bluuebunny/crossref_metadata_2025_split huggingface dataset:
Theoretical study on the electronic structure nature of single and double walled carbon nanotubes and its role on the electron transport
Authors: Espinosa‐Torres Néstor David , Guillén‐López Alfredo , Martínez‐Juárez Javier , Hernández de la Luz José Álvaro David , Rodríguez‐Victoria Ángel Pedro , Muñiz Jesús 
Published: May 2019

AbstractDensity functional theory and molecular dynamics (MD) calculations were used to evaluate electronic structure properties in a series of nanotubes with smallest possible diameters (both types: armchair and zigzag), and the corresponding chiral nanotubes (8,m) for 0 ≤ m ≤ 8. The calculations were performed considering a length of 16.5 Å. We evaluated a set of 26 combinations of dual nanotubes (armchair/armchair, zigzag/zigzag, armchair/zigzag, and zigzag/armchair), where the first label corresponds to the outer tube. We extended our study with nine additional systems of double‐walled carbon nanotubes (DWCNT) with semiconductor nature. In this regard, we gave insight into the semiconductive or metallic nature inherited to the dual tubes. DWCNT systems were possible to construct by maintaining a radial distance of 3.392 Å for the armchair/armchair arrangement and 3.526 Å for the zigzag/zigzag type. It was considered as a reference, the interplanar distance of graphite (3.350 Å). Electronic transport calculations were also performed on selected DWCNT systems in order to understand the role played by the different symmetries under study. It was evidenced that the electronic structure nature of the systems rules the ability to transport electrons through the DWCNT interface.
Effect of electron‐withdrawing groups on photovoltaic performance of thiophene‐vinyl‐thiophene derivative and benzochalcogenadiazole based copolymers: A computational study
Authors: Bhattacharya Labanya , Sahoo Smruti R. , Sharma Sagar , Sahu Sridhar 
Published: May 2019

AbstractWe report a density functional theory study of the effect of electron‐withdrawing groups such as –F, –CN, –NO2 on the geometrical, optoelectronic, intramolecular charge transfer (ICT), and photovoltaic properties of (E)‐1,2‐bis(5‐alkyl‐[2,3′‐bithiophene]‐2′‐yl)ethene (TVT‐T) based donor‐acceptor (D‐A) copolymers with different acceptor units, that is, benzo[c][1,2,5]thiadiazole, benzo[c][1,2,5]oxadiazole, and benzo[c][1,2,5]selenadiazole. The computed optical absorption spectra of the designed compounds lie in the visible and near‐infrared regions. Of all the studied copolymers, ‐CN substituted and Se‐based compound displays the lowest HOMO‐LUMO (E
H ‐ L) gap and optical band gap (E
opt). The exciton binding energy (E
b) is found to be smaller for O‐incorporated compounds and ‐CN substituted copolymer as well, inferring more ICT. The electron‐hole coherence concentrated over the D‐A units is nearly the same for ‐CN and ‐NO2 substituted compounds, but larger in ‐F derivatives, indicating weak electron‐hole coupling in the formers. Comparatively larger dipole moment (6.421 Debye‐9.829 Debye) and charge transfer length (D
CT) (1.976 Å‐3.122 Å) for ‐CN derivatives lead to enhanced ICT properties. The designed donors yield good hole mobilities (0.127‐6.61 cm2 V−1 s−1) and the predicted power conversion efficiencies are calculated to be as high as ~6%‐7% for –CN and –NO2 substituted compounds.
An investigation on the metabolic pathways of synthetic isoflavones by gas chromatography coupled to high accuracy mass spectrometry
Authors: Iannone Michele , Botrè Francesco , Parenti Silvia , Jardines Daniel , de la Torre Xavier 
Published: May 2019

