bluuebunny/crossref_metadata_2025 huggingface dataset:
Stratified Ekman layers evolving under a finite-time stabilizing buoyancy flux
Authors: Gohari S. M. Iman , Sarkar Sutanu
Published: February 2018

Stratified flow in nocturnal boundary layers is studied using direct numerical simulation (DNS) of the Ekman layer, a model problem that is useful to understand atmospheric boundary-layer (ABL) turbulence. A stabilizing buoyancy flux is applied for a finite time to a neutral Ekman layer. Based on previous studies and the simulations conducted here, the choice of $L_{\mathit{cri}}^{+}=Lu_{\ast }/\unicode[STIX]{x1D708}\approx 700$ ($L$ is the Obukhov length scale and $u_{\ast }$ is the friction velocity) provides a cooling flux that is sufficiently strong to cause the initial collapse of turbulence. The turbulent kinetic energy decays over a time scale of $4.06L/u_{\ast }$ during the collapse. The simulations suggest that imposing $L_{\mathit{cri}}^{+}\approx 700$ on the neutral Ekman layer results in turbulence collapse during the initial transient, independent of Reynolds number, $Re_{\ast }$. However, the long-time state of the flow, i.e. turbulent with spatial intermittency or non-turbulent, is found to depend on the initial value of $Re_{\ast }$ since the cooling flux and resultant stratification increase with $Re_{\ast }$ for a given $L^{+}$. The lower-$Re_{\ast }$ cases have sustained turbulence with shear and stratification profiles that evolve in a manner such that the gradient Richardson number, $Ri_{g}$, in the near-surface layer, including the low-level jet, remains subcritical. The highest $Re_{\ast }$ case has supercritical $Ri_{g}$ in the low-level jet and turbulence does not recover. A theoretical discussion is performed to infer that the bulk Richardson number, $Ri_{b}$, is more suitable than $L^{+}$ to determine the fate of stratified Ekman layers at late time. DNS results support the implications of $Ri_{b}$ for the effect of initial $Re_{\ast }$ and $L^{+}$ on the flow.
Optimal control of a separated boundary-layer flow over a bump
Authors: Passaggia Pierre-Yves , Ehrenstein Uwe
Published: February 2018

The optimal control of a globally unstable two-dimensional separated boundary layer over a bump is considered using augmented Lagrangian optimization procedures. The present strategy allows for controlling of the flow from a fully developed nonlinear state back to the steady state using a single actuator. The method makes use of a decomposition between the slow dynamics associated with the base flow modification and the fast dynamics, known as flapping, characterized by a large scale oscillation of the recirculation region. Starting from a steady state forced by a suction actuator located near the separation point, the base flow modification is shown to be controlled by a vanishing suction strategy. For weakly unstable flow regimes, this control law can be further optimized by means of direct–adjoint iterations of the nonlinear Navier–Stokes equations. In the absence of external noise, this novel approach proves to be capable of controlling the transient dynamics and the base flow modification simultaneously.
Dynamic linear response of a shock/turbulent-boundary-layer interaction using constrained perturbations
Authors: Adler Michael C. , Gaitonde Datta V.
Published: February 2018

Comprehensive experimental and computational investigations have revealed possible mechanisms underlying low-frequency unsteadiness observed in spanwise homogeneous shock-wave/turbulent-boundary-layer interactions (STBLI). In the present work, we extend this understanding by examining the dynamic linear response of a moderately separated Mach 2.3 STBLI to small perturbations. The statistically stationary linear response is analysed to identify potential time-local and time-mean linear tendencies present in the unsteady base flow: these provide insight into the selective amplification properties of the flow at various points in the limit cycle, as well as asymmetry and restoring mechanisms in the dynamics of the separation bubble. The numerical technique uses the synchronized large-eddy simulation method, previously developed for free shear flows, significantly extended to include a linear constraint necessary for wall-bounded flows. The results demonstrate that the STBLI fosters a global absolute linear instability corresponding to a time-mean linear tendency for upstream shock motion. The absolute instability is maintained through constructive feedback of perturbations through the recirculation: it is self-sustaining and insensitive to external forcing. The dynamics are characterized for key frequency bands corresponding to high–mid-frequency Kelvin–Helmholtz shedding along the separated shear layer$(St_{L}\sim 0.5)$, low–mid-frequency oscillations of the separation bubble$(St_{L}\sim 0.1)$and low-frequency large-scale bubble breathing and shock motion$(St_{L}\sim 0.03)$, where the Strouhal number is based on the nominal length of the separation bubble,$L$:$St_{L}=fL/U_{\infty }$. A band-pass filtering decomposition isolates the dynamic flow features and linear responses associated with these mechanisms. For example, in the low-frequency band, extreme shock displacements are shown to correlate with time-local linear tendencies toward more moderate displacements, indicating a restoring mechanism in the linear dynamics. However, a disparity between the linearly stable shock position and the mean shock position leads to an observed asymmetry in the low-frequency shock motion cycle, in which upstream motion occurs more rapidly than downstream motion. This is explained through competing linear and nonlinear (mass depletion through shedding) mechanisms and discussed in the context of an oscillator model. The analysis successfully illustrates how time-local linear dynamics sustain several key unsteady broadband flow features in a causal manner.
Testing a Transactional Model of Romantic Sensory Interactions in Male and Female Romantic Intimates
Authors: Miron Anca M. , Jiang Lixin , Weisensel Kenneth , Patterson Megan S. , Rizo Fabiola
Published: February 2018

