bluuebunny/crossref_metadata_2025_split huggingface dataset:
Realizing effectiveness across continents with hydroxyurea: Enrollment and baseline characteristics of the multicenter REACH study in Sub‐Saharan Africa
Authors: McGann Patrick T. , Williams Thomas N. , Olupot‐Olupot Peter , Tomlinson George A. , Lane Adam , Luís Reis da Fonseca José , Kitenge Robert , Mochamah George , Wabwire Ham , Stuber Susan , Howard Thad A. , McElhinney Kathryn , Aygun Banu , Latham Teresa , Santos Brígida , Tshilolo Léon , Ware Russell E. ,   for the REACH Investigators
Published: January 2018

AbstractDespite its well‐described safety and efficacy in the treatment of sickle cell anemia (SCA) in high‐income settings, hydroxyurea remains largely unavailable in sub‐Saharan Africa, where more than 75% of annual SCA births occur and many comorbidities exist. Realizing Effectiveness Across Continents with Hydroxyurea (REACH, ClinicalTrials.gov NCT01966731) is a prospective, Phase I/II open‐label trial of hydroxyurea designed to evaluate the feasibility, safety, and benefits of hydroxyurea treatment for children with SCA in four sub‐Saharan African countries. Following comprehensive training of local research teams, REACH was approved by local Ethics Committees and achieved full enrollment ahead of projections with 635 participants enrolled over a 30‐month period, despite half of families living >12 km from their clinical site. At enrollment, study participants (age 5.4 ± 2.4 years) had substantial morbidity, including a history of vaso‐occlusive pain (98%), transfusion (68%), malaria (85%), and stroke (6%). Significant differences in laboratory characteristics were noted across sites, with lower hemoglobin concentrations (P < .01) in Angola (7.2 ± 1.0 g/dL) and the DRC (7.0 ± 0.9 g/dL) compared to Kenya (7.4 ± 1.1 g/dL) and Uganda (7.5 ± 1.1 g/dL). Analysis of known genetic modifiers of SCA demonstrated a high frequency of α‐thalassemia (58.4% with at least a single α‐globin gene deletion) and G6PD deficiency (19.7% of males and 2.4% of females) across sites. The CAR β‐globin haplotype was present in 99% of participants. The full enrollment to REACH confirms the feasibility of conducting high‐quality SCA research in Africa; this study will provide vital information to guide safe and effective dosing of hydroxyurea for children with SCA living in Africa.
Palladium‐Catalyzed Direct Oxidative Esterification of Indoles at the C3 Position: A Novel Prospect for C(sp2)−H Acyloxylation
Authors: Song Jian , Cui Jie , Liang Hanbing , Liu Qing , Dong Yunhui , Liu Hui 
Published: January 2018

AbstractAn efficient palladium‐catalyzed direct oxidative esterification reaction of indoles with both aliphatic and aromatic carboxylic acids is reported. The use of Ag2CO3 is crucial to this transformation, as it functions as both a base and an oxidant for the regeneration of the palladium(II) catalyst. This methodology represents a novel prospect for C(sp2)−H acyloxylation and will promote interest in direct C(sp2)−H esterification.
Fiber type composition of epaxial muscles is geared toward facilitating rapid spinal extension in the leaper Galago senegalensis
Authors: Huq Emranul , Taylor Andrea B. , Su Zuowei , Wall Christine E. 
Published: January 2018

