bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reproductive health, obesity, and cardiometabolic risk factors among Samoan women
Authors: Maredia H. , Hawley N. L. , Lambert‐Messerlian G. , Fidow U. , Reupena M. S. , Naseri T. , McGarvey S. T. 
Published: April 2018

AbstractObjectivesObesity leads to deleterious effects on not only cardiovascular health but also on the reproductive health of women. We estimate the prevalence of menstrual irregularity and of polycystic ovarian syndrome (PCOS) in Samoan women, among whom obesity prevalence is extremely high. We explore the association of these reproductive health conditions with adiposity, cardiometabolic risk factors, and androgen levels.MethodsA cross‐sectional sample of Samoan women 25–39 years of age (n = 470) from a larger population‐based genome‐wide association study of adiposity and cardiometabolic disease was assessed for the prevalence of oligomenorrhea/amenorrhea (OM/AM) using a self‐reported questionnaire. Serum androgens and anti‐Müllerian hormone levels were assayed to determine hyperandrogenemia and presence of polycystic ovaries (PCO), respectively, using criterion values. PCOS was classified using NIH guidelines of having at least two of the three conditions: menstrual irregularity, hyperandrogenism, and PCO. We contrasted socio‐demographic, reproductive health, and cardiometabolic risk factors between those with and without OM/AM and similarly for PCOS.ResultsThe prevalence of OM/AM was 7.4% (95% CI: 5.1, 9.8), and women with OM/AM had significantly higher central adiposity. PCOS was estimated at 6.8% (95% CI: 4.5, 9.1), and those with PCOS were younger but had higher overall and central adiposity measures, higher triglycerides, and higher prevalence of insulin resistance than women without PCOS.ConclusionsThe prevalence of menstrual irregularity and PCOS are less than hypothesized given the high levels of adiposity in this population. Nevertheless, Samoan women with menstrual irregularity and other features of PCOS have significantly poorer metabolic health.
Synthesis of Alkyl‐Substituted Pyrazine N‐Oxides by Transition‐Metal‐Free Oxidative Cross‐Coupling Reactions
Authors: Lai Miao , Li Yuan , Wu Zhiyong , Zhao Mingqin , Ji Xiaoming , Liu Pengfei , Zhang Xiaoping 
Published: April 2018

AbstractDirect access to alkyl‐substituted pyrazine N‐oxides has been accomplished through an intermolecular dehydrogenative cross‐coupling reaction of ethers and pyrazine N‐oxides in the presence of tert‐butyl hydroperoxide (TBHP). This approach successfully provided a variety of alkyl‐substituted pyrazine N‐oxides in up to 96 % yield. Thermogravimetric analysis indicates that the degradation temperature of C2‐alkyated product 3 a is approximately 263 °C. Under pyrolysis conditions, 3 a generated several compounds such as 2,5‐dimethylpyrazine, 2,3,5‐trimethylpyrazine, and 3‐ethyl‐2,5‐dimethylpyrazine, which are characterized by their distinct aromas. The results of the pyrolysis experiment support the use of these compounds as possible flavor additives.
Schistosomiasis and hydration status: Schistosoma haematobium, but not Schistosoma mansoni increases urine specific gravity among rural Tanzanian women
Authors: Rosinger Asher Y. , Young Sera L. , Collins Shalean M. , Haider Syeda Razia , Mishra Pallavi , Nagai Honest T. , Petro Mnyeshi , Downs Jennifer A. 
Published: April 2018

