32 [95% confidence interval 2.79–19.20]). Both women who received cyclophosphamide and those who did not experienced involuntary childlessness.ConclusionEarlier menopause and primary ovarian insufficiency frequently develop after oral cyclophosphamide therapy in premenopausal women with AAV. Involuntary childlessness is common after the development of primary ovarian insufficiency, but it also occurs in women not treated with cyclophosphamide. These findings emphasize the importance of the use of drugs that are not toxic to gonadal function in women of childbearing age.
A Structuring Repeat for Peptide Design: Long Beta Ribbons
Authors: Kier Brandon L. , Newbloom Gregory M. , Pozzo Lilo D. , Andersen Niels H. 
Published: November 2015

AbstractBeta sheets are inherently length‐limited; adding residues to the ends of model β‐sheets does not necessarily grow the β‐sheet. Here, we present a method for extending β‐sheets to any length with a stabilizing repeat unit containing cross‐strand Trp residues. Beta ribbons as long as 35 residues (approaching 100 Å in length) are reported and characterized.
Low‐Temperature Synthesis and Electrochemical Properties of Mesoporous Titanium Oxysulfides
Authors: Smith Luke A. C. , Trudeau Michel L. , Provencher Manon , Smith Mark E. , Antonelli David M. 
Published: November 2015

AbstractThis paper describes the synthesis and electrochemical properties of mesoporous titanium oxysulfides prepared through the chemical treatment of pristine mesoporous titanium oxide under various synthesis conditions. The materials were doped with sulfur by using hexamethyldisilathiane (HMDST), a strategy that was developed to improve the conductivity of the material, whilst also retaining the porosity and thermal stability. Varying amounts of HMDST and different synthesis temperatures were tested to optimize the surface area and electrochemical performance. Lower temperatures generally yielded materials with superior properties and, even though the conductivity was improved by using higher loading levels of HMDST, it also led to a drop in initial capacity at the highest synthesis temperature of 200 °C (137–41 mAh g−1). The best performing material was, thus, synthesized by using the highest level of HMDST (3.5 mL) at lower heating temperatures (100–150 °C). This set of conditions maximizes the combination of surface area, initial capacity, conductivity, and capacity retention, the latter of which was notably superior to that of the pristine material (81 vs. 35 %), emphasizing the overall success of this doping strategy in improving the electrochemical properties of these otherwise insulating materials.
The Synthesis, Characterization and Dehydrogenation of Sigma‐Complexes of BN‐Cyclohexanes
Authors: Kumar Amit , Ishibashi Jacob S. A. , Hooper Thomas N. , Mikulas Tanya C. , Dixon David A. , Liu Shih‐Yuan , Weller Andrew S. 
Published: November 2015

AbstractThe coordination chemistry of the 1,2‐BN‐cyclohexanes 2,2‐R2‐1,2‐B,N‐C4H10 (R2=HH, MeH, Me2) with Ir and Rh metal fragments has been studied. This led to the solution (NMR spectroscopy) and solid‐state (X‐ray diffraction) characterization of [Ir(PCy3)2(H)2(η2η2‐H2BNR2C4H8)][BArF4] (NR2=NH2, NMeH) and [Rh(iPr2PCH2CH2CH2PiPr2)(η2η2‐H2BNR2C4H8)][BArF4] (NR2=NH2, NMeH, NMe2). For NR2=NH2 subsequent metal‐promoted, dehydrocoupling shows the eventual formation of the cyclic tricyclic borazine [BNC4H8]3, via amino‐borane and, tentatively characterized using DFT/GIAO chemical shift calculations, cycloborazane intermediates. For NR2=NMeH the final product is the cyclic amino‐borane HBNMeC4H8. The mechanism of dehydrogenation of 2,2‐H,Me‐1,2‐B,N‐C4H10 using the {Rh(iPr2PCH2CH2CH2PiPr2)}+ catalyst has been probed. Catalytic experiments indicate the rapid formation of a dimeric species, [Rh2(iPr2PCH2CH2CH2PiPr2)2H5][BArF4]. Using the initial rate method starting from this dimer, a first‐order relationship to [amine‐borane], but half‐order to [Rh] is established, which is suggested to be due to a rapid dimer–monomer equilibrium operating.
Synthesis of Plasmonic Cu2‐xSe@ZnS Core@Shell Nanoparticles
Authors: Wolf Andreas , Härtling Thomas , Hinrichs Dominik , Dorfs Dirk 
Published: November 2015

