bluuebunny/crossref_metadata_2025_split huggingface dataset:
Iron(II) Supramolecular Helicates Condense Plasmid DNA and Inhibit Vital DNA‐Related Enzymatic Activities
Authors: Malina Jaroslav , Hannon Michael J. , Brabec Viktor 
Published: June 2015

AbstractThe dinuclear iron(II) supramolecular helicates [Fe2L3]Cl4 (L=C25H20N4) bind to DNA through noncovalent (i.e., hydrogen‐bonding, electrostatic) interactions and exhibit antimicrobial and anticancer effects. In this study, we show that the helicates condense plasmid DNA with a much higher potency than conventional DNA‐condensing agents. Notably, molecules of DNA in the presence of the M enantiomer of [Fe2L3]Cl4 do not form intermolecular aggregates typically formed by other condensing agents, such as spermidine or spermine. The helicates inhibit the activity of several DNA‐processing enzymes, such as RNA polymerase, DNA topoisomerase I, deoxyribonuclease I, and site‐specific restriction endonucleases. However, the results also indicate that the DNA condensation induced by the helicates does not play a crucial role in these inhibition reactions. The mechanisms for the inhibitory effects of [Fe2L3]Cl4 helicates on DNA‐related enzymatic activities have been proposed.
Conformational and Chiral Properties of Cyclic‐tri(N‐methyl‐meta‐benzamide) Bearing Amidino Groups
Authors: Nishiyama Shizuka , Urushibara Ko , Masu Hyuma , Azumaya Isao , Kagechika Hiroyuki , Tanatani Aya 
Published: June 2015

AbstractCyclic triamides 4 bearing amidino groups at the meta position of the phenyl rings were synthesized, and their conformational properties in the crystal and in solution were examined. Compound 4a exists as a capsule‐type dimer of the enantiomers with a bowl‐shaped syn conformation in the crystal state. Compound 4 exists mainly in the syn form in solution, and chiral induction was observed upon addition of a chiral acid to a solution of 4a. Chirality 27:487–491, 2015. © 2015 Wiley Periodicals, Inc.
Folate‐mediated one‐carbon metabolism genes and interactions with nutritional factors on colorectal cancer risk: Women's Health Initiative Observational Study
Authors: Cheng Ting‐Yuan David , Makar Karen W. , Neuhouser Marian L. , Miller Joshua W. , Song Xiaoling , Brown Elissa C. , Beresford Shirley A. A. , Zheng Yingye , Poole Elizabeth M. , Galbraith Rachel L. , Duggan David J. , Habermann Nina , Bailey Lynn B. , Maneval David R. , Caudill Marie A. , Toriola Adetunji T. , Green Ralph , Ulrich Cornelia M. 
Published: June 2015

