bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spectroscopic Capture and Reactivity of a Low‐Spin Cobalt(IV)‐Oxo Complex Stabilized by Binding Redox‐Inactive Metal Ions
Authors: Hong Seungwoo , Pfaff Florian F. , Kwon Eunji , Wang Yong , Seo Mi‐Sook , Bill Eckhard , Ray Kallol , Nam Wonwoo 
Published: July 2014

AbstractHigh‐valent cobalt‐oxo intermediates are proposed as reactive intermediates in a number of cobalt‐complex‐mediated oxidation reactions. Herein we report the spectroscopic capture of low‐spin (S=1/2) CoIV‐oxo species in the presence of redox‐inactive metal ions, such as Sc3+, Ce3+, Y3+, and Zn2+, and the investigation of their reactivity in CH bond activation and sulfoxidation reactions. Theoretical calculations predict that the binding of Lewis acidic metal ions to the cobalt‐oxo core increases the electrophilicity of the oxygen atom, resulting in the redox tautomerism of a highly unstable [(TAML)CoIII(O.)]2− species to a more stable [(TAML)CoIV(O)(Mn+)] core. The present report supports the proposed role of the redox‐inactive metal ions in facilitating the formation of high‐valent metal–oxo cores as a necessary step for oxygen evolution in chemistry and biology.
Electrical Network of Single‐Crystalline Metal Oxide Nanoclusters Wired by π‐Molecules
Authors: Tsunashima Ryo , Iwamoto Yoshifumi , Baba Yusuke , Kato Chisato , Ichihashi Katsuya , Nishihara Sadafumi , Inoue Katsuya , Ishiguro Katsuya , Song Yu‐Fei , Akutagawa Tomoyuki 
Published: July 2014

AbstractIn a mixed‐valence polyoxometalate, electrons are usually delocalized within the cluster anion because of low level of inter‐cluster interaction. Herein, we report the structure and electrical properties of a single crystal in which mixed‐valence polyoxometalates were electrically wired by cationic π‐molecules of tetrathiafulvalene substituted with pyridinium. Electron‐transport characteristics are suggested to represent electron hopping through strong interactions between cluster and cationic π‐molecules.
Prediction of dyes solubility in supercritical carbon dioxide (CMM EOS)
Authors: Hallaji Sani Ahmad , Arif Amin , Salehi Mohammad Ali , Asgarpour Khansary Milad 
Published: July 2014

ABSTRACTOn the basis of the M‐factor theory, A new piece‐wise equation of state has been developed elsewhere for prediction of compressibility factor. On the basis of this model, a novel model for the special case of Tr<1.1 together with a specialized parameter was developed also. Critical modification on the model is proposed and applied in this work as a result of critical assessment of model application in solute solubility prediction in supercritical carbon dioxide. Two relationships were obtained for S12 that must be implemented together with this equation of state. Using this new modified model, the solubility prediction/correlation will be a straightforward calculation. © 2014 Curtin University of Technology and John Wiley & Sons, Ltd.
Sociodemographic and hispanic acculturation factors and isolated anotia/microtia
Authors: Hoyt Adrienne T. , Canfield Mark A. , Shaw Gary M. , Waller Dorothy K. , Polen Kara N.D. , Ramadhani Tunu , Anderka Marlene T. , Scheuerle Angela E. ,   the National Birth Defects Prevention Study
Published: July 2014

