bluuebunny/crossref_metadata_2025 huggingface dataset:
“Unleaded” Perovskites: Status Quo and Future Prospects of Tin‐Based Perovskite Solar Cells
Authors: Ke Weijun , Stoumpos Constantinos C. , Kanatzidis Mercouri G.
Published: October 2018

The tremendous interest focused on organic–inorganic halide perovskites since 2012 derives from their unique optical and electrical properties, which make them excellent photovoltaic materials. Pb‐based halide perovskite solar cells, in particular, currently stand at a record efficiency of ≈23%, fulfilling their potential toward commercialization. However, because of the toxicity concerns of Pb‐based perovskite solar cells, their market prospects are hindered. In principle, Pb can be replaced with other less‐toxic, environmentally benign metals. Sn‐based perovskites are thus the far most promising alternative due to their very similar and perhaps even superior semiconductor characteristics. After years of effort invested in Sn‐based halide perovskites, sufficient breakthroughs have finally been achieved that make them the next runners up to the Pb halide perovskites. To help the reader better understand the nature of Sn‐based halide perovskites, their optical and electrical properties are systematically discussed. Recent progress in Sn‐based perovskite solar cells, focusing mainly on film fabrication methods and different device architectures, and highlighting roadblocks to progress and opportunities for future work are reviewed. Finally, a brief overview of mixed Sn/Pb‐based systems with their anomalous yet beneficial optical trends are discussed. The current challenges and a future outlook for Sn‐based perovskites are discussed.
Electronic and Structural Engineering of Carbon‐Based Metal‐Free Electrocatalysts for Water Splitting
Authors: Wang Xuesi , Vasileff Anthony , Jiao Yan , Zheng Yao , Qiao Shi‐Zhang
Published: October 2018

Since first being reported as possible electrocatalysts to substitute platinum for the oxygen reduction reaction (ORR), carbon‐based metal‐free nanomaterials have been considered a class of promising low‐cost materials for clean and sustainable energy‐conversion reactions. However, beyond the ORR, the development of carbon‐based catalysts for other electrocatalytic reactions is still limited. More importantly, the intrinsic activity of most carbon‐based metal‐free catalysts is inadequate compared to their metal‐based counterparts. To address this challenge, more design strategies are needed in order to improve the overall performance of carbon‐based materials. Herein, using water splitting as an example, some state‐of‐the‐art strategies in promoting carbon‐based nanomaterials are summarized, including graphene, carbon nanotubes, and graphitic‐carbon nitride, as highly active electrocatalysts for hydrogen evolution and oxygen evolution reactions. It is shown that by rationally tuning the electronic and/or physical structure of the carbon nanomaterials, adsorption of reaction intermediates is optimized, consequently improving the apparent electrocatalytic performance. These strategies may facilitate the development in this area and lead to the discovery of advanced carbon‐based nanomaterials for various applications in energy‐conversion processes.
Butylamine‐Catalyzed Synthesis of Nanocrystal Inks Enables Efficient Infrared CQD Solar Cells
Authors: Kim Junghwan , Ouellette Olivier , Voznyy Oleksandr , Wei Mingyang , Choi Jongmin , Choi Min‐Jae , Jo Jea Woong , Baek Se‐Woong , Fan James , Saidaminov Makhsud I. , Sun Bin , Li Peicheng , Nam Dae‐Hyun , Hoogland Sjoerd , Lu Zheng‐Hong , García de Arquer F. Pelayo , Sargent Edward H.
Published: October 2018

The best‐performing colloidal‐quantum‐dot (CQD) photovoltaic devices suffer from charge recombination within the quasi‐neutral region near the back hole‐extracting junction. Graded architectures, which provide a widened depletion region at the back junction of device, could overcome this challenge. However, since today's best materials are processed using solvents that lack orthogonality, these architectures have not yet been implemented using the best‐performing CQD solids. Here, a new CQD ink that is stable in nonpolar solvents is developed via a neutral donor ligand that functions as a phase‐transfer catalyst. This enables the realization of an efficient graded architecture that, with an engineered band‐alignment at the back junction, improves the built‐in field and charge extraction. As a result, optimized IR CQD solar cells (Eg ≈ 1.3 eV) exhibiting a power conversion efficiency (PCE) of 12.3% are reported. The strategy is applied to small‐bandgap (1 eV) IR CQDs to augment the performance of perovskite and crystalline silicon (cSi) 4‐terminal tandem solar cells. The devices show the highest PCE addition achieved using a solution‐processed active layer: a value of +5% when illuminated through a 1.58 eV bandgap perovskite front filter, providing a pathway to exceed PCEs of 23% in 4T tandem configurations with IR CQD PVs.
Graphene/Organic Semiconductor Heterojunction Phototransistors with Broadband and Bi‐directional Photoresponse
Authors: Han Jiayue , Wang Jun , Yang Ming , Kong Xiao , Chen Xiaoqing , Huang Zehua , Guo Hui , Gou Jun , Tao Silu , Liu Zhijun , Wu Zhiming , Jiang Yadong , Wang Xinran
Published: October 2018

A graphene–semiconductor heterojunction is very attractive for realizing highly sensitive phototransistors due to the strong absorption of the semiconductor layer and the fast charge transport in the graphene. However, the photoresponse is usually limited to a narrow spectral range determined by the bandgap of the semiconductor. Here, an organic heterojunction (C60/pentacene) is incorporated on graphene to realize a broadband (405–1550 nm) phototransistor with a high gain of 5.2 × 105 and a response time down to 275 µs. The visible and near‐infrared parts of the photoresponsivity (9127 A W−1@650 nm and 1800 A W−1@808 nm) come from the absorption of the organic layer and the graphene, respectively. For the first time, a bi‐directional (positive and negative) photoresponse is demonstrated at different wavelengths, due to the opposite charge transfer direction of the photoexcited carriers enforced by the unique band alignment. Such tunability will enable new functionalities such as large‐scale real‐time optical image and infrared focal plane array detection in the future.
Hydrogels as Emerging Materials for Translational Biomedicine
Authors: Xue Kun , Wang Xiaoyuan , Yong Pei Wern , Young David James , Wu Yun‐Long , Li Zibiao , Loh Xian Jun
Published: October 2018

