bluuebunny/crossref_metadata_2025_split huggingface dataset:
Keto‐Enol Tautomerism in Nucleobase‐Substituted Aldols
Authors: Nigro Mariano J. , Iribarren Adolfo M. , Laurella Sergio L. , Lewkowicz Elizabeth S. 
Published: December 2018

AbstractAcyclic nucleosides, which exhibit significant antiviral activity, are usually synthesised using traditional chemical strategies. However, the efficient and selective formation of carbon‐carbon bonds using small organic molecules as catalysts provides a promising alternative route for the sustainable synthesis of this family of compounds. Following this organocatalytic strategy, 5‐(adenyl, thyminyl and cytosyl)‐4‐hydroxy‐2‐pentanones were prepared by the pyrrolidine catalysed reaction between the 2‐oxoethyl derivative of the corresponding nucleobases and acetone. In order to investigate the keto‐enol equilibrium of these compounds in basic media, H‐D exchange studies were carried out by 1H and 13C NMR spectroscopy. The obtained results suggest that the mechanism by which this exchange occurs is of first order with respect to all the substrates, but of second order with regard to pyrrolidine in the case of the cytosine and adenine derivatives and of first order for the thymine analogue. Theoretical calculations of the structures involved in this equilibrium also suggest that the stability of the different ionic intermediates depends on the pKa of the corresponding nucleobases.
Functionalization of Graphite with the Diels–Alder Reaction to Fabricate Metal‐Free Electrocatalysts for Highly Efficient Hydrogen Evolution Reaction
Authors: Abdolmaleki Amir , Mallakpour Shadpour , Mahmoudian Manzar , Kamali Saeedeh , Zhiani Mohammad , Rezaei Behzad , Jahromi Ahmad Reza Taghipour 
Published: December 2018

AbstractA facile method was reported to produce a modified graphene via Diels‐Alder cycloaddition reaction with malemide and graphite precursors. Two procedures were used for the embedding of malemide functional groups on surface or edge of graphene; MI‐EGnPs (maleimide edge‐functionalized graphene nanoparticles) with the more edges functional groups and MI‐GnPs (maleimide functionalized graphene nanoparticles) with the more surface functional groups. In order to investigate the influence of functionalization on the electrochemical behavior of the modified graphene structures, the prepared materials were used as the metal‐free electrocatalysts for hydrogen evolution reaction (HER) in alkaline media. MI‐ EGnPs showed a Tafel slope of −110 mV dec−1 compared to −168 mV dec−1 for MI‐GnPs. The observed difference in the electrochemical performances of the samples were interpreted due to the connection places of functional groups.
Biological Evaluation of Synthesized N‐Cinnamoyl Phenothiazine Derivatives
Authors: Selvendran Suresh , J Brindha , CS Vasavi , Munussami Punnagai , Pattusamy Nithya , Chanda Kaushik , MM Balamurali , Rajendran Saravanakumar 
Published: December 2018

AbstractN‐Cinnamoyl phenothiazines were synthesized and characterized by various spectroscopic techniques including vibrational, nuclear magnetic resonance and mass spectrometry. The potential applications of these compounds as antioxidants and antibacterials were evaluated. Compound 2 with –NO2 substituted cinnamoyl moiety in the phenothiazine ring nitrogen showed better antioxidant activity (77.8 μM for hydroxyl radicals and 85.0 μM for diphenyl picrylhydrazyl radicals). A moderate antibacterial activity (202‐330 μM) was observed for all the derivatives of phenothiazine against Gram‐positive and Gram‐negative bacteria, while the parent phenothiazine did not show any inhibitory activity up to 500 μM, indicating that the observed activity could be induced by the added cinnamoyl moiety. Nucleic acid and protein binding affinities were investigated for their applications as biomolecular probes. Both experimental and computational docking studies revealed an intercalative mode of binding with nucleic acids and 1:1 binding to bovine serum albumin.
Comparative Study of 1,1‐Diphenyl‐2‐picryl‐hydrazyl Radical (DPPH•) Scavenging Capacity of the Antioxidant Xanthones Family
Authors: Li Xican 
Published: December 2018

