bluuebunny/crossref_metadata_2025_split huggingface dataset:
N‐heterocyclic carbene complexes of Rh(I) and electronic effects on catalysts for 1,2‐addition of phenylboronic acid to aldehydes
Authors: Türkmen Hayati , Çetinkaya Bekir 
Published: December 2010

Abstract1,3‐Diarylsubstituted imidazolinium salts, (NHC‐H)Cl, 3, containing hydrogen or alkyl groups at the 4,5‐positions of the imidazolidine ring, served as precursors to rhodium(I) complexes [RhCl(NHC)COD], 4, which were converted into cis‐[RhCl(NHC)(CO)2] complexes, 5. All compounds prepared were characterized by elemental analyses, 1H NMR and 13C NMR. The relative σ‐donor/π‐acceptor strength of the NHC ligands was determined by means of IR spectroscopy of 5. The ability of NHCs in 4 to enchance activity was explored in the 1,2‐addition of phenylboronic acid to aldehydes. A good correlation was observed between catalytic activity and the electron‐donating power of the NHC ligands. Copyright © 2010 John Wiley & Sons, Ltd.
The Rawls‐Tawney theorem and the digital divide in postindustrial society
Authors: Duff Alistair S. 
Published: December 2010

AbstractThe digital divide continues to challenge political and academic circles worldwide. A range of policy solutions is briefly evaluated, from laissez‐faire on the right to “arithmetic” egalitarianism on the left. The article recasts the digital divide as a problem for the social distribution of presumptively important information (e.g., electoral data, news, science) within postindustrial society. Endorsing in general terms the left‐liberal approach of differential or “geometric” egalitarianism, it seeks to invest this with greater precision, and therefore utility, by means of a possibly original synthesis of the ideas of John Rawls and R. H. Tawney. It is argued that, once certain categories of information are accorded the status of “primary goods,” their distribution must then comply with principles of justice as articulated by those major 20th century exponents of ethical social democracy. The resultant Rawls‐Tawney theorem, if valid, might augment the portfolio of options for interventionist information policy in the 21st century.
Control of antagonistic swarm dynamics via Lyapunov's method
Authors: Sierra Daniel A. , McCullough Paul , Olgac Nejat , Adams Eldridge 
Published: December 2010

AbstractWe consider hostile conflicts between two multi‐agent swarms. First, we investigate the complex nature of a single pursuer attempting to intercept a single evader (1P‐1E), and establish some rudimentary rules of engagement. We elaborate on the stability repercussions of these rules. Second, we extend the modelling and stability analysis to multi‐agent swarms with conflicting interests. The present document considers only swarms with equal membership strengths for simplicity. This effort is based on a set of suggested momenta deployed on individual agents. Because pursuers and evaders differ in the influences that they exert on one another, we emphasize asymmetry in momenta between the two types of swarm members. The proposed centralized control law evolves from a Lyapunov concept. Swarm interactions are modelled in two phases: the approach phase during which the two swarms act like individuals in the 1P‐1E interaction; and the individual pursuit phase where each pursuer is assigned to an evader.Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Impacts on type I error rate with inappropriate use of learn and confirm in confirmatory adaptive design trials
Authors: Wang Sue‐Jane , James Hung H. M. , O'Neill Robert T. 
Published: December 2010

AbstractA two‐stage adaptive design trial is a single trial that combines the learning data from stage 1 (or phase II) and the confirming data in stage 2 (or phase III) for formal statistical testing. We call it a “Learn and Confirm” trial. The studywise type I error rate remains to be at issue in a “Learn and Confirm” trial. For studying multiple doses or multiple enpdoints, a “Learn and Confirm” adaptive design can be more attractive than a fixed design approach. This is because intuitively the learning data in stage 1 should not be subjected to type I error scrutiny if there is no formal interim analysis performed and only an adaptive selection of design parameters is made at stage 1. In this work, we conclude from extensive simulation studies that the intuition is most often misleading. That is, regardless of whether or not there is a formal interim analysis for making an adaptive selection, the type I error rates are always at risk of inflation. Inappropriate use of any “Learn and Confirm” strategy should not be overlooked.
A new and sensitive catalytic resonance scattering spectral assay for the detection of laccase using guaiacol as substrate
Authors: Jiang Caina , Ling Shaoming , Wang Pengfei , Liang Aihui , Chen Bin , Wen Guiqing , Jiang Zhiliang 
Published: December 2010