We propose atransactional model of romantic sensory interactions, according to which male and female intimates adapt to the specific context of their romantic relationships by adopting different sensory domains of interactions with their partners. To test this model, we measured romantic couples’ orientations toward using sensory modalities of romantic relating, and the importance of these modalities (N= 137 couples). Although not all hypotheses were supported, the findings suggest that men's relationship satisfaction, passionate love, and liking were driven by a stronger orientation toward touch, whereas women's relationship satisfaction, passionate love, liking, and commitment were predicted by a stronger preference for hearing. Higher differential valuing of touch and bodily sensations predicted higher passionate love for both men and women, suggesting that these sensory modalities have similar functions for both genders — to maintain sexual desire and passionate love for the partner. These findings underscore the importance of romantic couples’ differential sensory orientations in maintaining satisfying relationships.
On Updating Algorithms and Inference for Stochastic Point Processes
Authors: Vere-Jones D.
Published: February 2018

This paper is an attempt to interpret and extend, in a more statistical setting, techniques developed by D. L. Snyder and others for estimation and filtering for doubly stochastic point processes. The approach is similar to the Kalman-Bucy approach in that the updating algorithms can be derived from a Bayesian argument, and lead ultimately to equations which are similar to those occurring in stochastic approximation theory. In this paper the estimates are derived from a general updating formula valid for any point process. It is shown that almost identical formulae arise from updating the maximum likelihood estimates, and on this basis it is suggested that in practical situations the sequence of estimates will be consistent and asymptotically efficient. Specific algorithms are derived for estimating the parameters in a doubly stochastic process in which the rate alternates between two levels.
Diverse single-amino-acid repeat profiles in the genusCryptosporidium
Authors: Widmer Giovanni
Published: February 2018

Genome sequencing has greatly contributed to our understanding of parasitic protozoa. This is particularly the case forCryptosporidiumspecies (phylum Apicomplexa) which are difficult to propagate. Because of their polymorphic nature, simple sequence repeats have been used extensively as genotypic markers to differentiate between isolates, but no global analysis of amino acid repeats inCryptosporidiumgenomes has been reported. Taking advantage of several newly sequencedCryptosporidiumgenomes, a comparative analysis of single-amino-acid repeats (SAARs) in seven species was undertaken. This analysis revealed a striking difference between the SAAR profile of the gastric and intestinal species which infect mammals and one species which infects birds. In average, total SAAR length in gastric species is only 25% of the cumulative SAAR length in the genome ofCryptosporidium parvum,Cryptosporidium hominisandCryptosporidium meleagridis, species infectious to humans. The SAAR profile in the avian parasiteCryptosporidium baileyistands out due to the presence of long asparagine repeats.Cryptosporidium baileyiproteins with repeats ⩾20 residues are significantly enriched in regulatory functions. As postulated for the related apicomplexan speciesPlasmodium falciparum, these observations suggest thatCryptosporidiumSAARs evolve in response to selective pressure. The putative selective mechanisms driving SAAR evolution inCryptosporidiumspecies are unknown.
‘Two rules are at play when it comes to none’: A corpus-based analysis of singular versus plural none
Authors: Kim Sugene
Published: February 2018

This paper identifies discrepancies between prescriptive grammar rules concerning the number of the indefinite pronoun none and the actual use of this pronoun in modern academic English as shown in the Michigan Corpus of Academic Spoken English (MICASE) and Michigan Corpus of Upper-level Student Papers (MICUSP). Whereas prescriptive rules state that the number of none is determined by its referent or by the user's desired effect, the analyses of the MICASE and MICUSP search results suggest that, regardless of the modality of discourse, (1) the number of none with an anaphoric referent is determined by the number of its referent and (2) the principle of proximity applies without exception when none is used as part of a ‘none of + singular noun/pronoun’ phrase and applies frequently but not always when followed by an ‘of + plural noun/pronoun’ phrase.
Trends in rotavirus from 2001 to 2015 in two paediatric hospitals in Atlanta, Georgia
Authors: Sederdahl B. K. , Yi J. , Jerris R. C. , Gillespie S. E. , Westblade L. F. , Kraft C. S. , Shane A. L. , Anderson E. J.
Published: February 2018

We compared rotavirus detection patterns before (2001–2006) and after (2008–2015) rotavirus vaccine introduction. We also compared rotavirus detection patterns in odd (2009, 2011, 2013, 2015) and even (2008, 2010, 2012, 2014) years post-vaccine separately. Results of stool rotavirus antigen testing from inpatient, outpatient and emergency department encounters from July 2000 to July 2015 at two paediatric hospital laboratories in Atlanta, Georgia were reviewed. Post-vaccine, rotavirus detection declined (30.2% vs. 13.7% (overall 54.6% decline, P <0.001)), occurred more frequently outside the rotavirus season (19.8% vs. 3.5%; P < 0.001), and was more common among older children (26 vs. 13 median months of age; P < 0.001). During odd years post-vaccine, rotavirus detection was significantly higher than even years (20.2% vs. 6.4%; P < 0.001). Rotavirus detection declined substantially and developed a biennial pattern in the post-vaccine era. The intensity and temporality of rotavirus detection in odd years post-vaccine resembled that observed pre-vaccine, although considerably reduced in magnitude.
AGU Editor Suggestions for Navigating the Fall Meeting, Part II
Authors: Hanson Brooks
Published: February 2018

AGU's journal editors provide suggestions and recommendations of sessions and talks of particular interest.
Association of cytosolic sialidase Neu2 with plasma membrane enhances Fas-mediated apoptosis by impairing PI3K-Akt/mTOR-mediated pathway in pancreatic cancer cells
Authors: Nath Shalini , Mandal Chhabinath , Chatterjee Uttara , Mandal Chitra
Published: February 2018