Hydrogels have been extensively investigated as biomaterials because of their excellent biocompatibility, and recent developments such as 3D printing and the incorporation of dynamic crosslinks have advanced the field considerably. However, the next step of in vivo translational biomedicine requires an understanding of essential hydrogel properties so that they can be designed to overcome the challenges of the living environment. In this review, the stringent design criteria required for in vivo applications are highlighted and recent advances in the repair of organ tissues (heart, bone, eye, etc.) and the therapeutic delivery of bioactive molecules are described. Commercially available hydrogel systems that can be used for translational biomedicine are also discussed, as is the long and sometimes fraught journey from the laboratory to the clinic.
Identifying fossil Myrtaceae leaves: the first described fossils of Syzygium from Australia
Authors: Tarran Myall , Wilson Peter G. , Paull Rosemary , Biffin Ed , Hill Robert S.
Published: October 2018

Premise of the Study

Although leaves of Myrtaceae are easily identified to family level, very few studies have convincingly identified fossil Myrtaceae leaves to living genera. We used a broadly comparative approach with a large data set of extant taxa to confidently assign the mummified remains of myrtaceous leaves from early Miocene sediments at Kiandra (New South Wales, Australia) to a living genus.

Methods

Fossils were identified using a nearest living relative approach, against a database of 232 extant broadleaf rainforest species of Myrtaceae. Leaf cuticles were prepared from 106 species, sourced from herbarium specimens as well as some living individuals, and a further 127 records were assembled from the literature. A set of simple but phylogenetically informative cuticular characters were observed, described, and recorded under both scanning electron microscopy and standard light microscopy.

Key Results

A new fossil species of Syzygium Gaertn. is described from mummified remains found in early Miocene (21.5–21.7 Ma) sediments. The fossil taxon is here named Syzygium christophelii sp. nov., in honor of the late Australian paleobotanist David Christophel.

Conclusions

These fossils represent some of the most confidently described Myrtaceae leaf fossils published to date and are the first and oldest described fossil record of Syzygium from Australia. While several fossil parataxa have been illustrated from New Zealand, and several fossil species of Syzygium have previously been proposed in the literature, many of these fossils lack characters for a confident diagnosis.
Association of hypocalcemia with congenital heart disease in 22q11.2 deletion syndrome
Authors: Rayannavar Arpana , Levitt Katz Lorraine E. , Crowley Terrence Blaine , Lessig Megan , Grand Katheryn , Goldmuntz Elizabeth , Zackai Elaine H. , McDonald‐McGinn Donna M.
Published: October 2018

Hypocalcemia is one of the cardinal features of the chromosome 22q11.2 deletion syndrome (22q11.2DS), the most common cause of DiGeorge syndrome. Hypocalcemia and other features of 22q11.2DS including congenital heart disease (CHD) are primarily ascribed to problems with morphogenesis and function of the pharyngeal arch system derivatives including the parathyroid glands, the aortic arch, and the cardiac outflow tract. In light of the aforementioned embryology, we hypothesized that hypocalcemia would be identified more frequently in those patients with 22q11.2DS and CHD. We conducted a retrospective IRB approved chart review on 1,300 subjects with 22q11.2DS evaluated at the Children's Hospital of Philadelphia. χ2 test was used to evaluate the statistical significance of differences in hypocalcemia between the two groups. Eight hundred fifty‐two patients had calcium levels available for review. Of these, 466 (54.69%) had a history of hypocalcemia and 550 (64.55%) had CHD. Of those with CHD, 343 (62.36%) had a history of hypocalcemia, and of those without CHD, only 123 (40.73%) had a history of hypocalcemia. Thus, the frequency of diagnosed hypocalcemia was greater in patients with 22q11.2DS and CHD as compared to those without CHD (p < .001). We also analyzed age of onset of hypocalcemia and found that 66.47% of CHD/hypocalcemia group had neonatal/infantile hypocalcemia versus 43.09% in the non‐CHD/hypocalcemia group. In our large cohort of patients with 22q11.2DS, the prevalence of diagnosed hypocalcemia is elevated among patients with CHD, in whom it is more likely to be diagnosed during the neonatal/infancy period.
Palladium‐Catalyzed Direct Methylation and Benzylation of Enamides Using Iodomethane and Benzyl Halides with Retention of Alkenyl Moiety
Authors: Ding Ran , Yu Borong
Published: October 2018

A palladium‐catalyzed direct methylation and benzylation of enamides at β‐position with iodomethane and various benzyl halides was developed. The corresponding multisubstituted enamide products could be obtained in good yields under mild reaction conditions.
Endogenous genetic risk factor for serious heatstroke: the thermolabile phenotype of carnitine palmitoyltransferase II variant
Authors: Oda Jun , Yukioka Tetsuo , Azuma Kazunari , Arai Takao , Chida Junji , Kido Hiroshi
Published: October 2018

Aim

In serious heatstroke, elevated body temperature (>40°C) is considered the main cause of illness. Mitochondrial carnitine palmitoyltransferase II (CPT II) plays an important role in adenosine triphosphate (ATP) generation from long‐chain fatty acids, and its thermolabile phenotype of CPT2 polymorphisms leads to ATP production loss under high fever. Whether by heatstroke or influenza, high fever suppresses mitochondrial ATP production in patients with the thermolabile phenotype of CPT2 polymorphisms. We investigated the relation between CPT2 polymorphism and severity of heatstroke with a body temperature of over 40°C.

