bluuebunny/crossref_metadata_2025_split huggingface dataset:
A CT-based survey of supramedullary diverticula in extant birds
Authors: Atterholt Jessie , Wedel Mathew J 
Published: September 2018

Birds are unique among extant tetrapods in having pneumatic diverticula of the lungs and air sacs that pass among the viscera and muscles, under the skin, and into the skeleton. In addition, some birds also have supramedullary diverticula inside the neural canal, adjacent to the spinal cord. The anatomy of the supramedullary diverticula has only been documented in a handful of birds to date. Using CT scans, we surveyed the morphology of the supramedullary diverticula in a phylogenetically broad sample of extant birds.
Although supramedullary diverticula are present in some small-bodied taxa such as hummingbirds and pigeons, the diverticula are typically larger and more complex in large forms such as ostriches and pelicans. Absence of these diverticula in loons and grebes is consistent with the lack of skeletal pneumatization in diving birds. Other absences, for example in the kestrel, are less explicable.
When present, the supramedullary diverticula are best developed in presacral vertebrae, but only occasionally present in the synsacrum, and rarely present in caudal vertebrae. In most taxa we have surveyed, the diverticula are not continuous craniocaudally, but exist as separate segments extending fore and aft from each intervertebral joint, as documented by Müller for the pigeon.
Occasionally supramedullary diverticula communicate with interosseous diverticula through foramina in the wall or roof of the neural canal. These foramina are osteological correlates of supramedullary diverticula and allow the presence of these diverticula to be inferred in dry skeletal material and fossil organisms.
Open educational resources for cartography: the Thematic Mapping Tutor
Authors: Köbben Barend 
Published: September 2018

At the ITC faculty of the University of Twente, we have been teaching cartography for more then 60 years. Throughout this period, the technology of mapping has undergone spectacular changes and nowadays most students do not draw their maps any more, but use software instead. However, for maps to be effective in communication, their design still has to follow the same rules as before. Ideally, one wants to teach these design rules independently from the tools, such that the students understand how a good map works, not just which buttons to click to create it.
For this purpose, we created the Thematic Mapping Tutor. It is an open, web-based system that provides a structured way of constructing thematic maps out of selected data. The system uses the input of the student to construct a map in the Vega-Lite grammar, which is transformed to web-graphics.
In this paper we describe the educational philosophy behind the system, as well as technical details about its functionality. We report on first tests, and reflect on the possibilities and pitfalls of the system.
E-Foto: an educational photogrammetric workstation
Authors: Ribeiro João Araujo , Brito Jorge Silva , Bernardo Orlando , Badolato Irving , Dacome Rodrigo , Mota Guilherme Abelha 
Published: September 2018

This paper shows our experience at the Rio de Janeiro State University (UERJ), in Brazil, developing and using the E-Foto software, one of the main achievements of the E-Foto project that aims to built-up a software tool for teaching digital photogrammetry and software development, to both graduate and undergraduate students, in the fields of Cartographic and Computer Engineering.
E-Foto main objective is to diminish the gap that exists nowadays between the teaching of Photogrammetry and Remote Sensing in universities and Research Institutions of developing countries and the high-tech expensive systems that are used under the production environment.
Implementation and operation of incident learning across a newly‐created health system
Authors: Schubert Leah , Petit Josh , Vinogradskiy Yevgeniy , Peters Rick , Towery Jack , Stump Bryan , Westerly David , Ridings Jane , Kneeland Patrick , Liu Arthur 
Published: September 2018

AbstractPurposeThe purpose of this work is to describe our experience launching an expanded incident learning system for patient safety and quality that takes into account aspects beyond therapeutic dose delivery, specifically imaging/simulation incidents, medical care incidents, and operational issues.MethodsOur ILS was designed for a newly created health system comprised of a midsized academic hospital and two smaller community hospitals. The main design goal was to create a highly sensitive system to capture as much information throughout the department as possible. Reports were classified according to incidents and near misses involving therapeutic radiation, imaging/simulation, and patient care (not involving radiation), unsafe conditions, operational issues, and accolades/suggestions. Reports were analyzed according to impact on various steps in the process of care. Actions made in response to reports were assessed and characterized by intervention reliability.ResultsA total of 1125 reports were submitted in the first 23 months. For all three departments, therapeutic radiation incidents and near misses consisted of less than one‐third of all reports submitted. For the midsized academic department, operational issues and unsafe conditions comprised the largest percentage of reports (70%). Although the majority of reports impacted steps related to the technical aspects of treatment (simulation, planning, and treatment delivery), 20% impacted other steps such as scheduling or clinic visits. More than 160 actions were performed in response to reports. Of these actions, 63 were quality improvement interventions to improve practices, while 97 were learning actions for raising awareness.ConclusionsWe have developed an ILS that identifies issues related to the entire process of care delivery in radiation oncology, as evidenced by frequent and varied reported events. By identifying a broad spectrum of issues in a department, opportunities for improvement can be identified.
A novel KIF5A gene variant causes spastic paraplegia and cerebellar ataxia
Authors: Qiu Yusen , Zhong Shanshan , Cong Lu , Xin Ling , Gao Xuguang , Zhang Jun , Hong Daojun 
Published: September 2018