BACKGROUNDInvestigations of folate‐mediated one‐carbon metabolism (FOCM) genes and gene‐nutrient interactions with respect to colorectal cancer (CRC) risk are limited to candidate polymorphisms and dietary folate. This study comprehensively investigated associations between genetic variants in FOCM and CRC risk and whether the FOCM nutrient status modified these associations.METHODSTwo hundred eighty‐eight candidate and tagging single‐nucleotide polymorphisms (SNPs) in 30 FOCM genes were genotyped for 821 incident CRC case‐control matched pairs in the Women's Health Initiative Observational Study cohort. FOCM biomarkers (red blood cell [RBC] folate, plasma folate, pyridoxal‐5′‐phosphate [PLP], vitamin B12, and homocysteine) and self‐reported alcohol consumption were measured at the baseline. Conditional logistic regression was implemented; effect modification was examined on the basis of known enzyme‐nutrient relations.RESULTSStatistically significant associations were observed between CRC risk and functionally defined candidate SNPs of methylenetetrahydrofolate dehydrogenase 1 (MTHFD1; K134R), 5‐methyltetrahydrofolate‐homocysteine methyltransferase reductase (MTRR; P450R), and PR domain containing 2 with ZNF domain (PRDM2; S450N) and a literature candidate SNP of thymidylate synthase (TYMS; g.676789A>T; nominal P < .05). In addition, suggestive associations were noted for tagging SNPs in cystathionine‐β‐synthase (CBS), dihydrofolate reductase (DHFR), DNA (cytosine‐5‐)‐methyltransferase 3β (DNMT3B), methionine adenosyltransferase I α (MAT1A), MTHFD1, and MTRR (nominal P < .05; adjusted P, not significant). Significant interactions between nutrient biomarkers and candidate polymorphisms were observed for 1) plasma/RBC folate and folate hydrolase 1 (FOLH1), paraoxonase 1 (PON1), transcobalamin II (TCN2), DNMT1, and DNMT3B; 2) plasma PLP and TYMS TS3; 3) plasma B12 and betaine‐homocysteine S‐methyltransferase 2 (BHMT2); and 4) homocysteine and methylenetetrahydrofolate reductase (MTHFR) and alanyl–transfer RNA synthetase (AARS).CONCLUSIONSGenetic variants in FOCM genes are associated with CRC risk among postmenopausal women. FOCM nutrients continue to emerge as effect modifiers of genetic influences on CRC risk. Cancer 2015;121:3684–3691. © 2015 American Cancer Society.
Synthesis of Amorphous Ni−Zn Double Hydroxide Nanocages with Excellent Electrocatalytic Activity toward Oxygen Evolution Reaction
Authors: Wang Shuqian , Nai Jianwei , Yang Shihe , Guo Lin 
Published: June 2015

AbstractIn spite of potential favorable electrochemical properties, reports of amorphous materials as catalysts for water oxidation are quite few. Highly efficient amorphous Ni−Zn double hydroxide nanocages as electrocatalysts for oxygen evolution reaction (OER) were prepared through a co‐precipitate method. We investigated the influence of composition on electrocatalytic activity experimentally. Ni2.7Zn(OH)x turned out to be the optimal composition of these samples, which exhibited an OER onset overpotential as low as 0.20 V in 1 m KOH electrolyte solution. In addition, Ni2.7Zn(OH)x could reach a current density of 10 A g1 at an overpotential of approximately 0.20 V. Such high mass activity should take advantage of the unique amorphous hollow nanostructure of our sample, which can provide substantial exposure of surface active atoms for remarkable catalytic activity. This amorphous Ni−Zn double hydroxide material was found to be a remarkable OER electrocatalyst and exhibited higher electrocatalytic activity than commercial IrO2.
Demystifying commercial content delivery networks in China
Authors: Yin Hao , Qiao Bo , Luo Yan , Tian Chen , Yang Y. Richard 
Published: June 2015

SummaryOver the past decade, content delivery networks (CDNs) have attracted substantial Internet traffic and improved quality of experience for Internet users. However, the evolution of the Internet ecosystem, which is driven by underlying economic incentives and ever emerging technologies, posts great challenges to the existing commercial CDNs (CCDNs). Thoroughly understanding the CDN industry from different aspects including market choice, technology, performance, tendency and infrastructure is indispensable to future Internet. In this paper, we conduct the first comprehensive study of China's CDNs using continuous, at‐scale, content‐driven measurements. Based on the massive amount of measurement data with multidimensional properties, we demystify the CCDNs in China and answer two important questions: (1) what is the development trend of CCDNs in China and (2) what are their unique characteristics. The answers to these questions have significant implications on CDN providers and users. Copyright © 2015 John Wiley & Sons, Ltd.
Dithienothiophene‐Based Triphenylamine‐Containing Branched Copolymers for Electrochromic Applications
Authors: Cho Ching Mui , Neo Wei Teng , Ye Qun , Lu Xuehong , Xu Jianwei 
Published: June 2015