AbstractObjectivesWe hypothesized that the vertical leaper Galago senegalensis will have epaxial extensor muscles with a fast fiber phenotype to facilitate rapid spinal extension during leaping in comparison to the slow‐moving quadruped Nycticebus coucang. To test this, we determined the percentage of fiber cross‐sectional area (%CSA) devoted to Type 2 fibers in epaxial muscles of G. senegalensis compared to those of N. coucang.Materials and methodsImmunohistochemistry was used to identify Type 1, Type 2, and hybrid fibers in iliocostalis, longissimus, and multifidus muscles of G. senegalensis (n = 3) and N. coucang (n = 3). Serial muscle sections were used to estimate and compare proportions, cross‐sectional areas (CSAs), and %CSAs of Type 1, Type 2, and hybrid fibers between species.ResultsEpaxial muscles of G. senegalensis were comprised predominantly of Type 2 fibers with large CSAs (%CSA range ≈ 83–94%; range of mean CSA = 1,218–1,586 μm2). N. coucang epaxial muscles were comprised predominantly Type 1 fibers with large CSAs (%CSA range ≈ 69–77%; range of mean CSA = 983–1,220 μm2).DiscussionThe predominance of Type 2 fibers in G. senegalensis epaxial muscles facilitates rapid muscle excursion and spinal extension during leaping, and is consistent with their relatively long muscle fibers. The predominance of Type 1 fibers in N. coucang epaxial muscles may aid in maintaining stable postures during bridging and cantilevering behaviors characteristic of slow‐climbing. These histochemical characteristics highlight the major divergent locomotor repertoires of G. senegalensis and N. coucang.
Are multiple sinus cultures necessary during sinus surgery for chronic rhinosinusitis?
Authors: Miller Craig , Davis Greg E. 
Published: January 2018

BackgroundMultiple cultures are commonly obtained from different sinuses where purulence is encountered during endoscopic sinus surgery (ESS). This brings into question the utility and necessity of obtaining multiple cultures. The purpose of this study was to evaluate if multiple cultures obtained during a single case is informative in finding additional pathogens or if it is a redundant, cost‐increasing practice. We hypothesized that multiple sinus cultures are necessary to identify the pathogens responsible for an individual's sinus disease. We seek to add information on the utility of performing multiple sinus cultures from a patient care and a health economics standpoint.MethodsThis study was a retrospective review of a single rhinologist's surgical database from 2008 to 2016. Patients that underwent ESS for chronic rhinosinusitis (CRS) and had multiple cultures obtained during surgery were included. Culture difference was recorded as a discrepancy of an infectious pathogen between cultures.ResultsWe identified 231 patients with multiple sinus cultures. Of those, 39.4% had a difference of pathogens noted on culture between different sinuses. Only 5% of the cohort received clinically relevant benefit from the second culture obtained in regard to a change in antibiotics.ConclusionIn this retrospective review we showed that, for the practitioner who obtains sinus cultures intraoperatively, limiting this practice to a single culture rather than multiple is cost‐effective and sufficient for identifying the pathogen to be treated. This study, and the resultant change in practice, has the potential to reduce healthcare costs associated with the surgical care of the patient with CRS.
Signalverstärkung durch reversiblen Austausch (SABRE): von der Entdeckung zur diagnostischen Anwendung
Authors: Rayner Peter J. , Duckett Simon B. 
Published: January 2018

AbstractSignalverstärkung durch reversiblen Austausch (SABRE) wandelt typischerweise schwache Kernresonanz‐Aussagen in starke Signale um, wodurch sonst nicht durchführbare Messungen möglich werden. Aufgrund ihrer Geschwindigkeit und Einfachheit hat die Methode erhebliche Beliebtheit gewonnen. Dieser Kurzaufsatz beschreibt die Entwicklung von SABRE ausgehend von der ursprünglichen Hyperpolarisation von Pyridin im Jahr 2009 bis zu dem Punkt, bei dem 50‐prozentige 1H‐Polarisationsgrade für ein Dideuterionicotinat erzielt wurden, womit ein Schlüsselschritt des Wegs zu einer denkbaren klinischen Anwendung erreicht war. Einfache Wege zur hocheffizienten 15N‐Hyperpolarisation und zur Generierung langlebiger hyperpolarisierter magnetischer Zustände werden aufgezeigt. Abschließend beschreiben wir, wie das kürzlich berichtete SABRE‐RELAY‐Verfahren Parawasserstoff einen Weg bietet, einen viel größeren Umfang molekularer Baugruppen wie Amide, Alkohole, Carbonsäuren und Phosphate zu hyperpolarisieren, als dies früher für möglich gehalten wurde. Schon heute ist vorauszusehen, dass SABRE aufgrund dieser gebündelten Entwicklungen erhebliche Auswirkungen sowohl auf die chemische Analyse als auch auf die Diagnose von Krankheiten haben wird.
Near‐Infrared Fluorescent Molecular Probe for Sensitive Imaging of Keloid
Authors: Miao Qingqing , Yeo David C. , Wiraja Christian , Zhang Jianjian , Ning Xiaoyu , Xu Chenjie , Pu Kanyi 
Published: January 2018

