bluuebunny/crossref_metadata_2025 huggingface dataset:
Tungsten as “Adhesive” in Pt2CuW0.25 Ternary Alloy for Highly Durable Oxygen Reduction Electrocatalysis
Authors: Tu Wenzhe , Luo Wenjia , Chen Changli , Chen Kai , Zhu Enbo , Zhao Zipeng , Wang Zelin , Hu Tao , Zai Huachao , Ke Xiaoxing , Sui Manling , Chen Pengwan , Zhang Qingshan , Chen Qi , Li Yujing , Huang Yu
Published: December 2019

Pt‐based alloy nanocrystals have shown great success in oxygen reduction electrocatalysis owing to their unique surface and electronic structures. However, they suffer from severe stability issues due to the dissolution of non‐noble metal elements, leading to the “trade‐off” between activity and stability. In this work, targeting the stability issue of a PtxCuy‐based alloy, Pt2CuW0.25 ternary alloy nanoparticles are synthesized by thermal reduction strategy based on wet‐chemical method using W(CO)6 as a reductant. Apart from the competitive activity, the obtained Pt2CuW0.25/C shows remarkable stability, whereby the area specific activity and mass activity maintain 89.5% and 95.9% of the initial values, respectively, after 30 000 cycles of accelerated polarization between 0.6 and 1.1 V (vs reversible hydrogen electrode). By using vacancy formation energy of surface Pt as the descriptor, it is found that the enhanced stability of Pt2CuW0.25/C originates mainly from the stronger bonding between W and Pt/Cu atoms, acting as an “adhesive” to stabilize the atoms from dissolution, which is further verified by chemical stability experiments. This work demonstrates a rational design strategy for ternary alloy nano‐electrocatalyst that has high thermodynamic stability while maintaining high activity by employing high‐melting‐point metal.
High‐Performance NO2 Sensors Based on Ultrathin Heterogeneous Interface Layers
Authors: Zhu Yangyang , Xie Qiang , Sun Yang , Wang Lu , Sun Qiang , Wang Lijuan
Published: December 2019

Gas sensors based on different interface layers are prepared by vacuum evaporation method. In comparison with the microscope images of films on different interface layer, zinc phthalocyanine (ZnPc) films exhibit good continuity on the heterogeneous interface of p‐sexiphenyl/α‐sexithiophene (p‐6P/α‐6T). Under the optimal conditions of ZnPc films, ZnPc film sensors with high performance are obtained based on ultrathin heterogenous interface layers. The responsivity is up to 2271% at 3 ppm NO2 gas and the sensitivity is 570% ppm−1. The minimum detection limit of sensors is lower than 500 ppb and the responsivity is 157% to 500 ppb NO2 gas. The high performance of sensors is attributed to the ultrathin heterogeneous interface layer. The island‐like p‐6P domains at the bottom provide the precursor for the growth of α‐6T layer while the α‐6T molecules fill the interval of p‐6P islands, as a result, a continuous interface for the growth of ZnPc molecules came into being. In addition, the ZnPc and α‐6T films have high electrical characteristics. The results are favorable for the adsorption and desorption of NO2 gas molecules. The ultrathin heterogeneous interface layer provides a feasible research evidence for the further research and development of ultrathin and flexible electronic devices.
Active Nanointerface‐Assisted Co‐Assembly to Yolk–Shell Au@Ordered Mesoporous Carbon Nanospheres
Authors: Zhang Weicai , Peng Jing , Zheng Mingtao , Dong Hanwu , Hu Hang , Xiao Yong , Liu Yingliang , Liang Yeru
Published: December 2019

Assembling of well‐orientated mesopores and 0D substance into an orchestrate architecture for constructing advanced carbon‐based composites is highly attractive. Currently, this nanofabrication method is facing challenges, because of the difficulty in the co‐assembly of the building blocks is very hard to perform onto a high‐curvature and heterogeneous 0D substrate. Here, an efficient active nanointerface‐assisted co‐assembly approach for design and fabrication of a novel class of yolk–shell Au@ordered mesoporous carbon nanosphere is reported. The key point to this preparation strategy is construction of reactive aldehyde functional groups on the surface of Au@SiO2 nanospheres, which can react with the carbon source to in situ form a stable covalent bond at their nanointerface. The as‐synthesized yolk–shell Au@ordered mesoporous carbon nanosphere not only exhibits uniform spherical morphology and robust porosity but also possesses a totally new ordered mesoporous and fast permeable shell structure, providing a chance for greatly broadening their application scope.
Enantioenriched Methylene‐Bridged Benzazocanes Synthesis by Organocatalytic and Superacid Activations
Authors: Beaud Rodolphe , Michelet Bastien , Reviriot Yasmin , Martin‐Mingot Agnès , Rodriguez Jean , Bonne Damien , Thibaudeau Sébastien
Published: December 2019

Achieving in a straightforward way the synthesis of enantioenriched elaborated three‐dimensional molecules related to bioactive natural products remains a long‐standing quest in organic synthesis. Enantioselective organocatalysis potentially offers a unique opportunity to solve this problem, especially when combined with complementary modes of activation. Here, we report the sequential association of organocatalytic and superacid activations of simple linear achiral readily available precursors to promote the formation of unique highly elaborated chiral methylene‐bridged benzazocanes exhibiting three to five fully‐controlled stereocenters. This peculiar backbone, difficult to assemble by standard synthetic approaches, is closely related to bioactive natural and synthetic morphinans and benzomorphans. The formation of a highly reactive chiral 7‐membered ring N‐acyl iminium superelectrophilic ion, evidenced by low‐temperature in situ NMR experiments, triggers a challenging stereoselective Friedel–Crafts‐type cyclization.
On the Influence of Oxygen on the Degradation of Fe‐N‐C Catalysts
Authors: Kumar Kavita , Dubau Laetitia , Mermoux Michel , Li Jingkun , Zitolo Andrea , Nelayah Jaysen , Jaouen Frédéric , Maillard Frédéric
Published: December 2019