Methods

We analyzed blood chemistry test results, Japanese Association for Acute Medicine Disseminated Intravascular Coagulation (JAAM DIC), Acute Physiologic and Chronic Health Evaluation II, and Sequential Organ Failure Assessment (SOFA) scores, and CPT2 polymorphisms in 24 consecutive patients with severe heatstroke at two university hospitals.

Results

Eleven patients carried thermolabile CPT II variants (rs2229291; c.1055T˃G [p.Phe352Cys]) (F352C), and the genotype frequency was greater in heatstroke patients than in healthy volunteers. There was no significant difference in body temperature or blood chemistry data at emergency room arrival between patients with and without the CPT II variants. However, hospital days were longer and initial antithrombin activity was significantly lower in the variant group, suggesting a possible link with early phase vascular endothelial cell dysfunction. The JAAM DIC diagnostic criteria and SOFA scores were also higher in the group. There were no differences in the serum albumin, serum creatine kinase, and fibrin degradation product levels, and platelet counts.

Conclusions

In addition to known risks (e.g., environmental temperature and old age), the CPT II polymorphism [F352C] can be a predisposing genetic risk factor for serious heatstroke with organ disfunction, and lower antithrombin activity.
Visible‐Light‐Induced Pyridylation of Remote C(sp3)−H Bonds by Radical Translocation of N‐Alkoxypyridinium Salts
Authors: Kim Inwon , Park Bohyun , Kang Gyumin , Kim Jiyun , Jung Hoimin , Lee Hyeonyeong , Baik Mu‐Hyun , Hong Sungwoo
Published: October 2018

Metal‐free, visible‐light‐induced site‐selective heteroarylation of remote C(sp3)−H bonds has been accomplished through the design of N‐alkoxyheteroarenium salts serving as both alkoxy radical precursors and heteroaryl sources. The transient alkoxy radical can be generated by the single‐electron reduction of an N‐alkoxypyridinium substrate by a photoexcited quinolinone catalyst. Subsequent radical translocation of the alkoxy radical forms a nucleophilic alkyl radical intermediate, which undergoes addition to the substrate to achieve remote C(sp3)−H heteroarylation. This cascade strategy provides a powerful platform for remote C(sp3)−H heteroarylation in a controllable and selective manner and is well suited for late‐stage functionalization of complex bioactive molecules.
Eine chimäre pilzliche Diterpensynthase der Klade II‐D aus Colletotrichum gloeosporioides produziert Dolasta‐1(15),8‐dien
Authors: Bian Guangkai , Rinkel Jan , Wang Zhangqian , Lauterbach Lukas , Hou Anwei , Yuan Yujie , Deng Zixin , Liu Tiangang , Dickschat Jeroen S.
Published: October 2018

Basierend auf einer Plattform zur Überproduktion von Terpenoiden in Hefe für “Genome‐Mining” wurde eine chimäre Diterpensynthase aus dem endophytischen Pilz Colletotrichum gloeosporioides ES026 als (5R,12R,14S)‐Dolasta‐1(15),8‐dien‐Synthase charakterisiert. Die absolute Konfiguration wurde unabhängig durch die Verwendung enantioselektiv deuterierter Terpenvorstufen bestimmt, wodurch der vorhergesagte C1‐III‐IV‐Cyclisierungsmodus dieses ersten charakterisierten Enzyms der Klade II‐D bestätigt wurde. Isotopenmarkierungsexperimente und die Isolierung des Intermediates (1R)‐δ‐Araneosen stützen den vorgeschlagenen Cyclisierungsmechanismus.
Modulierung der elektronischen Strukturen anorganischer Nanomaterialien für eine effiziente elektrokatalytische Wasserspaltung
Authors: Du Xinchuan , Huang Jianwen , Zhang Junjun , Yan Yichao , Wu Chunyang , Hu Yin , Yan Chaoyi , Lei Tianyu , Chen Wei , Fan Cong , Xiong Jie
Published: October 2018

Elektrokatalytische Wasserspaltung ist eine der vielversprechendsten nachhaltigen Technologien zur Energieumwandlung, ist aber eingeschränkt durch die trägen elektrochemischen Reaktionen. Anorganische Nanomaterialien sind häufig als effiziente Katalysatoren zur Förderung der elektrochemischen Kinetik verwendet worden. Verschiedene Verfahren sind zur Aktivitätsoptimierung dieser Nanokatalysatoren entwickelt worden. Die elektronischen Strukturen der Katalysatoren spielen bei der Steuerung der Aktivität eine zentrale Rolle und sind daher ein wesentlicher Deskriptor. Allerdings sind die zugrundeliegenden Funktionsweisen der verfeinerten elektronischen Strukturen nach wie vor schwer fassbar. Um die Zusammenhänge zwischen Struktur, elektronischem Verhalten und Aktivität herzuleiten, wird hier eine umfassende Zusammenstellung der bisher entwickelten Strategien zur Regulierung der elektronischen Strukturen präsentiert, mit Betonung von Oberflächenmodifizierung, Spannung, Phasenübergang und Heterostruktur. Aktuelle Probleme beim grundsätzlichen Verständnis des Verhaltens von Elektronen in den Nanokatalysatoren werden detailliert diskutiert.
A Clade II‐D Fungal Chimeric Diterpene Synthase from Colletotrichum gloeosporioides Produces Dolasta‐1(15),8‐diene
Authors: Bian Guangkai , Rinkel Jan , Wang Zhangqian , Lauterbach Lukas , Hou Anwei , Yuan Yujie , Deng Zixin , Liu Tiangang , Dickschat Jeroen S.
Published: October 2018