BackgroundIt has been observed in several studies that infants with anotia/microtia are more common among Hispanics compared with other racial/ethnic groups. We examined the association between selected Hispanic ethnicity and acculturation factors and anotia/microtia in the National Birth Defects Prevention Study.MethodsWe examined data from mothers of 351 infants with isolated anotia/microtia and 8435 unaffected infants from the National Birth Defects Prevention Study with an expected delivery date from 1997 to 2007. Sociodemographic, maternal, and acculturation factors (e.g., age, maternal education, household income, body mass index, gestational diabetes, folic acid, smoking, alcohol intake, study center, parental birthplace, and years lived in the United States, maternal language) were assessed as overall risk factors and also as risk factors among subgroups of Hispanics (United States‐ and foreign‐born) versus non‐Hispanic whites.ResultsCompared with non‐Hispanic whites, both United States‐ and foreign‐born Hispanic mothers demonstrated substantially higher odds of delivering infants with anotia/microtia across nearly all strata of sociodemographic and other maternal factors (adjusted odds ratios range: 2.1–11.9). The odds of anotia/microtia was particularly elevated among Hispanic mothers who emigrated from Mexico after age five (adjusted odds ratios = 4.88; 95% confidence interval = 2.93–8.11) or who conducted the interview in Spanish (adjusted odds ratios = 4.97; 95% confidence interval = 3.00–8.24).ConclusionWe observed that certain sociodemographic and acculturation factors are associated with higher risks of anotia/microtia among offspring of Hispanic mothers. Birth Defects Research (Part A) 100:852–862, 2014. © 2014 Wiley Periodicals, Inc.
Toxicity Endpoint Selections for a Simazine Risk Assessment
Authors: Silva Marilyn , Iyer Poorni 
Published: July 2014

BACKGROUNDCalifornia uses simazine at one of the highest levels for states in the United States (approximately 2.5 million lbs 2006–2010). Simazine causes neuroendocrine disruption and mammary cancer in test animals. A risk assessment was prioritized by the California Department of Pesticide Regulation because of the nondietary concern for simazine exposure to occupational/nonoccupational simazine users, resident nonusers, and bystanders (especially children and children exhibiting pica) at greatest risk.METHODSNo observed effect levels (NOELs) from animal studies as well as human exposure data were used to determine nondietary values for the above populations. Registrant‐submitted and open literature studies focusing on oral (major human route) effects for simazine and the major metabolites desisopropyl‐s‐atrazine and diaminochlorotriazine were reviewed as part of the hazard identification process.RESULTSDevelopmental, reproduction, and chronic studies provided the lowest NOELs for the acute (5 mg/kg/day), subchronic (0.56 mg/kg/day), and chronic (0.52 mg/kg/day) exposure durations, respectively. A benchmark dose (95th percentile) was calculated for mammary tumorigenesis, assuming a threshold mechanism in rats (benchmark dose lower limit [95th percentile; BMDL05]: 2.9 mg/kg/day). Margins of exposure and uncertainty factors (100–300×, depending on exposure scenario) were used to characterize risk for designated population subgroups.CONCLUSIONSFetal developmental delays, endocrine disruption, and mammary tumors resulted from simazine treatment. Systemic and maternal/fetal effects determined the critical NOELs used in risk assessment. Margins of exposures for most scenarios were below acceptable levels, especially for children who may be bystanders where simazine is applied and children who exhibit pica. This risk characterization raises a concern for long‐term effects in humans
Anti‐social personality characteristics and psychotic symptoms: Two pathways associated with offending in schizophrenia
Authors: Van Dongen Josanne D. M. , Buck Nicole M. L. , Barendregt Marko , Van Beveren Nico M. , De Beurs Edwin , Van Marle Hjalmar J. C. 
Published: July 2014

