bluuebunny/crossref_metadata_2025 huggingface dataset:
NixCo3‐xO4 Nanoneedle Arrays Grown on Ni Foam as an Efficient Bifunctional Electrocatalyst for Full Water Splitting
Authors: Bao Jian , Liu Wenjun , Xie Junfeng , Xu Li , Guan Meili , Lei Fengcai , Zhao Yan , Huang Yunpeng , Xia Jiexiang , Li Huaming
Published: January 2019

Developing highly active, stable and robust electrocatalysts based on earth‐abundant elements for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is important for many renewable energy conversion processes. Herein, NixCo3‐xO4 nanoneedle arrays grown on 3D porous nickel foam (NF) was synthesized as a bifunctional electrocatalyst with OER and HER activity for full water splitting. Benefiting from the advantageous structure, the composite exhibits superior OER activity with an overpotential of 320 mV achieving the current density of 10 mA cm−2. An exceptional HER activity is also acquired with an overpotential of 170 mV at the current density of 10 mA cm−2. Furthermore, the catalyst also shows the superior activity and stability for 20 h when used in the overall water splitting cell. Thus, the hierarchical 3D structure composed of the 1D nanoneedle structure in NixCo3‐xO4/NF represents an avenue to design and develop highly active and bifunctional electrocatalysts for promising energy conversion.
X‐Shaped Polycyclic Aromatic Hydrocarbons: Optical Properties and Tunable Assembly Ability
Authors: Li Yongjun , Zhou Weixiang , Shen Han , Gu Yanan , Li Yuliang
Published: January 2019

Although a number of synthetic methodologies have been developed to prepare stable polycyclic aromatic hydrocarbons (PAHs), much less research has been devoted to functionalizing the peripheries of molecules to tune the self‐assembly ability or introduce functional groups without altering their photophysical properties. Herein, we report twisted “X”‐shaped molecules prepared through annulation of hexacene with benzoanthracene on the zigzag edge, and an investigation of their photophysical properties and self‐assembly properties. The shape‐complementary “X”‐shaped molecules prefer to dimerize, while the π‐extension would lead to one‐dimensional π‐stacking. Our findings give some insights into the design of stable PAHs without disturbing the electronic structures.
The PROTAC technology in drug development
Authors: Zou Yutian , Ma Danhui , Wang Yinyin
Published: January 2019

Currently, a new technology termed PROTAC, proteolysis targeting chimera, has been developed for inducing the protein degradation by a targeting molecule. This technology takes advantage of a moiety of targeted protein and a moiety of recognizing E3 ubiquitin ligase and produces a hybrid molecule to specifically knock down a targeted protein. During the first decade, three pedigreed groups worked on the development of this technology. To date, this technology has been extended by different groups, aiming to develop new drugs against different diseases including cancers. This review summarizes the contributions of the groups for the development of PROTAC.

Significance of the study

This review summarized the development of the PROTAC technology for readers and also presented the author's opinions on the application of the technology in tumor therapy.
A Metal‐Doped Fungi‐Based Biomaterial for Advanced Electrocatalysis
Authors: Krejčová Ludmila , Leonhardt Terza , Novotný Filip , Bartůněk Vilém , Mazánek Vlastimil , Sedmidubský David , Sofer Zdeněk , Pumera Martin
Published: January 2019

Nature and its highly sophisticated biomaterials are an endless source of inspiration for engineers and scientists across a wide range of disciplines. During the last decade, concepts of bioinspired synthesis of hierarchically structured nano‐ and micromaterials have been attracting increasing attention. In this article, we have utilized the natural ability of fungi to absorb metal ions for a bioinspired synthesis of carbonaceous material doped by selected transition metals. As an all‐around metal accumulator, Hebeloma mesophaeum was selected, and it was cultivated in the presence of three transition‐metal ions: NiII, FeII, and MnII. The metal‐doped carbonized biomaterial possessed enhanced catalytic activity toward hydrazine oxidation, oxygen reduction, and cumene hydroperoxide reduction. Thus, we have shown possible transformation of a waste product (fungi grown on a contaminated soil) into a value‐added carbonaceous material with tailored catalytic properties. This bioinspired synthesis can outline an attractive route for the fabrication of catalysts for important industrial applications on a large scale.
Difluorodiazoethane (CF2HCHN2): A New Reagent for the Introduction of the Difluoromethyl Group
Authors: Mykhailiuk Pavel K. , Koenigs Rene M.
Published: January 2019

Difluorodiazoethane (CF2HCHN2) is a small reactive diazoalkane. Its synthesis has been pursued since the 1970s, although only in the past three years have considerable advances been made. Today, difluorodiazoethane is a versatile reagent applied in [3+2]‐cycloadditions, esterification, and carbene transfer reactions. Difluorodiazoethane possesses markedly altered reactivity compared to the well‐studied trifluorodiazoethane (CF3CHN2). In this article, we discuss the differences between the two reagents: CF2HCHN2 and CF3CHN2. We highlight applications of difluorodiazoethane in organic synthesis, discuss bench‐stable analogues, and its unexplored areas.
Understanding Silica from the Viewpoint of Asymmetry
Authors: Jin Ren‐Hua
Published: January 2019