AbstractEarly detection of skin diseases is imperative for their effective treatment. However, fluorescence molecular probes that allow this are rare. The first activatable near‐infrared (NIR) fluorescent molecular probe is reported for sensitive imaging of keloid cells, skin cells from abnormal scar fibrous lesions. As keloid cells have high expression levels of fibroblast activation protein‐alpha (FAPα), the probe (FNP1) is designed to have a caged NIR dye and a FAPα‐cleavable peptide substrate linked by a self‐immolative segment. FNP1 can quickly and specifically turn on its fluorescence at 710 nm by 45‐fold in the presence of FAPα, allowing it to effectively recognize keloid cells from normal skin cells. Integration of FNP1 with a simple microneedle‐assisted topical application enables sensitive detection of keloid cells in metabolically‐active human skin tissue with a theoretical limit of detection down to 20 000 cells.
Total Synthesis of Aurofusarin: Studies on the Atropisomeric Stability of Bis‐Naphthoquinones
Authors: Qi Chao , Wang Wenyu , Reichl Kyle D. , McNeely James , Porco John A. 
Published: January 2018

AbstractAn efficient annulation involving pyrone addition to a quinone and Dieckmann condensation was developed for rapid assembly of a γ‐naphthopyrone monomeric precursor to the bis‐naphthoquinone natural product aurofusarin. Dimerization was achieved through PdII‐catalyzed dehydrogenative coupling. Further studies employing asymmetric nucleophilic epoxidation indicate that the atropisomers of aurofusarin and derivatives are not configurationally stable at ambient temperature.
Easy‐to‐Attach/Detach Solubilizing‐Tag‐Aided Chemical Synthesis of an Aggregative Capsid Protein
Authors: Tsuda Shugo , Mochizuki Masayoshi , Ishiba Hiroyuki , Yoshizawa‐Kumagaye Kumiko , Nishio Hideki , Oishi Shinya , Yoshiya Taku 
Published: January 2018

AbstractA solubilizing Trt‐K10 tag was developed for the effective chemical preparation of peptides/proteins with low solubility. The Trt‐K10 tag comprises a hydrophilic oligo‐Lys sequence and a trityl anchor, and can be selectively introduced to a side chain thiol of Cys of deprotected peptides/proteins with a trityl alcohol‐type introducing reagent Trt(OH)‐K10 under acidic conditions. Significantly, the ligation product in the reaction mixture of a thiol‐additive‐free native chemical ligation can be modified directly in a one‐pot manner to facilitate the isolation of the product by high‐performance liquid chromatography. Finally, the Trt‐K10 tag can be readily removed with a standard trifluoroacetic acid cocktail. Using this easy‐to‐attach/detach tag‐aided method, a hepatitis B virus capsid protein that is usually difficult to handle was synthesized successfully.
Ein aktiver und stabiler Cobaltkatalysator für die Sauerstoffentwicklungsreaktion: Polymerisation einer ionischen Flüssigkeit
Authors: Ding Yuxiao , Klyushin Alexander , Huang Xing , Jones Travis , Teschner Detre , Girgsdies Frank , Rodenas Tania , Schlögl Robert , Heumann Saskia 
Published: January 2018