Fe‐N‐C catalysts containing atomic FeNx sites are promising candidates as precious‐metal‐free catalysts for oxygen reduction reaction (ORR) in proton exchange membrane fuel cells. The durability of Fe‐N‐C catalysts in fuel cells has been extensively studied using accelerated stress tests (AST). Herein we reveal stronger degradation of the Fe‐N‐C structure and four‐times higher ORR activity loss when performing load cycling AST in O2‐ vs. Ar‐saturated pH 1 electrolyte. Raman spectroscopy results show carbon corrosion after AST in O2, even when cycling at low potentials, while no corrosion occurred after any load cycling AST in Ar. The load‐cycling AST in O2 leads to loss of a significant fraction of FeNx sites, as shown by energy dispersive X‐ray spectroscopy analyses, and to the formation of Fe oxides. The results support that the unexpected carbon corrosion occurring at such low potential in the presence of O2 is due to reactive oxygen species produced between H2O2 and Fe sites via Fenton reactions.
Synthesis of Biaryl‐Bridged Cyclic Peptides via Catalytic Oxidative Cross‐Coupling Reactions
Authors: Ben‐Lulu Mor , Gaster Eden , Libman Anna , Pappo Doron
Published: December 2019

Biaryl‐bridged cyclic peptides comprise an intriguing class of structurally diverse natural products with significant biological activity. Especially noteworthy are the antibiotics arylomycin and its synthetic analogue G0775, which exhibits potent activity against Gram‐negative bacteria. Herein, we present a simple, flexible, and reliable strategy based on activating‐group‐assisted catalytic oxidative coupling for assembling biaryl‐bridged cyclic peptides from natural amino acids. The synthetic approach was utilized for preparing a number of natural and unnatural biaryl‐bridged cyclic peptides, including arylomycin/G0775 and RP 66453 cyclic cores.
Acyclic Branched α‐Fluoro Ketones for the Direct Asymmetric Mannich Reaction Leading to the Synthesis of β‐Tetrasubstituted β‐Fluoro Amines
Authors: Trost Barry M. , Tracy Jacob S. , Yusoontorn Tas , Hung Chao‐I Joey
Published: December 2019

The preparation of acyclic β‐fluoro amines bearing tetrasubstituted fluorine stereocenters is described via a direct Zn/ProPhenol‐catalyzed Mannich reaction. The reaction utilizes branched vinyl or alkynyl α‐fluoro ketones that can be coupled with a range of aryl, heteroaryl, vinyl, or cyclopropyl aldimines in high yield and with excellent diastereo‐ (up to >20:1) and enantioselectivity (up to 99 %). The use of readily cleaved tert‐butoxycarbonyl (Boc) or carboxybenzyl (Cbz) imine protecting groups adds utility to the reaction by allowing for easy access to the free amine products under mild and chemoselective reaction conditions.
Visible‐Light‐Excited Room‐Temperature Phosphorescence in Water by Cucurbit[8]uril‐Mediated Supramolecular Assembly
Authors: Wang Jie , Huang Zizhao , Ma Xiang , Tian He
Published: December 2019

Solid‐state materials with efficient room‐temperature phosphorescence (RTP) emissions have found widespread applications in materials science, while liquid or solution‐phase pure organic RTP emission systems has been rarely reported, because of the nonradiative decay and quenchers from the liquid medium. Reported here is the first example of visible‐light‐excited pure organic RTP in aqueous solution by using a supramolecular host‐guest assembly strategy. The unique cucurbit[8]uril‐mediated quaternary stacking structure allows tunable photoluminescence and visible‐light excitation, enabling the fabrication of multicolor hydrogels and cell imaging. The present assembly‐induced emission approach, as a proof of concept, contributes to the construction of novel metal‐free RTP systems with tunable photoluminescence in aqueous solution, providing broad opportunities for further applications in biological imaging, detection, optical sensors, and so forth.
The Mutation of the “Nobel Prize in Chemistry” into the “Nobel Prize in Chemistry or Life Sciences”: Several Decades of Transparent and Opaque Evidence of Change within the Nobel Prize Program
Authors: Seeman Jeffrey I. , Restrepo Guillermo
Published: December 2019

Over the past several decades, the Nobel Prize program has slowly but steadily been modified in both transparent and opaque ways. A transparent change has been the creation of the Nobel Prize in Economic Sciences, officially known as the Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel. An opaque change has been the mutation of the Nobel Prize in Chemistry into what is effectively the “Nobel Prize in Chemistry or Life Sciences.” This paper presents a detailed study of this opaque change, including evidence that the disciplines of chemistry and biochemistry cover, today, intellectually quite distinct and generally scientifically‐unrelated intellectual territory. This paper supports the evolution of the Nobel Prizes, and encourages the Nobel Prize program to move from opaque to transparent change processes for the next generations of achievement in the sciences.
Rhodium‐Catalyzed Remote C(sp3)−H Borylation of Silyl Enol Ethers
Authors: Li Jie , Qu Shuanglin , Zhao Wanxiang
Published: December 2019