Modulation of sialylation by sialyltransferases and sialidases plays essential role in carcinogenesis. There are few reports on sialyltransferase, however, the contribution of cytosolic sialidase (Neu2) remains unexplored in pancreatic ductal adenocarcinoma (PDAC). We observed lower expression of Neu2 in different PDAC cells, patient tissues, and a significant strong association with clinicopathological characteristics. Neu2 overexpression guided drug-resistant MIAPaCa2 and AsPC1 cells toward apoptosis as evidenced by decreased Bcl2/Bax ratio, activation of caspase-3/caspase-6/caspase-8, PARP reduction, reduced CDK2/CDK4/CDK6, and cyclin-B1/cyclin-E with unaffected caspase-9. Neu2-overexpressed cells exhibited higher expression of Fas/CD95-death receptor, FasL, FADD, and Bid cleavage confirming extrinsic pathway-mediated apoptosis. α2,6-linked sialylation of Fas helps cancer cells to survive, which is a substrate for Neu2. Therefore, their removal should enhance Fas-mediated apoptosis. Neu2-overexpressed cells indeed showed increased enzyme activity even on membrane. Interestingly, this membrane-bound Neu2 exhibited enhanced association with Fas causing its desialylation and activation as corroborated by decreased association of Fas with α2,6-sialic acid-binding lectin. Additionally, enhanced cytosolic Neu2 inhibited the expression of several growth factor-mediated signaling molecules involved in PI3K/Akt–mTOR pathway probably through desialylation which in turn also causes Fas activation. Furthermore, Neu2-overexpressed cells exhibited reduced cell migration, invasion with decreased VEGF, VEGFR, and MMP9 levels. To the best of our knowledge, this is the first report of cytosolic Neu2 on membrane, its association with Fas, enhanced desialylation, activation, and Fas-mediated apoptosis. Taken together, our study ascertains a novel concept by which the function of Fas/CD95 could be modulated indicating a critical role of upstream Neu2 as a promising target for inducing apoptosis in pancreatic cancer.
RIPK1-dependent cell death: a novel target of the Aurora kinase inhibitor Tozasertib (VX-680)
Authors: Martens Sofie , Goossens Vera , Devisscher Lars , Hofmans Sam , Claeys Polien , Vuylsteke Marnik , Takahashi Nozomi , Augustyns Koen , Vandenabeele Peter
Published: February 2018

The Aurora kinase family (Aurora A, B and C) are crucial regulators of several mitotic events, including cytokinesis. Increased expression of these kinases is associated with tumorigenesis and several compounds targeting Aurora kinase are under evaluation in clinical trials (a.o. AT9283, AZD1152, Danusertib, MLN8054). Here, we demonstrate that the pan-Aurora kinase inhibitor Tozasertib (VX-680 and MK-0457) not only causes cytokinesis defects through Aurora kinase inhibition, but is also a potent inhibitor of necroptosis, a cell death process regulated and executed by the RIPK1, RIPK3 and MLKL signalling axis. Tozasertib’s potency to inhibit RIPK1-dependent necroptosis and to block cytokinesis in cells is in the same concentration range, with an IC50 of 1.06 µM and 0.554 µM, respectively. A structure activity relationship (SAR) analysis of 67 Tozasertib analogues, modified at 4 different positions, allowed the identification of analogues that showed increased specificity for either cytokinesis inhibition or for necroptosis inhibition, reflecting more specific inhibition of Aurora kinase or RIPK1, respectively. These results also suggested that RIPK1 and Aurora kinases are functionally non-interacting targets of Tozasertib and its analogues. Indeed, more specific Aurora kinase inhibitors did not show any effect in necroptosis and Necrostatin-1s treatment did not result in cytokinesis defects, demonstrating that both cellular processes are not interrelated. Finally, Tozasertib inhibited recombinant human RIPK1, human Aurora A and human Aurora B kinase activity, but not RIPK3. The potency ranking of the newly derived Tozasertib analogues and their specificity profile, as observed in cellular assays, coincide with ADP-Glo recombinant kinase activity assays. Overall, we show that Tozasertib not only targets Aurora kinases but also RIPK1 independently, and that we could generate analogues with increased selectivity to RIPK1 or Aurora kinases, respectively.
The gastrointestinal tract microbiota of northern white-cheeked gibbons (Nomascus leucogenys) varies with age and captive condition
Authors: Jia Ting , Zhao Sufen , Knott Katrina , Li Xiaoguang , Liu Yan , Li Ying , Chen Yuefei , Yang Minghai , Lu Yanping , Wu Junyi , Zhang Chenglin
Published: February 2018

Nutrition and health of northern white-cheeked gibbons (Nomascus leucogenys) are considered to be primarily influenced by the diversity of their gastrointestinal tract (GIT) microbiota. However, the precise composition, structure, and role of the gibbon GIT microbiota remain unclear. Microbial communities from the GITs of gibbons from Nanning (NN, n = 36) and Beijing (BJ, n = 20) Zoos were examined through 16S rRNA sequencing. Gibbon’s GITs microbiomes contained bacteria from 30 phyla, dominated by human-associated microbial signatures: Firmicutes, Bacteroidetes, and Proteobacteria. Microbial species richness was markedly different between adult gibbons (>8 years) under distinct captive conditions. The relative abundance of 14 phyla varied significantly in samples of adults in BJ versus NN. Among the age groups examined in NN, microbiota of adult gibbons had greater species variation and richer community diversity than microbiota of nursing young (<6 months) and juveniles (2–5 years). Age-dependent increases in the relative abundances of Firmicutes and Fibrobacteres were detected, along with simultaneous increases in dietary fiber intake. A few differences were detected between sex cohorts in NN, suggesting a very weak correlation between sex and GIT microbiota. This study is the first to taxonomically identify gibbon’s GITs microbiota confirming that microbiota composition varies with age and captive condition.
Role of intestinal trefoil factor in protecting intestinal epithelial cells from burn-induced injury
Authors: Hu Jianhong , Shi Yan , Wang Chao , Wan Hanxing , Wu Dan , Wang Hongyu , Peng Xi
Published: February 2018