ABSTRACTBackgroundSeveral research groups have shown that people with schizophrenia who offend do not form a homogenous group. A three‐group model claimed by Hodgins proposes distinguishing between people who start offending before the onset of psychosis (early starters), after psychosis onset but at age 34 years or under (late starters) and after psychosis onset but at age 35 years or older (late first offenders).AimsThis study aimed to test the hypotheses (1) that the personality of early starters and non‐psychotic offenders would be similar, but different from either late‐starter group; (2) that the late‐starter groups would be more likely to have positive psychotic symptoms than non‐criminal patients with schizophrenia; and (3) that symptom types would differentiate the psychotic groups.MethodsA retrospective file study was conducted on cases of 97 early starters, 100 late starters and 26 late first offenders all drawn from the Netherlands Institute of Forensic Psychiatry and Psychology (NIFP) archives 1993–2008, 115 non‐psychotic offenders from 2005–2008 NIFP archives and 129 patients with schizophrenia and no criminal history from one general service in Rotterdam.ResultsEarly starters closely resembled the non‐psychotic offenders in their premorbid anti‐social personality characteristics. The two late‐onset offending psychosis groups were more likely to have persecutory and/or grandiose delusions than non‐offenders with psychosis, but so were the early starters.ImplicationsIn a first study to compare subgroups of offenders with psychosis directly with non‐psychotic offenders and non‐offenders with psychosis, we found such additional support for a distinction between early and late starters with psychosis that different treatment strategies would seem indicated, focusing on personality and substance misuse for the former but psychotic symptoms for all. It remains to be seen whether the higher rate of alcohol misuse amongst late first offenders is a fundamental distinction or a function of age difference. Copyright © 2014 John Wiley & Sons, Ltd.
Foaming Process from Polystyrene/p‐Cymene Solutions Using CO2
Authors: Gutiérrez Cristina , Rodríguez Juan F. , Gracia Ignacio , de Lucas Antonio , García Maria T. 
Published: July 2014

AbstractFoaming of polystyrene by previous dissolution in p‐cymene is studied using CO2 to saturate the solution followed by a rapid decompression of samples. Although during the saturation stage the polymer is plasticized and the glass transition temperature is decreased, the main advantage offered by using a solvent is the reduction of the working temperature. The effects of pressure, temperature, and initial concentration of the polymer solutions on cell size, distribution of pores, and cell density of the foams are analyzed for optimization of the foaming process in order to achieve microcellular structures. Optimum conditions were achieved at high values of pressure and concentration and low temperature.
Asymmetric Modification of TiO2 Nanofibers with Gold by Electric‐Field‐Assisted Photochemistry
Authors: Ongaro Michael , Roche Jerôme , Kuhn Alexander , Ugo Paolo 
Published: July 2014

AbstractWe present a new procedure for the site‐specific deposition of metal on semiconductor nanofibers (NF). The semiconductor NFs are exposed to an external electric field while irradiated with UV light. This coupling allows the generation of excited electron–hole couples and drives them to the opposite extremities of the fibers where they can react with redox species in solution. We demonstrate here that, when both UV light and electric field are simultaneously applied, a metal deposit is formed at the cathodically polarized tip of the NF in a controlled way. Such an electric‐field‐assisted photochemical (EFAP) process is suitable for highly localized photodeposition of metals, leading to semiconductor Janus objects.
Endohedrally Filled [Ni@Sn9]4− and [Co@Sn9]5− Clusters in the Neat Solids Na12Ni1−xSn17 and K13−xCo1−xSn17: Crystal Structure and 119Sn Solid‐State NMR Spectroscopy
Authors: Hlukhyy Viktor , Stegmaier Saskia , van Wüllen Leo , Fässler Thomas F. 
Published: July 2014

AbstractA systematic approach to the formation of endohedrally filled atom clusters by a high‐temperature route instead of the more frequent multistep syntheses in solution is presented. Zintl phases Na12Ni1−xSn17 and K13−xCo1−xSn17, containing endohedrally filled intermetalloid clusters [Ni@Sn9]4− or [Co@Sn9]5− beside [Sn4]4−, are obtained from high‐temperature reactions. The arrangement of [Ni@Sn9]4− or [Co@Sn9]5− and [Sn4]4− clusters, which are present in the ratio 1:2, can be regarded as a hierarchical replacement variant of the hexagonal Laves phase MgZn2 on the Mg and Zn positions, respectively. The alkali‐metal positions are considered for the first time in the hierarchical relationship, which leads to a comprehensive topological parallel and a better understanding of the composition of these compounds. The positions of the alkali‐metal atoms in the title compounds are related to the known inclusion of hydrogen atoms in the voids of Laves phases. The inclusion of Co atoms in the {Sn9} cages correlates strongly with the number of K vacancies in K13−xCo1−xSn17 and K5−xCo1−xSn9, and consequently, all compounds correspond to diamagnetic valence compounds. Owing to their diamagnetism, K13−xCo1−xSn17, and K5−xCo1−xSn9, as well as the d‐block metal free binary compounds K12Sn17 and K4Sn9, were characterized for the first time by 119Sn solid‐state NMR spectroscopy.
Multivalent Inhibitors for Carbohydrate‐Processing Enzymes: Beyond the “Lock‐and‐Key” Concept
Authors: Gouin Sébastien G. 
Published: July 2014