AbstractThis study compares the antioxidant capacities of the xanthone family and analyzes structure‐activity relationship. Thirty xanthones with various structural features were selected as the references and their antioxidant capacities were determined using the 1,1‐diphenyl‐2‐picryl‐hydrazyl radical (DPPH•) scavenging assay. The results of the assay indicated that these xanthones could scavenge the DPPH• in a dose‐dependent manner. It was found that their Trolox equivalent antioxidant capacity (TEAC) values varied by the presence or absence of hydroquinone (or catechol) group within the molecule. The former 15 xanthones (1‐15, TEAC=2.030‐0.568) with hydroquinone (or catechol) pattern possessed much higher TEAC values than the latter 15 xanthones (16‐30, TEAC=0.019‐0.002) without hydroquinone (or catechol) pattern. It was concluded that the presence of the hydroquinone (or catechol) group governs the antioxidant capacity of xanthone family. Other structural factors, such as isoprenylation, methylation, and glycosidation, play a minor role, unless they remove the hydroquinone (or catechol) pattern. These findings can be used to directly predict the antioxidant capacity of xanthone.
Probing the Thermodynamics of Incorporation of N6‐methyl‐dATP Opposite an Abasic Site, dCMP, and dTMP During Simulated DNA Synthesis by Differential Scanning Calorimetry
Authors: Malina Jaroslav , Brabec Viktor 
Published: December 2018

AbstractPrevious reports indicated that when an abasic (apurinic/apyrimidinic, AP) site is bypassed by DNA polymerases, dATP is preferentially inserted. Here we evaluate, using differential scanning calorimetry, the thermodynamic changes associated with incorporation of N6‐methyl‐dATP opposite an AP site, dCMP, and dTMP during simulated DNA polymerization. The results confirm that AP sites block DNA polymerases one nucleotide prior to the lesion. Thermodynamic data imply that the propensity of N6‐methyl‐dAMP for elongation, when incorporated opposite an AP site, is higher than that of dAMP in agreement with a higher promutagenic potential of N6‐methyl‐dATP if placed opposite a non‐instructional DNA lesion, such as an AP site.
Microwave Intensified Synthesis: Batch and Flow Chemistry
Authors: Ching Lau Chi , Kemal Bayazit Mustafa , Reardon Philip James Thomas , Tang Junwang 
Published: December 2018

AbstractMany studies have been conducted on organic and inorganic synthesis by microwave heating owing to its special heating mechanism, leading to improved reaction rate, higher purity and yields. We specifically demonstrated microwave heating in the fabrication of nanoparticles and polyester. By fine‐tuning the microwave and experimental parameters, the materials prepared have shown excellent physical and bio‐properties, e. g. narrow particle size distribution, controlled morphology, varied molecular structure and so forth. We further highlight the recent procedure of using fluidic reactors on preparing both metals and metal oxides nanoparticles. The experimental design strategies and fundamentals of the microwave interaction with chemicals are presented. Furthermore, the key factors and issues facing in this area are also discussed.
Diversity in ancient Maya water management strategies and landscapes at Caracol, Belize, and Tikal, Guatemala
Authors: Chase Adrian S. Z. , Cesaretti Rudolf 
Published: December 2018

The Classic Period Maya cities of Caracol and Tikal possessed unique urban morphologies of water management. In part, the built environment at each city reflects adaptations to the hydrology of their landscapes. Caracol exists in a rugged, hilly, and karst environment; its residents invested their landesque capital in constructing agricultural terraces and residential reservoirs. These features created Caracol's anthropogenic garden‐city landscape. This landscape was unified through a dendritic causeway system and the distributed nature of monumental nodes. The landscape of Tikal exhibits a lower slope, is generally smoother, and its residents invested in constructing a large and condensed site core along with their monumental reservoirs. Additionally, the people of Tikal invested in bajo margin agriculture. The differences in urban form and hydrology conditioned the resulting water management strategies employed by both cities; the resulting built environmental features are preserved in the archeological record. Because of its higher slopes, Caracol's landscape presents a greater hazard for soil erosion and faster rainfall runoff. Yet, the construction of distributed residential reservoirs and agricultural terraces acted to collect rainfall, increase soil saturation, and reduce this runoff. Tikal's landscape on the whole presents fewer hazards in terms of soil erosion but perhaps greater issues from torrential rainfall. Water management infrastructure at both cities reflects both their unique urban morphologies and environmental conditions.This article is categorized under:Engineering Water > Planning WaterScience of Water > Water and Environmental Change
Thyroidectomy Then and Now: A 50‐Year Australian Perspective
Authors: Hii Belinda , Maher Dominic , Yeung Meei , Paul Eldho , Serpell Jonathan W. , Lee James C. 
Published: December 2018