Silica is abundant in the Earth's crust, and silicate materials are used on the global scale, from industrial products for architecture, vehicles, electronics, and optics to consumption as foods, medicines, supplements, and cosmetics. Silica has become increasingly important in current science and technology, as seen in the components of advanced materials. The characteristic formula of silica is very simply often expressed as SiO2. However, it is difficult to draw silica precisely owing to its intricate chemical structures. We need to make a greater effort in understanding silica, even though silica chemistry has existed for over 200 years. Similar to the homochirality observed in natural amino acids, natural silica of quartz is chiral, and in some sense, the origin of life with chirality might be partly related to quartz‐like silica chirality. This review focuses on the asymmetry of silica from the view of the formation of irregular tetrahedron structures of SiO4. Silica is composed of several repeated tetrahedron units of SiO4, leading to the formation of inorganic polymers with divergently expanded 3D structures. In this large polymeric skeleton, not every unit of SiO4 can maintain an ideal tetrahedron, and thus, it becomes twisted. The twisting results in an asymmetric point on the Si atom, leading silica to become racemic in the stereochemical sense. Therefore, enantioselective preparation of silica should endow silica with chirality through the silica skeleton. Some recent achievements exhibit that silica is an effective chiral material and has great potential for transferring chirality from silica to other matter.
Fluorogenic Detection and Characterization of Proteins by Aggregation‐Induced Emission Methods
Authors: Xie Sheng , Wong Alex Y. H. , Chen Sijie , Tang Ben Zhong
Published: January 2019

Protein is one of the four most important biomacromolecules in living systems. The detection, quantification, localization, and characterization of proteins is essential for an understanding of biological fundamentals, as well as for the diagnostics and treatment of protein‐related diseases. By using intrinsic and extrinsic fluorescence, different techniques have been established to study proteins, many of which are now being routinely used in research laboratories and clinics. This review summarizes the applications of aggregation‐induced emission (AIE) fluorescence in protein science. In contrast to traditional fluorescent dyes, the activation of AIE dyes is mainly attributed to the restriction of intramolecular motions. This unique turn‐on mechanism of AIE dyes allows researchers to develop novel fluorogenic strategies for sensitive, selective, and reliable analysis of proteins. This review focuses on introducing AIE strategies for 1) detection, localization, and quantification of proteins; 2) probing polymer conformational transitions of proteins; 3) characterization of protein–ligand interactions; and 4) evaluation of enzyme activities. Perspectives and challenges with respect to this emerging field of protein characterization are offered.
Stereochemical Insights into the Anaerobic Degradation of 4‐Isopropylbenzoyl‐CoA in the Denitrifying Bacterium Strain pCyN1
Authors: Küppers Julian , Becker Patrick , Jarling René , Dörries Marvin , Cakić Nevenka , Schmidtmann Marc , Christoffers Jens , Rabus Ralf , Wilkes Heinz
Published: January 2019

The constitutions and absolute configurations of two previously unknown intermediates, (1S,2S,4S)‐2‐hydroxy‐4‐isopropylcyclohexane‐1‐carboxylate and (S)‐3‐isopropylpimelate, of anaerobic degradation of p‐cymene in the bacterium Aromatoleum aromaticum pCyN1 are reported. These intermediates (as CoA esters) are involved in the further degradation of 4‐isopropylbenzoyl‐CoA formed by methyl group hydroxylation and subsequent oxidation of p‐cymene. Proteogenomics indicated 4‐isopropylbenzoyl‐CoA degradation involves (i) a novel member of class I benzoyl‐CoA reductase (BCR) as known from Thauera aromatica K172 and (ii) a modified β‐oxidation pathway yielding 3‐isopropylpimeloyl‐CoA analogously to benzoyl‐CoA degradation in Rhodopseudomonas palustris. Reference standards of all four diastereoisomers of 2‐hydroxy‐4‐isopropylcyclohexane‐1‐carboxylate as well as both enantiomers of 3‐isopropylpimelate were obtained by stereoselective syntheses via methyl 4‐isopropyl‐2‐oxocyclohexane‐1‐carboxylate. The stereogenic center carrying the isopropyl group was established using a rhodium‐catalyzed asymmetric conjugate addition. X‐ray crystallography revealed that the thermodynamically most stable stereoisomer of 2‐hydroxy‐4‐isopropylcyclohexane‐1‐carboxylate is formed during p‐cymene degradation. Our findings imply that the reductive dearomatization of 4‐isopropylbenzoyl‐CoA by the BCR of A. aromaticum pCyN1 stereospecifically forms (S)‐4‐isopropyl‐1,5‐cyclohexadiene‐1‐carbonyl‐CoA.
Spin‐State Variations of Iron(III) Complexes with Tetracarbene Macrocycles
Authors: Schremmer Claudia , Cordes (née Kupper) Claudia , Klawitter Iris , Bergner Marie , Schiewer Christine E. , Dechert Sebastian , Demeshko Serhiy , John Michael , Meyer Franc
Published: January 2019

Starting from their six‐coordinate iron(II) precursor complexes [L8RFe(MeCN)]2+, a series of iron(III) complexes of the known macrocyclic tetracarbene ligand L8H and its new octamethylated derivative L8Me, both providing four imidazol‐2‐yliden donors, were synthesized. Several five‐ and six‐coordinate iron(III) complexes with different axial ligands (Cl−, OTf−, MeCN) were structurally characterized by X‐ray diffraction and analyzed in detail with respect to their spin state variations, using a bouquet of spectroscopic methods (NMR, UV/Vis, EPR, and 57Fe Mößbauer). Depending on the axial ligands, either low‐spin (S=1/2) or intermediate‐spin (S=3/2) states were observed, whereas high‐spin (S=5/2) states were inaccessible because of the extremely strong in‐plane σ‐donor character of the macrocyclic tetracarbene ligands. These findings are reminiscent of the spin state patterns of topologically related ferric porphyrin complexes. The ring conformations and dynamics of the macrocyclic tetracarbene ligands in their iron(II), iron(III) and μ‐oxo diiron(III) complexes were also studied.
Copper‐Photocatalyzed Borylation of Organic Halides under Batch and Continuous‐Flow Conditions
Authors: Nitelet Antoine , Thevenet Damien , Schiavi Bruno , Hardouin Christophe , Fournier Jean , Tamion Rodolphe , Pannecoucke Xavier , Jubault Philippe , Poisson Thomas
Published: January 2019