AbstractObjectivesSchistosome infections can damage organs important for water homeostasis, especially the kidneys. Urogenital schistosomiasis (caused by Schistosoma haematobium) increases protein and blood in urine and intestinal schistosomiasis (caused by S. mansoni) affects total body water. However, no data exist on how different schistosome species affect urine specific gravity (USG), a hydration biomarker. Therefore, we assessed the relationship between S. haematobium‐ and S. mansoni‐infected and uninfected women and USG in rural Tanzania.Materials and methodsSurveys were conducted and stool and urine samples were collected among 211 nonpregnant women aged 18–50. S. haematobium eggs were detected using the urine filtration method. S. mansoni eggs were detected using the Kato Katz method. USG was measured using a refractometer and analyzed as both a continuous and dichotomous variable. Regression (linear/logistic) models were estimated to test the relationship between infection and hydration status.ResultsThe prevalence of S. haematobium was 5.9% and S. mansoni was 5.4% with no coinfections. In regression models, S. haematobium‐infected women had significantly higher USG (Beta = 0.007 g mL−1; standard error = 0.002; p = 0.001) and odds (Odds ratio: 7.76, 95% CI: 1.21‐49.5) of elevated USG (>1.020 g mL−1) than uninfected women, whereas S. mansoni‐infected women did not.DiscussionSchistosoma haematobium, but not S. mansoni, infection is associated with higher USG and risk of inadequate hydration. Future work should determine whether findings are attributable to parasite‐induced debris in urine or urinary tract pathologies and signs of renal damage. Human and non‐human primate studies using USG in schistosome‐endemic areas should account for schistosomiasis.
The inside tract: The appendicular, cecal, and colonic microbiome of captive aye‐ayes
Authors: Greene Lydia K. , McKenney Erin A. 
Published: April 2018

AbstractObjectivesThe aye‐aye (Daubentonia madagascariensis) is famous for its feeding strategies that target structurally defended, but high‐quality resources. Nonetheless, the influence of this digestible diet on gut microbial contributions to aye‐aye metabolism and nutrition remains unexplored. When four captive aye‐ayes were unexpectedly lost to persin toxicity, we opportunistically collected samples along the animals' gastrointestinal tracts. Here we describe the diversity and composition of appendicular, cecal, and colonic consortia relative to the aye‐aye's unusual feeding ecology.Materials and methodsDuring necropsies, we collected digestive content from the appendix, cecum, and distal colon. We determined microbiome structure at these sites via amplicon sequencing of the 16S rRNA gene and an established bioinformatics pipeline.ResultsThe aye‐ayes' microbiomes exhibited low richness and diversity compared to the consortia of other lemurs housed at the same facility, and were dominated by a single genus, Prevotella. Appendicular microbiomes were differentiated from more homogenized cecal and colonic consortia by lower richness and diversity, greater evenness, and a distinct taxonomic composition.DiscussionThe simplicity of the aye‐aye's gut microbiome could be attributed to captivity‐induced dysbiosis, or it may reflect this species' extreme foraging investment in a digestible diet that requires little microbial metabolism. Site‐specific appendicular consortia, but more similar cecal and colonic consortia, support the theory that the appendix functions as a safe‐house for beneficial bacteria, and confirm fecal communities as fairly reliable proxies for consortia along the lower gut. We encourage others to make similar use of natural or accidental losses for probing the primate gut microbiome.
Tuning in C‐nociceptors to reveal mechanisms in chronic neuropathic pain
Authors: Jonas Robin , Namer Barbara , Stockinger Lenka , Chisholm Kim , Schnakenberg Mark , Landmann Gunther , Kucharczyk Mateusz , Konrad Christoph , Schmidt Roland , Carr Richard , McMahon Stephen , Schmelz Martin , Rukwied Roman 
Published: April 2018

