bluuebunny/crossref_metadata_2025 huggingface dataset:
Who should own public science? Preprints, power, and publishers
Authors: Tennant Jon
Published: November 2018

Watch the VIDEO.What is Open Science? When we talk about it, we use technical terms like transparency and reproducibility, or use personal principles like fairness, equality, or justice. But aren’t these just traits of "good" science, conducted by humans with a good ethical purpose? Shouldn’t this be all science..? The problem is that in the present system we aren’t rewarded for doing good science, and academia has become a bit Game of Thrones-y. Almost every conversation about progressing scholarly communication comes down to one thing: Research evaluation and career progression. Researchers are just like everyone else, and aware of the risks associated with driving on the wrong side of the road. Modern research culture tells us not to innovate, not to question, and not to push boundaries. It is perversely non-traditional, and the system is defined by inertia, fear, and skewed power dynamics. How can we all work together to kick-start a new culture of ‘open’ scientific practices, without putting our best and brightest at risk? How do we want people in the future to remember this pivotal time in the history of science? What is the future system that we want students to inherit, and how can we build a path towards that today?
Potential of Positive Leadership for School Improvement
Authors: Louis Karen Seashore , Murphy Joseph F.
Published: November 2018

In this paper, we undertake four formative assignments: (1) We introduce the idea of positive school leadership (PSL) based largely on theory and research conducted outside the educational sector and introduce four orientations that anchor PSL; (2) we develop ideas about how asset-grounded concepts of leadership can be incorporated into schooling; (3) we examine how concepts underlying PSL may affect schools, classrooms, teachers, and students; and (4) using narrative research and grounded theory we introduce an overview of empirical evidence linking PSL and valued outcomes. We conclude by discussing the significance of PSL for organizational theory and leadership preparation and professional development.
Serum Neurofilament light correlates with CADASIL disease severity and survival
Authors: Gravesteijn Gido , Rutten Julie W. , Verberk Inge M. W. , Böhringer Stefan , Liem Michael K. , van der Grond Jeroen , Aartsma‐Rus Annemieke , Teunissen Charlotte E. , Lesnik Oberstein Saskia A. J.
Published: November 2018

Objective

To validate whether serum Neurofilament Light‐chain (NfL) levels correlate with disease severity in CADASIL, and to determine whether serum NfL predicts disease progression and survival.

Methods

Fourty‐one (pre‐) manifest individuals with CADASIL causing NOTCH3 mutations and 22 healthy controls were recruited from CADASIL families. At baseline, MRI‐lesion load and clinical severity was determined and serum was stored. Disease progression was measured in 30/41 patients at 7‐year follow‐up, and survival of all individuals was determined at 17‐year follow‐up. Serum NfL levels were quantified using an ultra‐sensitive molecule array. Generalized estimated equation regression (GEE) was used to analyze association between serum NfL, MRI‐lesion load, disease severity, and disease progression. With GEE‐based Cox regression, survival was analyzed.

Results

At baseline, serum NfL levels correlated with MRI‐lesion load [lacune count (s = 0.64, P = 0.002), brain atrophy (r = −0.50, P = 0.001), and microbleed count (s = 0.48, P = 0.044)], cognition [CAMCOG (s = −0.45, P = 0.010), MMSE (r = −0.61, P = 0.003), GIT (r = −0.61, P < 0.001), TMT‐A (r = 0.70, P < 0.001)) and disability (mRS (r = 0.70, P = 0.002)]. Baseline serum NfL predicted 7‐year changes in disability (B = 0.34, P < 0.001) and cognition (CAMCOG B = −4.94, P = 0.032), as well as 17‐year survival. Higher NfL levels were associated with increased mortality (HR=1.8 per twofold increase in NfL levels, P = 0.006).

Interpretation

Serum NfL levels correlate with disease severity, disease progression and 17‐year survival in CADASIL patients. Serum NfL is a promising biomarker to monitor and predict disease course in CADASIL, as well as potentially assessing therapeutic response in future clinical trials.
Polyhedral Oligomeric Silsesquioxane (POSS) Nano‐Composite Separation Membranes − A Review
Authors: Chen Xiao , Dumée Ludovic F.
Published: November 2018

Nano‐composite membranes are developed to overcome the limitation on trade‐off effect of permeability and selectivity from commercial membranes, however, careful selection of the nano‐fillers is required to match the selection criteria for specific applications. Polyhedral oligomeric silsesquioxane (POSS) nano‐particles are studied as the filler for nano‐composite membrane design for their unique 3‐dimensional building block property and flexible functionality toward the enhancement of separation. The review paper presents the benefits brought by POSS for nano‐composite membranes design, systematically compared to pristine or reference membranes. The scope of the review comprehensively includes liquid separation driven by pressure, desalination, solvent separation, gas separation, and proton exchange membranes. The free volume and surface charge modification as well as the structural enhancement from POSS incorporation are highlighted as keys to affect the trade‐off between permeation and selectivity and future developments for POSS nano‐composite membranes are discussed.
Sex differences in the genetic architecture of obsessive–compulsive disorder
Authors: Khramtsova Ekaterina A. , Heldman Raphael , Derks Eske M. , Yu Dongmei ,   Tourette Syndrome/Obsessive‐Compulsive Disorder Working Group of the Psychiatric Genomics Consortium, Davis Lea K. , Stranger Barbara E.
Published: November 2018