RationaleIsoflavones are a group of flavonoids that may be of interest in sport doping because they can be used by athletes in the recovery periods after the administration of anabolic steroids, with the aim of increasing the natural production of luteinizing hormone (LH) and, consequently, the biosynthesis of endogenous androgens.MethodsThe in vivo metabolism of methoxyisoflavone (5‐methyl‐7‐methoxyisoflavone) and ipriflavone (7‐isopropoxyisoflavone), respectively present in a dietary supplement and in a pharmaceutical preparation, was investigated. The study was carried out by the analysis of urinary samples collected from male Caucasian subjects before, during and after the oral administration of methoxyisoflavone or ipriflavone. After enzymatic hydrolysis and liquid–liquid extraction, all urinary samples were analyzed by gas chromatography/quadrupole time‐of‐flight (qTOF MS system/qTOF) electron ionization mass spectrometry (EI‐MS).ResultsEight metabolites of methoxyisoflavone and six metabolites of ipriflavone were isolated. The corresponding accurate mass spectra are specific for isoflavone structures and revealed also a retro‐Diels‐Alder fragmentation.ConclusionsWhen excreted in large amounts, the urinary metabolites of methoxyisoflavone and ipriflavone can be traced to potential confounding factors in doping analysis. As methoxyisoflavone and ipriflavone have been shown to inhibit the enzyme aromatase, thus interfering with the normal metabolic pathways of testosterone, the detection of their intake, by screening for the presence of their main metabolites in urine, might be helpful in routine doping control analysis.
pH‐Responsive Nanoparticles Loaded with Graphene Quantum Dots and Doxorubicin for Intracellular Imaging, Drug Delivery and Efficient Cancer Therapy
Authors: Liang Junlong , Huang Qianwei , Hua Chenxiang , Hu Jinhua , Chen Biling , Wan Junmin , Hu Zhiwen , Wang Bing 
Published: May 2019

AbstractMultifunctional core‐shell structural nanoparticles (NPs) integrating of therapeutic and imaging modalities have presented superior prospects as drug delivery systems in the treatment of cancer. In this work, graphene quantum dots (GQDs) and doxorubicin (DOX) were encapsulated into the cores of PLGA (Poly (D, L‐lactide‐co‐glycolide)) nanoparticles coated with bovine serum albumin via a double emulsion‐solvent evaporation method to construct pH‐responsive nanoparticles (DOX/PB and GQDs@DOX/PB NPs) with spherical core‐shell structures. Subsequently, the cellular uptake, cytotoxicity and biocompatibility of the NPs were studied via in vitro experiments. The results demonstrated that DOX/PB NPs and GQDs@DOX/PB NPs exhibit high drug‐loading efficiency and promote the release of DOX in a mild acidic microenvironment, which was expected to result in intelligent intracellular drug carriers. In vitro cytotoxicity measurements showed that all the NPs exhibit dose‐ and time‐dependent cytotoxicity to the HeLa cells and PLGA NPs loaded with GQDs contribute to reducing cancer cell viability. Moreover, no significant difference in ROS level was determined during the endocytosis. In addition, all the NPs displayed excellent blood compatibility by hemolysis assay. These results demonstrate that pH‐responsive NPs may be excellent candidates for efficient cancer therapy and in vivo biological imaging probes.
Fractionation of Wheat Straw Catalyzed by Recyclable Terephthalic Acid
Authors: Hronec Milan , Fulajtárová Katarína , Klempová Tatiana , Čertík Milan 
Published: May 2019

AbstractHere, we described an efficient method for the separation of hemicellulose, cellulose and lignin from the biomass. Solvent treatment in the presence of terephthalic acid was used to separate the lignin and hemicellulose fragments from the wheat straw. The obtained aqueous solution containing mostly xylooligomers, is free of the acid catalyst and the concentration of inhibitors in the solution which deteriorate the fermentation process is very low. About 50.9% of sugars present in the aqueous hydrolysate can be converted into microbial oils by Actinomucor elegans microorganisms. Terephthalic acid accumulated in the pulp enhances subsequent heteropoly acid H4[PMo11VO40] catalyzed oxidative conversion of cellulose into formic acid.
Modular Assembly of Tunable Fluorescent Chemosensors Selective for Pb2+ and Cu2+ Metal Ions via the Multicomponent Castagnoli‐Cushman Reaction
Authors: Bakulina Olga , Rashevskii Artem , Dar'in Dmitry , Halder Sandipan , Khagar Prerna , Krasavin Mikhail 
Published: May 2019

AbstractThe multicomponent Castagnoli‐Cushman reaction followed by post‐condensational modifications allowed for a flexible, modular construction of fluorescent chemosensor compounds. When tested against a panel of fourteen metal ions, one of the eight compounds investigated in this work was found to selectively respond to Cu2+ ions by fluorescence quenching (thus being a “turn‐off” chemosensor for this metal). Another compound was found to produce fluorescence increase in response to Pb2+ ions. Interestingly, the sensitivity of this “turn‐on” chemosensor to lead(II) ions was unaffected by the presence of a large excess of other metals. Analysis of the structure‐sensing property relationships of these sensors allowed developing a general understanding of the factors influencing the chemosensor properties. All of the critical structural factors employed in the chemosensor design were found to be important for the metal sensing and selectivity. These findings will allow designing next‐generation chemosensors based on the same modular construction approach in the future.
Room‐Temperature C‐H Bromination and Iodination with Sodium Bromide and Sodium Iodide Using N‐Fluorobenzenesulfonimide as an Oxidant
Authors: Shi Cuiying , Miao Qi , Ma Lifang , Lu Tao , Yang Dong , Chen Jiaming , Li Ziyuan 
Published: May 2019