The copper‐photocatalyzed borylation of aryl, heteroaryl, vinyl and alkyl halides (I and Br) was reported. The reaction proceeded using a new heteroleptic Cu complex under irradiation with blue LEDs, giving the corresponding boronic‐acid esters in good to excellent yields. The reaction was extended to continuous‐flow conditions to allow an easy scale‐up. The mechanism of the reaction was studied and a mechanism based on a reductive quenching (CuI/CuI*/Cu0) was suggested.
Transition‐Metal‐Induced Rearrangement of [(PhSn)4S6] Towards Ternary CuI/Sn/S or CuII/Sn/S Clusters
Authors: Dornsiepen Eike , Weigend Florian , Dehnen Stefanie
Published: January 2019

Direct access of ternary copper‐tin sulfide clusters by reactions of a binary organotin sulfide cluster, [(PhSn)4S6] (A), with transition metal complexes was achieved for the first time without extra addition of further chalcogenide sources. This indicates that an in situ rearrangement of the inorganic core takes place even without initial formation of anionic fragments. The use of [Cu(PPh3)3Cl] or [Cu(PPh3)2Cl2] as reactants yielded the ternary clusters [(CuPPh3)4(PhSn)18Cu6S31Cl2] (1) and [{Cu(PPh3)2}2(PhSn)3(SnCl)S8] (2), respectively. Whereas 1 represents the largest neutral Cu/Sn/S cluster known to date, compound 2, which is the first example of a ternary Cu/Sn/E (E=S, Se) cluster containing copper in the +II oxidation state, may be viewed as a very early stage of cluster formation. Apparently, the presence of CuII inhibits effective cluster growth, which rationalizes the lack of such species so far. The two ternary clusters exhibit very similar optical absorption energies despite their markedly different cluster sizes. According to time‐dependent DFT calculations, this is due to different characters of the electronic excitation in the triplet compound 2, as compared to the excitation of the closed shell cluster 1, which serve to compensate for the different extensions of the clusters.
Synthesis of Long‐Chain β‐Lactones and Their Antibacterial Activities against Pathogenic Mycobacteria
Authors: Santucci Pierre , Dedaki Christina , Athanasoulis Alexandros , Gallorini Laura , Munoz Anaïs , Canaan Stéphane , Cavalier Jean‐François , Magrioti Victoria
Published: January 2019

In the quest for new antibacterial agents, a series of novel long‐ and medium‐chain mono‐ and disubstituted β‐lactones was developed. Their activity against three pathogenic mycobacteria—M. abscessus,M. marinum, andM. tuberculosis—was assessed by the resazurin microtiter assay (REMA). Among the 16 β‐lactones synthesized, only 3‐hexadecyloxetan‐2‐one (VM005) exhibited promising activity againstM. abscessus, whereas most of the β‐lactones showed interesting activities againstM. marinum, similar to that of the classical antibiotic, isoniazid. RegardingM. tuberculosis, six compounds were found to be active against this mycobacterium, with β‐lactone VM008 [trans‐(Z)‐3‐(hexadec‐7‐en‐1‐yl)‐4‐propyloxetan‐2‐one] being the best growth inhibitor. The promising antibacterial activities of the best compounds in this series suggest that these molecules may serve as leads for the development of much more efficient antimycobacterial agents.
Coupled actuators with a mechanically synchronized phase during MR elastography: A phantom feasibility study
Authors: Neumann Wiebke , Lehnart Vanessa R. , Vetter Yannik , Bichert Andreas , Schad Lothar R. , Zöllner Frank G.
Published: January 2019

Introduction

Magnetic resonance elastography (MRE) is an MR imaging method for the quantification of spatial stiffness of soft tissues using mechanically induced dynamic shear waves. In some applications, the penetration of shear waves can be limited through attenuation and shadowing of the waves. In order to increase the actuator performance, we present a dual driver approach to compensate for shear wave attenuation and to achieve better coverage over the entire region of interest.

Materials and Methods

(a) We designed pneumatic turbines that created a sinusoidal centrifugal force due to an eccentric weight. Two turbines were connected in‐phase with each eccentric weight having the same angular position relative to its pivot point. (b) We developed a tissue elasticity mimicking abdominal phantom. (c) The phantom served as a test object to investigate the feasibility to generate shear waves at two surface origins with the dual actuator system and to compare it against a single actuation setup.

Results and Discussion

A stable phase relationship of the shear waves generated by the turbines was achieved as the positions of the eccentric weights were mechanically fixed. The abdominal phantom yielded sufficient MR signal. Liver and rib cage were clearly visible in MR imaging. The shear waves generated by the dual turbine propagated through the region of interest. Our turbine design is reproducible through 3D printing and can be integrated into existing clinical equipment for 1.5 T and 3 T scanners.
Are we meeting the informational needs of cancer patients and families? Perception of physician communication in pediatric oncology
Authors: Levine Deena R. , Liederbach Erik , Johnson Liza‐Marie , Kaye Erica C. , Spraker‐Perlman Holly , Mandrell Belinda , Pritchard Michele , Sykes April , Lu Zhaohua , Wendler Dave , Baker Justin N.
Published: January 2019

Background

High‐quality oncology care is marked by skillful communication, yet little is known about patient and family communication perceptions or content preferences. Our study sought to elicit pediatric oncology patient and parent perceptions of early cancer communication to establish whether informational needs were met and identify opportunities for enhanced communication throughout cancer care.