Based on a terpenoid overproduction platform in yeast for genome mining, a chimeric diterpene synthase from the endophytic fungus Colletotrichum gloeosporioides ES026 was characterized as the (5R,12R,14S)‐dolasta‐1(15),8‐diene synthase. The absolute configuration was independently verified through the use of enantioselectively deuterated terpene precursors, which unequivocally established the predicted C1‐III‐IV cyclization mode for this first characterized clade II‐D enzyme. Extensive isotopic labeling experiments and isolation of the intermediate (1R)‐δ‐araneosene supported the proposed cyclization mechanism.
Soil geochemical methods in archaeo‐geophysics: Exploring a combined approach at sites in Scotland
Authors: Cuenca‐García Carmen
Published: October 2018

This article explores the application of geophysical and soil geochemical methods to detect archaeological features in three traditionally ‘difficult’ survey environments in Scotland: wind‐blown sands (Bay of Skaill, Orkney), clay (Chesterhall Parks Farm, Lanarkshire) and glacial drift deposits (Forteviot, Perthshire). The results presented here are part of the first research project that systematically tested a combined approach using geophysical and soil characterisation to understand the proxy responses of known archaeological features. First, a range of geophysical techniques [earth resistance, magnetometry, frequency domain electromagnetics (FDEM) and ground‐penetrating radar (GPR)] was employed over archaeological targets. Second, the different geophysical results were considered with respect to soil chemical concentrations (total phosphate and multi‐element analysis), texture, pH, conductivity, organic matter content and magnetic susceptibility from archaeological deposits, topsoil and subsoil samples. This study demonstrates that, by focusing on the responses of single archaeological features and assessing their physical and chemical signatures, soil composition and processes involved in the ‘history’ of buried features are of importance in improving our understanding of the reasons behind their detection with geophysical means. For example, at the cropmark site at Forteviot, chemical transformations can be triggered by organic matter accumulation and increased water retention within prehistoric ditch deposits and can have an effect on the type of magnetic contrast. In addition, chemical concentrations revealing anthropogenic organic materials can explain the enhanced conductivity of theoretically impervious features, as illustrated at the Bay of Skaill site. The study also provide insights into how a particular soil environment may affect different geophysical techniques such as the masking effects of heterogeneous glacial drift deposits or deep windblown sands. These types of survey environments characterise many archaeologically rich areas in Scotland, where integrated strategies, such as the one used in this investigation, are the best option to maximise detection of subsurface features and provide confident and augmented interpretations.
Große Stabdurchmesser und hohe Bewehrungsgrade
Authors: Breit Felix , Schnell Jürgen
Published: October 2018

Bewehrungsstäbe mit großen Stabdurchmessern werden vorwiegend in hochbeanspruchten Stahlbetonkonstruktionen wie z. B. in Stützen, Behältern und dicken Bodenplatten eingesetzt. Solche oft hochbewehrten Bauteile können durch die Verwendung großer Stabdurchmesser in baupraktischer Hinsicht optimiert hergestellt werden (reduzierter Verlegeaufwand, vereinfachter Betoneinbau). Außerdem können bereits in der Tragwerksplanung statisch‐konstruktive Vorteile wie z. B. größere statische Nutzhöhen und höhere Bewehrungsgrade ausgenutzt werden. Die derzeit eingeführten Bemessungs‐ und Konstruktionsregeln in [1, 2] geben jedoch diverse Zusatzregeln vor, deren Einhaltung die wirtschaftlichen Vorteile der großen Stabdurchmesser beschneiden.

Systematische Untersuchungen zum Rissverhalten von Stahlbetonkonstruktionen mit großen Stabdurchmessern wurden erstmals in einem Verbundforschungsvorhaben [3] durchgeführt, an welchem die RWTH Aachen, die Technische Universität Kaiserslautern und die Technische Universität Braunschweig mitwirkten. Die Ergebnisse dieser grundlegenden Untersuchungen sind u. a. auch in [4–6] veröffentlicht.

Ungeklärt ist jedoch weiterhin, inwieweit die derzeit gültigen Bemessungsregeln im Rahmen der Rissbreitenbeschränkung für plattenartige Bauteile mit kreuzweise verlegten großen Stabdurchmessern zutreffend angewendet werden können. Aber auch bei baupraktisch üblichen Stabdurchmessern (z. B. ∅ 20 mm und ∅ 28 mm) stellt sich die Frage, ob die auftretenden Rissbreiten bei mehrlagiger Bewehrungsanordnung mit bekanntem Regelwerk zielführend begrenzt werden können.

Vor diesem Hintergrund wurden weitere, umfangreiche experimentelle Untersuchungen durchgeführt, welche u. a. in [7–9] veröffentlicht sind.
Study on bioequivalence of beraprost in healthy volunteers by liquid chromatography with tandem mass spectrometry
Authors: Prasaja Budi , Harahap Yahdiana , Lusthom Windy , Sofiana Anna , Safira Falah , Sandra Monika , Puspanegara Girinanda
Published: October 2018

Beraprost sodium is an oral prostacyclin analog that was first approved in 1992 (Japan) for the treatment of peripheral vascular disorders. It is administered orally as a tablet available in strength 20 μg. In this paper, we described a liquid chromatography tandem mass spectrometry method that was developed for the quantification of beraprost in human plasma with high sensitivity at picogram per milliliter concentration. The method had been validated in terms of selectivity, sensitivity, accuracy and precision, matrix effect, linearity, recovery and carry‐over according to the Guideline on Bioanalytical Validation from the European Medicines Agency. The standard calibration curve for beraprost was 9.5–1419 pg/mL. This method has been applied successfully to a bioequivalence study with 60 μg of beraprost (three tablets) in 29 healthy volunteers. The results showed that the two formulations of beraprost are bioequivalent.
An update and expansion on the role of the Violence Risk Appraisal Guide and Historical Clinical Risk Management‐20 in United States case law
Authors: Cox Jennifer , Fairfax‐Columbo Jaymes , DeMatteo David , Vitacco Michael J. , Kopkin Megan R. , Parrott Caroline Titcomb , Bownes Elizabeth
Published: October 2018