ObjectiveDevelop and validate a low‐intensity sinusoidal electrical stimulation paradigm to preferentially activate C‐fibers in human skin.MethodsSinusoidal transcutaneous stimulation (4Hz) was assessed psychophysically in healthy volunteers (n = 14) and neuropathic pain patients (n = 9). Pursuing laser Doppler imaging and single nociceptor recordings in vivo in humans (microneurography) and pigs confirmed the activation of “silent” C‐nociceptors. Synchronized C‐fiber compound action potentials were evoked in isolated human nerve fascicles in vitro. Live cell imaging of L4 dorsal root ganglia in anesthetized mice verified the recruitment of small‐diameter neurons during transcutaneous 4‐Hz stimulation of the hindpaw (0.4mA).ResultsTranscutaneous sinusoidal current (0.05–0.4mA, 4Hz) activated “polymodal” C‐fibers (50% at ∼0.03mA) and “silent” nociceptors (50% at ∼0.04mA), intensities substantially lower than that required with transcutaneous 1‐ms rectangular pulses (“polymodal” ∼3mA, “silent” ∼50mA). The stimulation induced delayed burning (nonpulsating) pain and a pronounced axon‐reflex erythema, both indicative of C‐nociceptor activation. Pain ratings to repetitive stimulation (1 minute, 4Hz) adapted in healthy volunteers by Numeric Rating Scale (NRS) –3 and nonpainful skin sites of neuropathic pain patients by NRS –0.5, whereas pain even increased in painful neuropathic skin by approximately NRS +2.InterpretationSinusoidal electrical stimulation at 4Hz enables preferential activation of C‐nociceptors in pig and human skin that accommodates during ongoing (1‐minute) stimulation. Absence of such accommodation in neuropathic pain patients suggest axonal hyperexcitability that could be predictive of alterations in peripheral nociceptor encoding and offer a potential therapeutic entry point for topical analgesic treatment. Ann Neurol 2018;83:945–957
Serotonin, β‐amyloid, and cognition in Parkinson disease
Authors: Kotagal Vikas , Spino Cathie , Bohnen Nicolaas I. , Koeppe Robert , Albin Roger L. 
Published: April 2018

ObjectiveSerotoninergic neurotransmission may modulate β‐amyloid peptide (Aβ) metabolism through upregulation of α‐secretase. Early Parkinson disease (PD) shows variable serotoninergic denervation, which may impact Aβ deposition.MethodsWe conducted 3 analyses to explore associations between serotoninergic neurotransmission and cerebral Aβ burden in PD. The first was a cross‐sectional imaging study of PD subjects (n = 23) using the serotoninergic transporter positron emission tomography (PET) ligand [11C]3‐amino‐4‐(2‐dimethylaminomethyl‐phenylsulfaryl)‐benzonitrile (DASB) and amyloid PET Pittsburgh compound B ([11C]PiB). The second was a baseline study of Parkinson's Progression Markers Initiative (PPMI) subjects exploring the influence of serotoninergic medications on cerebrospinal fluid (CSF) Aβ‐42 levels (n = 389), controlling for age, sex, Geriatric Depression Scale, disease duration, and education. Third, we fit an interval censored proportional hazard model with longitudinal PPMI data (n = 367) to test whether serotoninergic medication use associates with reduced risk of PD cognitive decline, defined as time to reach a Montreal Cognitive Assessment score ≤ 20, adjusting for baseline caudate dopamine transporter [123I]ioflupane single photon emission computed tomography and CSF Aβ‐42 levels.ResultsSerotoninergic DASB distribution volume ratio (DVR) inversely associated with PiB DVR in the cerebral cortex (Pearson r = −0.478, p = 0.021) but not the striatum (r = −0.264, p = 0.224). In the baseline PPMI analysis, serotoninergic medication use for ≥6 months associated with a lower level of CSF Aβ‐42 (t = −2.20, p = 0.029). In the longitudinal PPMI model, baseline serotoninergic medication use associated with a reduced risk of cognitive decline (t = −2.03, p = 0.043) after controlling for covariates.InterpretationCortical Aβ burden in PD associates inversely with serotoninergic innervation. Serotoninergic medications may alter Aβ metabolism and reduce the risk of PD cognitive decline. Ann Neurol 2018;83:994–1002
Atrophy and microglial distribution in primary progressive aphasia with transactive response DNA‐binding protein‐43 kDa
Authors: Kim Garam , Bolbolan Kabriya , Gefen Tamar , Weintraub Sandra , Bigio Eileen H. , Rogalski Emily , Mesulam Marek‐Marsel , Geula Changiz 
Published: April 2018