Method

An original survey instrument was developed, pretested, and administered to 129 patients, age 10‐18 years, and their parents at 3 cancer centers between 2011 and 2015. Statistical analysis of survey items about perceived communication, related associations, and patient/parent concordance was performed.

Results

A greater percentage of participants reported “a lot” of discussion about the physical impact of cancer (patients, 58.1% [n = 75]; parents, 69.8% [n = 90]) compared with impact on quality of life (QOL) (patients, 44.2% [n = 57]; parents, 55.8% [n = 72]) or emotional impact (patients, 31.8% [n = 41]; parents, 43.4% [n = 56]). One fifth of patients (20.9% [n = 27]) reported they had no up‐front discussion about the emotional impact of cancer treatment. Parents indicated a desire for increased discussion regarding impact on family life (27.9% [n = 36]), long‐term QOL (27.9% [n = 36]), and daily activities (20.2% [n = 26]). Patients more frequently than parents indicated a desire for increased physician/patient discussion around the impact on daily activities (patients, 40.3% [n = 52]; parents, 21.7% [n = 28]; P < .001), long‐term QOL (patients, 34.9% [n = 45]; parents, 16.3% [n = 21]; P < .001), pain management (patients, 23.3% [n = 30]; parents, 7% [n = 9]; P < .001), physical symptom management (patients, 24% [n = 31]; parents, 7.8% [n = 10]; P < .001), short‐term QOL (patients, 23.3% [n = 30]; parents, 9.3% [n = 12]; P = .001), and curative potential (patients, 21.7% [n = 28]; parents, 8.5% [n = 11]; P = .002, P values calculated using McNemar’s test).

Conclusion

Oncologists may not be meeting the informational needs of many patients and some parents/caregivers. Communication could be enhanced through increased direct physician–patient communication, as well as proactive discussion of emotional symptoms and impact of cancer on QOL.
Proton Relaxometry of Long‐Lived Spin Order
Authors: Kiryutin Alexey S. , Panov Mikhail S. , Yurkovskaya Alexandra V. , Ivanov Konstantin L. , Bodenhausen Geoffrey
Published: January 2019

A study of long‐lived spin order in chlorothiophene carboxylates at both high and low magnetic fields is presented. Careful sample preparation (removal of dissolved oxygen in solution, chelating of paramagnetic impurities, reduction of convection) allows one to obtain very long‐lived singlet order of the two coupled protons in chlorothiophene derivatives, having lifetimes of about 130 s in D2O and 240 s in deuterated methanol, which are much longer than the T1‐relaxation times (18 and 30 s, respectively, at a field
=9.4 T). In protonated solvents the relaxation times become shorter, but the lifetime is still substantially longer than
. In addition, long‐lived coherences are shown to have lifetimes as long as 30 s. Thiophene derivatives can be used as molecular tags to study slow transport, slow dynamics and slow chemical processes, as has been shown in recent years.
Computational Electrochemistry of Water Oxidation on Metal‐Doped and Metal‐Supported Defective h‐BN
Authors: Perilli Daniele , Selli Daniele , Liu Hongsheng , Di Valentin Cristiana
Published: January 2019

Metal‐doped and metal‐supported two‐dimensional materials are attracting a lot of interest as potentially active electrocatalysts for reduction and oxidation processes. Previously, when a non‐regular 2 D h‐BN layer was grown on a Cu(111) surface, metal adatoms were found to spontaneously emerge from the bulk to fill the atomic holes in the structure and become available for surface catalysis. Herein, computational electrochemistry is used to investigate and compare the performance of Cu‐doped and Cu‐supported pristine and defective h‐BN systems for the electrocatalytic water oxidation reaction. For the various model systems, the intermediate species of this multistep oxidation process are identified and the free‐energy variations for each step of reaction are computed, even for those steps that do not involve an electron or a proton transfer. Both associative and O2 direct evolution mechanisms are considered. On this thermodynamic basis, the potential‐determining step, the thermodynamic‐determining step, and consequently the theoretical overpotential are determined for comparison with experiments. Small Cu clusters (tetramers) trapped in the h‐BN defective lattice on a Cu(111) support are found to be very active for the water oxidation reaction since such systems are characterized by a low overpotential and by a small energy cost for O2 release from the catalyst, which is often observed to be a major limit for other potential electrocatalysts.
Pyridinic Nitrogen‐Doped Graphene Nanoshells Boost the Catalytic Efficiency of Palladium Nanoparticles for the N‐Allylation Reaction
Authors: Li Xinxin , Zhao Qingshan , Feng Xiang , Pan Lei , Wu Zhuangzhuang , Wu Xiaocui , Ma Tianwen , Liu Jialiang , Pan Yuanyuan , Song Yan , Wu Mingbo
Published: January 2019