ABSTRACTIn pH 4.0 succinic acid–sodium hydroxide buffer solution, laccase catalyzed the oxidization of guaiacol substrate to form red particles, which exhibited a strong resonance scattering (RS) peak at 590 nm. Under the chosen conditions, as the laccase increased, the RS intensity (ΔI) increased linearly. The ΔI was proportional to laccase activity in the range of 0.10–1.2 U/mL, with a regression equation of ΔI = 734.0 Ulaccase − 9.7, and a detection limit of 0.05 U/mL. This RS method was applied to the detection of laccase activity in real samples, and the results were agreement with those from spectrophotometry. Copyright © 2010 John Wiley & Sons, Ltd.
A highly selective fluorescent sensor for mercury ion (II) based on azathia‐crown ether possessing a dansyl moiety
Authors: Dai Huajun , Liu Fei , Gao Qianqian , Fu Tianhua , Kou Xingming 
Published: December 2010

ABSTRACTAn intramolecular charge transfer (ICT) fluorescent sensor 1 using a dansyl moiety as the fluorophore and an azathia‐crown ether as the receptor was designed, synthesized and characterized. The ions‐selective signaling behaviors of the sensor 1 were investigated in CH3CN‐H2O (1:1, v/v) by fluorescence spectroscopy. It exhibited remarkable fluorescence quenching upon addition of Hg2+, which was attributed to the 1:1 complex formation between 1 and Hg2+, while other selected metal ions induced basically no spectral changes. The sensor 1 showed a rapid and linear response towards Hg2+ in the concentration range from 5.0 × 10−7 to 1.0 × 10−5 mol L−1 with the detection limit of 1.0 × 10−7 mol L−1. Furthermore, the whole process could be carried out in a wide pH range of 2.0–8.0 and was not disturbed by other metal ions. Thus, the sensor 1 was used for practical determination of Hg2+ in different water samples with satisfactory results. Copyright © 2010 John Wiley & Sons, Ltd.
Chemical Composition and Antidiabetic Activity of Opuntia Milpa Alta Extracts
Authors: Luo Chuan , Zhang Wannian , Sheng Chunquan , Zheng Chengjian , Yao Jianzhong , Miao Zhenyuan 
Published: December 2010

AbstractThree new compounds, 1–3, and 20 known compounds were isolated from the AcOEt and BuOH extract of edible Opuntia Milpa Alta. The petroleum ether extract was examined by GC and MS. A total of 26 compounds were identified, representing 95.6% of the total extract, phytosterol (36.03%) being the most abundant component, and polyunsaturated fatty acids (18.57%) represented the second largest group, followed by phytol (12.28%), palmitic acid, palmitate (13.54%), vitamin E (4.51%), and other compounds (7.47%). The effects of various extracts from edible Opuntia Milpa Alta (petroleum ether extract, AcOEt extract, BuOH extract, aqueous extract, H2O parts) and the positive control (received dimethylbiguanide) were tested on streptozotocin (STZ)‐induced diabetic mice. The results indicated that all the treatment groups could significantly decrease blood glucose levels in STZ‐induced diabetic mice compared to the model control group (P<0.01), except the aqueous extract group (P<0.05). Especially, the petroleum ether extract group and the positive control group showed remarkable decrease of blood glucose levels. Taken together, the results indicate that the petroleum ether extract is the major hypoglycemic part in edible Opuntia Milpa Alta, which may be developed to a potential natural hypoglycemic functional ingredient.
Induction‐Driven Stabilization of the Anion–π Interaction in Electron‐Rich Aromatics as the Key to Fluoride Inclusion in Imidazolium‐Cage Receptors
Authors: Xu Zhaochao , Singh N. Jiten , Kim Sook Kyung , Spring David R. , Kim Kwang S. , Yoon Juyoung 
Published: December 2010