ObjectiveTo quantitatively determine the density and distribution of activated microglia across cortical regions and hemispheres in the brains of primary progressive aphasia (PPA) participants with pathological diagnoses of frontotemporal lobar degeneration with transactive response DNA‐binding protein‐43 (TDP‐43) inclusions and to examine the relationships between microglial densities, patterns of focal atrophy, (TDP‐43) inclusions, and clinical phenotype.MethodsActivated microglia and TDP‐43 inclusions were visualized in whole‐hemisphere brain sections using immunohistochemical methods from five participants with PPA‐TDP. Unbiased stereology was used to bilaterally quantify human leuckocyte antigen/D related–positive activated microglia and TDP‐43 inclusions across five language‐related regions. Density and distribution of both markers were compared across cortical regions and hemispheres, and their relationships to patterns of focal atrophy and clinical phenotype were determined.ResultsActivated microglia displayed asymmetric distribution favoring the language‐dominant hemisphere, consistent with greater postmortem and/or in vivo atrophy in that hemisphere, in PPA‐TDP. In one participant with no asymmetric atrophy, quantitative distribution of microglia also lacked asymmetry. Patterns of microglial activation also showed variation that favored areas of high atrophy in regions affiliated with language function, demonstrating concordance between patterns of microglial activation, atrophy, and clinical phenotype. TDP‐43 also showed higher inclusion densities in areas of high atrophy than in regions with low atrophy, but no clear relationship with microglia density at a regional level.InterpretationThe initial activation of microglia is most likely a response to cortical abnormalities in PPA‐TDP, which contribute to atrophy. The patterns of microglial activation, TDP‐43 inclusion deposition, atrophy, and clinical phenotype suggest that activated microglia may make unique contributions to cortical thinning and TDP‐43 inclusion formation. Ann Neurol 2018;83:1096–1104
Direct Access to Aryl Bis(trifluoromethyl)carbinols from Aryl Bromides or Fluorosulfates: Palladium‐Catalyzed Carbonylation
Authors: Domino Katrine , Veryser Cedrick , Wahlqvist Benjamin A. , Gaardbo Cecilie , Neumann Karoline T. , Daasbjerg Kim , De Borggraeve Wim M. , Skrydstrup Troels 
Published: April 2018

AbstractA palladium‐catalyzed carbonylative approach for the direct conversion of (hetero)aryl bromides into their α,α‐bis(trifluoromethyl)carbinols is described, and it employs only stoichiometric amounts of carbon monoxide and trifluoromethyltrimethylsilane. In addition, aryl fluorosulfates proved highly compatible with these reaction conditions. The method is tolerant of a diverse set of functional groups, and it is adaptable to late‐stage carbon‐isotope labeling.
A Very Short Uranium(IV)–Rhodium(I) Bond with Net Double‐Dative Bonding Character
Authors: Lu Erli , Wooles Ashley J. , Gregson Matthew , Cobb Philip J. , Liddle Stephen T. 
Published: April 2018

AbstractReaction of [U{C(SiMe3)(PPh2)}(BIPM)(μ‐Cl)Li(TMEDA)(μ‐TMEDA)0.5]2 (BIPM=C(PPh2NSiMe3)2; TMEDA=Me2NCH2CH2NMe2) with [Rh(μ‐Cl)(COD)]2 (COD=cyclooctadiene) affords the heterotrimetallic UIV−RhI2 complex [U(Cl)2{C(PPh2NSiMe3)(PPh[C6H4]NSiMe3)}{Rh(COD)}{Rh(CH(SiMe3)(PPh2)}]. This complex has a very short uranium–rhodium distance, the shortest uranium–rhodium bond on record and the shortest actinide–transition metal bond in terms of formal shortness ratio. Quantum‐chemical calculations reveal a remarkable Rh
UIV net double dative bond interaction, involving RhI 4d
‐ and 4dxy/xz‐type donation into vacant UIV 5f orbitals, resulting in a Wiberg/Nalewajski–Mrozek U−Rh bond order of 1.30/1.44, respectively. Despite being, formally, purely dative, the uranium–rhodium bonding interaction is the most substantial actinide–metal multiple bond yet prepared under conventional experimental conditions, as confirmed by structural, magnetic, and computational analyses.
Exposing the Origins of Irreproducibility in Fluorine NMR Spectroscopy
Authors: Rosenau Carl Philipp , Jelier Benson J. , Gossert Alvar D. , Togni Antonio 
Published: April 2018