AbstractA transition‐metal‐free electrophilic bromination and iodination of arene through C−H cleavage at room temperature has been developed in excellent to quantitative yields with broad arene scope and good regioselectivity, in which environment‐benign and readily available sodium halides, NaBr or NaI, were employed as halogen sources in accompany with N‐fluorobenzenesulfonimide (NFSI) as an oxidant. Studies have also demonstrated that, in this air‐ and moisture‐resistant scalable halogenation under mild conditions, the oxidant NFSI is reduced to dibenzenesulfonimide which usually serves as the starting material for the preparation of NFSI, rendering this facile and versatile protocol promising potentials for future applications in organic synthesis.
Synthesis of Polyfunctionalized Thiophenes and Pyrido[3,2‐c]Coumarines from 3‐Carbamoyl/3‐Thiocarbamoyl Chromones
Authors: Demin Dmitrii Y. , Myannik Ksenia A. , Lyssenko Konstantin A. , Krayushkin Mikhail M. , Yarovenko Vladimir N. 
Published: May 2019

AbstractNew transformations of N‐substituted 3‐carbamoylchromones and virtually uninvestigated 3‐thiocarbamoylchromones are described. The domino reactions result in the formation of pyridocoumarins and polyfunctional thiophene derivatives, respectively.
Strategically Constructed Bilayer Tin (IV) Oxide as Electron Transport Layer Boosts Performance and Reduces Hysteresis in Perovskite Solar Cells
Authors: Lin Liangyou , Jones Timothy W. , Wang Jacob Tse‐Wei , Cook Andre , Pham Ngoc Duy , Duffy Noel W. , Mihaylov Blago , Grigore Mihaela , Anderson Kenrick F. , Duck Benjamin C. , Wang Hongxia , Pu Jian , Li Jian , Chi Bo , Wilson Gregory J. 
Published: May 2019

AbstractNanostructured tin (IV) oxide (SnO2) is emerging as an ideal inorganic electron transport layer in n–i–p perovskite devices, due to superior electronic and low‐temperature processing properties. However, significant differences in current–voltage performance and hysteresis phenomena arise as a result of the chosen fabrication technique. This indicates enormous scope to optimize the electron transport layer (ETL), however, to date the understanding of the origin of these phenomena is lacking. Reported here is a first comparison of two common SnO2 ETLs with contrasting performance and hysteresis phenomena, with an experimental strategy to combine the beneficial properties in a bilayer ETL architecture. In doing so, this is demonstrated to eliminate room‐temperature hysteresis while simultaneously attaining impressive power conversion efficiency (PCE) greater than 20%. This approach highlights a new way to design custom ETLs using functional thin‐film coatings of nanomaterials with optimized characteristics for stable, efficient, perovskite solar cells.
Tiefenpsychische Dimensionen männlicher Sozialisation
Authors: Böhnisch Lothar 
Published: May 2019

ZusammenfassungIn der männlichen Sozialisation wirkt ein tiefenpsychischer Mechanismus der Idolisierung des Männlich-Starken und Abwertung des Weiblich-Schwachen, der in allen Jungen und Männern in unserer Kultur steckt und je nach biographischem Vermögen und sozialem Umfeld bewältigt werden muss. Trotz veränderter Rollenmodelle von Männlichkeit und Weiblichkeit ist dieser Mechanismus weiterhin, wenn auch heute oft verdeckt, wirksam. Im Folgenden wird versucht, diesen tiefenpsychischen Prozess entlang biografischer Stationen – frühe Kindheit, Pubertät, Adoleszenz und Integration ins Erwachsenenalter – zu beschreiben. Dabei wird deutlich, dass es vor allem männliche Gruppendynamiken sind, die diesen Mechanismus immer wieder freisetzen.
Lagos Art World: The Emergence of an Artistic Hub on the Global Art Periphery
Authors: Castellote Jess , Okwuosa Tobenna 
Published: May 2019

