bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rate‐enhanced ATRP in the presence of catalytic amounts of base: An example of iron‐mediated AGET ATRP of MMA
Authors: Bai Liangjiu , Zhang Lifen , Zhang Zhengbiao , Zhu Jian , Zhou Nianchen , Cheng Zhenping , Zhu Xiulin 
Published: July 2011

AbstractThe catalytic amount of inorganic bases (i.e., NaOH, Na3PO4, NaHCO3, and Na2CO3) and organic bases such as pyridine and triethylamine was used as the additives in an iron‐mediated atom transfer radical polymerization with activators generated by electron transfer (AGET ATRP) of a polar monomer methyl methacrylate (MMA) using FeCl3·6H2O as the catalyst, ethyl 2‐bromoisobutyrate (EBiB) as the initiator, ascorbic acid (AsAc) as the reducing agent, and tetrabutylammonium bromide (TBABr) as the ligand. All these bases can result in dual enhancement of polymerization rate and controllability over molecular weight while keeping low Mw/Mn values (<1.3) for the resultant polymers. For example, the polymerization rate of AGET ATRP with a molar ratio of [MMA]0/[EBiB]0/[FeCl3·6H2O]0/[TBABr]0/[AsAc]0/[NaOH]0 = 500/1/1/2/2/1.5 using NaOH as the additives was more than two times of that without NaOH. The nature of “living”/controlled free radical polymerization in the presence of base was confirmed by chain‐extension experiments. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
A thioxanthone‐based visible photoinitiator
Authors: Dogruyol Sevnur Keskin , Dogruyol Zekeriya , Arsu Nergis 
Published: July 2011

AbstractThioxanthone‐based 9‐(2‐Morpholine‐4yl‐acetyl)‐5‐thia‐napthasen‐12‐one (TX‐MPM) was synthesized and characterized as a one‐component novel visible photoinitiator. Its capability to act as an initiator for the polymerization of methyl methacrylate (MMA) was examined in photoreactor and also daylight. Photophysical properties: fluorescence and phosphorescence emission spectra and fluorescence quantum yield of TX‐MPM (ϕf = 0.29) were determined. The phosphorescence lifetime was found 131 ms for TX‐MPM and 110 ms for initiator‐attached polymer (PMMA) at 77 K, indicated a π→π* nature of the lowest triplet state. A model compound, morpholino acetonapthone was used as quencher for the triplet states of TX‐MPM and the quenching rate constant was determined (kq = 1.26 × 109 M−1s−1). According to laser flash photolysis studies, intermolecular hydrogen abstraction process was more dominant path to the formation of the initiating radicals. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Molten polystyrene structures above the glass transition, T > Tg
Authors: Utracki L. A. , Sammut P. 
Published: July 2011

AbstractThe old controversial idea of structures in molten amorphous polymers is being accepted with theoretical and experimental evidence. Wool's twinkling fractal theory of the glass transition and recent atomic force micrographs are convincing proof of the dynamic, solid aggregate presence below and above Tg. This article offers detailed analysis of the experimental data from high‐pressure dilatometry, as well as from the oscillatory shear tests in the glassy and the molten state of polystyrenes. The results indicate the presence of a transient structure at T > Tg; transient as it depends on the structure of the vitreous polymer and the rate of heating it across Tg. Thus, molten polymer is not always at the thermodynamic equilibrium. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 49: 1369–1380, 2011
Predictors of follow‐up exercise behavior 6 months after a randomized trial of supervised exercise training in lymphoma patients
Authors: Courneya Kerry S. , Stevinson Clare , McNeely Margaret L. , Sellar Christopher M. , Friedenreich Christine M. , Peddle‐McIntyre Carolyn J. , Chua Neil , Reiman Tony 
Published: July 2011