AbstractIntermolecular interactions that involve aromatic rings are key processes in both chemical and biological recognition. It is common knowledge that the existence of anion–π interactions between anions and electron‐deficient (π‐acidic) aromatics indicates that electron‐rich (π‐basic) aromatics are expected to be repulsive to anions due to their electron‐donating character. Here we report the first concrete theoretical and experimental evidence of the anion–π interaction between electron‐rich alkylbenzene rings and a fluoride ion in CH3CN. The cyclophane cavity bridged with three naphthoimidazolium groups selectively complexes a fluoride ion by means of a combination of anion–π interactions and (CH)+⋅⋅⋅F−‐type ionic hydrogen bonds. 1H NMR, 19F NMR, and fluorescence spectra of 1 and 2 with fluoride ions are examined to show that only 2 can host a fluoride ion in the cavity between two alkylbenzene rings to form a sandwich complex. In addition, the cage compounds can serve as highly selective and ratiometric fluorescent sensors for a fluoride ion. With the addition of 1 equiv of F−, a strongly increased fluorescence emission centered at 385 nm appears at the expense of the fluorescence emission of 2 centered at 474 nm. Finally, isothermal titration calorimetry (ITC) experiments were performed to obtain the binding constants of the compounds 1 and 2 with F− as well as Gibbs free energy. The 2‐F− complex is more stable than the 1‐F− complex by 1.87 kcal mol−1, which is attributable to the stronger anion–π interaction between F− and triethylbenzene.
Reversible Mutarotation in a Macrocyclic Ytterbium Complex
Authors: Ballistreri Francesco P. , Gentile Salvatore , Pappalardo Andrea , Tomaselli Gaetano A. , Pradhan Sanghamitra , Di Bari Lorenzo 
Published: December 2010

AbstractM40 is a four‐fold symmetry macrocyclic ligand endowed with axial and central chiral elements, all of R configuration. It promptly binds late lanthanides (YbIII and LuIII) yielding a negative helicity, as witnessed by NIR‐electronic circular dichroism. In the course of a few hours, a new conformation of the complex takes over, which has opposite helicity and allows for a dynamic free‐bound equilibrium. Upon slow solvent evaporation, the original conformation is retrieved and the whole dynamic process can be started again, as in a sandclock, allowing one to envisage applications as a time‐marker chiral switch.
Development of an ovarian cancer screening decision model that incorporates disease heterogeneity
Authors: Havrilesky Laura J. , Sanders Gillian D. , Kulasingam Shalini , Chino Junzo P. , Berchuck Andrew , Marks Jeffrey R. , Myers Evan R. 
Published: December 2010

AbstractBACKGROUND:Pathologic and genetic data suggest that epithelial ovarian cancer may consist of indolent and aggressive phenotypes. The objective of the current study was to estimate the impact of a 2‐phenotype paradigm of epithelial ovarian cancer on the mortality reduction achievable using available screening technologies.METHODS:The authors modified a Markov model of ovarian cancer natural history (the 1‐phenotype model) to incorporate aggressive and indolent phenotypes (the 2‐phenotype model) based on histopathologic criteria. Stage distribution, incidence, and mortality were calibrated to data from the Surveillance, Epidemiology, and End Results Program of the US National Cancer Institute. For validation, a Monte Carlo microsimulation (1000,000 events) of the United Kingdom Collaborative Trial of Ovarian Cancer Screening (UKCTOCS) multimodality prevalence screen was performed. Mortality reduction and positive predictive value (PPV) were estimated for annual screening.RESULTS:In validation against UKCTOCS data, the model‐predicted percentage of screen‐detected cancers diagnosed at stage I and II was 41% compared with 47% (UKCTOCS data), and the model‐predicted PPV of screening was 27% compared with 35% (UKCTOCS data). The model‐estimated PPV of a strategy of annual population‐based screening in the United States at ages 50 to 85 years was 14%. The mortality reduction using annual postmenopausal screening was 14.7% (1‐phenotype model) and 10.9% (2‐phenotype model). Mortality reduction was lower with the 2‐phenotype model than with the 1‐phenotype model regardless of screening frequency or test sensitivity; 68% of cancer deaths are accounted for by the aggressive phenotype.CONCLUSIONS:The current analysis suggested that reductions in ovarian cancer mortality using available screening technologies on an annual basis are likely to be modest. A model that incorporated 2 clinical phenotypes of ovarian carcinoma into its natural history predicted an even smaller potential reduction in mortality because of the more frequent diagnosis of indolent cancers at early stages. Cancer 2011. © 2010 American Cancer Society.
Does zinc supplementation improve dietary intake, symptoms of eating problems, and serum zinc levels in hemodialysis patients?
Authors: Ghaemmaghami Jamal , Mahdavi Reza , Faramarzi Elnaz , Mohammadpour Noshin , Argani Hassan 
Published: December 2010