AbstractBackgroundSince the mid‐1800s, thyroidectomy has transformed from a procedure associated with high to near‐zero mortality. Nonetheless, surgeons must continue to strive to improve patient care. Using historical records and contemporary data, this study compares the practice and outcomes of thyroid surgery at a tertiary institution during two periods, 50 years apart.Methods‘The Alfred Hospital Clinical Reports’ recorded all cases of surgically managed thyroid disease from 1946 to 1959. These historical cases were compared to contemporary thyroidectomy cases at the Alfred Hospital from 2007 to 2016. Cases were compared for surgical indication and post‐operative outcomes.ResultsThere were 746 patients in the historical group (mean age 53 years; 87% female) and 787 patients in the contemporary group (mean age 52 years; 80% female). The most common indication for thyroidectomy in both groups was non‐toxic nodular goitre. A greater proportion of the contemporary group were diagnosed with thyroid malignancy (27% vs. 8%; p < 0.001). The contemporary group recorded significantly fewer cases of thyrotoxic crisis (2.1% vs. 0%; p = 0.001), permanent nerve palsy (4.6% vs. 0.4%; p < 0.001) and bilateral nerve palsy (1.2% vs. 0%; p = 0.01). There were no mortalities in the contemporary group, while the historical data recorded three deaths (0.44%).
ConclusionsThis study compared thyroid surgery in two cohorts separated by a 50‐year period. While it is not surprising that outcomes of thyroidectomy have improved, this study uniquely demonstrates trends of thyroid surgery over time and areas in which further improvements may be made.
Rawls’s Self-Defeat: A Formal Analysis
Authors: Chung Hun 
Published: December 2018

AbstractOne of John Rawls’s major aims, when he wroteA Theory of Justice, was to present a superior alternative to utilitarianism. Rawls’s worry was that utilitarianism may fail to protect the fundamental rights and liberties of persons in its attempt to maximize total social welfare. Rawls’s main argument against utilitarianism was that, for such reasons, the representative parties in the original position will not choose utilitarianism, but will rather choose his justice as fairness, which he believed would securely protect the worth of everybody’s basic rights and liberties. In this paper, I will argue that, under close formal examination, Rawls’s argument against utilitarianism is self-defeating. That is, I will argue that Rawls’s own reasons, assumptions, and the many theoretical devices he employs demonstrably imply that the representative parties in the original position will choose utilitarianism instead of justice as fairness.
From bedside to benchmarks: A physician-scientist workforce dashboard for biomedical research institutions
Authors: Zell Adrienne , Smith Lindsey , Yanez N. David , Guise Jeanne-Marie , Pelkey Ryan , Ellison David H. 
Published: December 2018

AbstractIntroductionThere is growing concern about the declining physician-scientist workforce. NIH recently provided a national dashboard describing the biomedical research workforce, but local strategies are needed.MethodsWe used curated local and national data to develop a workforce dashboard.ResultsMany trends at Oregon Health & Science University (OHSU) were similar to those nationally, such as the increasing percentage of Research Project Grant (RPG)-holding PhDs and the aging RPG population, but differences were also apparent. At OHSU, nearly ¾ of physician-scientist RPGs hold MD-only, compared with nationally, where nearly half are MD/PhD. OHSU also lags in the percentage of RPGs held by women physician-scientists.ConclusionsOur analysis also permitted us to gain a more complete picture of research funding that has been done nationally. We used these data to develop a dashboard that allows our institution to develop policies to increase the numbers of physician-scientists. The data generation approaches and dashboard are likely to be useful at other institutions, as well.
A glacial refugium and zoogeographic boundary in the Slovak eastern Carpathians
Authors: Juřičková Lucie , Horáčková Jitka , Jansová Anna , Kovanda Jiří , Harčár Ján , Ložek Vojen 
Published: December 2018