Obsessive–compulsive disorder (OCD) is a highly heritable complex phenotype that demonstrates sex differences in age of onset and clinical presentation, suggesting a possible sex difference in underlying genetic architecture. We present the first genome‐wide characterization of the sex‐specific genetic architecture of OCD, utilizing the largest set of OCD cases and controls available from the Psychiatric Genomics Consortium. We assessed evidence for several mechanisms that may contribute to sex differences including a sex‐dependent liability threshold, the presence of individual sex‐specific risk variants on the autosomes and the X chromosome, and sex‐specific pleiotropic effects. Furthermore, we tested the hypothesis that genetic heterogeneity between the sexes may obscure associations in a sex‐combined genome‐wide association study. We observed a strong genetic correlation between male and female OCD and no evidence for a sex‐dependent liability threshold model, suggesting that sex‐combined analysis does not suffer from widespread loss of power because of genetic heterogeneity between the sexes. While we did not detect any significant sex‐specific genome‐wide single nucleotide polymorphisms (SNP) associations, we did identify two significant gene‐based associations in females: GRID2 and GRP135, which showed no association in males. We observed that the SNPs with sexually differentiated effects showed an enrichment of regulatory variants influencing expression of genes in brain and immune tissues. These findings suggest that future studies with larger sample sizes hold great promise for the identification of sex‐specific genetic risk factors for OCD.
Visualisierung der Phasensegregation in Gemischthalogenid‐ Perowskiteinkristallen
Authors: Mao Wenxin , Hall Christopher R. , Chesman Anthony S. R. , Forsyth Craig , Cheng Yi‐Bing , Duffy Noel W. , Smith Trevor A. , Bach Udo
Published: November 2018

Es hat sich gezeigt, dass Organoblei‐Gemischthalogenid‐Perowskite (MOHPs), CH3NH3Pb(BrxI1−x)3, unter Belichtung eine Phasensegregation zu I‐reichen Domänen eingehen, was eine Herausforderung für ihre Nutzung in Photovoltaik‐ und lichtemittierenden Elementen darstellt. Auf Basis neuster Resultate wird vermutet, dass die Phasensegregation entlang der Kristallkanten lokalisiert ist, weshalb sich die Forschung auf die Rolle von Grenzstrukturen und das Züchten größerer Kristalle mit geringerer Oberfläche konzentrierte. Hier wird eine Methode zur Züchtung großer (30×30×1 μm3) monokristalliner MA(BrxI1−x)3‐Einkristalle präsentiert. Durch direkte Visualisierung des Wachstums nanoclusterartiger I‐reicher Domänen über den gesamten Kristall hinweg konnte gezeigt werden, dass für diese Transformation Korngrenzen nicht essenziell sind. Bildgebende Verfahren auf Basis schmalbandiger Fluoreszenz sowie zeitaufgelöste Spektroskopie gaben neue Einblicke in die Phasensegregationsdomänen sowie deren Auswirkungen auf optoelektronische Eigenschaften dieser Materialien.
Catalytic C1 Alkylation with Methanol and Isotope‐Labeled Methanol
Authors: Sklyaruk Jan , Borghs Jannik C. , El‐Sepelgy Osama , Rueping Magnus
Published: November 2018

A metal‐catalyzed methylation process has been developed. By employing an air‐ and moisture‐stable manganese catalyst together with isotopically labeled methanol, a series of D‐, CD3‐, and 13C‐labeled products were obtained in good yields under mild reaction conditions with water as the only byproduct.
Reactive Dimerization of an N‐Heterocyclic Plumbylene: C−H Activation with PbII
Authors: Guthardt Robin , Oetzel Jan , Schweizer Julia I. , Bruhn Clemens , Langer Robert , Maurer Martin , Vícha Jan , Shestakova Pavletta , Holthausen Max C. , Siemeling Ulrich
Published: November 2018

The N‐heterocyclic plumbylene [Fe{(η5‐C5H4)NSiMe3}2Pb:] is in equilibrium with an unprecedented dimer in solution, whose formation involves the cleavage of a strong C−H bond and concomitant formation of a Pb−C and an N−H bond. According to a mechanistic DFT assessment, dimer formation does not involve direct PbIIinsertion into a cyclopentadienyl C−H bond, but is best described as an electrophilic substitution. The bulkier plumbylene [Fe{(η5‐C5H4)NSitBuMe2}2Pb:] shows no dimerization, but compensates its electrophilicity by the formation of an intramolecular Fe−Pb bond.
Visualizing Phase Segregation in Mixed‐Halide Perovskite Single Crystals
Authors: Mao Wenxin , Hall Christopher R. , Chesman Anthony S. R. , Forsyth Craig , Cheng Yi‐Bing , Duffy Noel W. , Smith Trevor A. , Bach Udo
Published: November 2018

Mixed organolead halide perovskites (MOHPs), CH3NH3Pb(BrxI1−x)3, have been shown to undergo phase segregation into iodide‐rich domains under illumination, which presents a major challenge to their development for photovoltaic and light‐emitting devices. Recent work suggested that phase‐segregated domains are localized at crystal boundaries, driving investigations into the role of edge structure and the growth of larger crystals with reduced surface area. Herein, a method for growing large (30×30×1 μm3) monocrystalline MAPb(BrxI1−x)3 single crystals is presented. The direct visualization of the growth of nanocluster‐like I‐rich domains throughout the entire crystal revealed that grain boundaries are not required for this transformation. Narrowband fluorescence imaging and time‐resolved spectroscopy provided new insight into the nature of the phase‐segregated domains and the collective impact on the optoelectronic properties.
Surface Modification Based on Diselenide Dynamic Chemistry: Towards Liquid Motion and Surface Bioconjugation
Authors: Xia Jiahao , Zhao Peng , Zheng Ke , Lu Chenjie , Yin Shouchun , Xu Huaping
Published: November 2018