AbstractA series of dithienothiophene‐based electrochromic polymers are synthesized by a Stille coupling reaction of 2,6‐bis(trimethylstannyl)dithieno[3,2‐b:2′,3′‐d]thiophene, 2,5‐dibromo‐3,4‐bis(dodecyloxy)thiophene, and tris(4‐bromophenylamine). The resulting polymers have high molecular weights in the range of 59 200 to 81 300 g mol−1, and good solubility in common organic solvents. The polymer films are purple/red in neutral states and gradually become gray when oxidized to an intermediate state and blue when fully oxidized. Incorporation of triphenylamine into the polymer chains has resulted in a significant increase in the redox stability, which renders this a potential method to create high‐performance electrochromic polymers.
Application of Fragment‐Based Drug Discovery against DNA Gyrase B
Authors: Chen Guo‐Ying , Ng Fui Mee , Tan Yih Wan , Poulsen Anders , Seetoh Weiguang , Lin Grace , Kang CongBao , Then Siew Wen , Ahmad Nur Huda , Wong Ying Lei , Ng Hui Qi , Chia C. S. Brian , Lau Qiu Ying , Hill Jeffrey , Hung Alvin W. , Keller Thomas H. 
Published: June 2015

AbstractBacterial resistance to antibiotics remains a serious threat to global health. The gyrase B enzyme is a well‐validated target for developing antibacterial drugs. Despite being an attractive target for antibiotic development, there are currently no gyrase B inhibitory drugs on the market. A fragment screen using 1,800 compounds identified 14 fragments that bind to Escherichia coli (E. coli) gyrase B. The detailed characterization of binding is described for all 14 fragments. With the aid of X‐ray crystallography, modifications on a low‐affinity fragment (KD=253 μM, IC50=634 μM) has led to the development of a new class of potent phenyl aminopyrazole inhibitors against E. coli gyrase B (IC50=160 nM). The study presented here combines the use of a set of biophysical techniques including differential scanning fluorimetry, nuclear magnetic resonance, isothermal titration calorimetry, and X‐ray crystallography to methodically identify, quantify, and optimize fragments into new chemical leads.
Novel approach to measure the size of plasma‐membrane nanodomains in single molecule localization microscopy
Authors: Ziomkiewicz Iwona , Sporring Jon , Pomorski Thomas Günther , Schulz Alexander 
Published: June 2015

AbstractMany membrane proteins are not evenly distributed over the plasma membrane, but gathered in domains assumed to have a particular lipid composition. Using single molecule localization microscopy (SMLM) we have immunolocalized a glycosylphosphatidylinositol (GPI)‐anchor protein that labels nanodomains in a specialized plant cell type, and compared the suitability of three methods to estimate their size. As conventional methods full width at half maximum (FWHM) and the full diameter (FWMin) of domains were used. A boundary detection method of the domain area (DA) was performed in order to take irregular shapes into account. In order to compare the influence of the chosen measurement methods, we have developed a MatLab program that allows for automated analysis of domain sizes from multiple SMLM images and provides the statistics of three key features of domains: FWHM and FWMin along their long and short axes as well as the DA, derived from the molecular density. Domains formed by the GPI‐anchor protein are approximating elliptical shapes. Direct and indirect immunolabeling resulted in a statistically significant difference in apparent domain size, reflecting the fact that the secondary antibody molecules extend the uncertainty along the nanodomain border. FWMin values along the long and short axis give good estimates of regular, geometrically centred domain shapes, while the DA value matches regular as well as irregular shapes best, as derived from computer‐generated, irregular point clusters. © 2015 International Society for Advancement of Cytometry
Role of high‐risk variants in the development of impaired glucose metabolism was modified by birth weight in Han Chinese
Authors: Zhang Yun , Xiao Xinhua , Zhang Zhenxin , Ma Xuejun , Xu Tao , Li Wenhui , Feng Kai , Sun Qi , Zhang Qian 
Published: June 2015