AbstractMutations in the kinesin family member 5A (KIF5A) gene are mainly associated with autosomal dominant spastic paraplegia 10 (SPG10). The additional complicated symptoms of SPG10 commonly include a wide spectrum. However, cerebellar ataxia is only noticed in a very few patients. Herein, we described a large autosomal dominant family, in which the affected individuals presented with progressive spastic paraparesis and marked cerebellar ataxia. Exome sequencing revealed that a novel variant in the KIF5A gene might be responsible for the phenotype. The obvious cerebellar ataxia indicated that the KIF5A gene should be included in the expanding gene list for spasticity‐ataxia spectrum.
Causes and Solutions of Recombination in Perovskite Solar Cells
Authors: Chen Jiangzhao , Park Nam‐Gyu 
Published: September 2018

AbstractOrganic–inorganic hybrid perovskite materials are receiving increasing attention and becoming star materials on account of their unique and intriguing optical and electrical properties, such as high molar extinction coefficient, wide absorption spectrum, low excitonic binding energy, ambipolar carrier transport property, long carrier diffusion length, and high defects tolerance. Although a high power conversion efficiency (PCE) of up to 22.7% is certified for perovskite solar cells (PSCs), it is still far from the theoretical Shockley–Queisser limit efficiency (30.5%). Obviously, trap‐assisted nonradiative (also called Shockley–Read–Hall, SRH) recombination in perovskite films and interface recombination should be mainly responsible for the above efficiency distance. Here, recent research advancements in suppressing bulk SRH recombination and interface recombination are systematically investigated. For reducing SRH recombination in the films, engineering perovskite composition, additives, dimensionality, grain orientation, nonstoichiometric approach, precursor solution, and post‐treatment are explored. The focus herein is on the recombination at perovskite/electron‐transporting material and perovskite/hole‐transporting material interfaces in normal or inverted PSCs. Strategies for suppressing bulk and interface recombination are described. Additionally, the effect of trap‐assisted nonradiative recombination on hysteresis and stability of PSCs is discussed. Finally, possible solutions and reasonable prospects for suppressing recombination losses are presented.
Organocatalytic and Regiodivergent Mannich Reaction of Ketones with Benzoxazinones
Authors: Viji Mayavan , Sim Jaeuk , Li Siyuan , Lee Heesoon , Oh Kyungsoo , Jung Jae‐Kyung 
Published: September 2018

AbstractIn this study, we have developed solvent‐controlled regioselective Mannich reaction of cyclicimines (benzoxazinones) with various ketones by using ʟ‐proline as catalyst to afford Mannich products in high yields with excellent enantio‐ and diastereoselectivity. The unsymmetrical ketones produced the linear isomer as the major product in chloroform solvent. On contrary, using the DMSO solvent favoured the formation of branch isomer product with excellent enantio‐ and diastereoselectivity. The aromatic auxiliary was successfully removed and afforded N‐protected chiral amino acid derivative.magnified image
Isobutyl Nitrite‐Mediated Synthesis of Quinoxalines through Double C−H Bond Amination of N‐Aryl Enamines
Authors: Jiao Yan‐Xiao , Wei Lin‐Su , Zhao Chun‐Yang , Wei Kai , Mo Dong‐Liang , Pan Cheng‐Xue , Su Gui‐Fa 
Published: September 2018