Surface modification is an important technique in fields, such as, self‐cleaning, surface patterning, sensing, and detection. The diselenide bond was shown to be a dynamic covalent bond that can undergo a diselenide metathesis reaction simply under visible light irradiation. Herein we develop this diselenide dynamic chemistry into a versatile surface modification method with a fast response and reversibility. The diselenide bond could be modified onto various substrates, such as, PDMS, quartz, and ITO conductive film glass. Different functional diselenide molecules could then be immobilized onto the surface via diselenide metathesis reaction. We demonstrated that by using this modification method we could achieve liquid motion in a capillary tube under light illumination. We also show that this approach has the potential to serve as an efficient modification method for surface bioconjugation, which has practical applications in clinical usage.
Exceptionally Long C−C Single Bonds in Diamino‐o‐carborane as Induced by Negative Hyperconjugation
Authors: Li Junxia , Pang Ronglin , Li Zhifang , Lai Guoqiao , Xiao Xu‐Qiong , Müller Thomas
Published: November 2018

The synthesis of a series of 1,2‐diamino‐o‐carboranes (1–4) is reported. The molecular structures of these diamino‐o‐carboranes are remarkable as the inner‐cluster C−C bonds are all ultra‐long (162.7–193.1 pm) and vary substantially with small variations in the substituents. The results of quantum mechanical investigations suggest that the origin of the bond elongation is significant in‐plane negative hyperconjugation of lone pairs of the nitrogen substituents with the σ* orbitals of the C−C bonds in o‐carboranes.
Pd‐Catalyzed Enantioselective Ring Opening/Cross‐Coupling and Cyclopropanation of Cyclobutanones
Authors: Cao Jian , Chen Ling , Sun Feng‐Na , Sun Yu‐Li , Jiang Ke‐Zhi , Yang Ke‐Fang , Xu Zheng , Xu Li‐Wen
Published: November 2018

A palladium‐catalyzed enantioselective sequential ring‐opening/cross‐coupling of cyclobutanones is disclosed that provides chiral indanones bearing C3‐quaternary stereocenters. The reaction process involves palladium‐catalyzed nucleophilic addition of cyclobutanones and aryl halides, enantioselective β‐carbon elimination, and intermolecular trapping of a transient σ‐alkylpalladium complex with boronic acids. Alternatively, an intramolecular cyclopropanation is realized through C−H bond functionalization in the absence of external coupling reagents, affording chiral cyclopropane‐fused‐indanones in good yields and enantioselectivity.
Synthesis of Porous Covalent Quinazoline Networks (CQNs) and Their Gas Sorption Properties
Authors: Buyukcakir Onur , Yuksel Recep , Jiang Yi , Lee Sun Hwa , Seong Won Kyung , Chen Xiong , Ruoff Rodney S.
Published: November 2018

The development of different classes of porous polymers by linking organic molecules using new chemistries still remains a great challenge. Herein, we introduce for the first time the synthesis of covalent quinazoline networks (CQNs) using an ionothermal synthesis protocol. Zinc chloride (ZnCl2) was used as the solvent and catalyst for the condensation of aromatic ortho‐aminonitriles to produce tricycloquinazoline linkages. The resulting CQNs show a high porosity with a surface area up to 1870 m2 g−1. Varying the temperature and the amount of catalyst enables us to control the surface area as well as the pore size distribution of the CQNs. Furthermore, their high nitrogen content and significant microporosity make them a promising CO2 adsorbent with a CO2 uptake capacity of 7.16 mmol g−1 (31.5 wt %) at 273 K and 1 bar. Because of their exceptional CO2 sorption properties, they are promising candidates as an adsorbent for the selective capture of CO2 from flue gas.
A cost‐effective shortcut to prepare organoselenium catalysts via decarboxylative coupling of phenylacetic acid with elemental selenium
Authors: Cao Hongen , Liu Mingxuan , Qian Rongrong , Zhang Xu , Yu Lei
Published: November 2018

An interesting decarboxylative coupling reaction of phenylacetic acid with elemental selenium was discovered and employed for the preparation efficient organoselenium catalysts for Baeyer–Villiger reaction and oxidative deoximation reaction. Compared with the traditionally used Grignard reagent method, the decarboxylative coupling reaction with selenium powders provides a shortcut for the preparation of organoselenium catalysts free of carcinogenic organohalide starting materials, toxic and odorous selenol intermediates and magnesium salt solid wastes. This may be helpful for reducing the cost of selenium catalysts to facilitate the application of organoselenium‐catalyzed green reactions in large‐scale production.
Quinoline and ferrocene conjugates: Synthesis, computational study and biological evaluations
Authors: Maračić Silvija , Lapić Jasmina , Djaković Senka , Opačak‐Bernardi Teuta , Glavaš‐Obrovac Ljubica , Vrček Valerije , Raić‐Malić Silvana
Published: November 2018

Novel O‐alkylated quinoline and N‐alkylated 4‐quinolone derivatives attached to the ferrocene moiety through 4,1‐ (7a–d, 8a–d and 12a–d) and 1,4‐disubstituted (9a, 9b, 10a and 10b) 1,2,3‐triazole moiety were synthesized. The observed regioselectivity of O‐ vs. N‐alkylation was explored by the use of NMR and computational techniques. Among the N‐alkylated derivatives, the quinolone‐ferrocene conjugate 9a displayed marked activities against chronic myeloid leukemia in blast crisis (K562) and Burkitt lymphoma (Raji). The 6‐chloroquinolone‐ferrocene conjugate 12c, with selective inhibitory activity on Raji cells and no cytostatic effect on normal MDCK1 cells was highlighted as the most promising anticancer organometallic complex in a group of O‐alkylated quinolines.
Threonine stabilizer‐controlled well‐dispersed small palladium nanoparticles on modified magnetic nanocatalyst for Heck cross‐coupling process in water
Authors: Sarvi Iraj , Gholizadeh Mostafa , Izadyar Mohammad
Published: November 2018