AbstractBackgroundThe aim of this study was to investigate the role of common variants in the genes SLC30A8, KCNQ1, and TCF7L2 in the association between birth weight and increased risk of type 2 diabetes in Han Chinese.MethodsSeven variants (SLC30A8‐rs13266634 and rs2466293; KCNQ1‐rs2237895 and rs2074196; and TCF7L2‐rs11196218, rs7903146, and rs290487) were genotyped in 1181 individuals born in Peking Union Medical College Hospital from 1921 to 1954 by Taqman allelic discrimination assay. All the subjects were stratified by birth weight into groups of ≥3000 g and <3000 g. Associations of genetic variants with birth weight and with risk of type 2 diabetes and impaired glucose tolerance (together as impaired glucose metabolism) were analysed.ResultsAfter adjustment for sex, gestational weeks, parity, and maternal age, the G allele of KCNQ1‐rs2074196 was associated with higher birth weight (p = 0.032). KCNQ1‐rs2074196, rs2234895, and TCF7L2‐rs290487 were associated with increased risk of impaired glucose metabolism. However, the associations were modified by size at birth. The associations above were only found in subjects with birth weights greater than (or equal to) 3000 g. In subjects with birth weights less than 3000 g, impaired glucose metabolism was associated with variants SLC30A8‐rs2466293 and TCF7L2‐rs11196218.ConclusionsThe role of common variants in susceptible genes in the development of impaired glucose metabolism was modified by birth weight in Han Chinese. This provides evidence that genetic variants influence birth weight and are involved in development of type 2 diabetes. Copyright © 2015 John Wiley & Sons, Ltd.
Adherence to Mediterranean diet and 10‐year incidence (2002–2012) of diabetes: correlations with inflammatory and oxidative stress biomarkers in the ATTICA cohort study
Authors: Koloverou E. , Panagiotakos D. B. , Pitsavos C. , Chrysohoou C. , Georgousopoulou E. N. , Grekas A. , Christou A. , Chatzigeorgiou M. , Skoumas I. , Tousoulis D. , Stefanadis C. ,   The ATTICA Study Group
Published: June 2015

AbstractBackgroundThe purpose of this work was to investigate the links between oxidative stress, inflammation and coagulation and their effect on Mediterranean diet–diabetes relationship.MethodsIn 2001–2002, a random sample of 1514 men (18–87 years old) and 1528 women (18–89 years old) was selected to participate in the ATTICA study, where Athens is the major metropolis. A validated questionnaire was used to assess lifestyle and dietary factors. Adherence to Mediterranean diet was recorded using MedDietScore. Among others, oxidative stress and inflammatory biomarkers were recorded. During 2011–2012, the 10‐year follow‐up was performed. Diabetes incidence was defined according to the American Diabetes Association criteria.ResultsA total of 191 incident cases of diabetes were documented, yielding an incidence of 12.9% (13.4% in men and 12.4% in women). Medium and high adherence was found to decrease diabetes risk by 49% (95% CI: 0.30, 0.88) and 62% (95% CI: 0.16, 0.88), respectively, compared with low adherence. A logarithmic trend between Mediterranean diet and diabetes incidence was also revealed (p for trend = 0.042). Individuals with abnormal waist circumference (>94 for men, >80 for women) were benefited the most. Wholegrain cereals, fruits and legumes had the greatest predictive ability. The anti‐diabetic effect of Mediterranean diet correlated with measurements of tumour necrosis factor‐α, homocysteine and total antioxidant capacity.ConclusionsThe reported results support the role of Mediterranean diet as a promising dietary tool for the primary prevention of diabetes, by attenuating inflammation and fostering total antioxidant capacity. This dietary pattern may have therapeutic potential for many cardiometabolic disorders associated with inflammation and/or oxidative stress. Copyright © 2015 John Wiley & Sons, Ltd.
Related male Drosophila melanogaster reared together as larvae fight less and sire longer lived daughters
Authors: Carazo Pau , Perry Jennifer C. , Johnson Fern , Pizzari Tommaso , Wigby Stuart 
Published: June 2015