AbstractFluorine chemistry has taken a pivotal role in chemical reaction discovery, drug development, and chemical biology. NMR spectroscopy, arguably the most important technique for the characterization of fluorinated compounds, is rife with highly inconsistent referencing of fluorine NMR chemical shifts, producing deviations larger than 1 ppm. Herein, we provide unprecedented evidence that both spectrometer design and the current unified scale system underpinning the calibration of heteronuclear NMR spectra have unintentionally led to widespread variation in the standardization of 19F NMR spectral data. We demonstrate that internal referencing provides the most robust, practical, and reproducible method whereby chemical shifts can be consistently measured and confirmed between institutions to less than 30 ppb deviation. Finally, we provide a comprehensive table of appropriately calibrated chemical shifts of reference compounds that will serve to calibrate 19F spectra correctly.
Application of In Situ Techniques for the Characterization of NiFe‐Based Oxygen Evolution Reaction (OER) Electrocatalysts
Authors: Zhu Kaiyue , Zhu Xuefeng , Yang Weishen 
Published: April 2018

AbstractDeveloping high‐efficiency and affordable electrocatalysts for the sluggish oxygen evolution reaction (OER) remains a crucial bottleneck on the way to the practical applications of rechargeable energy storage technologies and water splitting for producing clean fuel (H2). In recent years, NiFe‐based materials have proven to be excellent electrocatalysts for OER. Understanding the characteristics that affect OER activity and determining the OER mechanism are of vital importance for the development of OER electrocatalysts. Therefore, in situ characterization techniques performed under OER conditions are urgently needed to monitor the key intermediates together with identifying the OER active centers and phases. In this Minireview, recent advances regarding in situ techniques for the characterization of NiFe‐based electrocatalysts are thoroughly summarized, including Raman spectroscopy, X‐ray absorption spectroscopy, ambient pressure X‐ray photoelectron spectroscopy, Mössbauer spectroscopy, Ultraviolet–visible spectroscopy, differential electrochemical mass spectrometry, and surface interrogation scanning electrochemical microscopy. The results from these in situ measurements not only reveal the structural transformation and the progressive oxidation of the catalytic species under OER conditions, but also disclose the crucial role of Ni and Fe during the OER. Finally, the need for developing new in situ techniques and theoretical investigations is discussed to better understand the OER mechanism and design promising OER electrocatalysts.
F‐doped Ag/AgBr with enhanced visible‐light photocatalytic activity and mechanism
Authors: Bao Ting , Song Limin , Zhang Shujuan 
Published: April 2018

Novel F‐doped Ag/AgBr photocatalysts containing various amounts of F− were synthesized by an ion exchange method. The photocatalysts were characterized using X‐ray diffraction (XRD), scanning and transmission electron microscopies, X‐ray photoelectron, ultraviolet–visible absorption and photoluminescence spectroscopies and electron spin resonance (ESR). Powder XRD revealed that F− was inserted into the crystal lattices of AgBr and partially replaced Br−, resulting in the contraction of the AgBr lattices. Methyl orange photodegradation experiments showed that the photocatalytic activity of F‐doped Ag/AgBr was significantly dependent on the amount of F−. Ag/AgBr doped with 0.02 M F− achieved the highest activity of 91% after 8 min. ESR showed the main active species in methyl orange degradation was •OH. The main enhancement mechanism is that F− inhibits the recombination of electron–hole pairs.
Controllable preparation of highly dispersed TiO2 nanoparticles for enhanced catalytic oxidation of dibenzothiophene in fuels
Authors: Lu Qingqing , Peng Wenhui , Xun Suhang , He Minqiang , Ma Ruliang , Jiang Wei , Zhu Wenshuai , Li Huaming 
Published: April 2018