We report the synthesis of magnetically separable Fe3O4@Silica‐Threonine‐Pd0 magnetic nanoparticles with a core–shell structure. After synthesis of Fe3O4@Silica, threonine as an efficient stabilizer/ligand was bonded to the surface of Fe3O4@Silica. Then, palladium nanoparticles were generated on the threonine‐modified catalyst. The threonine stabilizer helps to generate palladium nanoparticles of small size (less than 4 nm) with high dispersity and uniformity. Magnetically separable Fe3O4@Silica‐Threonine‐Pd0 nanocatalyst was fully characterized using various techniques. This nanocatalyst efficiently catalysed the Heck cross‐coupling reaction of a variety of substrates in water medium as a green, safe and inexpensive solvent at 80°C. The Fe3O4@Silica‐Threonine‐Pd0 catalyst was used for at least eight successful consecutive runs with palladium leaching of only 0.05%.
A new air‐stable and reusable tetraphosphine ligand for rhodium‐catalyzed hydroformylation of terminal olefins at low temperature
Authors: Zhou Fanding , Zhang Lin , Wu Qianhui , Guo Fuya , Tang Songbai , Xu Bin , Yuan Maolin , Fu Haiyan , Li Ruixiang , Zheng Xueli , Chen Hua
Published: November 2018

Tetraphosphine and bisphosphine ligands were synthesized, characterized and employed in Rh‐catalyzed hydroformylation of 1‐octene and 1‐hexene. Conversion of over 97.7% and aldehyde yield of 94.1% were achieved at 60°C, 20 bar. This remarkable performance could also be retained at lower temperature (i.e. 40°C) by prolonging the reaction time. The tetraphosphine ligand‐modified Rh catalyst could be reused for at least seven successive runs with catalytic activity and selectivity almost unchanged; the catalyst was separated from the products and recycled directly in homogeneous hydroformylation, indicating that the catalyst might have good stability. 31P NMR and high‐resolution mass spectral characterization hinted that the reason for the reusability of the catalyst might be that the tetraphosphine ligand is relatively air‐stable and is probably slowly oxidized during the recycling runs. The tetraphosphine ligand has four phosphorus atoms to be partially oxidized and could still coordinate with the Rh center via the unoxidized phosphorus atoms to stabilize the catalyst, based on the multiple chelating modes of the tetraphosphine ligand. Hence, the catalytic activity and selectivity could be retained for a certain number of runs.
Isophorone‐boronate ester: A simple chemosensor for optical detection of fluoride anion
Authors: Ranjith Kumar Jakku , Rami Reddy Eda , Trivedi Rajiv , Vardhaman Anil Kumar , Giribabu Lingamallu , Mirzadeh Nedaossadat , Bhargava Suresh K.
Published: November 2018

A highly selective isophorone‐boronate ester based chemosensor, (1), having a dicyanovinyl moiety as a convenient colorimetric probe, has been designed. Different types of anionic analyte such as CH3COO−, ClO4−, Cl−, F−, PF6−, Br− and HSO4− were tested and among them only highly nucleophilic F− anion displayed significant response towards the sensor. Addition of the fluoride anion across the boron atom disrupts the π‐conjugation thereby shifts the absorption wavelength towards the redshift region due to the decrease in the HOMO‐LUMO energy gap and a colour change from yellow to blue is observed under visible light condition. The detection limit of this probe was calculated to be 3.25 × 10—8 M for fluoride anion. The binding constants and the detection limits of the sensor were calculated using absorption titration studies. The silica gel TLC strips dip‐coated by the chemosensor (1) revealed a colour change from yellow to brick red to naked eye.
Synthesis and Structures of Arene Ruthenium (II)–NHC Complexes: Efficient Catalytic α‐alkylation of ketones via Hydrogen Auto Transfer Reaction
Authors: Balamurugan Gunasekaran , Balaji Sundarraman , Ramesh Rengan , Bhuvanesh Nattamai S.P.
Published: November 2018

A panel of six new arene Ru (II)‐NHC complexes 2a‐f, (NHC = 1,3‐diethyl‐(5,6‐dimethyl)benzimidazolin‐2‐ylidene 1a, 1,3‐dicyclohexylmethyl‐(5,6‐dimethyl)benzimidazolin‐2‐ylidene 1b and 1,3‐dibenzyl‐(5,6‐dimethyl)benzimidazolin‐2‐ylidene 1c) were synthesized from the transmetallation reaction of Ag‐NHC with [(η6‐arene)RuCl2]2 and characterized. The ruthenium (II)‐NHC complexes 2a‐f were developed as effective catalysts for α‐alkylation of ketones and synthesis of bioactive quinoline using primary/amino alcohols as coupling partners respectively. The reactions were performed with 0.5 mol% catalyst load in 8 h under aerobic condition and the maximum yield was up to 96%. Besides, the different alkyl wingtips on NHC and arene moieties were studied to differentiate the catalytic robustness of the complexes in the transformations.
A comparative assessment of the difficulty of authorship attribution in Greek and in English
Authors: Juola Patrick , Mikros George K. , Vinsick Sean
Published: November 2018

Authorship attribution is an important problem in text classification, with many applications and a substantial body of research activity. Among the research findings are that many different methods will work, including a number of methods that are superficially language‐independent (such as an analysis of the most common “words” or “character n‐grams” in a document). Since all languages have words (and all written languages have characters), this method could (in theory) work on any language. However, it is not clear that the methods that work best on, for example English, would also work best on other languages. It is not even clear that the same level of performance is achievable in different languages, even under identical conditions. Unfortunately, it is very difficult to achieve “identical conditions” in practice. A new corpus, developed by George Mikros, provides very tight controls not only for author but also for topic, thus enabling a direct comparison of performance levels between the two languages Greek and English. We compare a number of different methods head‐to‐head on this corpus, and show that, overall, performance on English is higher than performance on Greek, often highly significantly so.
First Report about Mineral Content, Fatty Acids Composition and Biological Activities of Four Wild Edible Mushrooms
Authors: Dimitrijevic Marija V. , Mitic Violeta D. , Nikolic Jelena S. , Djordjevic Aleksandra S. , Mutic Jelena J. , Stankov Jovanovic Vesna P. , Stojanovic Gordana S.
Published: November 2018