An individual's risk for future violent behavior may be considered in various legal contexts, including civil commitment, criminal sentencing, or suitability for parole. Among the assessment tools forensic evaluators use to assess violence risk are the Violence Risk Appraisal Guide (VRAG; Quinsey, Harris, Rice, & Cormier, ) and the Historical Clinical Risk Managment‐20 (HCR‐20)/Historical Clinical Risk Management‐20, Version 3 (HCR‐20V3) (Webster, Douglas, Eaves, & Hart, and Douglas, Hart, Webster, & Belfrage, , respectively). Previous surveys and case law research suggest that these measures are widely used and perceived to be useful in aiding forensic clinicians. This study provides an update to Vitacco, Erickson, Kurus, and Apple () and examines the use of the HCR‐20 and VRAG in United States case law. A LexisNexis review revealed 134 cases decided between 1 January 2010 and 21 December 2016 that included the HCR‐20, VRAG, or both. Results revealed that these measures are typically introduced by the prosecution to inform opinions regarding general violence risk. In addition, consistent with previous research, these data suggest the introduction of the HCR‐20 and VRAG is rarely challenged and, when challenged, these challenges are rarely successful. However, data suggest that courts and parole boards may focus on specific risk factors (e.g., lack of insight) at the expense of other, more objective factors. Finally, we offer suggestions for clinicians who have transitioned to the newest version of the HCR‐20.
In Vitro and in Vivo Antischistosomal Activities of Chalcones
Authors: Pereira Vinícius R. D. , Junior Ismael J. Alves , da Silveira Lígia S. , Geraldo Reinaldo B. , de F. Pinto Priscila , Teixeira Fernanda S. , Salvadori Maria C. , Silva Marcos P. , Alves Lara A. , Capriles Priscila V. S. Z. , das C. Almeida Ayla , Coimbra Elaine S. , Pinto Pedro L. S. , Couri Mara R. C. , de Moraes Josué , Da Silva Filho Ademar A.
Published: October 2018

In this study, we evaluated the in vitro and in vivo schistosomicidal activities of chalcones against Schistosoma mansoni worms. In vitro assays revealed that chalcones 1 and 3 were the most active compounds, without affecting significantly mammalian cells. Confocal laser scanning microscopy and scanning electron microscopy studies revealed reduction on the numbers of tubercles and morphological alterations in the tegument of S. mansoni worms after in vitro incubation with chalcones 1 and 3. In a mouse model of schistosomiasis, the oral treatment (400 mg/kg) with chalcone 1 or 3 significantly caused a total worm burden reduction in mice. Chalcone 1 showed significant inhibition of the S. mansoni ATP diphosphohydrolase activity, which was corroborated by molecular docking studies. The results suggested that chalcones could be explored as lead compounds with antischistosomal properties.
Epoxy Isonitriles, A Unique Class of Antibiotics: Synthesis of Their Metabolites and Biological Investigations
Authors: Ernouf Guillaume , Wilt Ingrid K. , Zahim Sara , Wuest William M.
Published: October 2018

Epoxy isonitrile containing natural products often possess specific and potent antibacterial activity against Gram‐positive pathogens. This scaffold, however, is extremely labile under acidic and basic conditions, undergoing a Payne rearrangement to produce a stable epoxy ketone metabolite and releasing hydrogen cyanide. We synthesized and performed biological assays with epoxy ketone containing metabolites and identified that the epoxy isonitrile moiety is pertinent for biological activity. Serendipitously, we discovered an α,β‐unsaturated epoxy ketone analogue that exhibited moderate activity against Staphylococcus aureus.
Ultrathin Nanosheet Ni‐Metal Organic Framework Assemblies for High‐Efficiency Ascorbic Acid Electrocatalysis
Authors: Li Qing , Zheng Shasha , Hu Xiao , Shao Zhifang , Zheng Mingbo , Pang Huan
Published: October 2018

Owing to their unique porous structure, metal‐organic framework (MOF) nanosheets are considered one of the best active materials for high‐performance electrocatalysts. Ultrathin nanosheet Ni−MOF assemblies, [Ni3(OH)2(C8H4O4)2(H2O)4] ⋅ 2H2O, were synthesized by using a simple solvothermal method and used for efficiently catalyzing ascorbic acid (AA) in a common phosphate buffer solution (PBS, pH=7.2). Electrochemical data analysis revealed good catalytic activity performance and outstanding stability for the AA oxidation reaction. The reason for analyzing its intrinsic may depend on the structure of the ultrathin nanosheet. This structure not only provides a pathway for improving electrocatalytic performance, but its special aggregation state also makes it more stable in electrocatalytic AA.
Sample and feature augmentation strategies for calibration updating
Authors: Andries Erik , Kalivas John H. , Gurung Anit
Published: October 2018

Calibration updating—transfer and/or maintenance—has historically been implemented using a simple but effective technique: in addition to primary samples, include a small number of secondary samples and weight them. It would be beneficial if these classical weighting techniques could be enhanced. Moreover, it would be ideal if we could only use secondary spectra without reference measurements. In this paper, we examine multiple calibration updating scenarios involving unlabeled and labeled secondary spectra. First, we propose three new updating approaches involving sample augmentation whereby unlabeled secondary spectra are used to construct an “undesirable” subspace. This subspace is then used to steer the model vector away from a spectroscopically undesirable solution. Second, we propose two new feature augmentation approaches using labeled secondary samples. These three approaches involves the sum of two model vectors, a dedicated primary model vector plus a perturbation vector, that can accommodate new secondary samples. We rigorously vet the proposed approaches across two near‐infrared (NIR) data sets and across multiple data splits. Out of all of the approaches examined, one feature augmentation approach provides improved results compared with existing approaches, and one sample augmentation approach utilizing only unlabeled secondary spectra appears promising.
A Versatile New Paradigm for the Design of Optical Nanosensors Based on Enzyme‐Mediated Detachment of Labeled Reporters: The Example of Urea Detection
Authors: Llopis‐Lorente Antoni , Villalonga Reynaldo , Marcos M. Dolores , Martínez‐Máñez Ramón , Sancenón Félix
Published: October 2018