The aggregation of nanoparticle catalysts is one of the main problems in catalytic reactions. In this study, a series of TiO2 nanoparticle catalysts with various dispersions were prepared and applied in the catalytic oxidation of dibenzothiophene (DBT) systems. Compositions and structures of the as‐prepared samples were analyzed by means of wide‐angle X‐ray diffraction, Raman and X‐ray photoelectron spectroscopies. The dispersions of TiO2 nanoparticles were controlled by calcining at various temperatures and verified using transmission electron microscopy. It was found that the activities of TiO2 nanoparticles in the catalytic oxidation of DBT were positively correlated with the dispersions. TiO2 nanoparticles calcined at 500 °C (500‐TiO2) showed the best catalytic activity and the oxidation of DBT reached 99.8% under mild conditions. Based on the results of GC–MS analysis, radical trapping experiments and electron spin resonance spectra, •O2− radicals were proved to be the main active species in the oxidation process, and a mechanism is proposed. Meanwhile, the recycling performance of 500‐TiO2 was investigated, and no obvious decrease was observed after six recycles.
Chemometric Characterization of Eight Monovarietal Algerian Virgin Olive Oils
Authors: Guissous Mokhtar , Le Dréau Yveline , Boulkhroune Hasna , Madani Toufik , Artaud Jacques 
Published: April 2018

AbstractDifferences in triacylglycerol, fatty acid, squalene, and tocopherol compositions were demonstrated between 8 varieties of virgin olive oils (Aberkane, Aguenaou, Aharoun, Aimel, Bouchouk Guergour, Bouichret, Chemlal, and Sigoise) from Petite Kabylie area, north eastern Algeria. Fatty acid and triacylglycerol morphotypes characterized each variety. A principal component analysis, based on triacylglycerol, fatty acid, and squalene compositions, differentiates between varieties. Minor fatty acids and squalene, usually not taken into account individually in authentication studies, are strongly involved in this differentiation, whereas the discriminant power of tocopherols is weak. Soft Independent Modeling of Class Analogy classification using chemical compositions as variables showed a high potential to authenticate the varietal origin of Algerian virgin olive oils.
Effects of hydrophilic/hydrophobic surfaces on polymer‐complexation kinetics
Authors: Sayama Daisuke , Hatanaka Masashi , Miyasaka Makoto 
Published: April 2018

ABSTRACTTo establish hydrophilic/hydrophobic effects on polymer‐complexation kinetics, chitosan resins were prepared by radical copolymerization of methacryloyl‐modified chitosans with 2‐hydroxyethyl methacrylate and/or styrene monomers. The primary particles of the gelled copolymers in the suspensions were nicely solidified by basic coagulation bath to form globular beads. Degree of the hydrophilic/hydrophobic properties was controlled by the copolymerization ratio, and each ion‐adsorption kinetics was evaluated by batch method. The initial rate of adsorption in hydrophilic chitosans was higher than that in hydrophobic chitosans, which was attributed to less thickness of the boundary film. We quantitatively evaluated the rate‐determining steps by the initial‐rate analysis, in which the viscosity of the suspension contributes to the film‐diffusion kinetic resistance. The role of hydrophilic/hydrophobic properties of the resins is reasonably rationalized to the length of the boundary films by considering long‐range interactions between the ion and surface. Our results are robust evidence for the ion‐surface interactions. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46493.