AbstractWe report the synthesis of plasmonic Cu2‐xSe@ZnS core@shell nanoparticles (NPs). We used a shell growth approach, starting from Cu2‐xSe NPs that have been shown before to exhibit a localized surface plasmon resonance (LSPR). By careful synthesis planning we avoided cation exchange reactions and received core@shell nanoparticles that, after oxidation under air, exhibit a strong LSPR in the NIR. Interestingly, the crystalline, closed ZnS shell that we grew with variable thickness still allowed a slow oxidation of the core under ambient conditions, while the core was effectively protected from reduction, even in the presence of reducing agents such as borane tert‐butyamine complex and diisobutylaluminum hydride, giving rise to a stable particle LSPR, also under strongly reducing conditions.
Proline Sulfonamide‐Catalyzed, ­Domino Process for Asymmetric Synthesis of Amino‐ and Hydroxy‐Substituted Bicyclo[2.2.2]octanes
Authors: El‐Mansy Mohamed F. , Kang Jun Yong , Lingampally Rajinikanth , Carter Rich G. 
Published: November 2015

AbstractA generalized method for accessing highly functionalized amino‐substituted bicyclo[2.2.2]octanes via p‐dodecylphenylsulfonamide catalyst in a good enantio‐ and diastereoselective fashion has been developed. A discussion of the mechanistic underpinnings of this transformation is presented. Finally, an unexpected discovery enabling the extension of this protocol to the synthesis of OH‐substituted bicyclo[2.2.2]octanes with encouraging levels of stereoselectivity is discussed.
Total Synthesis of (–)‐C/D‐cis‐De­hydro‐3‐O‐methyl‐estradiols
Authors: Kaluza Nora M. , Schollmeyer Dieter , Nubbemeyer Udo 
Published: November 2015

AbstractA convergent synthesis of (–)‐dehydro‐3‐O‐methyl‐C/D‐cis‐estradiol started from stereochemically defined substituted optically active 3‐(2‐arylethyl)‐γ‐butyrolactones. Regioselective bromination of the anisyl moiety, reductive ring opening of the iodolactone, and protecting‐group changes led to a Weinreb amide. This then underwent an intramolecular Grignard reaction closing the B‐ring to give a tetralone with defined configuration. Introduction of C‐11 through an allyl Grignard addition and subsequent ring‐closing metathesis gave a tetrahydro phenanthrene derivative. Oxidation of the side‐chain alcohol resulted in the key aldehyde group, and a final samarium‐diiodide‐mediated reductive D‐ring annulation resulted in the generation of the target dehydro‐C/D‐cis‐estradiol derivatives with high stereoselectivity. Structure elucidation was carried out using NOEDS (nuclear Overhauser enhanced differential spectroscopy) analysis on the one hand, and conversion into known 3‐O‐methyl‐13β‐estradiols by double‐bond hydrogenation on the other. Further efforts to use this estradiol synthetic strategy to generate more complex steroidal natural products and pharmaceutically interesting compounds are in progress.
Bisphenol S alters embryonic viability, development, gallbladder size, and messenger RNA expression in chicken embryos exposed via egg injection
Authors: Crump Doug , Chiu Suzanne , Williams Kim L. 
Published: November 2015

Abstract

Amid concerns about the toxicological effects and environmental prevalence of bisphenol A (BPA), efforts to find suitable, safer replacement alternatives are essential. Bisphenol S (BPS) is a potential chemical substitute for BPA; however, few studies are available confirming that it has a more desirable ecotoxicological profile. In the present study, BPS was injected into the air cell of unincubated, fertilized chicken embryos at 6 concentrations ranging from 0 μg/g to 207 μg/g egg to determine effects on pipping success, development, hepatic messenger ribonucleic acid (mRNA) expression, thyroid hormone levels, and circulating bile acid concentrations. Concentrations of BPS increased in a dose-dependent manner in whole-embryo homogenates, and exposure to the highest dose, 207 μg/g, resulted in decreased pipping success (estimated median lethal dose = 279 μg/g; 95% confidence interval = 161–486 μg/g). Exposure to BPS also reduced growth metrics including embryo mass and tarsus length, whereas the most pronounced phenotypic effect was the concentration-dependent, significant increase in gallbladder size at concentrations ≥52.8 μg/g. These adverse phenotypic outcomes were associated with the modulation of gene targets from a chicken ToxChip polymerase chain reaction array, which are involved with xenobiotic metabolism, lipid homeostasis, bile acid synthesis, and the thyroid hormone pathway. Expression levels of 2 estrogen-responsive genes, apolipoprotein II and vitellogenin, were too low at the sampling time point assessed (i.e., pipping embryos) to quantify changes, and no effects were observed on circulating free thyroxine or bile acid concentrations. The present study provides novel, whole-animal toxicological data for a BPA replacement alternative that is not well characterized. Environ Toxicol Chem 2016;35:1541–1549. © 2015 SETAC
Exposure to the lampricide 3-trifluoromethyl-4-nitrophenol results in increased expression of carbohydrate transporters in Saccharomyces cerevisiae
Authors: Hinkle Karen L. , Anderson Chad C. , Forkey Blake , Griffin Jacob , Cone Kelsey , Vitzthum Carl , Olsen Darlene 
Published: November 2015