AbstractAn efficient and metal‐free double C−H bond amination of N‐aryl enamines using isobutyl nitrite (IBN) has been developed. This method enables the preparation of functionalized quinoxalines in good to excellent yields and tolerates a variety of N‐aryl enamines with diverse functional substituents. Mechanistic studies revealed the presence of a key β‐imino oxime ester intermediate. A quinoxaline derivative could be prepared from β‐carbonyl ester in one‐pot sequence on a gram scale. Finally, two important quinoxaline scaffolds were easily prepared in moderate yields over two steps.magnified image
The Diverse Reactivity of Disilenes Toward Isocyanides
Authors: Tashkandi Nada Y. , McOnie Sarah L. , Bourque Jeremy L. , Reinhold Crispin R. W. , Baines Kim M. 
Published: September 2018

AbstractThe addition of 2,6‐dimethylphenyl isocyanide andt‐butyl isocyanide to tetramesityldisilene was examined. In both cases, the initially formed product is an iminodisilirane; however, the iminodisiliranes are unstable under the reaction conditions and react with a second equivalent of the isocyanide to give either a 3‐silaazetidine or a novel bicyclic double enamine, respectively. Taken together with the previous examples in the literature, the results demonstrate that subtle differences in the steric bulk of the disilene or the electronic effects of the isocyanide can lead to dramatic differences in the reaction pathway.
Enantioselektive Lewis‐Säure‐katalysierte ortho‐Photocycloaddition von Phenanthren‐9‐carbaldehyden
Authors: Stegbauer Simone , Jandl Christian , Bach Thorsten 
Published: September 2018

AbstractDie Bestrahlung mit sichtbarem Licht (λ=457 nm) ermöglicht eine enantioselektive ortho‐Photocycloaddition von Olefinen an Phenanthren‐9‐carbaldehyde (15 Beispiele, 46–93 % Ausbeute, 82–98 % ee). Eine chirale Oxazaborolidin‐Lewis‐Säure (20 mol %) wurde als Katalysator verwendet, die durch Koordination an den Aldehyd eine bathochrome Verschiebung der Absorption bewirkt, die über die ursprüngliche nπ*‐Absorption des unkomplexierten Aldehyds hinausgeht. Bei großer Wellenlänge wird ausschließlich der Lewis‐Säure‐Komplex angeregt und eine der beiden enantiotopen Seiten des aromatischen Aldehyds wird effizient abgeschirmt. Die Lewis‐Säure‐Koordination verändert überdies die Typselektivität und die einfache Diastereoselektivität der Photocycloaddition.
Fast Magic‐Angle Spinning 19F NMR Spectroscopy of HIV‐1 Capsid Protein Assemblies
Authors: Wang Mingzhang , Lu Manman , Fritz Matthew P. , Quinn Caitlin M. , Byeon In‐Ja L. , Byeon Chang‐Hyeock , Struppe Jochem , Maas Werner , Gronenborn Angela M. , Polenova Tatyana 
Published: September 2018

Abstract19F NMR spectroscopy is an attractive and growing area of research with broad applications in biochemistry, chemical biology, medicinal chemistry, and materials science. We have explored fast magic angle spinning (MAS) 19F solid‐state NMR spectroscopy in assemblies of HIV‐1 capsid protein. Tryptophan residues with fluorine substitution at the 5‐position of the indole ring were used as the reporters. The 19F chemical shifts for the five tryptophan residues are distinct, reflecting differences in their local environment. Spin‐diffusion and radio‐frequency‐driven‐recoupling experiments were performed at MAS frequencies of 35 kHz and 40–60 kHz, respectively. Fast MAS frequencies of 40–60 kHz are essential for consistently establishing 19F–19F correlations, yielding interatomic distances of the order of 20 Å. Our results demonstrate the potential of fast MAS 19F NMR spectroscopy for structural analysis in large biological assemblies.
Double‐Helical Nanostructures with Controllable Handedness in Bulk Diblock Copolymers
Authors: Lu Xuemin , Li Jingmin , Zhu Dandan , Xu Min , Li Weihua , Lu Qinghua 
Published: September 2018