AbstractObjectivesSupervised exercise is beneficial for lymphoma patients, but it needs to be maintained to optimize long‐term benefits. Here, we report the predictors of follow‐up exercise behavior 6 months after a randomized controlled trial in lymphoma patients.MethodsLymphoma patients were randomly assigned to 12 weeks of supervised aerobic exercise (n = 60) or usual care (n = 62). At baseline and post‐intervention, data were collected on demographic, medical, health‐related fitness, quality of life, and motivational variables. At 6‐month follow‐up, participants were mailed a questionnaire that assessed exercise behavior and were categorized as meeting or not meeting public health exercise guidelines.ResultsAt 6‐month follow‐up, 110 participants (90.2%) responded, of which 61 (55.5%) were meeting public health exercise guidelines. In univariate analyses, 16 variables predicted 6‐month follow‐up exercise behavior. In a stepwise regression analysis, five variables entered the model and explained 38% (p < 0.001) of the variance including the following: accepting a post‐intervention exercise prescription (β = 0.33; p < 0.001), achieving a higher peak power output at post‐intervention (β = 0.28; p = 0.001), experiencing a larger positive change in perceived behavioral control (β = 0.18; p = 0.028), having Hodgkin lymphoma (β = 0.19; p = 0.025), and having a stronger post‐intervention intention (β = 0.18; p = 0.034).ConclusionExercise behavior in lymphoma patients 6 months after a randomized trial was predicted by a wide range of demographic, medical, health‐related fitness, quality of life, and motivational variables. These findings may help facilitate the uptake of self‐directed exercise after short‐term supervised exercise in lymphoma patients. Copyright © 2011 John Wiley & Sons, Ltd.
Information about chemotherapy‐associated cognitive problems contributes to cognitive problems in cancer patients
Authors: Schagen Sanne B. , Das Enny , Vermeulen Ivar 
Published: July 2011

AbstractObjectiveAlthough increasing attention is directed at identifying biological mechanisms underlying cognitive changes observed in cancer patients without central nervous system disease following chemotherapy, psychological factors that can contribute to these cognitive changes are much less studied.MethodsIn an online experiment, the influence of informing patients about the association between cognitive problems and chemotherapy on self‐reported cognitive functioning and neuropsychological test performance was investigated.ResultsCancer patients treated with chemotherapy (n = 150) reported higher levels of cognitive complaints after receiving such information (M = 21.20) than without such information (M = 18.98; p = 0.032). No difference was found for patients without (a history of) chemotherapy (n = 86; M = 18.85 vs. 20.08; NS). A similar interaction pattern was observed on a word‐learning test. Patients treated with chemotherapy recalled fewer words after being informed about the association between cognitive problems and chemotherapy (M = 24.44) than without such information (M = 27.63; p = 0.010). No difference was found for patients not treated with chemotherapy (M = 26.35 vs. 25.38; NS).ConclusionPatient information may induce a stereotype threat, which affects self‐reported cognitive function and neuropsychological test performance in cancer patients for whom this information is relevant. Copyright © 2011 John Wiley & Sons, Ltd.
Dirac gauginos: a user manual
Authors: Benakli K. 
Published: July 2011

AbstractThe issue of a Majorana, Dirac or pseudo‐Dirac mass for gauginos must not be reduced to a question of an extension of the Minimal Supersymmetric Standard Model by extra states, parameters and phenomenological implications. On the contrary, it is intimately related to the fundamental issue of the realization of new symmetries in nature, R‐symmetries. We present here a very dense compilation of the main features of models with (pseudo‐)Dirac gauginos.
Enhancing systematic protein–protein docking methods using ray casting: Application to ATTRACT
Authors: Li Yi , Cortés Juan , Siméon Thierry 
Published: July 2011

AbstractSystematic protein–protein docking methods need to evaluate a huge number of different probe configurations, thus leading to high computational cost. We present an efficient filter—ray casting filter (RCF)—that enables a notable speed‐up of systematic protein–protein docking. The high efficiency of RCF is the outcome of the following factors: (i) extracting of pockets and protrusions on the surfaces of the proteins using visibilities; (ii) a ray casting method that finds aligned receptor pocket/probe protrusion pairs without explicit similarity computations. The RCF method enables the integration of systematic methods and local shape feature matching methods. To verify the efficiency and the accuracy of RCF, we integrated it with a systematic protein–protein docking approach (ATTRACT) based on a reduced protein representation. The test results show that the integrated docking approach is much faster. At the same time, it ranks the lowest ligand root‐mean‐square deviation (RMSD) (L_rms) solutions higher when docking enzyme–enzyme inhibitor complexes. Consequently, RCF not only enables much faster execution of systematic docking runs but also improves the qualities of docking predictions. Proteins 2011; © 2011 Wiley‐Liss, Inc.
Further studies on the antiviral activity of alloferon and its analogues
Authors: Kuczer Mariola , Midak‐Siewirska Anna , Zahorska Renata , Łuczak Mirosław , Konopińska Danuta 
Published: July 2011