AbstractInspiriert durch die katalytischen Eigenschaften von Single‐site‐Katalysatoren und der erhöhten Leistungsfähigkeit von Metallkatalysatoren durch ionische Flüssigkeiten wurde eine Methode zur gezielten und skalierbaren Platzierung von einzelnen Cobaltatomen auf Kohlenstoffnanoröhrenoberflächen mithilfe einer polymerisierten ionischen Flüssigkeit entwickelt. Durch eine ionische Flüssigkeit wurden einzelne, fein verteilte Cobaltionen koordiniert und als heterogener Katalysator für die Sauerstoffententwicklungsreaktion (OER) genutzt. Die erhaltenen Daten zeigen eine hohe Aktivität bei gleichzeitig vorhandener Stabilität.
Molekulare Brandbekämpfung – wie moderne Phosphorchemie zur Lösung der Flammschutzaufgabe beitragen kann
Authors: Velencoso Maria M. , Battig Alexander , Markwart Jens C. , Schartel Bernhard , Wurm Frederik R. 
Published: January 2018

AbstractMaterialien aus Kunststoffen sind allgegenwärtig im täglichen Leben und haben ein hohes Brandrisiko. Die nachhaltige Entwicklung effizienter Flammschutzmittel ist essenziell, um die Sicherheit unserer Güter und der Bevölkerung vor zufällig auftretenden Bränden zu gewährleisten. Phosphor, ein vielseitiges und wirksames Element für den Einsatz in Flammschutzmitteln, hat das Potenzial, die heute noch weit verbreiteten halogenierten Verbindungen abzulösen: Die verschiedenen Formulierungen phosphorhaltiger Flammschutzmittel beruhen auf einer Vielzahl von Wirkmechanismen und Implementierungen, als Additive oder als reaktive flammhemmende Verbindungen. Phosphorflammschutzmittel können während eines Brandes sowohl in der Gas‐ als auch in der kondensierten Phase aktiv sein. Dieser Aufsatz fasst die aktuelle Phosphorchemie zur Verringerung der Entflammbarkeit von Polymeren zusammen und stellt potenziell nachhaltige, effiziente und sichere phosphorbasierte Flammschutzmittel aus erneuerbaren Quellen für zukünftige Anwendungen vor.
Disilenylsilylen‐Reaktivität eines Cyclotrisilens
Authors: Zhao Hui , Leszczyńska Kinga , Klemmer Lukas , Huch Volker , Zimmer Michael , Scheschkewitz David 
Published: January 2018

AbstractDie hoch reaktiven Silicium‐Kongenere des Cyclopropens, die Cyclotrisilene (c‐Si3R4), reagieren typischerweise unter π‐Addition an ihre Si=Si‐Doppelbindung oder unter σ‐Insertion in eine ihrer Si‐Si‐Einfachbindungen. Im Gegensatz dazu führt die Behandlung von c‐Si3Tip4 (Tip=2,4,6‐iPr3C6H2) mit Styrol und Benzil zur Ringöffnung des Dreirings zum formalen [1+2]‐ bzw. [1+4]‐Cycloadditionsprodukt des isomeren Disilenysilylens mit der C=C‐Bindung bzw. dem Diketon. Bei erhöhten Temperaturen setzt das [1+2]‐Additionsprodukt Styrol frei, das in einer [2+2]‐Cycloaddition mit c‐Si3Tip4 zu der thermodynamisch stabileren Hausan‐Spezies reagiert.
Enantioselective Desymmetrization of Cyclobutanones Enabled by Synergistic Palladium/Enamine Catalysis
Authors: Wang Meng , Chen Jun , Chen Zongjia , Zhong Changxu , Lu Ping 
Published: January 2018

AbstractThe enantioselective intramolecular α‐arylation of cyclobutanones has been established by combining palladium and enamine catalyst systems. Two different enantioselective control strategies have been developed for cyclobutanone substrates bearing O‐ or N‐tethered aryl bromides. Further synthetic applications are also reported.
Spectroscopic Characterization of a [C−F−C]+ Fluoronium Ion in Solution
Authors: Pitts Cody Ross , Holl Maxwell Gargiulo , Lectka Thomas 
Published: January 2018