AbstractDouble‐helical nanostructures with controllable handedness in bulk materials is of high interest in science and technology for the design and fabrication of new materials, in particular metamaterials, which mimic their natural homologues or even show superior properties. Herein, we report the fabrication of double‐helical structures with controlled handedness through the self‐assembly of an achiral diblock copolymer doped with d‐ and l‐tartaric acid (TA). The helices showed clear handedness dependence on the chirality of the TA. The chiral arrangement of different achiral tectonic units, such as nanoparticles and organic molecules, was confirmed using this helical structure as a template. The double‐helical structure will provide new knowledge for understanding the function of helices, and will enable the application of these systems as chiroptical materials.
Cathode Material Determines Product Selectivity for Electrochemical C−H Functionalization of Biaryl Ketoximes
Authors: Zhao Huai‐Bo , Xu Pin , Song Jinshuai , Xu Hai‐Chao 
Published: September 2018

AbstractThe synthesis of polycyclic N‐heteroaromatic compounds and their corresponding N‐oxides has been developed through electrochemical C−H functionalization of biaryl ketoximes. The oxime substrates undergo dehydrogenative cyclization when a Pt cathode is used, resulting in unprecedented access to a wide range of N‐heteroaromatic N‐oxides. The products of the electrosynthesis are switched to the deoxygenated N‐heteroaromatics by employing a Pb cathode through sequential anode‐promoted dehydrogenative cyclization and cathodic cleavage of the N−O bond in the initially formed N‐oxide.
Supported rhodium liquid metal catalysts for the hydroformylation of olefins
Authors: Sun Hao , Guo Wanwan , Liu Junmei , Feng Zhipeng , Li Ruyue , Zhou Xuyang , Huang Jun 
Published: September 2018

The hydroformylation of olefins in supported room temperature liquid metals was developed, and the supported Rh liquid metal catalysts (Rh SLMCs) showed unprecedented activity and high selectivity for the hydroformylation of olefins to aldehydes. The turnover frequency is up to 7000 h−1, much higher than that of homogeneous RhCl3 + 3PPh3 catalyst. Moreover, the Rh SLMCs can be recovered conveniently without obvious deactivation, and the total turnover number is up to 250 000. The active Rh(I) catalyst formed in situ can be reduced back to Rh(0) by the free electrons in liquid metal when H2/CO gas is emitted, and thus Rh is not leaked into the organic solvent. Long‐chain olefins, cycloolefins and styrenes were applied, and the corresponding aldehydes were obtained in good to excellent yields.
Three Multicenter, Randomized, Double‐Blind, Placebo‐Controlled Studies Evaluating the Efficacy and Safety of Ustekinumab in Axial Spondyloarthritis
Authors: Deodhar Atul , Gensler Lianne S. , Sieper Joachim , Clark Michael , Calderon Cesar , Wang Yuhua , Zhou Yiying , Leu Jocelyn H. , Campbell Kim , Sweet Kristen , Harrison Diane D. , Hsia Elizabeth C. , van der Heijde Désirée 
Published: September 2018

ObjectiveTo evaluate the efficacy and safety of ustekinumab in 3 randomized, placebo‐controlled studies in patients with axial spondyloarthritis (SpA). Studies 1 and 2 included patients with radiographic axial SpA (anti–tumor necrosis factor [anti‐TNF]–naive patients and patients with inadequate response or intolerance to anti‐TNF, respectively); study 3 patients had nonradiographic axial SpA.MethodsIn all 3 studies, patients were randomly assigned (1:1:1) to receive subcutaneous ustekinumab at 45 mg or 90 mg or placebo up to 24 weeks, after which placebo‐treated patients were rerandomized to receive ustekinumab at 45 mg or 90 mg. The primary end point in studies 1 and 2 was the proportion of patients who met the Assessment of SpondyloArthritis international Society criteria for 40% improvement in disease activity (achieved an ASAS40 response). The primary end point in study 3 was the proportion of patients who achieved an ASAS20 response. Other disease activity and safety measures were also evaluated. A week 24 analysis of study 1 was preplanned to determine continuation of studies 2 and 3.ResultsFor study 1, the primary and major secondary end points were not met, and the study was discontinued. As a result, studies 2 and 3 were prematurely discontinued before they were fully enrolled. For all 3 studies, neither ustekinumab dose group demonstrated clinically meaningful improvement over placebo on key efficacy end points. The proportion of patients experiencing adverse events in the ustekinumab groups was consistent with that in previous studies.ConclusionIn these 3 placebo‐controlled trials, efficacy of ustekinumab in the treatment of axial SpA was not demonstrated. The safety profile was consistent with that of studies in other indications.
Multistate modeling and simulation of patient trajectories after allogeneic hematopoietic stem cell transplantation to inform drug development
Authors: James David A. , Ng Jennifer , Wei Jiawei , Vandemeulebroecke Marc 
Published: September 2018