AbstractThe subject of our studies was the synthesis, biological evaluation, and conformational studies of insect tridecapeptide alloferon (H‐His‐Gly‐Val‐Ser‐Gly‐His‐Gly‐Gln‐His‐Gly‐Val‐His‐Gly‐OH) and its analogues such as: [des‐His1]‐, [Lys1]‐, [Arg1]‐, and [Ala1]‐alloferon. These peptides were synthesized to check the influence of the His residue at position 1 of the alloferon chain on its antiviral activity. Two aspects of the biological effects of these peptides were determined: (i) the cytotoxicity in vitro in the Vero, LLC‐MK2, and HEp‐2 cell lines, and (ii) the antiviral activity in vitro in respect to DNA and RNA viruses. We found that alloferon inhibited the herpes virus multiplication and failed to affect the coxsackie virus replication, whereas [Lys1]‐alloferon exhibited a high inhibitory action towards both viruses. Moreover, the peptides did not show any cytotoxic activity against the Vero, LLC‐MK2, and HEp‐2 cells. The preliminary circular dichroism conformational studies showed that the peptides investigated seem to prefer an unordered conformation. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.
Total synthesis of a depsidomycin analogue by convergent solid‐phase peptide synthesis and macrolactonization strategy for antitubercular activity
Authors: Narayanaswamy Venugopala K. , Albericio Fernando , Coovadia Yacoob Mohamed , Kruger Hendrik G. , Maguire Glenn E. M. , Pillay Melendhran , Govender Thavendran 
Published: July 2011

AbstractDepsidomycin is a cyclic heptadepsi‐peptide isolated from the cultured broth of Streptomyces lavendofoliae MI951‐62F2. It exhibits significant antimicrobial and immunosuppressive activity. The total synthesis of a depsidomycin analogue in which 1,2‐piperazine‐3‐carboxylic acid was substituted with proline is described. After several trials using different strategies, the desired depsidomycin analogue was obtained via stepwise synthesis starting by the amino acid ‘head’ and macrolactonization under Yamaguchi conditions. The cyclic depsipeptide was evaluated to have an minimum inhibitory concentration (MIC) of 4 µg/ml against H37RV and 16 µg/ml against MDR clinical strains of MTB (MDR‐MTB), while the linear precursor 8 also had MICs of 4 and 16 µg/ml for the susceptible and resistant strains, respectively. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.
A theoretical study on hydrogen transport mechanism in SrTio3 perovskite
Authors: Onishi Taku , Helgaker Trygve 
Published: July 2011

AbstractHybrid‐DFT calculations were performed to clarify the hydrogen transport mechanism in SrTiO3 perovskite. From a molecular‐orbital analysis, we discussed the changes of the chemical bonding between conductive hydrogen and others, and the proton conduction paths. It is concluded that the conductive hydrogen is almost neutral, with a diagonal conduction path favored inside of Ti4O4 square. We considered the nitrogen doping at the oxygen site to enhance the proton conductivity. Doped nitrogen exists as the part of NH2− ion, enhancing proton conductivity. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012
Ab initio fragment molecular orbital calculations on specific interactions between aryl hydrocarbon receptor and dioxin
Authors: Miyagi Satoshi , Sawamura Satoshi , Yoshikawa Eri , Dedachi Kenichi , Itoh Satoshi , Ishihara‐Sugano Mitsuko , Kurita Noriyuki 
Published: July 2011

AbstractAryl hydrocarbon receptor (AhR) regulates expression of genes in a ligand‐dependent manner. Although AhR was found to contain basic helix‐loop‐helix and Per‐Arnt‐Sim (PAS) domains, three‐dimensional structures of AhR and its complex with ligand have not been determined yet. We here obtain some modeled structures for the PAS domain of mouse AhR by using homology modeling and classical molecular mechanics methods. In addition, the stable structure of solvated AhR–dioxin complex is determined by the protein–ligand docking and the classical molecular dynamics simulations, and the specific interactions between AhR and dioxin are investigated at an electronic level by using ab initio fragment molecular orbital method. The computed results highlight the important amino acid residues of AhR for the binding between AhR and dioxin. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012
Neuroendocrine Changes and Natriuresis in Response to Social Stress in Rats
Authors: Niebylski A. , Boccolini A. , Bensi N. , Binotti S. , Hansen C. , Yaciuk R. , Gauna H. 
Published: July 2011