Although intestinal trefoil factor (ITF) can alleviate the burn-induced intestinal mucosa injury, the underlying mechanisms remains elusive. In this study, we investigated if ITF alters glutamine transport on the brush border membrane vesicles (BBMVs) of the intestines in Sprague-Dawley rats inflicted with 30% TBSA and the underlying mechanisms. We found that ITF significantly stimulated intestinal glutamine transport in burned rats. Mechanistically, ITF enhanced autophagy, reduces endoplasmic reticulum stress (ERS), and alleviates the impaired PDI, ASCT2, and B0AT1 in IECs and BBMVs after burn injury likely through AMPK activation. Therefore, ITF may protect intestinal epithelial cells from burn-induced injury through improving glutamine transport by alleviating ERS.
Transcriptomics reveals a cross-modulatory effect between riboflavin and iron and outlines responses to riboflavin biosynthesis and uptake in Vibrio cholerae
Authors: Sepúlveda-Cisternas Ignacio , Lozano Aguirre Luis , Fuentes Flores Andrés , Vásquez Solis de Ovando Ignacio , García-Angulo Víctor Antonio
Published: February 2018

Vibrio cholerae, a pandemic diarrheagenic bacterium, is able to synthesize the essential vitamin riboflavin through the riboflavin biosynthetic pathway (RBP) and also to internalize it through the RibN importer. In bacteria, the way riboflavin biosynthesis and uptake functions correlate is unclear. To gain insights into the role of the riboflavin provision pathways in the physiology of V. cholerae, we analyzed the transcriptomics response to extracellular riboflavin and to deletions of ribD (RBP-deficient strain) or ribN. Many riboflavin-responsive genes were previously reported to belong to the iron regulon, including various iron uptake genes. Real time PCR analysis confirmed this effect and further documented that reciprocally, iron regulates RBP and ribN genes in a riboflavin-dependent way. A subset of genes were responding to both ribD and ribN deletions. However, in the subset of genes specifically affected in the ∆ribD strain, the functional terms protein folding and oxidation reduction process were enriched, as determined by a Gene Ontology analysis. In the gene subset specifically affected in the ∆ribN strain, the cytochrome complex assembly functional term was enriched. Results suggest that iron and riboflavin interrelate to regulate its respective provision genes and that both common and specific effects of biosynthesized and internalized riboflavin exist.
Prevalence and impact of baseline resistance-associated substitutions on the efficacy of ledipasvir/sofosbuvir or simeprevir/sofosbuvir against GT1 HCV infection
Authors: Wang Gary P. , Terrault Norah , Reeves Jacqueline D. , Liu Lin , Li Eric , Zhao Lisa , Lim Joseph K. , Morelli Giuseppe , Kuo Alexander , Levitsky Josh , Sherman Kenneth E. , Frazier Lynn M. , Ramani Ananthakrishnan , Peter Joy , Akuskevich Lucy , Fried Michael W. , Nelson David R.
Published: February 2018

Baseline resistance-associated substitutions (RASs) have variable impacts in clinical trials but their prevalence and impact in real-world patients remains unclear. We performed baseline resistance testing using a commercial assay (10% cutoff) for 486 patients treated with LDV/SOF or SMV/SOF, with or without ribavirin, in the multi-center, observational HCV-TARGET cohort. Linkage of RASs was evaluated in selected samples using a novel quantitative single variant sequencing assay. Our results showed that the prevalence of NS3, NS5A, NS5B RASs was 45%, 13%, and 8%, respectively, and 10% of patients harbored RASs in 2 or more drug classes. Baseline LDV RASs in GT1a, TE, and cirrhosis LDV/SOF subgroup was associated with 2–4% lower SVR12 rates. SMV RASs was associated with lower SVR12 rates in GT1a, treatment-experienced, cirrhotics SMV/SOF subgroup. Pooled analysis of all patients with baseline RASs revealed that SVR12 was 100% (19/19) in patients treated for longer than 98 days but was 87% (81/93) in patients treated for shorter than 98 days. These results demonstrate that RASs prevalence and their impact in real world practice are in general agreement with registration trials, and suggest that longer treatment duration may overcome the negative impact of baseline RASs on SVR12 rates in clinical practice.
Nest substrate reflects incubation style in extant archosaurs with implications for dinosaur nesting habits
Authors: Tanaka Kohei , Zelenitsky Darla K. , Therrien François , Kobayashi Yoshitsugu
Published: February 2018

Dinosaurs thrived and reproduced in various regions worldwide, including the Arctic. In order to understand their nesting in diverse or extreme environments, the relationships between nests, nesting environments, and incubation methods in extant archosaurs were investigated. Statistical analyses reveal that species of extant covered nesters (i.e., crocodylians and megapodes) preferentially select specific sediments/substrates as a function of their nesting style and incubation heat sources. Relationships between dinosaur eggs and the sediments in which they occur reveal that hadrosaurs and some sauropods (i.e., megaloolithid eggs) built organic-rich mound nests that relied on microbial decay for incubation, whereas other sauropods (i.e., faveoloolithid eggs) built sandy in-filled hole nests that relied on solar or potentially geothermal heat for incubation. Paleogeographic distribution of mound nests and sandy in-filled hole nests in dinosaurs reveals these nest types produced sufficient incubation heat to be successful up to mid latitudes (≤47°), 10° higher than covered nesters today. However, only mound nesting and likely brooding could have produced sufficient incubation heat for nesting above the polar circle (>66°). As a result, differences in nesting styles may have placed restrictions on the reproduction of dinosaurs and their dispersal at high latitudes.
High quality self-separated GaN crystal grown on a novel nanoporous template by HVPE
Authors: Huo Qin , Shao Yongliang , Wu Yongzhong , Zhang Baoguo , Hu Haixiao , Hao Xiaopeng
Published: February 2018