A rhodium‐catalyzed remote C(sp3)−H borylation of silyl enol ethers (SEEs, E/Z mixtures) by alkene isomerization and hydroboration is reported. The reaction exhibits mild reaction conditions and excellent functional‐group tolerance. This method is compatible with an array of SEEs, including linear and branched SEEs derived from aldehydes and ketones, and provides direct access to a broad range of structurally diverse 1,n‐borylethers in excellent regioselectivities and good yields. These compounds are precursors to various valuable chemicals, such as 1,n‐diols and aminoalcohols.
Difunctionalization of Alkenes Involving Metal Migration
Authors: Li Yuqiang , Wu Dong , Cheng Hong‐Gang , Yin Guoyin
Published: December 2019

The direct difunctionalization of alkenes, a cheap and abundant feedstock, represents one of the most attractive strategies for increasing molecular complexity in synthetic organic chemistry. In contrast with the 1,2‐difunctionalization of alkenes, recent advances showcase alkene 1,n‐difunctionalizations (n≠2) involving metal migration is an emerging and rapidly growing area of research. This promising strategy not only opens a novel avenue for future development of alkene transformations, but also significantly expands upon the bond disconnections available in modern organic synthesis. This Minireview summarizes recent progress in the migratory difunctionalization of alkenes, with an emphasis on the driving force for metal migration.
Copper coordinated‐poly(α‐amino acid) decorated on magnetite graphene oxide as an efficient heterogeneous magnetically recoverable catalyst for the selective synthesis of 5‐ and 1‐substituted tetrazoles from various sources: A comparative study
Authors: Kazemnejadi Milad , Mahmoudi Boshra , Sharafi Zeinab , Nasseri Mohammad A. , Allahresani Ali , Esmaeilpour Mohsen
Published: December 2019

In this work, poly(α‐amino acid)‐Cu(II) complex immobilized on magnetite graphene oxide (GO/Fe3O4@PAA‐Cu‐complex) was prepared via a multistep synthesis and employed as an efficient, heterogeneous, magnetically recyclable nanocatalyst for one‐pot, three component synthesis of 5‐ and 1‐substituted tetrazoles using different substrates including benzaldehydes, benzonitriles, and anilines in mild conditions. The different approaches were mechanically investigated and compared. The catalyst was fully characterized by Fourier transform infrared (FTIR), thermogravimetric analysis (TGA), X‐ray diffraction (XRD), vibrating sample magnetometer (VSM), energy dispersive X‐ray spectroscopy (EDX), inductively coupled plasma (ICP), FE‐SEM and TEM analyses. The magnetic nanocatalyst could be readily separated from the reaction mixture by an external magnet and reused for several times without significant loss of catalytic activity. Also, the spectroscopic analysis revealed the stability and durability of the catalyst. Finally, the chemoselectivity of the method was investigated by the various combinations of aldehyde, nitrile, and oxime.
Well‐defined PEPPSI‐themed palladium–NHC complexes: synthesis, and catalytic application in the direct arylation of heteroarenes
Authors: Kaloğlu Murat , Gürbüz Nevin , Yıldırım İlkay , Özdemir Namık , Özdemir İsmail
Published: December 2019

In this study, a series of benzimidazolium salts were synthesized as unsymmetrical N‐heterocyclic carbene (NHC) precursors. Benzimidazolium salts were used for synthesis of the PEPPSI (pyridine enhanced precatalyst preparation stabilization and initiation)‐themed, six new Pd‐complexes with the general formula [PdX2(NHC)(pyridine)]. The structures of all compounds were characterized by various spectroscopic techniques such as 1H NMR, 13C NMR and FT‐IR. The more detailed structural characterization of four of the complexes was determined by single‐crystal X‐ray diffraction study. The catalytic activities of all Pd‐complexes were evaluated in the direct arylation of the 2‐acetylfuran and 2‐acetylthiophene with aryl bromides in the presence of 1 mol% catalyst loading.
Creating and renewing identity and value through the use of non‐invasive archaeological methods: Mapoon unmarked graves, potential burial mounds and cemeteries project, western Cape York peninsula, Queensland
Authors: SUTTON MARY‐JEAN , CONYERS LAWRENCE B. , PEARCE SIMON , PIERRE EMMA ST , NICHOLLS PITT DIANE
Published: December 2019

In 2010, Elders from Mapoon watched “Time Team” and saw ground‐penetrating radar (GPR) and other non‐invasive scientific methods being used to identify cultural features on archaeological sites. This led Elders to express their desire for such techniques, particularly GPR, to be brought on country to assist with documenting and protecting cultural heritage sites. This paper explores how Mapoon families have employed these techniques in archaeological settings to reconnect and reimagine specific features in their cultural landscape, as well as to explore, create and renew narratives from their interpretations of the results from the project. We also investigate the nature of Traditional Owner interactions with these technologies in archaeological settings to understand their impact on how cultural identity and value are recreated and renewed, on “caring for country” programmes, and on modernising culturally appropriate forms of engagement with ancestors’ remains. We apply these findings to a discussion of how Mapoon people think about their cultural history, identity and connections to country, particularly in relation to mortuary practices and settlement patterns from pre‐contact to the “mission time”.
Artemisinin‐derived dimers as potential anticancer agents: Current developments, action mechanisms, and structure–activity relationships
Authors: Zhang Bo
Published: December 2019