Here, a new bio‐inspired nanoarchitectonics approach for the design of optical probes is presented. It is based on nanodevices that combine 1) an enzymatic receptor subunit, 2) a signaling subunit (consisting of a labeled reporter attached to a silica surface), and 3) a mechanism of communication between the two sites based on the production of chemical messengers by the enzymatic subunit, which induces the detachment of the reporter molecules from the silica surface. As a proof of concept, a urea nanosensor based on the release of Alexa‐Fluor‐647‐labeled oligonucleotide from enzyme‐functionalized Janus gold–mesoporous‐silica nanoparticles (Au–MSNPs) was developed. The Janus particles were functionalized on the silica face with amino groups to which the labeled oligonucleotides were attached by electrostatic interactions, whereas the gold face was used for grafting urease enzymes. The nanodevice was able to release the fluorescent oligonucleotide through the enzyme‐mediated hydrolysis of urea to ammonia and the subsequent deprotonation of amino groups on the silica face. This simple nanodevice was applied for the fluorometric detection of urea in real human blood samples and for the identification of adulterated milk. Given the large variety of enzymes and reporter species that could be combined, this is a general new paradigm that could be applied to the design of a number of optical probes for the detection of target analytes.
Shell Cross‐Linked Micelles as Nanoreactors for Enantioselective Three‐Step Tandem Catalysis
Authors: Kuepfert Michael , Cohen Aaron E. , Cullen Olivia , Weck Marcus
Published: October 2018

Functionalized amphiphilic poly(2‐oxazoline)‐based triblock copolymers that assemble into shell cross‐linked micelles (SCMs) are described. These micelles permit the site isolation of three incompatible catalysts through compartmentalization, thereby enabling three‐step non‐orthogonal tandem processes in one pot. In particular, the acid‐catalyzed ketal hydrolysis to prochiral ketones proceeded in the hydrophilic corona, followed by the Rh‐catalyzed asymmetric transfer hydrogenation to enantio‐enriched alcohols in the cross‐linked shell, and nucleophilic base‐catalyzed acylation in the hydrophobic core. The catalysts are positioned in close proximity on a single micelle support to take advantage of the intramicellar substrate diffusion, yet they are sufficiently spaced apart from each other in physically distinct microenvironments. These compartmentalized micelles are substrate selective and, on a basic level, mimic compartmentalized catalytic architectures found in nature.
Eisen‐Chrom‐Redox‐Flow‐Batterie für Schülerversuche
Authors: le Plat Dennis , Henkel Rouven , Hickmann Thorsten , Tuckermann Rudolf
Published: October 2018

In dieser Arbeit wird eine Reihe von Schülerexperimenten zu Redox‐Flow‐Batterien vorgestellt, bei denen die SchülerInnen sich selbstständig mit den Vorteilen und Herausforderungen dieser innovativen Energiewandler auseinandersetzen. Dazu wurde zunächst eine Eisen‐Chrom‐Redox‐Flow‐Batterie aufgebaut und charakterisiert. Anschließend wurde eine vierteilige Experimentreihe entwickelt, in der sich Schüler und Schülerinnen in einzelnen Stationen intensiv mit dem Aufbau der Zelle, der Charakterisierung dieser, sowie der Färbung der Elektrolyten und der Herausforderung des Crossovers befassen. Zur Durchführung der einzelnen Stationen werden zusätzliche Konzepte, wie Ersatzschaltbilder, Spektralphotometrie und Diffusion vermittelt. Die Schüler, die die Reihe getestet haben, begrüßten das eigenständige Arbeiten und die Verzahnung der einzelnen Stationen untereinander. Eine anschließende Evaluation zeigte eine Verbesserung des Verständnisses der teilnehmenden SchülerInnen gegenüber einer Vergleichsgruppe.
Parental distress and desire for information regarding long‐term implications of pediatric cancer treatment
Authors: Greenzang Katie A. , Cronin Angel M. , Kang Tammy I. , Mack Jennifer W.
Published: October 2018

Background

Parents of children with cancer have unmet information needs regarding future limitations resulting from cancer or its treatment. Prior research has demonstrated that, in early care discussions, clinicians focus on the acute effects of therapy rather than long‐term limitations, partly due to worries of causing distress. The validity of concerns regarding distress is unknown. In the current study, the authors evaluated parental distress associated with information regarding future limitations, and the extent to which distress is associated with information preferences.

Methods

The authors surveyed 355 parents of children with cancer within 3 months of diagnosis, and the children’s physicians at Dana‐Farber Cancer Institute/Boston Children’s Cancer and Blood Disorders Center and the Children’s Hospital of Philadelphia. The primary outcome was parental distress associated with information regarding long‐term limitations.

Results

Approximately 46% of parents found information regarding future limitations to be extremely or very upsetting. In multivariate analysis, parents were more likely to consider information regarding future limitations distressing if they also found prognostic information upsetting (odds ratio [OR], 5.36; P<.001), struggled to accept their child’s illness (OR, 2.57; P<.001), or had depression (OR, 1.79; P=.01). However, approximately 92% of parents considered information regarding potential future limitations to be extremely/very important. Those who found information regarding future limitations distressing were more likely to consider it important (96% vs 89%; P=.03) and to desire a precise understanding of their child’s risks (92% vs 80%; P=.001).