AbstractWe present a case study for developing clinical trial scenarios in a complex progressive disease with multiple events of interest. The idea is to first capture the course of the disease in a multistate Markov model, and then to simulate clinical trials from this model, including a variety of hypothesized drug effects. This case study focuses on the prevention of graft‐versus‐host disease (GvHD) after allogeneic hematopoietic stem cell transplantation (HSCT). The patient trajectory after HSCT is characterized by a complex interplay of various events of interest, and there is no established best method of measuring and/or analyzing treatment benefits. We characterized patient trajectories by means of multistate models that we fitted to a subset of the Center for International Blood and Marrow Transplant Research (CIBMTR) database. Events of interest included acute GvHD of grade III or IV, severe chronic GvHD, relapse of the underlying disease, and death. The transition probability matrix was estimated using the Aalen‐Johansen estimator, and patient characteristics were identified that were associated with different transition rates. In a second step, clinical trial scenarios were simulated from the model assuming various drug effects on the background transition rates, and the operating characteristics of different endpoints and analysis strategies were compared in these scenarios. This helped devise a drug development strategy in GvHD prevention after allogeneic HSCT. More generally, multistate models provide a rich framework for exploring complex progressive diseases, and the availability of a corresponding simulation machinery provides great flexibility for clinical trial planning.
Are green consumers really green? Exploring the factors behind the actual consumption of organic food products
Authors: Testa Francesco , Sarti Silvia , Frey Marco 
Published: September 2018

AbstractThe increasing interest in sustainable consumption has lead several scholars to investigate the determinants that drive the consumption of organic food. Most of this research is based on consumers' self‐reports of their purchasing behavior by exploring declared behavioral intentions. There is a lack of understanding concerning the determinants of organic food consumption based on actual purchasing behavior. To fill this gap, this study is based on a combination of actual purchasing data and self‐reported data from a sample of 79 Italian consumers. The determinants of organic food consumption are explored by analyzing the effects of subjective norms, attitude, perceived behavioral control, intention to buy, organic knowledge, and health consciousness on actual purchasing behavior. Our results suggest that actual purchasing behavior is positively influenced by intention to buy and negatively by subjective norms. Although attitude towards buying organics is positively affected by health consciousness and perceived behavioral control, consumer knowledge about organics is found to influence purchase intentions. Theoretical and managerial implications, along with avenues for future research, are discussed.
Strategies Towards Capturing Nitrogenase Substrates and Intermediates via Controlled Alteration of Electron Fluxes
Authors: Hiller Caleb J. , Lee Chi Chung , Stiebritz Martin T. , Rettberg Lee A. , Hu Yilin 
Published: September 2018

AbstractNitrogenase utilizes an ATP‐dependent reductase to deliver electrons to its catalytic component to enable two important reactions: the reduction of N2 to NH4+, and the reduction of CO to hydrocarbons. The two nitrogenase‐based reactions parallel the industrial Haber–Bosch and Fischer–Tropsch processes, yet they occur under ambient conditions. As such, understanding the enzymatic mechanism of nitrogenase is crucial for the future development of biomimetic strategies for energy‐efficient production of valuable chemical commodities. Mechanistic investigations of nitrogenase has long been hampered by the difficulty to trap substrates and intermediates relevant to the nitrogenase reactions. Recently, we have successfully captured CO on the Azotobacter vinelandii V‐nitrogenase via two approaches that alter the electron fluxes in a controlled manner: one approach utilizes an artificial electron donor to trap CO on the catalytic component of V‐nitrogenase in the resting state; whereas the other employs a mismatched reductase component to reduce the electron flux through the system and consequently accumulate CO on the catalytic component of V‐nitrogenase. Here we summarize the major outcome of these recent studies, which not only clarified the catalytic relevance of the one‐CO (lo‐CO) and multi‐CO (hi‐CO) bound states of nitrogenase, but also pointed to a potential competition between N2 and CO for binding to the same pair of reactive Fe sites across the sulfur belt of the cofactor. Together, these results highlight the utility of these strategies in poising the cofactor at a well‐defined state for substrate‐ or intermediate‐trapping via controlled alteration of electron fluxes, which could prove beneficial for further elucidation of the mechanistic details of nitrogenase‐catalyzed reactions.