Anticancer agents play a pivotal role in cancer treatment. However, most of the anticancer drugs currently used in the clinics have a severe anticancer scenario, as well as low specificity and fatal side effects. Thus, there is an urgent demand to develop novel drugs with great efficacy, high specificity, and low side effects. Artemisinin and its semisynthetic derivatives are mainstays of chemotherapy against malaria, and artemisinin‐based compounds, especially artemisinin‐derived dimers, also exhibit excellent in vitro and in vivo anticancer activity. The structure–activity relationship (SAR) demonstrated that the linker between the two artemisinin moieties influenced the anticancer activity significantly; so, the rational design of the linker may provide valuable therapeutic intervention for the treatment of cancer. This review outlines the potential anticancer activity of artemisinin‐derived dimers tethered by different linkers. The SARs, as well as mechanisms of action, are discussed to provide insights for the rational design of more effective dimers.
Diffraction stack imaging as a potential tool for detecting underground voids – the case of the ancient copper mines of Timna Valley (Israel)
Authors: Wechsler Neta , Shustak Matan , Ben‐Yosef Erez
Published: December 2019

Detection of subsurface features using geophysical methods is an important component of archaeological research. Most geophysical methods suffer from loss of resolution with depth and are most successful when employed on hyper‐shallow targets. We present a novel imaging method that utilizes summation of diffracted seismic energy in the depth domain to image the subsurface and detect areas of material contrasts, which is especially useful for detecting subsurface voids. The diffraction imaging (DI) method was validated in a synthetic case and in two archaeological sites where known ancient tunnels exist and then employed in the ancient copper ore district of Timna Valley (southern Israel). The results demonstrate the feasibility of the DI method to detect ancient underground mining galleries that connected between (now blocked) mining shafts, which in turn constitutes a significant contribution to the study of ancient prospection and mining technologies and related social and historical aspects.
Co‐contributorship network and division of labor in individual scientific collaborations
Authors: Lu Chao , Zhang Yingyi , Ahn Yong‐Yeol , Ding Ying , Zhang Chenwei , Ma Dandan
Published: December 2019

Collaborations are pervasive in current science. Collaborations have been studied and encouraged in many disciplines. However, little is known about how a team really functions from the detailed division of labor within. In this research, we investigate the patterns of scientific collaboration and division of labor within individual scholarly articles by analyzing their co‐contributorship networks. Co‐contributorship networks are constructed by performing the one‐mode projection of the author–task bipartite networks obtained from 138,787 articles published in PLoS journals. Given an article, we define 3 types of contributors: Specialists, Team‐players, and Versatiles. Specialists are those who contribute to all their tasks alone; team‐players are those who contribute to every task with other collaborators; and versatiles are those who do both. We find that team‐players are the majority and they tend to contribute to the 5 most common tasks as expected, such as “data analysis” and “performing experiments.” The specialists and versatiles are more prevalent than expected by our designed 2 null models. Versatiles tend to be senior authors associated with funding and supervision. Specialists are associated with 2 contrasting roles: the supervising role as team leaders or marginal and specialized contributors.
Social and Object Attention Is Influenced by Biological Sex and Toy Gender‐Congruence in Children With and Without Autism
Authors: Harrop Clare , Jones Desiree R. , Sasson Noah J. , Zheng Shuting , Nowell Sallie W. , Parish‐Morris Julia
Published: December 2019

Emerging research suggests social attention in autism spectrum disorder (ASD) girls is enhanced relative to ASD boys but may also be affected by the type of social and nonsocial content presented. This study examined how biological sex and gender norms interact to influence visual attention in 79 school‐aged children observing scenes that included gender‐associated toys and actors of both sexes. Attention to social (faces) and object activity (hands with toys) stimuli was measured. Previously described distinctions between social attention in ASD boys and girls were replicated, with ASD girls looking more at faces than ASD boys. Irrespective of diagnosis, males and females attended more to actors that shared their same sex, and attended more to toys with gender‐associations that were consistent with their own sex, suggesting that social and object salience increases for children under sex‐consistent conditions. Importantly, ASD and typically developing (TD) children increased their gaze to faces when male actors were shown playing with female‐associated toys, suggesting that both groups of children are sensitive to societal messages about the acceptability of males playing with female‐associated toys. Our findings provide further evidence of heightened attention to faces in ASD girls relative to ASD boys, and indicate that social attention in ASD and TD children is influenced by who (male or female actor) and what (male‐ or female‐associated toy) is being observed. Collectively, these results present a nuanced profile of attention in ASD that adds to a growing body of research indicating subtle phenotypic differences in ASD girls that may impact identification, assessment, and intervention. Autism Res 2020, 13: 763–776.. © 2019 International Society for Autism Research, Wiley Periodicals, Inc.

Lay Summary

Sex differences observed in typical development may also be present in individuals with autism. In this study, we developed an eye‐tracking paradigm featuring videos of boys and girls playing with toys that varied in their gender associations. Attention to faces differed between autistic and non‐autistic children but was also influenced by the sex of the actor and gender‐association of toys. Autistic females demonstrated subtle attention differences that distinguished them from autistic males and may influence referral, diagnosis, and intervention.
Systematic review of the introduction and evaluation of magnetic augmentation of the lower oesophageal sphincter for gastro-oesophageal reflux disease
Authors: Kirkham E N , Main B G , Jones K J B , Blazeby J M , Blencowe N S
Published: December 2019

Background

Magnetic sphincter augmentation (MSA) is reported to be an innovative alternative to antireflux surgery for patients with gastro-oesophageal reflux disease. Although used in practice, little is known about how it has been evaluated. This study aimed to systematically summarize and appraise the reporting of MSA and its introduction into clinical practice, in the context of guidelines (such as IDEAL) for evaluating innovative surgical devices.