AbstractAlthough the Carpathians in Europe have often been considered a glacial refugium for temperate plants, vertebrates, and molluscs, the fossil records, the only indisputable evidence surviving glacial periods, are as yet scarce. Moreover, the distribution of fossil records is uneven, and some areas have remained unstudied. We present here three molluscan successions from such an area—the border between the western and eastern Carpathians. This area is not only a geographic border but also a border between the oceanic and continental climate in Europe, and the molluscan fauna reflects this. We found a fluctuation of this zoogeographical border during the late glacial period and the Holocene for several snail species with their easternmost or westernmost distribution situated at this border. Such a fluctuation could reflect a small-scale shifting of climate character during the Holocene. For the first time, we recorded the fossil shells of three local endemics, Carpathica calophana, Petasina bielzi, and Perforatella dibothrion. We also found a fully developed woodland snail fauna radiocarbon dated to the Bølling period. This early occurrence of canopy forest snails indicates a possible eastern Carpathian glacial refugium for them, including local endemics, and may reflect a more moderate glacial impact on local biota than expected.
Older Men’s Definitions of Frailty – The Manitoba Follow-up Study
Authors: St. John Philip D. , McClement Susan S. , Swift Audrey U. , Tate Robert B. 
Published: December 2018

RÉSUMÉIntroduction: Peu de recherches empiriques ont été réalisées sur les définitions non cliniques de la fragilité. Objectifs : 1. Explorer comment les hommes plus âgés définissent la fragilité, et 2. Explorer si ces définitions correspondent aux définitions cliniques de la fragilité qui sont couramment utilisées. Méthodes : Analyses des réponses à des questions ouvertes d’un sondage présenté dans le cadre d’une étude de cohorte prospective réalisée chez des hommes âgés qui avaient travaillé comme aviateurs. Les définitions de la fragilité ont été recueillies et groupées en fonction de thèmes. Résultats : 147 hommes (âge moyen : 93 ans) ont répondu au sondage. Une grande hétérogénéité a été observée dans les définitions de la fragilité recueillies chez ces participants, et aucun des thèmes de la fragilité ne pouvait être qualifié de prédominant. Les incapacités dans les activités de la vie quotidienne étaient le thème le plus fréquemment évoqué. Aucune correspondance ne pouvait être établie entre les définitions de la fragilité énoncées par les hommes âgés et les théories médicales couramment utilisées pour la fragilité. Conclusions : La plupart des hommes âgés pensent que la fragilité est un problème important, bien que leurs définitions de la fragilité diffèrent. La fragilité se manifesterait d’une manière hétérogène et affecterait différemment chaque individu.
Comparison between household food purchase and individual food consumption in Brazil
Authors: de Oliveira Dayan Carvalho Ramos Salles , de Moura Souza Amanda , Levy Renata Bertazzi , Sichieri Rosely , Verly-Jr Eliseu 
Published: December 2018

AbstractObjectiveThe present study aimed to compare Household Budget Survey (HBS) data on food purchasing and individual food consumption, collected in the same nationwide survey.DesignFood purchase information for each household was collected by a seven-day collective acquisition diary, applied to 55 970 households. Food consumption information was obtained from household members over 10 years old by the application of two non-consecutive food records in a sub-sample of the HBS. Cooking and correction factors were applied when necessary, and all food items reported were grouped into twelve main food groups. Food purchase and consumption data were presented as absolute weight (g/person per d) and as relative contribution to energy intake (%) for the overall study population, which was stratified according to household income.SettingBrazil.ParticipantsNational estimates of food consumption and purchase for Brazil.ResultsThe greatest differences between purchase and consumption data (purchase minus consumption) were observed for meat (−168 g), beans/legumes (−48 g), roots/tubers (−36 g) and fruits (−31 g). When expressed in terms of energy contribution, the highest differences were found for cereals (13 %) and oils and fats (11 %). Differences between purchase and consumption data were generally lower in the highest compared with the lowest household income quintile; and were lower for most main food groups when considering only foods reported as being eaten at home.ConclusionsWith few exceptions, food purchase expressed as relative energy contribution, as opposed to absolute weight, can provide a good picture of actual consumption in the Brazilian population.
Occurrence and possible sources of organochlorine pesticides in soils of Ningbo, East China
Authors: TANG Jianfeng , FENG Jiayong , LI Gang , LIANG Mengqi , WANG Ruijie , CAI Chao 
Published: December 2018