Conclusions

Although information regarding future limitations caused by cancer treatment is upsetting to many parents, the majority of them desire this information, and those who are distressed are more likely to value this information.
Improving energy efficiency in LTE‐A networks with the reduction of failure rate in eNB components
Authors: Bhuvaneswari P. , Nithyanandan L.
Published: October 2018

Small cell networks provide optimistic and realistic way to meet the growth of increasing demand for higher rates of services in wireless networks. Energy efficiency (EE) is a high‐priority design parameter in a long‐term evolution‐advanced (LTE‐A) network. Generally, LTE‐A base stations are referred to as evolved Node B (eNB). To improve EE with small cell deployment, one way is to switch off some of the eNB components while the difficulty is to control the failure rate activated by fatigue processes of eNB subjected to Discontinuous Transmission mode (DTX). Specifically, if the time spent in DTX modes increases, then the failure rate of eNB decreases. Despite the variation of power states turned to enlarge the failure rate of eNB. The objective is to deal the difficulty of reducing the LTE‐A eNB failure rate subject to DTX mode and the new algorithm named AFEE (Acceleration Factor and Energy efficiency) is proposed and energy analysis is performed and numerical results are given. Specifically, the proposed algorithm is strong enough to attain power saving nearly of 55%.
Novel Rapid Screening of Basic Immobilized Amine Sorbent/Catalyst Water Stability by a UV/Vis/Cu2+ Technique
Authors: Wilfong Walter Christopher , Kail Brian W. , Wang Qiuming , Gray McMahan L.
Published: October 2018

Time‐consuming thermogravimetric analysis (TGA) decomposition study is a typical practice to assess the stability of fresh and water‐treated basic immobilized amine sorbents (BIAS)/catalysts. This work presents a faster and more precise spectroscopic UV/Vis/Cu2+ sorbent screening technique that quantifies aqueous amines washed from the BIAS by using UV‐active amine/Cu2+ complexes. Six BIAS‐based catalysts, containing different amine species and a crosslinker within silica, were treated with ultrapure water and then analyzed for their CO2 capture performance and amine leach resistance/stability by using TGA (catalysts, approximately 4 h) and UV/Vis/Cu2+ techniques (wash solution, few minutes). A comparative analysis revealed that directly quantifying washed amines with UV/Vis/Cu2+ is 9–127 times more precise than indirect testing of the sorbents by TGA. Similar trends in the H2O stability profiles of the catalysts [organic content retained values (OCR)] were reported by both analysis methods, allowing UV/Vis/Cu2+ to replace TGA for quantifying unstable leached amines. The UV/Vis/Cu2+ OCR results could be used to predict the CO2‐capture stability profile of the sorbents, confirming the reliability of this technique to rapidly screen catalyst stability and performance.
The anatomy of single cell mass cytometry data
Authors: Olsen Lars R. , Leipold Michael D. , Pedersen Christina B. , Maecker Holden Terry
Published: October 2018

Mass cytometry enables the measurement of up to 50 features on single cell. This has catalyzed a shift toward multidimensional data analysis methods, rather than the manual gating strategies as traditionally for in flow cytometry data. This shift means that data scientists are involved in the analysis process to an increasing degree. As the data is analyzed in a more unbiased fashion, where noisy or uninformative observations are not easily excluded, a deeper knowledge of the origin, noise, and modalities of the data is therefore needed to embark on useful data analysis. In this primer, we introduce the idiosyncrasies of mass cytometry data with a focus on the technical properties of how data generated with the CyTOF® system, and the characteristics of protein expression in the cells of the hematopoietic continuum, specifically targeted toward data scientists. We also provide a comprehensive online repository of scripts, tutorials, and example data. © 2018 International Society for Advancement of Cytometry
A field ecologist's adventures in the virtual world: using simulations to design data collection for complex models
Authors: Thomas Freya M. , Vesk Peter A. , Hauser Cindy E.
Published: October 2018

Field data collection can be expensive, time consuming, and difficult; insightful research requires statistical analyses supported by sufficient data. Pilot studies and power analysis provide guidance on sampling design but can be challenging to perform, as ecologists increasingly collect multiple types of data over different scales. Despite a growing simulation literature, it remains unclear how to appropriately design data collection for many complex projects. Approaches that seek to achieve realism in decision‐making contexts, such as management strategy evaluation and virtual ecologist simulations, can help. For a relatively complex analysis, we develop and demonstrate a flexible simulation approach that informs what data are needed and how long those data will take to collect, under realistic fieldwork constraints. We simulated data collection and analysis under different constraint scenarios that varied in deterministic (field trip length, travel, and measurement times) and stochastic (species detection and occupancy rates and inclement weather) features. In our case study, we fit plant height data to a multispecies, three‐parameter, nonlinear growth model. We tested how the simulated data sets, based on the varying constraint scenarios, affected the model fit (parameter bias, uncertainty, and capture rate). Species prevalence in the field exerted a stronger influence on the data sets and downstream model performance than deterministic aspects such as travel times. When species detection and occupancy were not considered, the field time needed to collect an adequate data set was underestimated by 40%. Simulations can assist in refining fieldwork design, estimating field costs, and incorporating uncertainties into project planning. We argue that combining data collection, analysis, and decision‐making processes in a flexible virtual setting can help address many of the decisions that field ecologists face when designing field‐based research.
Isomerization Processes on Organoruthenium Complexes Bearing κ2(P,C)‐Bidentate Ligands Generated Through Nucleophilic Addition to Coordinated Alkenyl Phosphanes
Authors: de la Arada Isaac García , Díez Josefina , Gamasa M. Pilar , Lastra Elena
Published: October 2018