Methods

Systematic searches were used to identify all published studies reporting MSA insertion. Data collected included patient selection, governance arrangements, surgeon expertise, technique description and outcome reporting.

Results

Searches identified 587 abstracts; 39 full-text papers were included (1 RCT 5 cohort, 3 case–control, 25 case series, 5 case reports). Twenty-one followed US Food and Drug Administration eligibility criteria for MSA insertion. Twenty-six documented that ethical approval was obtained. Two reported that participating surgeons received training in MSA; 18 provided information about how MSA insertion was performed, although techniques varied between studies. Follow-up ranged from 4 weeks to 5 years; in 14 studies, it was less than 1 year.

Conclusion

Most studies on MSA lacked information about patient selection, governance, expertise, techniques and outcomes, or varied between studies. Currently, MSA is being used despite a lack of robust evidence for its effectiveness.
Identification of Vaccinia‐H1 Related Phosphatase as an Anticancer Target for 1,2,3,4,6‐O‐Pentagalloylglucose
Authors: Yoon Sun‐Young , Kim Do‐Hwi , Min Roh Kyung , Ahn Dohee , Jin Kang Hyo , Chung Sang J.
Published: December 2019

Protein tyrosine phosphatases are involved in diverse human diseases, including cancer, diabetes and inflammatory disorders. Loss of Vaccinia‐H1 related phosphatase (VHR) has been shown to arrest at the G1‐S and G2‐M transitions of the cell cycle, and to increases cell death of prostate cancer cells through JNK activation, suggesting that VHR can be considered as an anticancer target. In this study, 658 natural products were screened through in vitro enzyme assay to identify VHR inhibitor. Among the VHR‐inhibitory compounds, 1,2,3,4,6‐O‐pentagalloylglucose (PGG) was selected for further study as it has been reported to show antitumor effects against tumor model mice, but its direct target has not been identified. PGG inhibited the catalytic activity of VHR (Ki=53 nm) in vitro. Furthermore, the incubation of HeLa cervical cancer cells with PGG dramatically decreased cell viability and markedly increased the protein levels of the cleaved PARP, a hallmark of apoptosis. In addition, treatment of HeLa cells with PGG significantly reduced the protein levels of cyclin D1, Bcl‐2 and STAT3 phosphorylation. Taken together, these results suggest that PGG could be a potential therapeutic candidate for the treatment of cervical cancer through VHR inhibition.
Barriers to use of radial access for percutaneous coronary intervention
Authors: Riangwiwat Tanawan , Mumtaz Tayebah , Blankenship James C.
Published: December 2019

Objectives

The aim of this study was to identify barriers to transradial access percutaneous coronary intervention (PCI).

Background

Transradial access yields fewer vascular complications, earlier ambulation, and more patient comfort. However, the adoption to practice is slow, and transfemoral access is still commonly used.

Methods

We identified all PCIs done by one operator in a radial‐first trainee‐driven practice. The individual charts were reviewed for all PCIs using femoral access. Reasons for not using radial access were identified. Descriptive statistics were used to report reasons for not using transradial access. Analyses were performed on a per‐procedure basis.

Results

Of 1,948 PCIs, 1,790 (92%) were via radial access and 158 (8%) via femoral access. Femoral access was used to bail out unsuccessful radial access in 21 PCIs (13% of all femoral PCIs, 1% of all PCIs). Radial access was unsuccessful due to failure to cannulate radial artery, radial artery spasm, and radial loop in majority of radial access failure PCIs (n = 13). Femoral access was used as a primary strategy in 137 PCIs (87% of all femoral PCIs, 7% of all PCIs), mostly due to undetectable radial artery pulse (both left and right) (n = 40).

Conclusions

Radial access can be used for PCI safely and effectively. Inadequate radial pulse is the main barrier. Adjunctive strategies such as ulnar access and use of ultrasound may further increase the success rate of arterial access from the upper extremities.
Duration of dual antiplatelet therapy in elective drug‐coated balloon angioplasty
Authors: Corballis Natasha H. , Wickramarachchi Upul , Vassiliou Vassilios S. , Eccleshall Simon C.
Published: December 2019

Objectives

We sought to answer whether 1‐month duration of dual antiplatelet therapy (DAPT) is safe after elective drug‐coated balloon only (DCB) angioplasty.

Background

The duration of DAPT after elective DCB was called into question after the ESC Focused DAPT Update of 2017. Until then, a 1‐month duration of DAPT was considered safe by national consensus groups (German, Italian, and Chinese) supported by data from prospective worldwide registries.

The ESC Guidelines recommended a 6‐month duration of DAPT based on evidence from in‐stent restenosis randomized controlled trials only.

Methods

Retrospective, real‐world population, single‐center analysis conducted from January 1, 2012 to March 31, 2017 in a high‐volume, tertiary PCI center. Consecutive patients receiving 1‐month duration of DAPT after elective DCB angioplasty were included. We identified a primary composite outcome of cardiac death, myocardial infarction and target lesion revascularization at 6‐months.

Results

A total of 303 patients (78.5% male) with mean age of 67 ± 12.5 were included. This incorporated 86.1% de novo lesions and 56.5% nonsmall (≥3 mm diameter) coronary arteries treated. There were no reported outcomes of lesion thrombosis, target vessel MI, target lesion revascularization or cardiac death at 6‐months. There were two (0.6%) nontarget vessel MIs and one (0.3%) noncardiac death.