Abstract:The global geography of art has changed greatly in recent years. Whereas global art hubs were formerly found only in the West, they now exist in locations all over the world, including Africa. Though some art worlds in Asia and Latin America have been studied in recent times, there is insufficient empirical data on art worlds in Africa. This is a study of the Lagos art world, which shows how an “art system,” with all of its attendant structures and agents, has emerged in the city of Lagos, Nigeria, in the last few years. Lagos reflects the dynamics of globalization and is building up the art infrastructure and the critical mass needed for a sustainable art world: an ambitious and fast-growing group of young local collectors, an art fair, an international photography festival, regular art auctions, new art galleries, historical and critical publications, a university art museum, symposiums, art foundations, residencies, and competitions. Lagos is becoming not only a “global city,” but also a “global art hub.”
Recruitment and retention of US South Asians for an epidemiologic cohort: Experience from the MASALA study
Authors: Kanaya Alka M. , Chang Ann , Schembri Michael , Puri-Taneja Ankita , Srivastava Shweta , Dave Swapna S. , Vijayakumar Evangeline N. , Qamar Zubaida , Naik Hemalatha D. , Siddiqui Faiza , Kandula Namratha R. 
Published: May 2019

AbstractIntroduction:There are few longitudinal studies about South Asians (SAs) and little information about recruitment and retention approaches for this ethnic group.Methods:We followed 906 SAs enrolled in the Mediators of Atherosclerosis in South Asians Living in America (MASALA) cohort for 5 years. Surviving participants were invited for a second clinical exam from 2015 to 2018. A new wave of participants was recruited during 2017–2018. We assessed the yields from different methods of recruitment and retention.Results:A total of 759 (83%) completed the second clinical exam, and 258 new participants were enrolled. Providing a nearby community hospital location for the study exam, offering cab/shared ride reimbursement, and conducting home visits were the most effective methods for enhancing retention. New participant recruitment targeted women and individuals with lower socioeconomic status, and we found that participant referrals and active community engagement were most effective. Mailing invitational letters to those identified by electronic health records had very low yield.Conclusion:Recruitment and retention strategies that address transportation barriers and increase community engagement will help increase the representation of SAs in health research.
Temperature effects on three downy brome (Bromus tectorum) seed collections inoculated with the fungal pathogen Pyrenophora semeniperda
Authors: Ehlert Krista A. , Miller Zachariah , Mangold Jane M. , Menalled Fabian , Thornton Alexandra 
Published: May 2019

AbstractDowny brome (Bromus tectorum L., syn. cheatgrass) is a winter annual grass that invades North American cropping, forage, and rangeland systems. Control is often difficult to achieve, because B. tectorum has a large seedbank, which results in continuous propagule pressure. Pyrenophora semeniperda (Brittlebank and Adam) Shoemaker, a soilborne fungal pathogen, has been investigated as a biological control for B. tectorum, because it can kill seeds that remain in the seedbank, thereby reducing propagule pressure. Temperature influences P. semeniperda and has not been investigated in the context of seeds collected from different B. tectorum locations, that may vary in susceptibility to infection. We compared the effects of temperature (13, 17, 21, 25 C) and B. tectorum seed locations (range, crop, subalpine) with different mean seed weights on infection rates of P. semeniperda using a temperature-gradient table. Infection differed by seed location (P &lt; 0.001) and temperature (P &lt; 0.001), with lighter-weight seeds (i.e., range and subalpine) more susceptible to P. semeniperda infection. Infection increased as temperature increased and was higher at 21 C (66.7 ± 6.7%) and 25 C (73.3 ± 6.0%). Germination was affected by seed location (P &lt; 0.001) and temperature (P = 0.019). Germination was highest for the crop seed location (45.4 ± 4.2%) and overall decreased at higher temperatures (21 and 25 C). Our results suggest that B. tectorum seeds from a crop location are less affected by P. semeniperda than those from range and subalpine locations. Moreover, this demonstrates a temperature-dependent effect on all populations.
Retrospective study of a first-episode psychosis service embedded within a home-based treatment team
Authors: Murray Nuala , O’Connor Karen 
Published: May 2019

ObjectivesTo evaluate if having an early intervention service (EIS), which is embedded within a home-based treatment team (HBTT), is associated with (1) shorter duration of untreated psychosis (DUP), (2) lower rates of hospital admissions at first presentation, (3) a lesser number of hospital admissions within 6 months of presentation and (4) a reduced mean bed usage for the first 6 months.MethodsThe files of those who presented with a first-episode psychosis (FEP) to the South Lee Mental Health Service from January 2016 to February 2017 were identified and a retrospective case review was carried out. The demographics, clinical characteristics and hospital admissions were compared for those admitted to either the EIS or community mental health teams.ResultsForty patients were assessed. DUP was found to be longer for those who presented to the EIS (U= 121,p= 0.03). There were fewer admissions at first presentation (χ2(1) = 6.51p= 0.01), fewer admissions within the first 6 months of presentation (χ2(1) = 5.56p= 0.02) and less bed usage overall (U= 131,p= 0.047) for those who presented to the EIS.ConclusionThe study provides a baseline clinical and demographic profile of patients with FEP in an Irish mental health service and demonstrates current pathways to care. EIS embedded within an HBTT was associated with fewer hospital admissions and less bed usage. It is unclear whether these findings may have occurred due to the EIS or due to the benefits provided by an HBTT.
Optimized Volume Determinations and Uncertainties for Accurate and Precise Manometry
Authors: Lu Xi , Beaupré Steven R 
Published: May 2019