AbstractOBJECTIVEThe objectives of this study were to determine the effects of zinc supplementation on dietary intake, symptoms of eating problems, and serum zinc levels in hemodialysis patients.METHODSThirty‐nine patients who received chronic maintenance hemodialysis were randomized to experimental (n = 21) and placebo (n = 18) groups given a daily supplement of 100 mg elemental zinc and corn starch, respectively, for 60 days. Dietary intake, body composition, and eating problems were assessed using 2‐day dietary records, bioelectric impedance tests, and a questionnaire, respectively. Serum zinc levels were determined by atomic absorption before and after intervention.RESULTSThe mean daily macro‐ and micronutrients intakes and percentage of body fat in the supplemented group increased insigniﬁcantly. Administration of zinc improved appetite loss, dry mouth, nausea, and hypogeusia, while incidence of these symptoms increased in control group. A signiﬁcant increase (p < 0.01) was observed in the mean serum zinc levels in the experimental group (102 ± 4 vs. 76 ± 3 µg/dL) while changes in the placebo group were not signiﬁcant.CONCLUSIONSDespite observed improvement in symptoms of eating problems and serum zinc levels in the supplemented group, more study over a longer period must be carried out to achieve clearer results.
Growth in children after renal transplantation: An update
Authors: Modini Vinai M. , Seikaly Mouin G. 
Published: December 2010

AbstractImproving general health, sense of well‐being, and quality of life are the primary objectives of renal transplanta‐tion in children with chronic kidney disease (CKD). Final adult height achieved has a significant impact on medical, psychological, and social aspects of these patients. Growth is an important indicator of health in children with CKD. It seems intuitive then to expect improvement in growth after renal transplantation. Unfortunately, even with a functioning renal allograft, optimal growth remains elusive at times. Optimizing growth prior to transplant, early identification of growth delay, and timely intervention are essential in achieving optimal final adult height. Multiple factors lead to stunted growth in children after renal transplant.
A Simple Route to Chelating, Structurally Different Triazole‐Based Bis(N‐heterocyclic carbene) Ligands and Their Coordination to PtII
Authors: Zanardi Alessandro , Mata Jose A. , Peris Eduardo 
Published: December 2010

AbstractTwo new bis(triazolium) salts have been prepared and used as N‐heterocyclic carbene (NHC) precursors. The structure of the salts is highly dependent on the synthetic route, which implies the sequential alkylation of two of the three N atoms at the triazole rings. This method allows the easy preparation of bistriazolium salts with the bridge at the 1,1′ or 4,4′ positions. The two bis(triazolium) salts have been used for the preparation of three different bis(NHC)PtII complexes that have been fully characterized and the molecular structures of all three new complexes have been determined. The new Pt compounds have been tested in the hydrosilylation of terminal alkynes.
Fast Electrochemical Characterization of Historical Glasses Using Carbon Screen‐Printed Electrodes and Ultrasonic Assisted Sampling
Authors: Palomar T. , García‐Heras M. , Villegas M. A. , Sevilla M. T. 
Published: December 2010

AbstractA new method for lead oxide (PbO) analysis in glasses, using a carbon screen printed electrode (SPE) is proposed. A suspension of the powdered glass sample in nitric acid is prepared using an ultrasonic probe, 100 µL of slurry are deposited on the SPE and the voltammetric measurement is carried out. Structural information of PbO in the glass matrix is obtained by CV. Lead quantification is performed by DPV. In the best conditions a LOD of 2.30 wt% of PbO was obtained. The method has been applied with good results in the analysis of historical glasses samples.
Increase in posterior alpha activity during rehearsal predicts successful long‐term memory formation of word sequences
Authors: Meeuwissen Esther B. , Takashima Atsuko , Fernández Guillén , Jensen Ole 
Published: December 2010