Conclusion

One‐month duration of DAPT appears safe after elective DCB‐only angioplasty, highlighting this strategy for patients at high‐risk of bleeding. These results also show favorable clinical outcomes for de novo coronary artery disease and nonsmall coronary arteries treated with DCB‐only angioplasty. A 1‐month duration of DAPT appears a safe and attractive option.
Early clinical and procedural outcomes in large series of 34‐mm self‐expanding transcatheter aortic valve replacement
Authors: Ali Zuber , Sharma Payal , Mengesha Tadele , Dalmar Ahmed , Ammar Khawaja Afzal , Allaqaband Suhail Q. , O'Hair Daniel P. , Khandheria Bijoy K. , Jain Renuka , Bajwa Tanvir
Published: December 2019

Objectives

We aimed to evaluate early clinical and procedural outcomes with the 34‐mm Evolut R transcatheter aortic valve replacement (TAVR) prosthesis.

Background

The 34‐mm Evolut R (Medtronic, Minneapolis, MN) self‐expanding TAVR prosthesis was designed to treat patients with larger annuli.

Methods

Clinical, demographic, procedural, and echocardiographic data on consecutive patients who underwent TAVR with a 34‐mm Evolut R prosthesis at our institution were collected and analyzed.

Results

One hundred ninety‐six patients underwent TAVR with this prosthesis from November 2016 to July 2018, a majority (n = 188, 96%) through transfemoral access and with conscious sedation (n = 182, 93%). Mean age, Society of Thoracic Surgery risk score, and follow‐up were 82 ± 8 years, 5.4 ± 5%, and 8.2 ± 5.3 months, respectively. Mean aortic valve (AV) peak velocity was 4.0 ± 0.6 m/s, mean AV gradient was 38 ± 13 mmHg, AV area was 0.79 ± 0.23 cm2; calcium score was 3,503 ± 1,970 Agatston units, and perimeter was 85 ± 4.3 mm. Device implantation was successful in all but one patient. Postprocedure mean AV peak velocity, AV mean gradient, and AV area were 1.9 ± 0.4 m/s, 7 ± 3 mmHg, and 2.6 ± 0.7 cm2, respectively. New pacemaker requirement rate was 16%, and moderate paravalvular leak was present in six patients (3%), which improved to mild in three patients at 6‐month follow‐up. In‐hospital, 30‐day, 6‐month, and 12‐month survival rates were 98%, 96% (hospital discharge), 96% (30‐day), 89% (6‐month), and 83% (12‐month).

Conclusion

These data demonstrate high success and good procedural, echocardiographic, and clinical outcomes of 34‐mm Evolut R in patients with large annuli.
Nitrogen‐Doped Hard Carbon on Nickel Foam as Free‐Standing Anodes for High‐Performance Sodium‐Ion Batteries
Authors: Li Ruizi , Huang Jianfeng , Li Jiayin , Cao Liyun , Luo Yijia , He Yuanyuan , Lu Guoxing , Yu Aimin , Chen Shaoyi
Published: December 2019

Nitrogen‐doped hard carbon on Ni foam (NC/NF) with numerous active sites, expanded interlayer distance (0.49 nm), and highly ordered pseudo‐graphic structure is synthesized by a melamine‐assisted hydrothermal pretreatment and subsequent pyrolysis procedure. The high content configurations of pyrrolic‐nitrogen and pyridinic‐nitrogen in NC/NF could provide abundant active sites and defects for efficient Na+ adsorption/desorption and improved transport kinetics. The obvious flocculent structures on carbon surface, corresponding to the highly ordered pseudo‐graphic structure, could enhance the transport kinetics for electrons. The strong electrostatic repulsion of pyrrolic‐nitrogen could expand interlayer distance, facilitating Na+ insertion/extraction process. The balance between high nitrogen content and sufficient graphitization degree comes into strong carbon frameworks with enhanced structural stability and electronic conductivity. When served as free‐standing anodes for sodium‐ion batteries (SIBs), NC/NF presents high rate capability of 128.5 mAh g−1 at 10 A g−1, and excellent cycling stability of 225.4 mAh g−1 after 1000 cycles under high current density of 5 A g−1. These results demonstrate a new light to prepare advanced anodes for SIBs.
Design of High‐Performance Co‐Based Alloy Nanocatalysts for the Oxygen Reduction Reaction
Authors: Zhao Zheng , Xu Haoxiang , Feng Zongyu , Zhang Yongqi , Cui Meisheng , Cao Dapeng , Cheng Daojian
Published: December 2019

Co‐based nanoalloys show potential applications as nanocatalysts for the oxygen reduction reaction (ORR), but improving their activity is still a great challenge. In this paper, a strategy is proposed to design efficient Co‐M (M=Au, Ag, Pd, Pt, Ir, and Rh) nanoalloys as ORR catalysts by using density functional theory (DFT) calculations. Through the Sabatier analysis, the overpotential as a function of ΔGOH* is identified as a quantitative descriptor for analyzing the effect of dopants and atomic structures on the activity of the Co‐based nanoalloys. By adopting the suitable dopants and atomic structures, ΔGOH* accompanied by overpotential could be adjusted to the optimal range to enhance the activity of the Co‐based nanoalloys. With this strategy, the core–shell structured Ag42Co13 nanoalloy is predicted to have the highest catalytic activity for ORR among these Co‐based nanoalloys. To give a deeper insight into the properties of Ag‐Co nanoalloys, the structure, thermal stability, and reaction mechanism of Ag‐Co nanoalloys with different compositions are also studied by using molecular simulations and DFT calculations. It is found that core–shell Ag42Co13 exhibits the highest structural and thermal stability among these Ag‐Co nanoalloys. In addition, the core–shell Ag42Co13 shows the lowest ORR reaction energy barriers among these Ag‐Co nanoalloys. It is expected that this kind of strategy could provide a viable way to design highly efficient heterogeneous catalysts in extensive applications.
Titanium‐Catalyzed Hydroaminoalkylation of Ethylene
Authors: Rosien Michael , Töben Iris , Schmidtmann Marc , Beckhaus Rüdiger , Doye Sven
Published: December 2019