The goal of this research was a comprehensive analysis of four wild edible mushroom species, Cantharellus cinereus, Clavariadelphus pistillaris, Clitocybe nebularis and Hygrocybe punicea, which have not been analyzed so far. Extracts of different polarities have been prepared and evaluated for their antioxidant activities by DPPH, ABTS, FRAP, TRP and CUPRAC methods. For all extracts, total phenolic content was determined. Based on the analysis, it was shown that solvent type had a significant effect on the antioxidant capacities of mushroom extracts, so water extracts showed the highest activity. Furthermore, the analysis includes determination of mineral composition, fatty acid profiles and antimicrobial activity. Unsaturated fatty acids, which are very important for human health, are dominant in the studied mushroom species. Linoleic and oleic acid consist of over 50 % of the total fatty acid composition. Seventeen biologically important and toxic elements have been analyzed by ICP‐OES and ICP‐MS and results showed that the element concentrations were species‐dependent. Also, it has been found that analyzed mushrooms did not show any antimicrobial activity. Chemometric analysis was used to understand the connection between the extracts of different polarities.
Development of Sulfonic‐Acid‐Functionalized Mesoporous Materials: Synthesis and Catalytic Applications
Authors: Doustkhah Esmail , Lin Jianjian , Rostamnia Sadegh , Len Christophe , Luque Rafael , Luo Xiliang , Bando Yoshio , Wu Kevin C.‐W. , Kim Jeonghun , Yamauchi Yusuke , Ide Yusuke
Published: November 2018

Sulfonic acid based mesostructures (SAMs) have been developed in recent years and have important catalytic applications. The primary applications of these materials are in various organic synthesis reactions, such as multicomponent reactions, carbon–carbon bond couplings, protection reactions, and Fries and Beckman rearrangements. This review aims to provide an overview of the recent developments in the field of SAMs with a particular emphasis on the reaction scope and advantages of heterogeneous solid acid catalysts.
Polar‐Group Activated Isospecific Coordination Polymerization of ortho‐Methoxystyrene: Effects of Central Metals and Ligands
Authors: Chai Yunjie , Wang Lingfang , Liu Dongtao , Wang Zichuan , Run Mingtao , Cui Dongmei
Published: November 2018

Stereoselective polymerization of polar vinyl monomers has been a long‐standing challenge because the employed transition‐metal catalysts are easily poisoned by polar groups of monomers. In this contribution, a series of β‐diketiminato rare‐earth metal complexes 1–5 (L1–5Ln(CH2SiMe3)2(THF)n, Ln=Gd–Lu, Y, and Sc) were successfully synthesized. In combination with AliBu3 and [Ph3C][B(C6F5)4], complexes 1 c(Tb)–1 g(Tm) exhibited high activities and excellent isoselectivities for the polymerization of ortho‐methoxystyrene (oMOS), in which, the polar methoxy group of oMOS did not poison but activated the polymerization through σ–π chelation to the active species together with the vinyl group. Moreover, the large Gd‐attached precursor 1 b showed a higher activity, albeit with a slightly decreased isoselectivity. The small Sc‐attached precursor 1 i was completely inert. Meanwhile, the spatial steric arrangement and the coordination mode of the β‐diketiminato ligand could clearly affect and even block oMOS polymerization. This work sheds new light on the coordination polymerization of polar monomers.
Diverse Reactivity of Dienes with Pentaphenylborole and 1‐Phenyl‐2,3,4,5‐Tetramethylborole Dimer
Authors: Baker J. J. , Al Furaiji Khadilah H. M. , Liyanage O. Tara , Wilson David J. D. , Dutton Jason L. , Martin Caleb D.
Published: November 2018

The reactions of a monomeric borole and a dimeric borole with 2,3‐dimethyl‐1,3‐butadiene and 1,3‐cyclohexadiene were investigated. The monomeric borole reacted at ambient temperature whereas heat was required to crack the dimer to form the monomer and induce reactivity. 2,3‐Dimethyl‐1,3‐butadiene reacts to give diverse products resulting from a cycloaddition process with the B−C moiety of the boroles acting as a dienophile, followed by rearrangements to furnish bicyclic species. For 1,3‐cyclohexadiene, a [4+2] process is observed in which 1,3‐cyclohexadiene serves as the dienophile and the boroles as the diene partner. The experimental results are corroborated with mechanistic theoretical calculations that indicate boroles can serve as either a diene or dienophile in cycloaddition reactions with dienes.
Adsorption of Cyclohexane in Pure Silica Zeolites: High‐Throughput Computational Screening Validated by Experimental Data
Authors: Sławek Andrzej , Grzybowska Karolina , Vicent‐Luna José Manuel , Makowski Wacław , Calero Sofía
Published: November 2018

Adsorption of cyclohexane in pure silica zeolites was studied experimentally and by molecular simulations. Based on the adsorption isobars obtained from the quasi‐equilibrated temperature adsorption and desorption (QE‐TPDA) measurements and reported adsorption isotherms for high‐silica zeolites Y, ZSM‐5, and ZSM‐11 we refined Lennard‐Jones parameters for guest‐host interactions available in the literature. Adsorption of cyclohexane from equimolar mixture of twisted‐boat and chair conformations has been screened in 171 pure silica zeolitic structures using grand canonical Monte Carlo simulations. Almost 20 frameworks showing extraordinary preference for adsorption of the chair conformation over the twisted boat one or vice versa were found. This selectivity was attributed to the geometry of channels and cavities present in the pore structures, as all t‐boat selective structures possess channels or cavities of 8.3–9.1 Å. We also differentiated ways of chair‐selectivity depending on the size and shape of the channels or cavities and also on the arrangement of the guest molecules in the pores.
A Model‐Based Meta‐Analysis of 24 Antihyperglycemic Drugs for Type 2 Diabetes: Comparison of Treatment Effects at Therapeutic Doses
Authors: Maloney Alan , Rosenstock Julio , Fonseca Vivian
Published: November 2018