In this study, a novel nanoporous template was obtained by a two-step etching process from MOCVD-GaN/Al2O3 (MGA) with electrochemical etching sequentially followed by chemical wet etching. The twice-etched MOCVD-GaN/Al2O3 (TEMGA) templates were utilized to grow GaN crystals by hydride vapor phase epitaxy (HVPE) method. The GaN crystals were separated spontaneously from the TEMGA template with the assistance of voids formed by the etched nanopores. Several techniques were utilized to characterize the quality of the free-standing GaN crystals obtained from the TEMGA template. Results showed that the quality of the as-obtained GaN crystals was improved obviously compared with those grown on the MGA. This convenient technique can be applied to grow high-quality free-standing GaN crystals.
Correction: Corrigendum: Novel concept for neutron detection: proportional counter filled with 10B nanoparticle aerosol
Authors: Amaro F. D. , Monteiro C. M. B. , dos Santos J. M. F. , Antognini A.
Published: February 2018

Scientific Reports 7: Article number: 41699; published online: 09 February 2017; updated: 12 February 2018 The Acknowledgements section in this Article is incomplete. “F.D.A. and C.M.B.M. acknowledge the support of FCT, under contracts SFRH/BPD/74775/2010 and SFRH/BPD/76842/2011, respectively. We acknowledge R.
Barbituric acid-modified graphitic carbon nitride nanosheets for ratiometric fluorescent detection of Cu2+
Authors: Chen Ling , Song Zhiping , Liu Xueting , Guo Liangqia , Li Mei-jin , Fu Fengfu
Published: February 2018

A ratiometric and visual fluorescent sensor for Cu2+ions based on barbituric acid-modified graphitic carbon nitride nanosheets was designed.
Compact layer free mixed-cation lead mixed-halide perovskite solar cells
Authors: Hu Zhelu , Xiang Hengyang , Schoenauer Sebag Mathilde , Billot Laurent , Aigouy Lionel , Chen Zhuoying
Published: February 2018

Thickness-tunable and compact FA0.83Cs0.17Pb(I0.6Br0.4)3 perovskite thin films are achieved with a large grain size up to 12 microns. They are then employed to fabricate planar electron-transport-layer-free solar cells.
Catalytic asymmetric inverse electron demand Diels–Alder reaction of fulvenes with azoalkenes
Authors: Wei Liang , Zhu Qiao , Song Zhi-Min , Liu Kang , Wang Chun-Jiang
Published: February 2018

An unprecedented copper(i)-catalyzed asymmetric inverse electron demand Diels–Alder reaction of azoalkenes with fulvenes is reported. This methodology offers a directed entry to synthesize bicyclic tetrapyridazine derivatives in good yield with exclusive regioselectivity and excellent stereoselectivity.
Polymorphism of chlorpropamide on liquid-assisted mechanical treatment: choice of liquid and type of mechanical treatment matter
Authors: Bouvart Nadia , Palix Roland-Marie , Arkhipov Sergey G. , Tumanov Ivan A. , Michalchuk Adam A. L. , Boldyreva Elena V.
Published: February 2018

Different types of mechanical treatment (tableting, grinding, milling,etc.) are important technological operations in the pharmaceutical industry.
Atmospheric chemistry of CH3CHO: the hydrolysis of CH3CHO catalyzed by H2SO4
Authors: Tan Xing-Feng , Long Bo , Ren Da-Sen , Zhang Wei-Jun , Long Zheng-Wen , Mitchell Ellen
Published: February 2018

We found the catalytic effect of H2SO4 on the hydrolysis of CH3CHO in the atmosphere.
Electronic structure of dipeptides in the gas-phase and as an adsorbed monolayer
Authors: Guo Cunlan , Sarkar Soumyajit , Refaely-Abramson Sivan , Egger David A. , Bendikov Tatyana , Yonezawa Keiichirou , Suda Yosuke , Yamaguchi Takuma , Pecht Israel , Kera Satoshi , Ueno Nobuo , Sheves Mordechai , Kronik Leeor , Cahen David
Published: February 2018

UPS and DFT reveal how frontier energy levels and molecular orbitals of peptides are modified upon peptide binding to a gold substrate.
Computational prediction of a high ZT of n-type Mg3Sb2-based compounds with isotropic thermoelectric conduction performance
Authors: Li Juan , Zheng Shuqi , Fang Teng , Yue Luo , Zhang Shuai , Lu Guiwu
Published: February 2018

The maximum ZT of n-type Mg3Sb2 can be up to 3.1.
In situ fabrication of two-dimensional g-C3N4/Ba5Ta4O15 nanosheet heterostructures with efficient charge separations and photocatalytic hydrogen evolution under visible light illumination
Authors: Hua Erbing , Liu Gang , Zhang Guan , Xu Xiaoxiang
Published: February 2018

Two dimensional g-C3N4/Ba5Ta4O15 nanosheet heterostructures ensure firm anchorage of g-C3N4 onto Ba5Ta4O15 nanosheets as well as a face-to-face contact.
Modified optical properties via induced cation disorder in self-activated NaMg2V3O10
Authors: Mi Longqing , Huang Yanlin , Cao Lei , Feng Yongyi , Seo Hyo Jin
Published: February 2018

Cation substitutions of (Mo6+ → V5+) and (Na+ → Mg2+) in NaMg2V3O10 induce structural disorder and narrow the band gap. The introduction of cation substitution improved emission and prolonged the lifetime. The thermal stability of phosphors was consolidated by the cation substitution. Cation disorder could be an effective approach to improve the luminescence nature in self-activated phosphors.
Effects of superfoods on risk factors of metabolic syndrome: a systematic review of human intervention trials
Authors: van den Driessche José J. , Plat Jogchum , Mensink Ronald P.
Published: February 2018