AbstractCompetition over access to reproductive opportunities can lead males to harm females. However, recent work has shown that, in Drosophila melanogaster, male competition and male harm of females are both reduced under conditions simulating male‐specific population viscosity (i.e., in groups where males are related and reared with each other as larvae). Here, we seek to replicate these findings and investigate whether male population viscosity can have repercussions for the fitness of offspring in the next generation. We show that groups of unrelated‐unfamiliar (i.e., unrelated individuals raised apart) males fight more intensely than groups of related‐familiar males (i.e., full siblings raised together as larvae), supporting previous findings, and that exposure to a female is required to trigger these differential patterns of male–male competition. Importantly, we show that differences in male–male competition can be associated with transgenerational effects: the daughters of females exposed to unrelated‐unfamiliar males suffered higher mortality than the daughters of females exposed to related‐familiar males. Collectively, these results suggest that population structure (i.e., variation in the relatedness and/or larval familiarity of local male groups) can modulate male–male competition with important transgenerational consequences.
Border control: Anatomical origins of the thymus medulla
Authors: Anderson Graham , Jenkinson William E. 
Published: June 2015

The thymus is an anatomically compartmentalized primary lymphoid organ that fosters the production of self‐tolerant T cells. The thymic cortex provides a specialized microenvironment in which cortical thymic epithelial cells (cTECs) support the positive selection and further differentiation of self‐MHC‐restricted thymocytes. Following their migration into the medulla, positively selected thymocytes are further screened for self‐reactivity, which involves both negative selection and Foxp3+ regulatory T cell generation via interactions with medullary thymic epithelial cells (mTECs). Given the importance of both cortical and medullary microenvironments for T cell development, studies that address the developmental origins of cTECs and mTECs are important in understanding the processes that shape the developing T cell receptor repertoire, and reduce the frequency of self‐reactive T cells that initiate autoimmune disease. In this issue of the European Journal of Immunology, Onder et al. [Eur. J. Immunol. 2015. 45: 2218‐2231] identified a subset of podoplanin+ mTECs in mice that reside at the corticomedullary junction (CMJ), show that their development is important to establish self‐tolerance, and require the presence of self‐reactive T cells. Collectively, their findings highlight the CMJ as a potential repository for precursors of the mTEC lineage, and provide a better understanding of thymus medulla formation.
Platinum Nanoparticles Stabilized by Glycerodendrimers: Synthesis and Application to the Hydrogenation of α,β‐Unsaturated Ketones under Mild Conditions
Authors: Menot Bérengère , Salmon Lionel , Bouquillon Sandrine 
Published: June 2015

AbstractAir‐stable platinum nanoparticles stabilized by glycerodendrimers were prepared in water and analyzed by TEM. These platinum nanoparticles showed good catalytic activity for the reduction of α,β‐unsaturated ketones to saturated ketones at room temperature in water or in water/THF (1:1) under H2 (101.3 kPa). The catalytic species was recovered and recycled several times.
Synthesis and analysis of tocopheryl quinone and tocopherol esters with fatty acids in heated sunflower oil
Authors: Kreps František , Kyselka Jan , Burčová Zuzana , Schmidt Štefan , Filip Vladimír , Dubaj Tibor , Gajdoš Peter , Čertík Milan 
Published: June 2015