AbstractSympathetic activation is detected by the tachycardic, hypertensive and hyperthermic responses during social conflicts in rodents and primates. Sympathetic nervous system activation promoting sodium retention has long been recognized to play a significant role in the development and maintenance of salt‐sensitive hypertension. The objective was to investigate neuroendocrine activation and renal sodium excretion in response to chronic social stress. Male Wistar rats were subjected to social stress in accordance with the resident–intruder paradigm. Intruder rats were subjected to social confrontation once daily for 6 days. After the last confrontation, plasma corticosterone and urinary catecholamines were determined to assess the neuroendocrine activation. Plasma aldosterone, plasma and urinary creatinine, Na+, K+ and urinary volume were also measured. Chronic social stress increased the urinary norepinephrine, dopamine and plasma corticosterone levels, with no changes in epinephrine levels. On the other hand, high plasma aldosterone levels and low urinary sodium excretion without differences in creatinine clearance were observed. In conclusion, social stress had a strong antinatriuretic effect, which is coincident with noradrenergic and corticoadrenal activation and an increase in plasma aldosterone levels. Activation of these factors may promote sodium retention, which has long been recognized to play a significant role in the development and maintenance of hypertension. Copyright © 2011 John Wiley & Sons, Ltd.
The data type of spatial objects
Authors: Johnson Kenneth , Tucker John V. 
Published: July 2011

AbstractA spatial object consists of data assigned to points in a space. Spatial objects, such as memory states and three dimensional graphical scenes, are diverse and ubiquitous in computing. We develop a general theory of spatial objects by modelling abstract data types of spatial objects as topological algebras of functions. One useful algebra is that of continuous functions, with operations derived from operations on space and data, and equipped with the compact-open topology. Terms are used as abstract syntax for defining spatial objects and conditional equational specifications are used for reasoning. We pose a completeness problem:Given a selection of operations on spatial objects, do the terms approximate all the spatial objects to arbitrary accuracy?We give some general methods for solving the problem and consider their application to spatial objects with real number attributes.
Gluconeogenesis and protein-induced satiety
Authors: Veldhorst Margriet A. B. , Westerterp Klaas R. , Westerterp-Plantenga Margriet S. 
Published: July 2011

Increased gluconeogenesis (GNG) has been suggested to contribute to protein-induced satiety via modulation of glucose homoeostasis. The objective was to determine GNG and appetite in healthy human subjects after a high-proteinv.a normal-protein diet and to assess whether GNG contributes to protein-induced satiety. A total of twenty-two healthy subjects (ten men and twelve women: age 23 (sem1) years, BMI 22·1 (sem0·5) kg/m2) received an isoenergetic high-protein (30/0/70 % of energy from protein/carbohydrate/fat) or normal-protein diet (12/55/33 % of energy from protein/carbohydrate/fat) for 1·5 d in a randomised cross-over design. Appetite ratings were measured using visual analogue scales (VAS); endogenous glucose production and GNG were measured via infusion of [6,6-2H2]glucose and ingestion of2H2O. Moreover, fasting glucose and β-hydroxybutyrate concentrations were measured. Glycogen stores were lowered at the start with a glycogen-lowering exercise test. During the high-protein compared with the normal-protein diet, GNG was increased and appetite was suppressed (GNG: 148 (sem7)v.133 (sem6) g/24 h,P < 0·05; and 24 h area under the curve for hunger: 694 (sem46)v.1055 (sem52) mmVAS × 24 h,P < 0·001; fullness: 806 (sem59)v.668 (sem64) mm VAS × 24 h,P < 0·05; desire to eat: 762 (sem48)v.1004 (sem66) mm VAS × 24 h,P < 0·001). There was no correlation between appetite ratings and GNG. Glucose concentration was lower (4·09 (sem0·10)v.4·89 (sem0·06) mmol/l,P < 0·001) and β-hydroxybutyrate concentration was higher (1349 (sem139)v.234 (sem25) μmol/l,P < 0·001) after the high-protein compared with the normal-protein diet. In conclusion, after a high-protein diet, GNG was increased and appetite was lower compared with a normal-protein diet; however, these were unrelated to each other. An increased concentration of β-hydroxybutyrate may have contributed to appetite suppression on the high-protein diet.
DNA topoisomerase 2 mutant allele mildly delays the mitotic progression and activates the checkpoint protein kinase Chk1 in fission yeast Schizosaccharomyces pombe
Authors: YADAV SUDHANSHU , VERMA SUMIT KUMAR , AHMED SHAKIL 
Published: July 2011