AbstractIt is becoming increasingly clear that demanding cognitive tasks rely on an extended network engaging task‐relevant areas and, importantly, disengaging task‐irrelevant areas. Given that alpha activity (8–12 Hz) has been shown to reflect the disengagement of task‐irrelevant regions in attention and working memory tasks, we here ask if alpha activity plays a related role for long‐term memory formation. Subjects were instructed to encode and maintain the order of word sequences while the ongoing brain activity was recorded using magnetoencephalography (MEG). In each trial, three words were presented followed by a 3.4 s rehearsal interval. Considering the good temporal resolution of MEG this allowed us to investigate the word presentation and rehearsal interval separately. The sequences were grouped in trials where word order either could be tested immediately (working memory trials; WM) or later (LTM trials) according to instructions. Subjects were tested on their ability to retrieve the order of the three words. The data revealed that alpha power in parieto‐occipital regions was lower during word presentation compared to rehearsal. Our key finding was that parieto‐occipital alpha power during the rehearsal period was markedly stronger for successfully than unsuccessfully encoded LTM sequences. This subsequent memory effect demonstrates that high posterior alpha activity creates an optimal brain state for successful LTM formation possibly by actively reducing parieto‐occipital activity that might interfere with sequence encoding. Hum Brain Mapp, 2011. © 2010 Wiley Periodicals, Inc.
Impact of early percutaneous endoscopic gastrostomy tube placement on nutritional status and hospitalization in patients with head and neck cancer receiving definitive chemoradiation therapy
Authors: Rutter Charles E. , Yovino Susannah , Taylor Rodney , Wolf Jeffrey , Cullen Kevin J. , Ord Robert , Athas Mindy , Zimrin Ann , Strome Scott , Suntharalingam Mohan 
Published: December 2010

AbstractBackgroundThis study analyzed the impact of timing of percutaneous endoscopic gastrostomy (PEG) tube placement on clinical endpoints in patients undergoing concurrent chemoradiation therapy (CRT).MethodsIn all, 111 patients who underwent CRT for locally advanced squamous cell carcinoma of the head and neck (SCCHN) were retrospectively analyzed to determine the effect of timing of PEG placement on weight loss, hospitalizations, and rates of PEG complications/dependence.ResultsEarly PEG tube placement was correlated to reductions in weight loss during CRT (p < .001, R = 0.495), hospitalization for nutritional deficits (p = .011, R = 0.262), and magnitude of persistent weight loss at 6 weeks post‐CRT (p = .003, R = 0.347). Disease control was the only predictor of PEG dependence. No differences were seen in PEG complication or dependence rates with earlier placement.ConclusionsThe results of our series show that patients with locally advanced SCCHN undergoing definitive CRT may derive significant clinical benefit from the early placement of PEG tubes for nutritional supplementation. © 2010 Wiley Periodicals, Inc. Head Neck, 2010
Patatin-Like Phospholipase Domain-Containing 3 I148M Polymorphism, Steatosis, and Liver Damage in Chronic Hepatitis C σ
Authors: Valenti Luca , Rumi MariaGrazia , Galmozzi Enrico , Aghemo Alessio , Del Menico Benedetta , De Nicola Stella , Dongiovanni Paola , Maggioni Marco , Fracanzani Anna Ludovica , Rametta Raffaela , Colombo Massimo , Fargion Silvia 
Published: December 2010

Abstract

Steatosis has been reported to negatively influence the natural history of chronic hepatitis C (CHC), but controversy remains over its causal role due to the confounding effect of adiposity, insulin resistance, and diabetes. The rs738409 C>G patatin-like phospholipase domain-containing 3 (

PNPLA3

) single nucleotide polymorphism (SNP), encoding for the I148M protein variant, influences liver fat without affecting insulin resistance and body composition. The aim of this study was to evaluate the effect of the rs738409 CG genotype on liver fat and fibrosis in CHC patients. We also explored the possible effect of

PNPLA3

genotype on other steatosis-related complications, namely, treatment failure and hepatocellular carcinoma (HCC) development. To this end we considered two independent series of 325 and 494 CHC patients with available DNA and liver biopsy followed at tertiary referral centers in northern Italy. The rs738409 genotype was determined by a Taqman assay. The rs738409 GG genotype, observed in 10% of patients, was associated with steatosis independently of age, sex, body mass index (BMI), diabetes, alcohol intake, and viral genotype (odds ratio [OR] 1.90, 95% confidence interval [CI] 1.4-2.7;

P

< 0.001). The association with rs738409 genotype was confirmed for severe steatosis, was independent of alanine aminotransferase (ALT) and gamma-glutamyl transferase (GGT) values, and was observed in all viral genotypes but the 3. The rs738409 GG genotype was associated with fibrosis stage and cirrhosis (OR 1.47, 95% CI 1.2-1.9;

P

= 0.002), treatment response (n = 470; OR 0.63, 95% CI 0.4-0.8;

P

= 0.006), and HCC occurrence (n = 325; OR 2.16, 95% CI 1.3-3.6;

P

= 0.002), independently of confounders.

Conclusion:

The rs738409

PNPLA3

genotype influences steatosis development in CHC and is independently associated with cirrhosis and other steatosis-related clinical outcomes, such as lack of response to antiviral treatment and possibly HCC. (Hepatology 2011)