In this study, nitrogen‐doped graphene nanoshells (N‐GNS) were developed to support palladium nanoparticles (Pd/N‐GNS) as an efficient and recyclable catalyst for the N‐allylation reaction. N‐GNS was synthesized through a facile hard‐template method by using petroleum asphalt, followed by nitrogen doping by thermal annealing with urea, the contents and species of which could be altered by the calcination temperature. Palladium nanoparticles (Pd NPs) with an average diameter of 3.3 nm were homogeneously deposited onto the N‐GNS support through a mild solvent‐growth approach. The Pd/N‐GNS exhibited a superior activity towards the N‐allylation reaction, 6‐fold higher than that of the pristine graphene nanoshells supporting the palladium catalyst. The Pd/N‐GNS could be recycled several times without activity deterioration and metal leaching. The catalytic activity showed a linear correlation relationship with the pyridinic N content. Experimental and theoretical studies reveal strong metal–support interactions between the pyridinic N and palladium species, which can downsize the Pd NPs, modulate the electronic properties, and promote the adsorption of reactant, thereby significantly boosting the catalytic efficiency and stability for the N‐allylation process. The present work could help unravel the roles of nitrogen‐doped carbon supports and provides a feasible strategy to rationally design superior palladium catalysts for chemical transformations.
Scaling Up Electrodes for Photoelectrochemical Water Splitting: Fabrication Process and Performance of 40 cm2LaTiO2N Photoanodes
Authors: Dilger Stefan , Trottmann Matthias , Pokrant Simone
Published: January 2019

A scalable process for fabrication of particle‐based photoanodes is developed. The electrodes are versatilely made of photocatalytically active semiconductor particles, in this case LaTiO2N, and optionally coated with cocatalysts and protecting components, all immobilized on a conducting substrate. The involved fabrication steps are restricted to scalable processes such as electrophoretic deposition, annealing in air, and dip coating. Special care is taken to ensure efficient charge transport in‐between particles and to the substrate by incorporating conducting connectors. By adapting the fabrication steps, the electrode geometrical dimension is increased from the size of a typical lab electrode of 1 to 40 cm2. The quality of the scale‐up process is characterized by comparing the photoanodes in terms of thickness, light‐absorption properties, and morphology. For several compositions, the electrochemical performance of both electrode sizes is assessed by measuring the photocurrents and faradaic efficiencies. The comparison revealed a complex upscaling behavior and showed that the photoelectrode size affects performance already on the 0.1 m scale.
Predictive value of the anal cytology for detecting anal intraepithelial neoplasia or worse: A systematic review and meta‐analysis
Authors: Chen Cheng‐Chieh , Chou Yuh‐Yu
Published: January 2019

Background

Anal intraepithelial neoplasia (AIN) refers to a precancerous lesion of anal squamous cell carcinoma (SCC). Human papillomavirus (HPV) is considered a crucial risk factor for AIN. Individuals with high‐risk sexual behaviour, such as receptive anal intercourse and multiple sexual partners, as well as men who have sex with men exhibit a relatively high rate of AIN. The anal cytology is a screening method for AIN in high‐risk individuals, and patients with abnormal anal cytology may benefit from high‐resolution anoscopy. This study explored the predictive value of the anal cytology for the detection of AIN or worse (AIN+).

Methods

We searched the databases of PubMed, BioMed Central, Cochrane Library, and Google Scholar for relevant studies. Studies on the diagnostic efficacy of the anal cytology for predicting anal cancer on a per‐patient basis were included. We excluded review articles. Either prospective trials or retrospective studies were included. We performed the meta‐analysis by using a random‐effects model to generate a pooled sensitivity, specificity, and diagnostic odds ratio (DOR). All analyses were performed using the MetaDiSc version 1.4 software (Universidad Complutense, Madrid, Spain).

Results

Twelve studies with 2541 participants were retrieved. The meta‐analysis of the studies assessing the predictive value of the anal cytology for detecting AIN+ generated a pooled sensitivity of 0.79 (95% confidence interval [CI], 0.77‐0.82) and a pooled specificity of 0.66 (95% CI, 0.64‐0.69). The pooled DOR for the anal cytology was 5.31 (95% CI, 3.31‐8.49).

Conclusions

Our results revealed that the anal cytology might be effective in diagnosing AIN+.
Sex‐biased survival contributes to population decline in a long‐lived seabird, the Magellanic Penguin
Authors: Gownaris N. J. , Boersma P. D.
Published: January 2019

We developed a Hidden Markov mark–recapture model (R package marked) to examine sex‐specific demography in Magellanic Penguins (Spheniscus magellanicus). Our model was based on 33 yr of resightings at Punta Tombo, Argentina, where we banded ~44,000 chicks from 1983 to 2010. Because we sexed only 57% of individuals over their lifetime, we treated sex as an uncertain state in our model. Our goals were to provide insight into the population dynamics of this declining colony, to inform conservation of this species, and to highlight the importance of considering sex‐specific vital rates in demographic seabird studies. Like many other seabirds, Magellanic Penguins are long‐lived, serially monogamous, and exhibit obligate biparental care. We found that the non‐breeding‐season survival of females was lower than that of males and that the magnitude of this bias was highest for juveniles. Biases in survival accumulated as cohorts aged, leading to increasingly skewed sex ratios. The survival bias was greatest in years when overall survival was low, that is, females fared disproportionality worse when conditions were unfavorable. Our model‐estimated survival patterns are consistent with independent data on carcasses from the species’ non‐breeding grounds, showing that mortality is higher for juveniles than for adults and higher for females than for males. Juveniles may be less efficient foragers than adults are and, because of their smaller size, females may show less resilience to food scarcity than males. We used perturbation analysis of a population matrix model to determine the impact of sex‐biased survival on adult sex ratio and population growth rate at Punta Tombo. We found that adult sex ratio and population growth rate have the greatest proportional response, that is, elasticity, to female pre‐breeder and adult survival. Sex bias in juvenile survival (i.e., lower survival of females) made the greatest contribution to population declines from 1990 to 2009. Because starvation is a leading cause of morality in juveniles and adults, precautionary fisheries and spatial management in the region could help to slow population decline. Our data add to growing evidence that knowledge of sex‐specific demography and sex ratios are necessary for accurate assessment of seabird population trends.
Contrasting nitrogen fluxes in African tropical forests of the Congo Basin
Authors: Bauters Marijn , Verbeeck Hans , Rütting Tobias , Barthel Matti , Bazirake Mujinya Basile , Bamba Fernando , Bodé Samuel , Boyemba Faustin , Bulonza Emmanuel , Carlsson Elin , Eriksson Linnéa , Makelele Isaac , Six Johan , Cizungu Ntaboba Landry , Boeckx Pascal
Published: January 2019