This work focuses on degradation of α‐tocopherol and formation of α‐tocopherol degradation products in sunflower oil heated at frying temperature. We determined the content and measured the kinetics of α‐tocopherol, α‐tocopheryl quinone, α‐tocopheryl fatty acid formation in heated sunflower oil without aeration (So) and in aerated oil (air flow 20 L/h) (SoAir). During 10 h of So oil heating, the α‐tocopherol was depleted and the content of α‐tocopheryl quinone in So grew from 3 to 84 mg/kg, as did the content of tocopherol free fatty acid esters from the initial 5 to 185 mg/kg. In SoAir oil, the rate constants of formation and decomposition of tocopherol degradation products were determined. Accelerated oxidation in SoAir caused depletion of the degradation products of tocopherol after 2 h of heating. The reason for this was significant oxidation and polymerization of fatty acids in SoAir oil. The unique features of this work are the syntheses and spectral analysis of tocopherol oxidation products and the development of a suitable method for quantitative analysis of α‐tocopheryl fatty acids. For the first time, we confirmed formation and degradation of tocopheryl fatty acids during oil heating at frying temperature.Practical applications: All the results presented here, consisting of organic syntheses, qualitative and quantitative analysis of α‐tocopheryl fatty acids as well as oxidation and degradation products of tocopherols and fatty acids, will aid future research focused on the degradation of tocopherols. So far the content of α‐tocopheryl fatty acids has not been determined by GC‐FID or HPLC‐UV. This is why there has been little interest in α‐tocopheryl fatty acids, although they are formed both in culinary treatment of food and in oil refining.Free fatty acids (FFAs), fatty acids (FAs), oxidation [o], products (i) and products (ii) are unspecified products of α‐tocopheryl FAs and α‐TQ degradation. Degradation products of α‐tocopherol were formed in heated sunflower oil and further heating of oil caused decomposition of α‐tocopherol degradation products.
Synthesis of a C–N Axially Chiral N‐Arylisatin through Asymmetric Intramolecular N‐Arylation
Authors: Nakazaki Atsuo , Miyagawa Keitaro , Miyata Noriaki , Nishikawa Toshio 
Published: June 2015

AbstractWe describe the first synthesis of an enantiomerically pure C–N axially chiral N‐arylisatin from the corresponding N‐aryloxindole, which was synthesized by an asymmetric intramolecular Buchwald–Hartwig N‐arylation. This novel isatin would be a potentially versatile synthetic intermediate for a variety of 3,3‐disubstituted oxindoles bearing a C3 stereogenic center.
Solid–Electrolyte Interphase Evolution of Carbon‐Coated Silicon Nanoparticles for Lithium‐Ion Batteries Monitored by Transmission Electron Microscopy and Impedance Spectroscopy
Authors: Van Havenbergh Kristof , Turner Stuart , Driesen Kris , Bridel Jean‐Sébastien , Van Tendeloo Gustaaf 
Published: June 2015

AbstractThe main drawbacks of silicon as the most promising anode material for lithium‐ion batteries (theoretical capacity=3572 mAh g−1) are lithiation‐induced volume changes and the continuous formation of a solid–electrolyte interphase (SEI) upon cycling. A recent strategy is to focus on the influence of coatings and composite materials. To this end, the evolution of the SEI, as well as an applied carbon coating, on nanosilicon electrodes during the first electrochemical cycles is monitored. Two specific techniques are combined: Transmission Electron Microscopy (TEM) is used to study the surface evolution of the nanoparticles on a very local scale, whereas electrochemical impedance spectroscopy (EIS) provides information on the electrode level. A TEM–EELS fingerprint signal of carbonate structures from the SEI is discovered, which can be used to differentiate between the SEI and a graphitic carbon matrix. Furthermore, the shielding effect of the carbon coating and the thickness evolution of the SEI are described.
High‐Performance Lithium–Sulfur Batteries using Yolk–Shell Type Sulfur–Silica Nanocomposite Particles with Raspberry‐Like Morphology
Authors: Lodi‐Marzano Fernanda , Leuthner Sven , Sommer Heino , Brezesinski Torsten , Janek Jürgen 
Published: June 2015

AbstractA simple and scalable method to coat 1–2 micrometer sulfur particles with silica is presented. The fabricated shell has a unique morphology that resembles a raspberry. Lithium–sulfur batteries with reasonably high areal loading using this nanocomposite show very stable performance, with little capacity fading over hundreds of cycles.