A new term was introduced recently to describe foods with additional health benefits: “superfoods”, for which up to date no generally accepted definitions exist. Nonetheless, their consumption might contribute to the prevention of metabolic syndrome.
Studies towards elucidating the potential of 5,10,15,20-tetrakis(p-carboxy-methyleneoxyphenyl)porphyrin as a theranostic agent for applications in PET and PDT
Authors: Guleria Mohini , Kumar Chandan , Das Tapas , Amirdhanayagam Jeyachitra , Sharma Rohit , Sarma Haladhar D. , Dash Ashutosh
Published: February 2018

Demonstration of the theranostic potential of a porphyrin derivative: as a PET agent and a photosensitizer in PDT.
Aurophilicity vs. thiophilicity: directing the crystalline supramolecular arrangement in luminescent gold compounds
Authors: Moreno-Alcántar Guillermo , Romo-Islas Guillermo , Flores-Álamo Marcos , Torrens Hugo
Published: February 2018

The fluorination of thiolate ligands is applied as a tool that allows control of the prevalence of thiophilic (Au–S) interactions over the expected aurophilic contacts in luminescent gold compounds.
The interaction of silver nanoparticles with papain and bromelain
Authors: Li Xiangrong , Yang Zhenhua , Peng Yanru
Published: February 2018

These fundamental studies will provide some new insights into the safe and effective application of AgNPs in biological and medical areas.
Nanoscale mechanism of the stabilization of nanoporous gold by alloyed platinum
Authors: El-Zoka A. A. , Langelier B. , Korinek A. , Botton G. A. , Newman R. C.
Published: February 2018

3D atom maps of Pt-modified nanoporous gold with corresponding cross-sections.
A collaborative strategy for stable lithium metal anodes by using three-dimensional nitrogen-doped graphene foams
Authors: Li Zihao , Li Xianglong , Zhou Lu , Xiao Zhichang , Zhou Shanke , Li Lidong , Zhi Linjie
Published: February 2018

A collaborative strategy is developed for constructing stable lithium metal anodes by using a self-supporting multifunctional host matrix.
Waterborne polyurethanes prepared from benzophenone derivatives with delayed fluorescence and room-temperature phosphorescence
Authors: Wang Tao , Zhou Cao , Zhang Xingyuan , Xu Dong
Published: February 2018

Charge-transfer states serve as a bridge between singlet and triplet states and polymerization can further promote communication between them.
Sequence-dependent attack on peptides by photoactivated platinum anticancer complexes
Authors: Wootton Christopher A. , Sanchez-Cano Carlos , Lopez-Clavijo Andrea F. , Shaili Evyenia , Barrow Mark P. , Sadler Peter J. , O'Connor Peter B.
Published: February 2018

Octahedral anticancer platinum(iv) complexes such as trans,trans,trans-[Pt(N3)2(OH)2(pyridine)2] (1) can target peptides (and proteins) by sequence-dependent platination and radical mechanisms when activated by UVA or visible light; the specific products are highly dependent on their amino acid composition of the peptide.
Complex crystalline structures in a two-dimensional core-softened system
Authors: Kryuchkov Nikita P. , Yurchenko Stanislav O. , Fomin Yury D. , Tsiok Elena N. , Ryzhov Valentin N.
Published: February 2018

A transition from a square to a hexagonal lattice is studied in a 2D system of particles interacting via a core-softened potential.
Ionic liquid syntheses via click chemistry: expeditious routes toward versatile functional materials
Authors: Mirjafari Arsalan
Published: February 2018

The application of click reaction (e.g. CuAAC, thiol–X, oxime formation and nucleophilic ring opening) has recently begun to draw attention for efficient and robust synthesis of new functional ionic liquids, requiring minimal purification.
Singlet and triplet energy transfer dynamics in self-assembled axial porphyrin–anthracene complexes: towards supra-molecular structures for photon upconversion
Authors: Gray Victor , Küçüköz Betül , Edhborg Fredrik , Abrahamsson Maria , Moth-Poulsen Kasper , Albinsson Bo
Published: February 2018

Singlet and triplet energy transfer dynamics in anthracene–ruthenium porphyrin complexes, and their application to photon upconversion.
A macrocyclic silver polycarbene complex based on 1,2,4-triazole units: synthesis and postsynthetic modification
Authors: Zhang Le , Han Ying-Feng
Published: February 2018

A method for the synthesis of a new rectangular 1,2,4-triazole-containing macrocycle via photochemical [2 + 2] cycloaddition with a metal–carbene template was developed.
Clean chlorination of silica surfaces by a single-site substitution approach
Authors: Maity Niladri , Barman Samir , Abou-Hamad Edy , D'Elia Valerio , Basset Jean-Marie
Published: February 2018

Unveiling a clean, selective chlorination method for the quantitative substitution of well-defined non-hydrogen bonded silanol groups of the silica surface.
Yb3+-sensitized upconversion and downshifting luminescence in Nd3+ ions through energy migration
Authors: Zhu Qi , Sun Tianying , Chung Mei Nog , Sun Xinwen , Xiao Yao , Qiao Xvsheng , Wang Feng
Published: February 2018

A core–shell–shell nanostructure composed of NaGdF4:Yb/Tm@NaGdF4:Nd@NaYF4 is developed to realize Yb3+-sensitized upconversion and downshifting luminescence in Nd3+ ions.
Efficient and robust photocatalysts based on {P2W18} modified by an Ag complex
Authors: Fan Xiao-ying , Guo Heng , Lv Jing-hua , Yu Kai , Su Zhan-hua , Wang Lu , Wang Chun-mei , Zhou Bai-bin
Published: February 2018

Ag+ and the flexible ligand bimb were introduced into Dawson phosphomolybdate systems as linkage units to induce two fascinating 3-D inorganic–organic networks, which exhibit excellent electro- and photo-catalytic behavior.
Diversity of metal–organic macrocycles assembled from carbazole based ligands with different lengths
Authors: Yu Hao , Wang Jing , Guo Xiangyang , Zhang Rong , He Cheng , Duan Chunying
Published: February 2018