The observation of high losses of bioavailable nitrogen (N) and N richness in tropical forests is paradoxical with an apparent lack of N input. Hence, the current concept asserts that biological nitrogen fixation (BNF) must be a major N input for tropical forests. However, well‐characterized N cycles are rare and geographically biased; organic N compounds are often neglected and soil gross N cycling is not well quantified. We conducted comprehensive N input and output measurements in four tropical forest types of the Congo Basin with contrasting biotic (mycorrhizal association) and abiotic (lowland–highland) environments. In 12 standardized setups, we monitored N deposition, throughfall, litterfall, leaching, and export during one hydrological year and completed this empirical N budget with nitrous oxide (N2O) flux measurement campaigns in both wet and dry season and in situ gross soil N transformations using15N‐tracing and numerical modeling. We found that all forests showed a very tight soil N cycle, with gross mineralization to immobilization ratios (M/I) close to 1 and relatively low gross nitrification to mineralization ratios (N/M). This was in line with the observation of dissolved organic nitrogen (DON) dominating N losses for the most abundant, arbuscular mycorrhizal associated, lowland forest type, but in contrast with high losses of dissolved inorganic nitrogen (DIN) in all other forest types. Altogether, our observations show that different forest types in central Africa exhibit N fluxes of contrasting magnitudes and N‐species composition. In contrast to many Neotropical forests, our estimated N budgets of central African forests are imbalanced by a higher N input than output, with organic N contributing significantly to the input‐output balance. This suggests that important other losses that are unaccounted for (e.g.,NOxand N2as well as particulate N) might play a major role in the N cycle of mature African tropical forests.
Quantifying specialist avifaunal decline in grassland birds of the Northern Great Plains
Authors: Correll Maureen D. , Strasser Erin H. , Green Adam W. , Panjabi Arvind O.
Published: January 2019

Habitat specialists are declining worldwide, often paralleling rapid loss of habitat. Grassland habitats across North America are declining precipitously, due in part to intense conversion of grasslands to agriculture and rangelands, and specialist communities reliant upon this landscape are at particular risk of decline and collapse. We explored the relationship between grassland habitat specialism in birds and species population trends using several different grassland specialism indices (GSIs). Our data sources for these indices included (1) a regional bird dataset employing a spatially stratified sampling design (Integrated Monitoring of Bird Conservation Regions) of bird surveys in the Northern Great Plains of North America, and (2) geospatial data of species ranges (BirdLife Int'l) and grassland habitat (CEC North American Land Cover). We found a negative relationship between degree of habitat specialism and species population trends for all specialism metrics. We also found some evidence to support that specialism to grasslands on the wintering grounds partially explains population trends during the breeding season, giving added weight to the consideration of habitat conservation across the full annual cycle of a species to reverse or lessen population decline. Our work is the first to use quantitative methods to confirm the precarious state of grassland specialist songbirds in North America as well as demonstrate multiple methods for quantifying habitat specialism across different types of datasets.
Efficacy and safety of serelaxin when added to standard of care in patients with acute heart failure: results from a PROBE study, RELAX‐AHF‐EU
Authors: Maggioni Aldo P. , López‐Sendón José , Nielsen Olav W. , Hallén Jonas , Aalamian‐Mattheis Maryam , Wang Yaqin , Ertl Georg
Published: January 2019

Aim

Serelaxin is a recombinant human relaxin‐2 hormone, which confers receptor‐mediated vasodilatation in a tissue‐specific fashion. The RELAX‐AHF‐EU study assessed the effect of serelaxin when added to standard‐of‐care (SoC) therapy on worsening heart failure (WHF)/all‐cause death through Day 5 in patients hospitalised for acute heart failure (AHF) in Europe.

Methods and results

This multicentre, prospective, randomised, open‐label, blinded‐endpoint validation study enrolled hospitalised AHF patients and randomised (2:1) eligible patients (mild‐to‐moderate renal impairment and systolic blood pressure ≥ 125 mmHg) within 16 h of presentation with signs/symptoms of AHF, to receive 48 h intravenous infusion of 30 μg/kg/day serelaxin + SoC or SoC alone. The primary endpoint was adjudicated WHF/all‐cause death through Day 5. Of 3183 patients targeted, 2666 were randomised when the study was terminated early by the sponsor due to the neutral results of the pivotal RELAX‐AHF‐2 study. Adjudicated WHF/all‐cause death through Day 5 was significantly reduced in the serelaxin + SoC vs. SoC group (5.0% vs. 6.9%; hazard ratio 0.71; 95% confidence interval 0.51–0.98; P = 0.0172) (absolute risk reduction 1.9%, number needed to treat 53). The difference between treatment groups was not significant for WHF/all‐cause death/heart failure rehospitalisation through Day 14 and length of hospital stay. A significantly smaller proportion of patients in the serelaxin + SoC vs. SoC group experienced persistent heart failure signs/symptoms at each visit until Day 4, or renal deterioration through Day 5 (all P ≤ 0.01). Overall incidence of treatment‐emergent adverse events was comparable between treatment groups. Hypotension and decrease in haemoglobin/haematocrit were more frequent in the serelaxin + SoC group.