Model‐based meta‐analysis was used to compare glycemic control, weight changes, and hypoglycemia risk across 24 antihyperglycemic drugs used to treat type 2 diabetes. Electronic searches identified 229 randomized controlled studies comprising 121,914 patients. To ensure fair and unbiased treatment comparisons, the analyses adjusted for important differences between studies, including duration of treatment, baseline glycated hemoglobin, and drug dosages. At the approved doses, glycemic control was typically greatest with glucagon‐like peptide 1 receptor agonists (GLP‐1RAs), and least with dipeptidyl peptidase‐4 (DPP‐4) inhibitors. Weight loss was highly variable across GLP‐1RAs but was similar across sodium‐glucose cotransporter 2 (SGLT2) inhibitors. Large weight increases were observed with sulfonylureas and thiazolidinediones. Hypoglycemia risk was highest with sulfonylureas, although gliclazide was notably lower. Hypoglycemia risk for DPP‐4 inhibitors, SGLT2 inhibitors, and thiazolidinediones was generally very low but increased slightly for both GLP‐1RAs and metformin. In summary, important differences between and within drug classes were identified.
Synthesis, Crystal Growth, and Optical Characterization of a Novel Nonlinear Optical Organic Material: N,N‐Diarylbenzamide
Authors: Lakshmi Radhakrishnan , Prabukanthan Peethambaram , Harichandran Gurusamy , Sudarsana Kumar C.
Published: November 2018

Nonlinear optical organic materials of N,N‐diphenylbenzamide (NNDPB) and 4‐fluoro‐N,N‐diphenylbenzamide (FNNDPB) are synthesized from benzoylation of N,N‐diphenylamine using the substituted benzoyl chlorides. The single crystals of NNDPB and FNNDPB are grown by a slow evaporation technique. Single‐crystal X‐ray diffraction shows that both the crystals belong to orthorhombic crystallographic system with space group Pbca. Fourier transform infrared spectrum shows the chemical bonding and various functional groups, the carbonyl peak appeared at 1647 and 1651 cm−1 in NNDPB and FNNDPB compounds, respectively. 1H and 13C nuclear magnetic resonance analysis examines the placement of aromatic protons and carbons are identified to the synthesized materials. UV–vis near IR spectra analysis showed 100% transmission in the visible region for both NNDPB and FNNDPB crystals. As‐grown crystal dielectric constant and dielectric loss are inversely proportional to the frequency at all the temperatures. The thermal properties of NNDPB and FNNDPB crystals are studied from thermogravimetric analysis/differential thermal analysis analysis, it is thermally stable up to 483 and 503 K. Crystal growth mechanism and defects are observed from etching studies. The relative second harmonic generation efficiency is measured by Kurtz–Perry powder technique and is found to be 1.55 and 1.7 times as that of potassium dihydrogen phosphate.
Microsponge: An emerging drug delivery strategy
Authors: Singhvi Gautam , Manchanda Prachi , Hans Neha , Dubey Sunil K. , Gupta Gaurav
Published: November 2018

Microsponges are the spherical particles ranging from 5 to 300 μm in size. These are further made up of clusters of smaller spheres. They are designed for delivering the drug efficiently at a comparatively lesser dose and enhancing the stability, modifying the drug release profile and minimizing the side effects. Microsponge drug delivery system decrease transdermal invasion of the active ingredient into the skin while increasing the time the drug remains on the skin surface or within the epidermis. Preparation of the microsponges includes two techniques: Liquid–liquid suspension polymerization and Quasi‐emulsion solvent diffusion method. Their characterization and evaluation can be done in many ways like particle‐size measurement and porosity, morphology, true density determination, analyzing the rheological properties, and dissolution studies. Present work focuses on the detailed study of the microsponge drug delivery system. This will help the reader to get all the information regarding the microsponge delivery systems.
Numerical response of mammalian carnivores to rodents affects bird reproduction in temperate forests: A case of apparent competition?
Authors: Grendelmeier Alex , Arlettaz Raphaël , Pasinelli Gilberto
Published: November 2018

Resource pulses such as mast seeding in temperate forests may affect interspecific interactions over multiple trophic levels and link different seed and nonseed consumers directly via predation or indirectly via shared predators. However, the nature and strength of interactions among species remain unknown for most resource pulse–driven ecosystems. We considered five hypotheses concerning the influence of resource pulses on the interactions between rodents, predators, and bird reproduction with data from northern Switzerland collected between 2010 and 2015. In high‐rodent‐abundance‐years (HRAYs), wood warbler (Phylloscopus sibilatrix) nest survival was lower than in low‐rodent‐abundance‐years, but rodents were not important nest predators, in contrast to rodent‐hunting predators. The higher proportion of nests predated by rodent‐hunting predators and their increased occurrence in HRAYs suggests a rodent‐mediated aggregative numerical response of rodent‐hunting predators, which incidentally prey on the wood warbler's ground nests. There was no evidence that rodent‐hunting predators responded behaviorally by switching prey. Lastly, nest losses caused by nonrodent‐hunting predators were not related to rodent abundance. We show that wood warblers and rodents are linked via shared predators in a manner consistent with apparent competition, where an increase of one species coincides with the decrease of another species mediated by shared predators. Mast seeding frequency and annual seed production appear to have increased over the past century, which may result in more frequent HRAYs and generally higher peaking rodent populations. The associated increase in the magnitude of apparent competition may thus at least to some extent explain the wood warbler's decline in much of Western Europe.
Direct and Selective C‐H Carbamoylation of (Hetero)aromatics with TMSOTf‐Activated Carbamoyl Chloride
Authors: Uehara Ayaka , Olivero Sandra , Michelet Bastien , Martin‐Mingot Agnès , Thibaudeau Sébastien , Duñach Elisabet
Published: November 2018