The first examples of titanium‐catalyzed hydroaminoalkylation reactions of ethylene with secondary amines are presented. The reactions can be achieved with various titanium catalysts and they do not require the use of high pressure equipment. In addition, the first solid‐state structure of a titanapyrrolidine that is formed by insertion of an alkene into the Ti−C bond of a titanaaziridine is reported.
Effect of Fe/Zn ratio in composite catalyst for synthesizing polyoxymethylene dimethyl ethers
Authors: Zhang Wujie , Li Xiangjun , Nawaz Muhammad A. , Pan Jiahao , Cao Jiancheng , Liu Dianhua
Published: December 2019

Polyoxymethylene dimethyl ethers (PODEn) are extremely effective diesel additives to reduce soot formation during combustion. We introduce a series of Fe‐Zn composite solid acid catalysts (SO42−/xFe2O3‐yZnO), for the condensation reaction of methanol and paraformaldehyde (PF) with a cheap and feasible route to efficiently synthesize PODEn. These catalysts were characterized by different characterization techniques, namely BET, XRD, SEM, EDS, FTIR, and NH3‐TPD and the results showed that Fe/Zn molar ratios strongly influenced the physicochemical characteristics of catalysts, thus affecting the methanol conversion and PODE1‐6 and PODE3‐6 selectivity. Accordingly, the methanol conversion was decreased and the selectivity of PODE3‐6 was increased after increasing the Zn molar content. Comparatively, SO42−/Fe2O3‐2ZnO exhibited superior catalytic activity among the various investigated catalysts due to the high acid density of strong acid sites. The optimal reaction conditions were observed to be at a 3.0 wt% catalyst loading (catalyst/reactant mass ratio), 2.5 hours ours of reaction time, a reaction temperature of 403 K, and a molar ratio of 3:1 of CH2O to methanol, achieving a high selectivity of 99.09% PODE1‐6 and 28.23% PODE3‐6 with 55.16% methanol conversion during the reaction.
Solubility of propane in N‐formyl morpholine
Authors: Jou Fang‐Yuan , Mather Alan E. , Schmidt Kurt A. G.
Published: December 2019

N‐formyl morpholine (NFM) is a solvent that has been used to separate acid gases from gas streams. An advantage of NFM is the high solubility of acid gases compared with the low solubility of light hydrocarbons. The solubility of the light hydrocarbons in NFM is important, as the hydrocarbons constitute a loss to the process, and result in hydrocarbon emissions to the atmosphere. However, there are only a few experimental data sets dealing with the solubility of hydrocarbons in NFM. To provide data to be used in the design of plants in the natural gas processing industry, the solubility of propane (C3H8) in NFM was measured at 298.15, 313.15, and 343.15 K at pressures up to 20.15 MPa. The Peng‐Robinson equation of state was employed to correlate the experimental data and to obtain binary interaction parameters. The binary interaction parameters were used to obtain the parameters of the Krichevsky‐Ilinskaya equation and Henry's law constants for propane were calculated. Henry's law constants for propane were compared with those of hydrogen sulphide, carbon dioxide, methane, and ethane in NFM.
In vitro optical characterization of dental resin composite aged in darkness
Authors: Mikhail Sarah S. , Johnston William M.
Published: December 2019

The overall objective of this study is to confirm the method of determining the accuracy of Kubelka‐Munk reflectance theory (KMRT) for composite materials after undergoing aging unrelated to surface exposure. The specific aims of this study include comparisons of optical characterizations for two dental resin composite materials before and after aging in darkness. Aging of five shades of two nanohybrid dental resin composite materials was accomplished under relatively normal room conditions in a dark enclosure for over 3 years. The accuracy of KMRT was assessed and optical absorption and scattering and color and translucency characterizations were performed. The magnitudes of the error of nonlinear regression of reflectance after aging to KMRT are well within the limits of expected measurement error as applied to regression analysis. The characterizations of inherent optical scattering, inherent color, and translucency indicate that aging in darkness will have some effect for at least some shades of the materials studied. KMRT is a reliable method to predict the reflectance of dental resin aged in darkness and permits subsequent clinically relevant optical characterizations of materials aged in this manner. Although changes in optical scattering were detected due to this aging, such changes appear to have a negligible clinical effect on color and translucency.
Autotuning of configuration for program execution in GPUs
Authors: Balaiah Thanasekhar , Parthasarathi Ranjani
Published: December 2019

Graphics Processing Units (GPUs) are used as accelerators for improving performance while executing highly data parallel applications. The GPUs are characterized by a number of Streaming Multiprocessors (SM) and a large number of cores within each SM. In addition to this, a hierarchy of memories with different latencies and sizes is present in the GPUs. The program execution in GPUs is thus dependent on a number of parameter values, both at compile time and runtime. To obtain the optimal performance with these GPU resources, a large parameter space is to be explored, and this leads to a number of unproductive program executions. To alleviate this difficulty, machine learning–based autotuning systems are proposed to predict the right configuration using a limited set of compile‐time parameters. In this paper, we propose a two‐stage machine learning–based autotuning framework using an expanded set of attributes. The important parameters such as block size, occupancy, eligible warps, and execution time are predicted. The mean relative error in prediction of different parameters ranges from of 16% to 6.5%. Dimensionality reduction for the features set reduces the features by up to 50% with further increase in prediction accuracy.
Physical deployment of enhanced visible light communication system using forward error correction codes
Authors: Khalid Arslan , Rashid Faizan , Muhammad Asif Hafiz , Ali Assad , Al‐Otaibi Sattam
Published: December 2019