AbstractWe report the first spectroscopic evidence for a [C−F−C]+ fluoronium ion in solution. Extensive NMR studies (19F, 1H, 13C) characterize a symmetric cage‐like species in which fluorine exhibits substantial covalent bonding to each of the two carbon atoms involved in the three‐center interaction. Experimental NMR data comport well with calculated values to lend credence to the structural assignment. As the culminating experiment, a Saunders isotopic perturbation test confirmed the symmetric structure. Congruent with the trend in other types of onium ions, the calculated charge at fluorine moves in a more positive (less negative) direction from the neutral. It is this important trend that explains in part the extraordinary historical difficulty in making theoretical predictions of fluoronium ions come true in solution, and why it takes fluorine captured in a cage to produce, finally, a stable ion and complete the historical arc of the organic halonium ion story.
Palladium/Copper Dual Catalysis for the Cross‐Coupling of Aryl(trialkyl)silanes with Aryl Bromides
Authors: Komiyama Takeshi , Minami Yasunori , Furuya Yuki , Hiyama Tamejiro 
Published: January 2018

AbstractWhereas aryl(trialkyl)silanes are considered to be ideal organometallic reagents for cross‐coupling reactions owing to their stability, low toxicity, solubility, and easy accessibility, they are generally inert under typical cross‐coupling conditions. Disclosed herein is a palladium/copper catalytic system that enables the cross‐coupling of trimethyl, triethyl, tert‐butyldimethyl, and triisopropyl aryl silanes with aryl bromides. This process is applicable to the sequential C−H and C−Si bond arylation of thiophenes and the synthesis of poly(thiophene–fluorene)s.
Visible‐Light‐Mediated Decarboxylative Radical Additions to Vinyl Boronic Esters: Rapid Access to γ‐Amino Boronic Esters
Authors: Noble Adam , Mega Riccardo S. , Pflästerer Daniel , Myers Eddie L. , Aggarwal Varinder K. 
Published: January 2018

AbstractThe synthesis of alkyl boronic esters by direct decarboxylative radical addition of carboxylic acids to vinyl boronic esters is described. The reaction proceeds under mild photoredox catalysis and involves an unprecedented single‐electron reduction of an α‐boryl radical intermediate to the corresponding anion. The reaction is amenable to a diverse range of substrates, including α‐amino, α‐oxy, and alkyl carboxylic acids, thus providing a novel method to rapidly access boron‐containing molecules of potential biological importance.
N‐Substituted Hydrazones by Manganese‐Catalyzed Coupling of Alcohols with Hydrazine: Borrowing Hydrogen and Acceptorless Dehydrogenation in One System
Authors: Das Uttam Kumar , Ben‐David Yehoshoa , Diskin‐Posner Yael , Milstein David 
Published: January 2018

AbstractAn unprecedented one‐step synthesis of N‐substituted hydrazones by coupling of alcohols with hydrazine is reported. This partial hydrogen‐borrowing reaction is catalyzed by a new manganese pincer complex under mild reaction conditions, thus liberating water and dihydrogen as the only byproducts. Mechanistic insight, based on the observation of intermediates, is provided.
An Oxygen‐Tolerant PET‐RAFT Polymerization for Screening Structure–Activity Relationships
Authors: Gormley Adam J. , Yeow Jonathan , Ng Gervase , Conway Órla , Boyer Cyrille , Chapman Robert 
Published: January 2018

AbstractThe complexity of polymer–protein interactions makes rational design of the best polymer architecture for any given biointerface extremely challenging, and the high throughput synthesis and screening of polymers has emerged as an attractive alternative. A porphyrin‐catalysed photoinduced electron/energy transfer–reversible addition‐fragmentation chain‐transfer (PET‐RAFT) polymerisation was adapted to enable high throughput synthesis of complex polymer architectures in dimethyl sulfoxide (DMSO) on low‐volume well plates in the presence of air. The polymerisation system shows remarkable oxygen tolerance, and excellent control of functional 3‐ and 4‐arm star polymers. We then apply this method to investigate the effect of polymer structure on protein binding, in this case to the lectin concanavalin A (ConA). Such an approach could be applied to screen the structure–activity relationships for any number of polymer–protein interactions.
Molecular Firefighting—How Modern Phosphorus Chemistry Can Help Solve the Challenge of Flame Retardancy
Authors: Velencoso Maria M. , Battig Alexander , Markwart Jens C. , Schartel Bernhard , Wurm Frederik R. 
Published: January 2018