Conclusion

When added to SoC, serelaxin reduced adjudicated WHF or all‐cause death through Day 5 in AHF patients. The results from this open‐label study should be considered in the context of the totality of the double‐blind, randomised evidence on serelaxin in AHF.
1‐Aminovinylphosphonate Esters as Substrates for the Diels‐Alder Reaction: First Synthetic and Theoretical Study
Authors: Jiménez‐Andreu M. Mercedes , Bueno‐Morón Jorge , Sayago Francisco J. , Cativiela Carlos , Tejero Tomás , Merino Pedro
Published: January 2019

The Diels‐Alder reaction of 1‐aminovinylphosphonate esters has been studied for the first time as a suitable procedure leading to quaternary carbocyclic α‐aminophosphonates. The reaction is influenced by steric effects at the phosphonate functionality (bulky groups hinder the reaction) and electronic effects at the amino group (electron‐withdrawing substituents increase the reaction rate). The exo/endo ratio is constant, and no influence of the solvent is observed. The experimental results have been rationalized by DFT methods.
Organic and Coordination Chemistry of 1,2,4‐Trithiolanes
Authors: Mlostoń Grzegorz , Romański Jarosław , Weigand Wolfgang , Heimgartner Heinz
Published: January 2019

The review is aimed in summarizing the most important aspects of the chemistry of 1,2,4‐trithiolanes, which form a relevant class of cyclic polysulfides abundant in nature. Some of them were identified as components of Lenthinus edodes (shiitaki mushrooms) extracts as well as of Parkia speciosa (stink bean), which are well known in Asian cuisine. In addition, they determine the flavor of boiled beef and roasted chicken. Thermal decomposition of 1,2,4‐trithiolanes, either in solution or in the gas phase, results in [3+2]‐cycloelimination leading to the release of reactive thiocarbonyl S‐sulfides existing in equilibrium with sulfur‐rich, three‐membered dithiiranes. Both, 1,2,4‐trithiolanes and the products of their decomposition react with low‐valent platinum and iron compounds forming the corresponding sulfur‐metal complexes. For example, iron‐sulfur clusters formed in these reactions are of interest as structural models of [Fe,Fe]‐hydrogenase mimics.
Terminal Acetylenic Iminium Salts: Cycloaddition Reactions with Azides Leading to 1,2,3‐Triazoles and Bicyclic 1,2,3‐Triazolium Salts
Authors: Keim Michael , Maas Gerhard
Published: January 2019

Terminal acetylenic iminium triflate salts [HC≡C‐C(R)=N+Me2 TfO–] represent very potent dipolarophiles which undergo [3+2] cycloadditions with aryl and benzyl azides at very mild and uncatalyzed conditions, yielding 1,4‐disubstituted 1,2,3‐triazoles with complete regioselectivity. Addition of nucleophiles at the iminium group of the cycloadducts leads to diverse 1‐aryl‐(or benzyl‐)‐4‐dimethylaminomethyl‐1,2,3‐triazoles. The first formed cycloaddition adducts subsequently react with a second molecule of the acetylenic iminium salt by a consecutive Michael addition/1,5‐cyclization to form 2,4‐dihydropyrrolo[1,2‐c][1,2,3]triazol‐7‐ium triflates. Further transformations of the latter salts are described, among them the conversion into a mesoionic carbene, isolated as a monomeric silver(I) complex.
Parallel Synthesis and Biological Evaluation of Destruxin E Analogs Modified with a Side Chain in the α‐Hydroxycarboxylic Acid Moiety
Authors: Yoshida Masahito , Adachi Kenta , Murase Hayato , Nakagawa Hiroshi , Doi Takayuki
Published: January 2019

This study demonstrates the synthesis and biological evaluation of destruxin E analogs possessing various functional groups in the α‐hydroxycarboxylic acid moiety. Parallel synthesis of eleven analogs was successfully achieved through solution‐phase peptide synthesis and macrolactonization. Biological evaluation of the synthetic analogs using osteoclast‐like multi nuclear cells (OCLs) revealed that the epoxide group in the side chain of α‐hydroxycarboxylic acid and the orientation of the oxygen atom are essential factors in the desired potent activity that induces morphological changes in OCLs for the inhibition of bone‐resorbing activity.
Fine‐Tuning Aromatic Stacking and Single‐Crystal Photoluminescence Through Coordination Chemistry
Authors: Chen Chaoyuan , Wu Yilei , Li Hui
Published: January 2019

Organic aromatics usually show a decrease in fluorescence efficiency in the solid state on account of well‐known aggregation induced quenching. We have found that single crystals of coordination polymers consisting of γ‐aminobutyric acid functionalized naphthalenediimide ligand (H2GABA‐NDI) can give rise to highly emissive, broad, and red‐shifted photoluminescence (PL) in the solid state. To better understand the origin of the bandwidth broadening with the π–π stacking distances, we performed time‐resolved PL studies in a series of polymers with a variety of metal centers. We conclude that the broad steady‐state PL signals is originated from a superposition of two emissive states with differing energy and lifetimes, with the lower energy one produced by the interchromophoric interactions mediated by π–π stacking of neighboring NDI units. Our work demonstrates that coordination chemistry is an effective tool to modulate interchromophoric couplings and that simple PL analysis can be used as a measure of the degree of π‐stacking.
Non‐lethal defense of livestock against predators: flashing lights deter puma attacks in Chile
Authors: Ohrens Omar , Bonacic Cristian , Treves Adrian
Published: January 2019