Exploiting trimethylsilyltrifluoromethanesulfonate as Lewis acid, (hetero)aromatics underwent regioselective and direct carbamoylation. The method is based on the in situ generation of a highly electrophilic carbamoyl triflate active species.
Improved electrocompetence and metabolic engineering of Clostridium pasteurianum reveals a new regulation pattern of glycerol fermentation
Authors: Schmitz Rebekka , Sabra Wael , Arbter Philipp , Hong Yaeseong , Utesch Tyll , Zeng An‐Ping
Published: November 2018

Clostridium pasteurianum produces industrially valuable chemicals such as n‐butanol and 1,3‐propanediol from fermentations of glycerol and glucose. Metabolic engineering for increased yields of selective compounds is not well established in this microorganism. In order to study carbon fluxes and to selectively increase butanol yields, we integrated the latest advances in genome editing to obtain an electrocompetent Clostridium pasteurianum strain for further engineering. Deletion of the glycerol dehydratase large subunit (dhaB) using an adapted S. pyogenes Type II CRISPR/Cas9 nickase system resulted in a 1,3‐propanediol‐deficient mutant producing butanol as the main product. Surprisingly, the mutant was able to grow on glycerol as the sole carbon source. In spite of reduced growth, butanol yields were highly increased. Metabolic flux analysis revealed an important role of the newly identified electron bifurcation pathway for crotonyl‐CoA to butyryl‐CoA conversion in the regulation of redox balance. Compared to the parental strain, the electron bifurcation pathway flux of the dhaB mutant increased from 8 to 46% of the overall flux from crotonyl‐CoA to butyryl‐CoA and butanol, indicating a new, 1,3‐propanediol‐independent pattern of glycerol fermentation in Clostridium pasteurianum.
PPARβ/δ‐agonist GW0742 ameliorates dysfunction in fatty acid oxidation in PSEN1ΔE9 astrocytes
Authors: Konttinen Henna , Gureviciene Irina , Oksanen Minna , Grubman Alexandra , Loppi Sanna , Huuskonen Mikko T. , Korhonen Paula , Lampinen Riikka , Keuters Meike , Belaya Irina , Tanila Heikki , Kanninen Katja M. , Goldsteins Gundars , Landreth Gary , Koistinaho Jari , Malm Tarja
Published: November 2018

Astrocytes are the gatekeepers of neuronal energy supply. In neurodegenerative diseases, bioenergetics demand increases and becomes reliant upon fatty acid oxidation as a source of energy. Defective fatty acid oxidation and mitochondrial dysfunctions correlate with hippocampal neurodegeneration and memory deficits in Alzheimer's disease (AD), but it is unclear whether energy metabolism can be targeted to prevent or treat the disease. Here we show for the first time an impairment in fatty acid oxidation in human astrocytes derived from induced pluripotent stem cells of AD patients. The impairment was corrected by treatment with a synthetic peroxisome proliferator activated receptor delta (PPARβ/δ) agonist GW0742 which acts to regulate an array of genes governing cellular metabolism. GW0742 enhanced the expression of CPT1a, the gene encoding for a rate‐limiting enzyme of fatty acid oxidation. Similarly, treatment of a mouse model of AD, the APP/PS1‐mice, with GW0742 increased the expression of Cpt1a and concomitantly reversed memory deficits in a fear conditioning test. Although the GW0742‐treated mice did not show altered astrocytic glial fibrillary acidic protein‐immunoreactivity or reduction in amyloid beta (Aβ) load, GW0742 treatment increased hippocampal neurogenesis and enhanced neuronal differentiation of neuronal progenitor cells. Furthermore, GW0742 prevented Aβ‐induced impairment of long‐term potentiation in hippocampal slices. Collectively, these data suggest that PPARβ/δ‐agonism alleviates AD related deficits through increasing fatty acid oxidation in astrocytes and improves cognition in a transgenic mouse model of AD.
Condensations based on 5‐(indol‐3‐yl)‐pyrrolidin‐2‐thiones
Authors: Sadovoy Andrey V. , Kattsyna Veronica V. , Protopopova Polina S. , Nelyubina Yulia V. , Pavlov Alexander A. , Kochetkov Konstantin A. , Sviridova Lyudmila A.
Published: November 2018

New activated indolylpyrrolidones—their methylthiopyrrolinium salts—in the reactions with several CH‐acids were studied. 2‐Nitromethylene‐ and 2‐dicyanomethyleneindolylpyrrolidines were obtained from 5‐indolyl‐2‐methylthiopyrrolinium salts with good yields. The reduction in these nitro compounds yields the respective aminomethylpyrolidines. The rigid structure of the starting compounds has significant stereoelectronic requirements of nucleophilic agents.
Cortactin expression: Association with disease progression and survival in oral squamous cell carcinoma
Authors: Horn Dominik , Gross Madeleine , Dyckhoff Gerhard , Fuchs Jennifer , Grabe Niels , Weichert Wilko , Herpel Esther , Herold‐Mende Christel , Lichter Peter , Hoffmann Jürgen , Hess Jochen , Freier Kolja
Published: November 2018

Background

Cortactin (CTTN) is located on chromosome 11q13 and is associated with invasiveness in various cancer entities. CTTN protein expression could be a prognosticator of oral squamous cell carcinoma (OSCC) in terms of recurrence and survival.

Methods

CTTN‐dependent invasion was performed using migration assay in human papillomavirus‐negative head and neck squamous cell carcinoma (HNSCC) cells. Cortactin protein analysis in tissue microarrays was used for correlation with clinical parameters, as well as for survival analysis. Gene expression profiling in HNSCC cells was performed to unreveal CTTN signaling.