More species of metal–organic macrocycles coexist in solution due to the increase of the length of the carbazole ligands.
Correction: Colchicine metallocenyl bioconjugates showing high antiproliferative activities against cancer cell lines
Authors: Kowalczyk Karolina , Błauż Andrzej , Ciszewski Wojciech M. , Wieczorek Anna , Rychlik Błażej , Plażuk Damian
Published: February 2018

Correction for ‘Colchicine metallocenyl bioconjugates showing high antiproliferative activities against cancer cell lines’ by Karolina Kowalczyk et al., Dalton Trans., 2017, 46, 17041–17052.
Correction: Challenge in optoelectronic duplex switches: a red emission large-size single crystal and a unidirectional flexible thin film of a hybrid multifunctional material
Authors: Zhu Xiao , Zhang Wan-Ying , Chen Cheng , Ye Qiong , Fu Da-Wei
Published: February 2018

Correction for ‘Challenge in optoelectronic duplex switches: a red emission large-size single crystal and a unidirectional flexible thin film of a hybrid multifunctional material’ by Xiao Zhu et al., Dalton Trans., 2018, DOI: 10.1039/c7dt04489e.
A facile strategy for fabricating AgI–MIL-53(Fe) composites: superior interfacial contact and enhanced visible light photocatalytic performance
Authors: Han Yide , Bai Chunpeng , Zhang Lianxia , Wu Junbiao , Meng Hao , Xu Junli , Xu Yan , Liang Zhiqiang , Zhang Xia
Published: February 2018

Through a simple grinding process, AgI–MIL-53(Fe) composites with superior interfacial contact between AgI and MIL-53(Fe) have been successfully fabricated and exhibit improved visible light photocatalytic activity for dye degradation.
Room temperature ionic liquidsversusorganic solvents as lithium–oxygen battery electrolytes
Authors: Knipping E. , Aucher C. , Guirado G. , Aubouy L.
Published: February 2018

Correlation between the physicochemical properties of ionic liquid-based electrolytes and lithium–oxygen battery performance.
Correction: Band gap modification and photoluminescence enhancement of graphene nanoribbon filled single-walled carbon nanotubes
Authors: Chernov A. I. , Fedotov P. V. , Lim H. E. , Miyata Y. , Liu Z. , Sato K. , Suenaga K. , Shinohara H. , Obraztsova E. D.
Published: February 2018

Correction for ‘Band gap modification and photoluminescence enhancement of graphene nanoribbon filled single-walled carbon nanotubes’ by A. I. Chernov et al., Nanoscale, 2018, DOI: 10.1039/c7nr07054c.
Air promoted annulation of thiophenols with alkynes leading to benzothiophenes
Authors: Wang Yajun , Wu Rui , Zhao Shijun , Quan Zhengjun , Su Yingpeng , Huo Congde
Published: February 2018

Air promoted intermolecular annulation of thiophenols with alkynes, leading to complex benzothiophenes, is reported.
Palladium-catalyzed synthesis of quinolin-2(1H)-ones: the unexpected reactivity of azodicarboxylate
Authors: Peng Jin-Bao , Chen Bo , Qi Xinxin , Ying Jun , Wu Xiao-Feng
Published: February 2018

A Pd(ii)-catalyzed synthesis of quinolin-2(1H)-ones from quinoline N-oxides with azodicarboxylates as the activating agent has been developed.
Tandem radical cyclization for the construction of 1-difluoroalkylated isoquinolines via Cu catalyzed and visible light-promoted pathways
Authors: Ding Fangwei , Jiang Yanqiu , Lin Kaifeng , Shi Lei
Published: February 2018

A Cu/B2pin2 system promoted cyclization for the synthesis of 1-difluoroalkylated isoquinolines with vinyl isocyanides and bromodifluoroacetic derivatives in moderate to good yields was reported.
A visible-light photocatalytic thiolation of aryl, heteroaryl and vinyl iodides
Authors: Czyz M. L. , Weragoda G. K. , Monaghan R. , Connell T. U. , Brzozowski M. , Scully A. D. , Burton J. , Lupton D. W. , Polyzos A.
Published: February 2018

A method for the light-driven synthesis of aryl and vinyl alkyl thioethers from a range of C(sp2)–I bonds is reported.
Conformational properties and the entropic barrier in the “head-on” adsorption of a single polymer chain towards a flat surface
Authors: Wang Yanwei , Shu Xin , Liu Jiaping , Ran Qianping
Published: February 2018

This work investigates the change in conformations and the entropic free energy barrier in the “head-on” adsorption process of a flexible polymer chain towards a flat surface in the framework of the Gaussian chain model.
Identification of progesterone receptor membrane component-1 as an interaction partner and possible regulator of fatty acid 2-hydroxylase
Authors: Hardt Robert , Winter Dominic , Gieselmann Volkmar , Eckhardt Matthias
Published: February 2018

The fatty acid 2-hydroxylase (FA2H) is essential for synthesis of 2-hydroxylated fatty acids in myelinating and other cells, and deficiency of this enzyme causes a complicated form of hereditary spastic paraplegia also known as fatty acid hydroxylase-associated neurodegeneration. Despite its important role in sphingolipid metabolism, regulation of FA2H and its interaction with other proteins involved in the same or other metabolic pathways is poorly understood. To identify potential interaction partners of the enzyme, quantitative mass spectrometry using stable isotope labeling of cells was combined with formaldehyde cross-linking and proximity biotinylation, respectively. Besides other enzymes involved in sphingolipid synthesis and intermembrane transfer of ceramide, and putative redox partners of FA2H, progesterone receptor membrane component-1 (PGRMC1) and PGRMC2 were identified as putative interaction partners. These two related heme-binding proteins are known to regulate several cytochrome P450 enzymes. Bimolecular fluorescence complementation experiments confirmed the interaction of FA2H with PGRMC1. Moreover, the PGRMC1 inhibitor AG-205 significantly reduced synthesis of hydroxylated ceramide and glucosylceramide in FA2H-expressing cells. This suggests that PGRMC1 may regulate FA2H activity, possibly through its heme chaperone activity.
Coronary computed tomography angiography detection of short- and long-term outcomes after heart valve surgery with high risk cardiovascular patients
Authors: Zhu Zhi , Li Shuofeng
Published: February 2018