ABSTRACTStudy of the residues of organochlorine pesticides (OCPs) can assist with the assessment of the contamination level, distribution, sources, transportation and trends in these selected OCPs. We investigated the concentration levels of hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethane (DDT), chlordane, which is currently used, and the never-used aldrin and dieldrin in the Ningbo region – a heavily industrialised and urbanised area in East China. OCPs were found in all soil samples and were predominantly composed of HCHs, DDT and its metabolites. The concentration of DDTs in the soil ranged from 2.2 to 566.6ngg–1, with a mean value of 55.6±94.8ngg–1, while the concentration of HCHs ranged from 2.7 to 28.2ngg–1, with an average of 4.6±2.9ngg–1. Aldrin, dieldrin, endrin and heptachlor were detected at much lower concentrations. The wide distribution of these never-used OCPs indicates that they have been input via long-range atmospheric processes. The results from analysis suggest that HCHs and DDTs were mainly derived from use in historical times.
Coordinates and Maps of the Apollo 17 Landing Site
Authors: Haase Isabel , Wählisch Marita , Gläser Philipp , Oberst Jürgen , Robinson Mark S. 
Published: December 2018

AbstractWe carried out an extensive cartographic analysis of the Apollo 17 landing site and determined and mapped positions of the astronauts, their equipment, and lunar landmarks with accuracies of better than ±1 m in most cases. To determine coordinates in a lunar body‐fixed coordinate frame, we applied least squares (2‐D) network adjustments to angular measurements made in astronaut imagery (Hasselblad frames). The measured angular networks were accurately tied to lunar landmarks provided by a 0.5 m/pixel, controlled Lunar Reconnaissance Orbiter Camera (LROC) Narrow Angle Camera (NAC) orthomosaic of the entire Taurus‐Littrow Valley. Furthermore, by applying triangulation on measurements made in Hasselblad frames providing stereo views, we were able to relate individual instruments of the Apollo Lunar Surface Experiment Package (ALSEP) to specific features captured in LROC imagery and, also, to determine coordinates of astronaut equipment or other surface features not captured in the orbital images, for example, the deployed geophones and Explosive Packages (EPs) of the Lunar Seismic Profiling Experiment (LSPE) or the Lunar Roving Vehicle (LRV) at major sampling stops. Our results were integrated into a new LROC NAC‐based Apollo 17 Traverse Map and also used to generate a series of large‐scale maps of all nine traverse stations and of the ALSEP area. In addition, we provide crater measurements, profiles of the navigated traverse paths, and improved ranges of the sources and receivers of the active seismic experiment LSPE.
Teleseismic Traveltime Tomography of Northern Sumatra
Authors: Liu Shaolin , Suardi Iman , Yang Dinghui , Wei Shengji , Tong Ping 
Published: December 2018

AbstractWe imaged the mantle structure beneath northern Sumatra by inverting high‐quality seismic arrival time data and using a newly developed eikonal equation‐based teleseismic tomography method. Traveltime differences between neighboring stations were reliably extracted by cross‐correlating teleseismic waveforms, which were recorded by 26 stations from January 2009 to January 2018. Both P and S wave tomographic results show the oblique subduction of the Indo‐Australian oceanic lithosphere beneath the Sunda plate. The maximum penetration depth of the subducted slab into the mantle varies roughly from 400 km in the north to 800 km in the south. The plunging fold of the subducted slab, which mimics the shape of the trench and the volcanic arc, has less curvature than that reported in the literature; additionally, our results suggest that the gentle slab fold can be traced to a depth of about 500 km. Furthermore, a slab tear may exist beneath northern Sumatra.
Earlier Seasonal Onset of Intense Mesoscale Convective Systems in the Congo Basin Since 1999
Authors: Taylor Christopher M. , Fink Andreas H. , Klein Cornelia , Parker Douglas J. , Guichard Françoise , Harris Philip P. , Knapp Kenneth R. 
Published: December 2018

AbstractMesoscale convective systems (MCSs) produce some of the most intense rainfall on the planet, and their response to climate variability and change is rather uncertain. Under global warming, increased water vapor is expected to intensify the most extreme rain events and enhance flood frequency. However, MCS dynamics are also sensitive to other atmospheric variables, most notably, wind shear. Here we build on a recent study showing strong MCS intensification in the African Sahel, and examine evidence of similar trends elsewhere in tropical Africa. Using satellite data, we find a remarkable increase post‐1999 in intense MCS frequency over the Congo Basin during the month of February. This earlier onset of the spring rainy season has been accompanied by strong increases in the February meridional temperature gradient and associated wind shear. This supports the hypothesis that contrasts in warming across the continent can drive important decadal‐scale trends in storm intensity.