AbstractThe ubiquity of polymeric materials in daily life comes with an increased fire risk, and sustained research into efficient flame retardants is key to ensuring the safety of the populace and material goods from accidental fires. Phosphorus, a versatile and effective element for use in flame retardants, has the potential to supersede the halogenated variants that are still widely used today: current formulations employ a variety of modes of action and methods of implementation, as additives or as reactants, to solve the task of developing flame‐retarding polymeric materials. Phosphorus‐based flame retardants can act in both the gas and condensed phase during a fire. This Review investigates how current phosphorus chemistry helps in reducing the flammability of polymers, and addresses the future of sustainable, efficient, and safe phosphorus‐based flame‐retardants from renewable sources.
Cobalt‐Catalyzed Coupling of Benzoic Acid C−H Bonds with Alkynes, Styrenes, and 1,3‐Dienes
Authors: Nguyen Tung Thanh , Grigorjeva Liene , Daugulis Olafs 
Published: January 2018

AbstractA method for cobalt‐catalyzed, carboxylate‐directed functionalization of arene C−H bonds is reported. Alkynes, styrenes, and 1,3‐dienes can be coupled with benzoic acids to provide cyclic products in good yields. The reactions proceed in the presence of a cobalt(II) hexafluoroacetylacetonate catalyst, (TMS)2NH base, Ce(SO4)2 cooxidant, and oxygen oxidant.
Dual Ligand‐Enabled Nondirected C−H Olefination of Arenes
Authors: Chen Hao , Wedi Philipp , Meyer Tim , Tavakoli Ghazal , van Gemmeren Manuel 
Published: January 2018

AbstractThe application of the Pd‐catalyzed oxidative C−H olefination of arenes, also known as the Fujiwara–Moritani reaction, has traditionally been limited by the requirement for directing groups on the substrate or the need to use the arene in large excess, typically as a (co)solvent. Herein the development of a catalytic system is described that, through the combined action of two complementary ligands, makes it possible to use directing‐group‐free arenes as limiting reagents for the first time. The reactions proceed under a combination of both steric and electronic control and enable the application of this powerful reaction to valuable arenes, which cannot be utilized in excess.
Active Molybdenum‐Based Anode for Dehydrogenative Coupling Reactions
Authors: Beil Sebastian B. , Müller Timo , Sillart Sydney B. , Franzmann Peter , Bomm Alexander , Holtkamp Michael , Karst Uwe , Schade Wolfgang , Waldvogel Siegfried R. 
Published: January 2018

AbstractA new and powerful active anode system that can be operated in 1,1,1,3,3,3‐hexafluoro‐2‐propanol (HFIP) has been discovered. In HFIP the molybdenum anode forms a compact, conductive, and electroactive layer of higher‐valent molybdenum species. This system can replace powerful but stoichiometrically required MoV reagents for the dehydrogenative coupling of aryls. This electrolytic reaction is more sustainable and allows the conversion of a broad scope of activated arenes.
Modifying the Steric Properties in the Second Coordination Sphere of Designed Peptides Leads to Enhancement of Nitrite Reductase Activity
Authors: Koebke Karl J. , Yu Fangting , Salerno Elvin , Van Stappen Casey , Tebo Alison G. , Penner‐Hahn James E. , Pecoraro Vincent L. 
Published: January 2018

AbstractProtein design is a useful strategy to interrogate the protein structure‐function relationship. We demonstrate using a highly modular 3‐stranded coiled coil (TRI‐peptide system) that a functional type 2 copper center exhibiting copper nitrite reductase (NiR) activity exhibits the highest homogeneous catalytic efficiency under aqueous conditions for the reduction of nitrite to NO and H2O. Modification of the amino acids in the second coordination sphere of the copper center increases the nitrite reductase activity up to 75‐fold compared to previously reported systems. We find also that steric bulk can be used to enforce a three‐coordinate CuI in a site, which tends toward two‐coordination with decreased steric bulk. This study demonstrates the importance of the second coordination sphere environment both for controlling metal‐center ligation and enhancing the catalytic efficiency of metalloenzymes and their analogues.