Coronary computed tomography angiography (CCTA) is a promising alternative technique to detect significant coronary artery lesions in high-risk cardiovascular patients with left ventricular dysfunction (left ventricular ejection fractions < 40%) referred for elective valve surgery, while little research about the use of CCTA to detect the outcomes of heart valve surgery was performed. Forty-six consecutive high-risk cardiovascular patients with the New York Heart Association (NYHA) classification were retrospectively studied. Immediate, 10-week, 20-week, and 40-week outcomes after heart valve surgery were assessed with CCTA. Patients’ average age at the time of surgery was 73 years, with the majority being male (54.35%). Among the CCTA parameters detected after 10, 20, and 40 weeks after heart valve surgery, only segment involvement score (SIS) did reach statistical significance when compared with baseline levels. The cumulative mortality rate at 10, 20, and 40 weeks were 19.56%, 30.43%, and 39.13% respectively. It can be seen that the early death is mainly due to complications, and with the time-lapse of surgery, the impact of complications on death is gradually eliminated. CCTA might be a useful tool to detect the outcomes of short- and long-term outcomes after heart valve surgery with high risk cardiovascular patients, and SIS level is associated with the short- and long-term outcomes.
Broadband radio spectro-polarimetric observations of high-Faraday-rotation-measure AGN
Authors: Pasetto Alice , Carrasco-González Carlos , O’Sullivan Shane , Basu Aritra , Bruni Gabriele , Kraus Alex , Curiel Salvador , Mack Karl-Heinz
Published: February 2018

We present broadband polarimetric observations of a sample of high-Faraday-rotation-measure (high-RM) active galactic nuclei (AGN) using the Karl. G. Jansky Very Large Array (JVLA) telescope from 1 to 2 GHz, and 4 to 12 GHz. The sample (14 sources) consists of very compact sources (linear resolution smaller than ≈5 kpc) that are unpolarized at 1.4 GHz in the NRAO VLA Sky Survey (NVSS). Total intensity data have been modeled using a combination of synchrotron components, revealing complex structure in their radio spectra. Depolarization modeling, through the so-called qu-fitting (the modeling of the fractional quantities of the Stokes Q and U parameters), has been performed on the polarized data using an equation that attempts to simplify the process of fitting many different depolarization models. These models can be divided into two major categories: external depolarization (ED) and internal depolarization (ID) models. Understanding which of the two mechanisms is the most representative would help the qualitative understanding of the AGN jet environment and whether it is embedded in a dense external magneto-ionic medium or if it is the jet-wind that causes the high RM and strong depolarization. This could help to probe the jet magnetic field geometry (e.g., helical or otherwise). This new high-sensitivity data shows a complicated behavior in the total intensity and polarization radio spectrum of individual sources. We observed the presence of several synchrotron components and Faraday components in their total intensity and polarized spectra. For the majority of our targets (12 sources), the depolarization seems to be caused by a turbulent magnetic field. Thus, our main selection criteria (lack of polarization at 1.4 GHz in the NVSS) result in a sample of sources with very large RMs and depolarization due to turbulent magnetic fields local to the source. These broadband JVLA data reveal the complexity of the polarization properties of this class of radio sources. We show how the new qu-fitting technique can be used to probe the magnetized radio source environment and to spectrally resolve the polarized components of unresolved radio sources.
Nitrogen isotope fractionation in protoplanetary disks
Authors: Visser Ruud , Bruderer Simon , Cazzoletti Paolo , Facchini Stefano , Heays Alan N. , van Dishoeck Ewine F.
Published: February 2018

Aims. The two stable isotopes of nitrogen, 14N and 15N, exhibit a range of abundance ratios both inside and outside the solar system. The elemental ratio in the solar neighborhood is 440. Recent ALMA observations showed HCN/HC15N ratios from 83 to 156 in six T Tauri and Herbig disks and a CN/C15N ratio of 323 ± 30 in one T Tauri star. We aim to determine the dominant mechanism responsible for these enhancements of 15N: low-temperature exchange reactions or isotope-selective photodissociation of N2.

Methods. Using the thermochemical code DALI, we model the nitrogen isotope chemistry in circumstellar disks with a 2D axisymmetric geometry. Our chemical network is the first to include both fractionation mechanisms for nitrogen. The model produces abundance profiles and isotope ratios for several key N-bearing species. We study how these isotope ratios depend on various disk parameters.

Results. The formation of CN and HCN is closely coupled to the vibrational excitation of H2 in the UV-irradiated surface layers of the disk. Isotope fractionation is completely dominated by isotope-selective photodissociation of N2. The column density ratio of HCN over HC15N in the disk’s inner 100 au does not depend strongly on the disk mass, the flaring angle or the stellar spectrum, but it is sensitive to the grain size distribution. For larger grains, self-shielding of N2 becomes more important relative to dust extinction, leading to stronger isotope fractionation. Between disk radii of ~50 and 200 au, the models predict HCN/HC15N and CN/C15N abundance ratios consistent with observations of disks and comets. The HCN/HC15N and CN/C15N column density ratios in the models are a factor of 2–3 higher than those inferred from the ALMA observations.