Abstract

The lampricide 3-trifluoromethyl-4-nitrophenol (TFM) is used to control sea lamprey (Petromyzon marinus) populations in freshwater lakes. Although TFM can have sublethal and lethal effects, little is known about gene expression changes with TFM exposure. Microarray analysis was used to determine differential gene expression over 4 h of exposure in Saccharomyces cerevisiae. Among the most significantly up-regulated genes were regulators of carbohydrate transport, including HXT1, HXT3, HXT4, IMA5, MIG2, and YKR075C. Environ Toxicol Chem 2016;35:1727–1732. © 2015 SETAC
The Oxidation of Coated SOFC Interconnects in Fuel Side Environments
Authors: Sachitanand R. , Sattari M. , Svensson J.‐E. , Froitzheim J. 
Published: November 2015

AbstractThis study focuses on examining the effect of PVD coatings on the oxidation performance of interconnects in fuel (anode) side environments. A Fe‐22Cr ferritic steel was coated with (i) Ce 10 nm (ii) La 10 nm and (iii) Co 600 nm. The samples were exposed at 850 °C in Ar‐5% H2‐3% H2O in a tubular furnace over 500 h. Additionally, the effect of a pre‐oxidation step was investigated by exposure in air prior to the simulated fuel gas environment. Chemical analysis on the samples was subsequently performed with SEM/EDX and XRD. It was established that the Ce and La coatings brought about a factor 2–3 reduction (kp values of 2.16 × 10−14 ± 3.6 × 10−15 g2 cm−4 s−1 for the La 10 nm coated steel compared to 7.72 × 10−14 ± 5.86 × 10−15 g2 cm−4 s−1 for the uncoated steel) in the oxidation rate while the Co coating disintegrated into metallic islands in and on the thermally grown oxide after exposure. Additionally, the La coating resulted in the formation of a continuous perovskite layer by reaction with the thermally grown oxide.
Cholinergic neuronal lesions in the medial septum and vertical limb of the diagonal bands of Broca induce contextual fear memory generalization and impair acquisition of fear extinction
Authors: Knox Dayan , Keller Samantha M. 
Published: November 2015

ABSTRACTPrevious research has shown that the ventral medial prefrontal cortex (vmPFC) and hippocampus (Hipp) are critical for extinction memory. Basal forebrain (BF) cholinergic input to the vmPFC and Hipp is critical for neural function in these substrates, which suggests BF cholinergic neurons may be critical for extinction memory. In order to test this hypothesis, we applied cholinergic lesions to different regions of the BF and observed the effects these lesions had on extinction memory. Complete BF cholinergic lesions induced contextual fear memory generalization, and this generalized fear was resistant to extinction. Animals with complete BF cholinergic lesions could not acquire cued fear extinction. Restricted cholinergic lesions in the medial septum and vertical diagonal bands of Broca (MS/vDBB) mimicked the effects that BF cholinergic lesions had on contextual fear memory generalization and acquisition of fear extinction. Cholinergic lesions in the horizontal diagonal band of Broca and nucleus basalis (hDBB/NBM) induced a small deficit in extinction of generalized contextual fear memory with no accompanying deficits in cued fear extinction. The results of this study reveal that MS/vDBB cholinergic neurons are critical for inhibition and extinction of generalized contextual fear memory, and via this process, may be critical for acquisition of cued fear extinction. Further studies delineating neural circuits and mechanisms through which MS/vDBB cholinergic neurons facilitate these emotional memory processes are needed. © 2015 Wiley Periodicals, Inc.