Nucleophilic attack on complex [RuCl(η6‐C10H14){κ3(P,C,C)‐Ph2PCH2CH=CH2}][BPh4] (2) takes place, either to the metal or to the coordinated olefin depending on the nucleophile and the reaction conditions. The nucleophilic attack of phosphanes on the coordinated olefin leads diastereoselectively to complexes [RuCl(η6‐C10H14){ĸ2(P,C)‐Ph2PCH2CH(PR3)CH2}]+ bearing κ2(P,C)‐ligands obtained as a racemic mixture of the enantiomers RRuSc/SRuRC. These kinetically stable isomers, undergo an isomerization process leading to the thermodynamically stable products isolated as the diastereoisomer RRuRC/SRuSC. 31P{1H} NMR monitoring experiments on the isomerization processes have been carried out.
Synthesis and Avidin Binding of Ruthenium Complexes Functionalized with a Light‐Cleavable Free Biotin Moiety
Authors: Siewert Bianka , Langerman Michiel , Pannwitz Andrea , Bonnet Sylvestre
Published: October 2018

Invited for the cover of this issue is the group of Sylvestre Bonnet from Leiden University, The Netherlands. The cover image shows the attachment of a free biotin group to a Ru compound by a light‐sensitive coordination bond.
Synthesis of Phenyl Dithiocarbamates Starting from Sodium Dialkyldithiocarbamates and Aryl Boronic Acids: a Copper Catalyzed S‐Arylation
Authors: Gao Ming‐Yuan , Xu Wan , Zhang Shi‐Bo , Li Yue‐Sheng , Dong Zhi‐Bing
Published: October 2018

A convenient and efficient protocol for the S‐arylation of sodium dialkyldithiocarbamates was developed. With the catalysis of copper(I) bromide, sodium dialkyldithiocarbamates coupled with aryl boronic acids giving the C‐S coupling products smoothly in good to excellent yields. This protocol features easily available starting materials, easy performance, short reaction time, broad substrate scope and good yields, showing its potential synthetic value for the convenient preparation of some potentially biologically active compounds.
Base‐Promoted Cycloisomerization for the Synthesis of Oxazoles and Imidazoles
Authors: Zhang Lidan , Xiao Ke , Qiao Yan , Li Xin , Song Chuanjun , Chang Junbiao
Published: October 2018

Treatment of propargylamides or propargylamidines with cesium carbonate in DMSO results in the formation of the corresponding oxazoles or imidazoles in good yields. A large variety of substrates with various functional groups are tolerated. DFT study on a model substrate reveals that the reactions proceed via a sequence involving allene formation, intramolecular cyclization, and double‐bond isomerization.
A macromolecular halogen‐free flame retardant and its effect on the properties of thermoplastic polyesters
Authors: Adner David , Helmy Mina , Otto Tobias , Schellenberg Jürgen , Schadewald Anke
Published: October 2018

A halogen‐free flame retardant with a macromolecular structure is presented. Its synthesis proceeds via polymerization of phosphorus‐containing acrylate monomers. The flame retardant was incorporated into poly(ethylene terephthalate) by extrusion. Samples with different concentrations (0.5, 2.5, and 5.0 wt%) as well as a 25 wt% masterbatch were prepared. All samples were transparent and colorless without any visible irregularities. Thermal investigations reveal an unchanged glass transition temperature. Tensile tests show the typical mechanical behavior of poly(ethylene terephthalate), but with an elevated Young's modulus. The burning behavior was investigated by several small‐flame tests in vertical and horizontal orientation, as well as by cone calorimetry. It is shown that samples with 2.5 wt% flame retardant pass the vertical UL94 test (V‐2, 20‐mm flame). The sample cannot be ignited in the horizontal fire test according to FMVSS 302. The oxygen index was measured to 28 vol%. Cone calorimetric measurements show that the effective heat of combustion as well as the total heat evolved is reduced.
A novel group of spindle cell tumors defined by S100 and CD34 co‐expression shows recurrent fusions involving RAF1, BRAF, and NTRK1/2 genes
Authors: Suurmeijer Albert J. H. , Dickson Brendan C. , Swanson David , Zhang Lei , Sung Yun‐Shao , Cotzia Paolo , Fletcher Christopher D. M. , Antonescu Cristina R.
Published: October 2018

Tumors characterized by co‐expression of S100 and CD34, in the absence of SOX10, remain difficult to classify. Triggered by a few index cases with monomorphic cytomorphology and distinctive stromal and perivascular hyalinization, immunopositivity for S100 and CD34, and RAF1 and NTRK1 fusions, the authors undertook a systematic review of tumors with similar features. Most of the cases selected were previously diagnosed as low‐grade malignant peripheral nerve sheath tumors, while others were deemed unclassified. The tumors were studied with targeted RNA sequencing and/or FISH. A total of 25 cases (15 adults and 10 children) with kinase fusions were identified, including 8 cases involving RAF1, 2 BRAF, 14 NTRK1, and 1 NTRK2 gene rearrangements. Most tumors showed a monomorphic spindle cell proliferation with stromal and perivascular keloidal collagen, in a patternless architecture, with only occasional scattered pleomorphic or multinucleated cells. Most cases showed low cellularity, a low mitotic count, and absence of necrosis. Although a subset showed overlap with lipofibromatosis‐like neural tumors, the study group showed distinctive hyalinization and overt malignant features, such as highly cellular fascicular growth and primitive appearance. All tumors showed co‐expression of S100 and CD34, ranging from focal to diffuse. SOX10 was negative in all cases. NTRK1 immunohistochemistry showed high levels of expression in all tumors with NTRK1 gene rearrangements. H3K27me3 expression performed in a subset of cases was retained. These findings together with the recurrent gene fusions in RAF1, BRAF, and NTRK1/2 kinases suggest a distinct molecular tumor subtype with consistent S100 and CD34 immunoreactivity.