SummaryDNA topoisomerases are specialized nuclear enzymes that perform topological modifications on double-stranded DNA (dsDNA) and hence are essential for DNA metabolism such as replication, transcription, recombination, condensation and segregation. In a genetic screen, we identified a temperature-sensitive mutant allele of topoisomerase 2 that exhibits conditional synthetic lethality with a chk1 knockout strain. The mutant allele of topoisomerase 2 is defective in chromosome segregation at a non-permissive temperature and there was increase in chromosome segregation defects in the double mutant of top2–10 and chk1 delete at a non-permissive temperature. More importantly, topoisomearse 2 mutant cells mildly delay the mitotic progression at non-permissive temperature that is mediated by checkpoint protein kinase Chk1. Additionally, top2–10 mutant cells also activate the Chk1 at a non-permissive temperature and this activation of Chk1 takes place at the time of mitosis. Interestingly, top2–10 mutant cells retain their viability at a non-permissive temperature if the cells are not allowed to enter into mitosis. Taking together our results, we speculate that in the top2–10 mutant, the segregation of entangled chromatids during mitosis could result in delaying the mitotic progression through the activation of Chk1 kinase.
Genetic variation of dietary restriction and the effects of nutrient-free water and amino acid supplements on lifespan and fecundity ofDrosophila
Authors: DICK KENNETH B. , ROSS CHELSEA R. , YAMPOLSKY LEV Y. 
Published: July 2011

SummaryWe measure genetic variation in lifespan and fecundity at two food levels in 34 core lines of theDrosophilaGenetic Reference Panel collection. Lines were significantly different from each other in lifespan and fecundity at both restricted and full food. There was a strong food-by-line interaction for the slope of age-specific mortality, fecundity and proportion of fertilized eggs, indicating the presence of genetic variation for the strength of the dietary restriction effect, likely to represent standing genetic variation in a natural population from which the lines used have originated. No trade-off between fecundity and lifespan manifested in life-history variation among inbred lines. Our data partially corroborate the recent proposition that availability of nutrient-free water eliminates the apparent dietary restriction at least in some conditions. Although flies on full food with water added had lifespan slightly higher than those without a water source, it was still significantly lower than that in flies on restricted food, with no indication of interaction. We fully corroborate the recently discovered effect of addition of essential amino acids to the medium: addition of 1·5 mM methionine to restricted food significantly increased fecundity without a measurable decrease in lifespan; addition of each of 10 essential amino acids increased fecundity and decreased females lifespan to the levels observed on full food, again with no evidence of line-by-food interactions. We propose a mechanistic hypothesis explaining the observed data, based on the assumption that food consumption by flies is adjusted according to flies’ saturation in water and methionine.
Ancestral polymorphisms inDrosophila pseudoobscuraandDrosophila miranda
Authors: NOWELL REUBEN W. , CHARLESWORTH BRIAN , HADDRILL PENELOPE R. 
Published: July 2011

SummaryAncestral polymorphisms are defined as variants that arose by mutation prior to the speciation event that generated the species in which they segregate. Their presence may complicate the interpretation of molecular data and lead to incorrect phylogenetic inferences. They may also be used to identify regions of the genome that are under balancing selection. It is thus important to take into account the contribution of ancestral polymorphisms to variability within species and divergence between species. Here, we extend and improve a method for estimation of the proportion of ancestral polymorphisms within a species, and apply it to a dataset of 33 X-linked and 34 autosomal protein-coding genes for which sequence polymorphism data are available in bothDrosophila pseudoobscuraandDrosophila miranda, usingDrosophila affinisas an outgroup. We show that a substantial proportion of both X-linked and autosomal synonymous variants in these two species are ancestral, and that a small number of additional genes with unusually high sequence diversity seem to have an excess of ancestral polymorphisms, suggestive of balancing selection.