ABSTRACTPrecise manometric pressure, volume, and temperature (P-V-T) measurements of carbon in samples, standards, and blanks are critical for radiocarbon studies. While P and T uncertainties depend on instrument choice and environmental stability, V uncertainties depend on their method of measurement and are often overlooked. We used numerical simulations and error propagation to find optimum procedures for measuring “cold-finger” volumes equipped with capacitance diaphragm gauges (CDGs) by two common application of Boyle’s Law: cryogenic transfers and serial gas expansions with a reference flask of known volume. Minimum relative uncertainties of cold-finger volumes are comparable for these two methods (∼0.002), but the serial gas expansion method is preferred due to its convenience. Serial gas expansions can be performed to high precision by using dry air, an initial pressure ∼76% full-scale (e.g., 760 Torr), and a reference flask with an optimal volume based on preliminary estimates of cold-finger volumes and an empirical power function. The volumes of cold-fingers ≥ 12 cm3 can be determined with minimum achievable relative uncertainties of 0.0021 to 0.0023. This limit translates to minimum achievable relative uncertainties of 0.0026 to 0.0027 for P-V-T measurements of moles of gas simulated here.
Modeling Unstratified Burials via Bayesian Analysis with Log-Normal Interval Priors
Authors: Kidd R S 
Published: May 2019

ABSTRACTTombs and cairns present a dating challenge when the human remains are unstratified, incomplete and dispersed. By considering the distribution of time intervals between deaths as a possiblea prioricondition of multiple burials of select groups, a Bayesian model is suggested that may constrain the uncertainty date range of the group. The method may also address the wide uncertainties seen in radiocarbon calibration on a calibration curve plateau. The mathematical justification for the choice of Log Normal intervals, between death events, is first presented, followed by worked examples that compare the treatment of groups of 22 dates using Phase then Sequence with interval gaps. Finally, scenarios of potential Select Groups are examined, to demonstrate the efficacy of this alternative heuristic model to current model treatments.
Intervalidation of Dendrochronology and14C Dating on a 700-yr Tree-Ring Sequence Originating from the Eastern Carpathians
Authors: Sava Gabriela O , Popa Ionel , Sava Tiberiu B , Meghea Aurelia , Mănăilescu Cristian , Ilie Maria , Robu Andrei , Tóth Boglárka 
Published: May 2019

ABSTRACTWe present a comparative study on a 700-yr sequence of dendrochronologically ordered tree-rings ofPinus cembraoriginating from Eastern Carpathians for the period AD 1009–1709. This period covers the solar minima of the Little Ice Age. The aim of this study was to assess the accuracy of our radiocarbon (14C) determinations interpreted on the IntCal13 calibration data and to observe any apparent offsets. The14C measurements on single and double tree-rings were “wiggle-matched” to secure the dendrochronology cross-matching of all thePinus cembrawood pieces. The results showed a very good agreement between the age datasets for four out of five wood trunks. However, for one of them a new cross-matching was performed after a quality assurance test, establishing an earlier 48-yr position, recommended by wiggle-matching Bayesian statistics and dendrochronological analysis. Following this adjustment, the quantification of the14C level variability with respect to the IntCal13 calibration curve was obtained by calculating Δ14C for all tree-ring samples. As a final conclusion, an insignificant14C concentration offset of –0.63 ± 3.76‰ was found for the Romanian samples.
The Effect of Sweep on Conditions at Separation in Turbulent Boundary-Layer/Shock-Wave Interaction
Authors: Myring D F 
Published: May 2019

SummaryAn approximate analysis of conditions at separation produced by turbulent boundary-layer/shock-wave interaction is presented for swept, cylindrically symmetric flows. An integral boundary-layer prediction method is used, incorporating Johnston crossflow profiles. The results indicate a marked reduction in pressure rise required to produce separation as sweep is increased. At low Reynolds numbers the skin friction at separation is inferred to be small, whereas at higher Reynolds numbers the presence of a vigorous streamwise flow may be detected. In the limiting case of zero sweep, or two-dimensional flow, predictions using the approximate analysis are shown to compare well with experimental results of pressure rise to separation.