With the development of new generation lighting sources, visible light communication (VLC) system has become a complementary solution to traditional radio frequency wireless system. However, the error performance of VLC system is degraded because of multipath effects and interference from other lighting sources that, in turn, reduce the communication range. This work targets the issue of performance degradation of VLC systems in terms of communication range and demonstrates a VLC system design that utilizes forward error correction (FEC) codes as the main tool to fix this issue. Furthermore, the work also covers practical implementation of the proposed VLC system using UART modules programmed in MATLAB. The hardware results demonstrate that the communication range of the proposed VLC system is enhanced up to 0.5 m. Over and above, it is also shown through simulations that the coding gain of the proposed design is more when compared with existing VLC system(s).
Synthesis and antimicrobial evaluation of piperic acid amides and their lower homologues
Authors: Achanta Prabhakar S. , Raj Sneha , Horam Soyar , Arockiaraj Jesu , Bobbala Ravi Kumar , Akkinepally Raghuram Rao , Pasupuleti Mukesh , Achanta Appa Rao V. N.
Published: December 2019

Seven piperic acid amides along with their lower homologs (12) were synthesized using HATU‐DIPEA coupling reagent. All the synthesized derivatives were evaluated for their antibacterial activities against Staphylococcus aureus, Pseudomonas aeruginosa, and vancomycin‐resistant P. aeruginosa. They were found to be more active on P. aeruginosa than on S. aureus. However, they did not exhibit potent activity on Vancomycin resistant P. aeruginosa. Among the tested compounds, methylenedioxycinnamic acid amide of anthranilic acid (MDCA‐AA, 2a) was found to be most active against S. aureus with MIC of 3.125 μg/ml. The PAS and INH amides of piperic acid were screened against Mycobacterium tuberculosis H37Ra strain. They were found to be most active among all the tested compounds but were found to be less active than the standard drug, isoniazid.
Heat tolerance and acclimation capacity in subterranean arthropods living under common and stable thermal conditions
Authors: Pallarés Susana , Colado Raquel , Pérez‐Fernández Toni , Wesener Thomas , Ribera Ignacio , Sánchez‐Fernández David
Published: December 2019

Cave‐dwelling ectotherms, which have evolved for millions of years under stable thermal conditions, could be expected to have adjusted their physiological limits to the narrow range of temperatures they experience and to be highly vulnerable to global warming. However, most of the few existing studies on thermal tolerance in subterranean invertebrates highlight that despite the fact that they show lower heat tolerance than most surface‐dwelling species, their upper thermal limits are generally not adjusted to ambient temperature. The question remains to what extent this pattern is common across subterranean invertebrates. We studied basal heat tolerance and its plasticity in four species of distant arthropod groups (Coleoptera, Diplopoda, and Collembola) with different evolutionary histories but under similar selection pressures, as they have been exposed to the same constant environmental conditions for a long time. Adults were exposed at different temperatures for 1 week to determine upper lethal temperatures. Then, individuals from previous sublethal treatments were transferred to a higher temperature to determine acclimation capacity. Upper lethal temperatures of three of the studied species were similar to those reported for other subterranean species (between 20 and 25°C) and widely exceeded the cave temperature (13–14°C). The diplopod species showed the highest long‐term heat tolerance detected so far for a troglobiont (i.e., obligate subterranean) species (median lethal temperature after 7 days exposure: 28°C) and a positive acclimation response. Our results agree with previous studies showing that heat tolerance in subterranean species is not determined by environmental conditions. Thus, subterranean species, even those living under similar climatic conditions, might be differently affected by global warming.
An Iodido‐Bridged Dimer of Cubane‐Type RuIr3S4 Cluster: Structural Rearrangement to New Octanuclear Core and Catalytic Reduction of Hydrazine
Authors: Seino Hidetake , Hirata Keiichi , Arai Yusuke , Jojo Risa , Okazaki Masaaki
Published: December 2019

Nitrogen‐fixing enzymes contain octanuclear metal–sulfur clusters at the active site, which are constructed on the basis of combined two cubic M4S3C skeletons. In this study, the dimer of cubane‐type RuIr3S4 cluster [{(Cp*Ir)3(µ3‐S)4Ru}2(µ2‐I)3]I (2: Cp* = η5‐C5Me5) was synthesized via oxidation of [(Cp*Ir)3(µ3‐S)4(CymRu)] (Cym = η6‐p‐iPrC6H4Me) with I2 followed by ligand exchange. Two cubane cores are bridged by three iodido ligands in 2, while these cubes are fused into a unique Ru2Ir6S8 framework by 2e‐reductuion to give [(Cp*Ir)6Ru2(µ3‐S)8][I]2. Addition of excess PhNHNH2 to 2 cleaved the dimer structure to form the hydrazine adduct of single cubane [(Cp*Ir)3(µ3‐S)4{RuI(NH2NHPh)2}]I. Reduction of N2H4 with Cp2Co and [HNEt3][BF4] was catalyzed by 2 in much higher rate than disproportionation of N2H4. The molecular structures of all new cluster compounds were characterized by X‐ray diffraction studies.