Anthropogenic mortality among populations of large terrestrial carnivores undermines the health of ecosystems globally, and generally increases when people respond lethally to real or perceived threats to property, including livestock. Reducing such threats through the use of non‐lethal methods could therefore protect both large predators and human interests. However, the scarcity of information on the effectiveness of methods to prevent livestock predation hinders the formulation of science‐based policy. We present the results of a randomized crossover experimental test of a method to prevent predation on livestock, which to our knowledge is the first such test in Latin America. By relying on a so‐called “gold‐standard” design, we evaluated the effectiveness of using flashing lights to deter predators. We found that light deterrents discouraged pumas (Puma concolor) but not Andean foxes (Lycalopex culpaeus) from preying on alpacas (Vicugna pacos) and llamas (Lama glama), and demonstrated that gold‐standard experiments are feasible in large natural ecosystems, contradicting assumptions that people will reject placebo controls and that such systems contain too many confounding variables. Functionally effective non‐lethal methods can protect wildlife, livestock, and people. Strong inference is needed for the development of sound policy concerning wildlife management, livestock husbandry, environmental conservation, and biodiversity.
High carbon burial rates by small ponds in the landscape
Authors: Taylor Scott , Gilbert Peter J , Cooke David A , Deary Michael E , Jeffries Michael J
Published: January 2019

Temperate ponds may be important sinks and sources of greenhouse gases but just how quickly ponds bury carbon (C) is poorly understood. We derived – to the best of our knowledge – the first organic carbon (OC) burial rates for small ponds of known age by digging out the whole sediment from ponds, and determined that the average C burial rate was 142 g m−2 yr−1, with a range of 79–247 g m−2 yr−1, depending on the ponds' vegetation. Burial rates in the ponds were 20–30 times higher than rates estimated for many other habitat types, such as woodlands or grasslands, and higher than those of other natural wetlands. Although small ponds occupy a very small proportion of the landscape as compared to these other habitats, their high OC burial rates result in comparable annual OC burial overall. Ponds are easy to create, can fit in with other land uses, and are a globally ubiquitous habitat. Our results indicate that ponds have the potential to be a very useful additional tool for mitigating C emissions.
Institutional quality and sovereign credit default swap spreads
Authors: Huang Wei , Lin Shu , Yang Jian
Published: January 2019

We examine how the quality of political, legal, and regulatory institutions impacts sovereign risk premia. An improvement in institutional quality significantly lowers a country's sovereign credit default swap (CDS) spread, even after controlling for domestic and global macroeconomic factors. The incremental effect of institutional quality may also be economically important in explaining the variations in the level of sovereign CDS spreads. The basic results are robust to alternative model specifications, samples, control variables, measures of institutional quality, estimation methods, and controls for endogeneity. Overall, the evidence suggests that institutional quality may play a significant role in explaining sovereign CDS spreads.
A review of kernel methods for genetic association studies
Authors: Larson Nicholas B. , Chen Jun , Schaid Daniel J.
Published: January 2019

Evaluating the association of multiple genetic variants with a trait of interest by use of kernel‐based methods has made a significant impact on how genetic association analyses are conducted. An advantage of kernel methods is that they tend to be robust when the genetic variants have effects that are a mixture of positive and negative effects, as well as when there is a small fraction of causal variants. Another advantage is that kernel methods fit within the framework of mixed models, providing flexible ways to adjust for additional covariates that influence traits. Herein, we review the basic ideas behind the use of kernel methods for genetic association analysis as well as recent methodological advancements for different types of traits, multivariate traits, pedigree data, and longitudinal data. Finally, we discuss opportunities for future research.
Where is the “where” in the brain? A meta‐analysis of neuroimaging studies on spatial cognition
Authors: Cona Giorgia , Scarpazza Cristina
Published: January 2019

Spatial representations are processed in the service of several different cognitive functions. The present study capitalizes on the Activation Likelihood Estimation (ALE) method of meta‐analysis to identify: (a) the shared neural activations among spatial functions to reveal the “core” network of spatial processing; (b) the specific neural activations associated with each of these functions. Following PRISMA guidelines, a total of 133 fMRI and PET studies were included in the meta‐analysis. The overall analysis showed that the core network of spatial processing comprises regions that are symmetrically distributed on both hemispheres and that include dorsal frontoparietal regions, presupplementary motor area, anterior insula, and frontal operculum. The specific analyses revealed the brain regions that are selectively recruited for each spatial function, such as the right temporoparietal junction for shift of spatial attention, the right parahippocampal gyrus, and the retrosplenial cortex for navigation and spatial long‐term memory. The findings are integrated within a systematic review of the neuroimaging literature and a new neurocognitive model of spatial cognition is proposed.
MVA E2 therapeutic vaccine for marked reduction in likelihood of recurrence of respiratory papillomatosis
Authors: Cabo Beltran Olga Rodriguez , Rosales Ledezma Ricardo
Published: January 2019

Background

Recurrent respiratory papillomatosis (RRP) or laryngeal papillomatosis is a disease caused by papillomavirus infection.

Methods

In this phase I/II clinical trial, we evaluated the efficacy of the modified vaccinia Ankara (MVA) E2 virus in the treatment of RRP. Twenty‐nine patients (18 female and 11 male) underwent injection of MVA E2 directly into the borders of the vocal cords where lesions were seen and were monitored by direct laryngoscopy. The immune response was assessed by the determination of CD3+, CD4+, and CD8+ lymphocytes counts. The presence of papillomavirus was determined by polymerase chain reaction analysis.

Results

Lesions were completely eliminated in 13 patients (44.8%). In 16 patients (55.2%), lesions recurred between 6 and 18 months after treatment; these patients received a second round of treatment with MVA E2, and they are not seen with new recurrences.

Conclusion

The MVA E2 vaccine has excellent potential for generating complete regression of RRP lesions.