Results

Knockdown of CTTN in HNSCC cells showed less invasion in vitro. Gene expression profiling showed various deregulated genes known to be involved in progression. We confirmed the link between CTTN overexpression and progression in a large clinical cohort. High expression was associated with worse overall and progression‐free survival.

Conclusions

We propose CTTN for managing OSCC in terms of adjuvant therapy and aftercare. Furthermore, our study reveals new potential targets in CTTN signaling for individualized OSCC therapy.
Neuroimaging computer‐aided diagnosis systems for Alzheimer's disease
Authors: Karami Vania , Nittari Giulio , Amenta Francesco
Published: November 2018

This paper has reviewed the state‐of‐the‐art approaches for Computer Aided Diagnosis Systems (CADS) for Alzheimer's Disease (AD) using neuroimaging. Identification of the current approaches leads to improving the efficiency of these techniques. The analysis covered 110 articles published between 2009 and January 2018. Papers were chosen according to the Newcastle‐Ottawa criteria. MeSH terms were “computer aided diagnosis systems for Alzheimer's disease” and “computer aided diagnosis systems methods for diagnosis of Alzheimer's disease”. CADS algorithms have been presented with specific methods. There is no standardized approach to determine the best one. This study has tables that aimed to conclude all methods in a precise way. Among them, Statistical Parametric Mapping (SPM), Principal Component Analysis (PCA), and Support Vector Machine (SVM) were the most common, respectively. CADS for AD could become important in clinical practice in the near future. The evaluation criteria approved their efficiency as a second opinion besides the neurologist.
Dexmedetomidine alleviates cerebral ischemia‐reperfusion injury in rats via inhibition of hypoxia‐inducible factor‐1α
Authors: Wang Yuan‐Qing , Tang Yu‐Feng , Yang Ming‐Kun , Huang Xi‐Zhao
Published: November 2018

Dexmedetomidine (Dex) was reported to reduce ischemia‐reperfusion (I/R) injury in kidney and brain tissues. Thus, we aimed to study the role and mechanism of Dex in cerebral I/R injury by inhibiting hypoxia‐inducible factor‐1α (HIF‐1α) and apoptosis. First, I/R injury models were established. Six groups were assigned after different treatments: sham, I/R, I/R+Dex, I/R+2‐methoxyestradiol (2ME2) (HIF‐1α inhibitor), I/R+CoCl
2 (HIF‐1α activator), and I/R+Dex+CoCl
2 groups. Neurological function, cerebral infarction volume, survival, and apoptosis of brain cells were then analyzed. Besides, immunohistochemistry and Western blot analysis were used to detect the expression of HIF‐1α, BCL‐2[B‐cell leukemia/lymphoma 2] adenovirus E1B interacting protein 3 (BNIP3), B‐cell leukemia/lymphoma 2 (BCL2), BCL2[B‐cell leukemia/lymphoma 2] associated X (Bax), and cleaved‐caspase3 proteins in brain tissues. I/R rats showed cerebral infarction, increased neurological function score, number of terminal‐deoxynucleoitidyl transferase mediated nick end labeling (TUNEL)‐positive cells and HIF‐1α–positive cells as well as decreased neurons. Inhibition of HIF‐1α can reduce the apoptosis induced by I/R, and overexpression of HIF‐1α can aggravate apoptosis in brain tissue of I/R rats. Furthermore, activation of HIF‐1α expression blocks the inhibitory effect of Dex on neuronal apoptosis in I/R rats. Dex may inhibit the neuronal apoptosis of I/R rats by inhibiting the HIF‐1α pathway and then improve the cerebral I/R injury in rats.
Downregulation of long noncoding RNA LOC101928134 inhibits the synovial hyperplasia and cartilage destruction of osteoarthritis rats through the activation of the Janus kinase/signal transducers and activators of transcription signaling pathway by upregulating IFNA1
Authors: Yang Da‐Wei , Zhang Xin , Qian Gui‐Bin , Jiang Ming‐Jiu , Wang Peng , Wang Kun‐Zheng
Published: November 2018

Osteoarthritis (OA) is the most common disease of arthritis, a chronic joint disease that is always correlated with massive destruction such as cartilage destruction, inflammation of the synovial membrane, and so on. This study aims to explore the role of long noncoding RNA (lncRNA) LOC101928134 in the synovial hyperplasia and cartilage destruction, more specifically, in the Janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling pathway in an OA rat model. Microarray‐based gene expression analysis was conducted to screen out the lncRNA differentially expressed in OA and predict the target gene of the lncRNA with the involvement of the signaling pathway through Kyoto encyclopedia of genes and genomes (KEGG) analysis. A model of OA was established and treated with the small interfering RNA LOC101928134/inhibitor of JAK/STAT signaling pathway to investigate the relationship among LOC101928134, IFNA1, and the JAK/STAT signaling pathway in OA. The effect of LOC101928134 on the serum levels of IFNA1, interleukin‐1β, and tumor necrosis factor‐α, and the apoptosis of synovial and cartilage cells was evaluated. LOC101928134, which was found to be highly expressed in knee joint synovial tissues of OA rats, regulated the expression of IFNA1 gene and inhibited JAK/STAT signaling pathway. Downregulation of LOC101928134 resulted in reduced knee joint synovitis, relived inflammatory damage, and knee joint cartilage damage of OA rats. Besides, synovial cell apoptosis was enhanced upon LOC101928134 downregulation, while cartilage cell apoptosis of OA rats was suppressed. These results demonstrate that downregulation of LOC101928134 suppresses the synovial hyperplasia and cartilage destruction of OA rats via activation of JAK/STAT signaling pathway by upregulating IFNA1, providing a new candidate for the treatment of OA.