AbstractDuring the last decades, tremendous chemical efforts have been dedicated to design monovalent inhibitors of carbohydrate‐processing enzymes, with comparatively few rewards in terms of marketed drugs. Recently, an alternative to the traditional “lock and key” approach has emerged. Multivalency, a widely used strategy for lectin inhibition, has been successfully applied to specific glycosidases and glycosyltransferases.
Geometric Influence on Intramolecular Photoinduced Electron Transfer in Platinum(II) Acetylide‐Linked Donor–Acceptor Assemblies
Authors: Molina‐Ontoria Agustín , Rivera‐Nazario Danisha M. , Tigreros Alexis , Ortiz Alejandro , Nuñez José E. , Insuasty Braulio , Lueders Daniela , Wolfrum Silke , Guldi Dirk M. , Echegoyen Luis 
Published: July 2014

AbstractA new donor–acceptor system, in which the electron donor triphenylamine (TPA) and the electron acceptor C60 are bridged through a cis‐ or trans‐platinum(II) acetylide spacer have been prepared. Ground‐state studies were conducted using electrochemistry and UV/Vis spectroscopy. Fluorescence studies suggested that charge transfer is the deactivation mechanism for the singlet excited state, and this was verified by transient absorption spectroscopy. Selective photoexcitation of 1 and 2 at 387 nm leads to a fast charge transfer between the TPA and C60, which gives rise to a radical ion‐pair state (TPA.+–Pt–C60.−). Our results suggest that charge transfer is favored for the cis configuration while the presence of the trans configuration in the PtII diacetylide results in a longer‐lived charge separated states.
New Concepts for Designing d10‐M(L)n Catalysts: d Regime, s Regime and Intrinsic Bite‐Angle Flexibility
Authors: Wolters Lando P. , van Zeist Willem‐Jan , Bickelhaupt F. Matthias 
Published: July 2014

AbstractOur aim is to understand the electronic and steric factors that determine the activity and selectivity of transition‐metal catalysts for cross‐coupling reactions. To this end, we have used the activation strain model to quantum‐chemically analyze the activity of catalyst complexes d10‐M(L)n toward methane CH oxidative addition. We studied the effect of varying the metal center M along the nine d10 metal centers of Groups 9, 10, and 11 (M=Co−, Rh−, Ir−, Ni, Pd, Pt, Cu+, Ag+, Au+), and, for completeness, included variation from uncoordinated to mono‐ to bisligated systems (n=0, 1, 2), for the ligands L=NH3, PH3, and CO. Three concepts emerge from our activation strain analyses: 1) bite‐angle flexibility, 2) d‐regime catalysts, and 3) s‐regime catalysts. These concepts reveal new ways of tuning a catalyst’s activity. Interestingly, the flexibility of a catalyst complex, that is, its ability to adopt a bent L‐M‐L geometry, is shown to be decisive for its activity, not the bite angle as such. Furthermore, the effect of ligands on the catalyst’s activity is totally different, sometimes even opposite, depending on the electronic regime (d or s) of the d10‐M(L)n complex. Our findings therefore constitute new tools for a more rational design of catalysts.
Synthesis and Antiviral Properties of Spirocyclic [1,2,3]‐Triazolooxazine Nucleosides
Authors: Dell'Isola Antonio , McLachlan Matthew M. W. , Neuman Benjamin W. , Al‐Mullah Hawaa M. N. , Binks Alexander W. D. , Elvidge Warren , Shankland Kenneth , Cobb Alexander J. A. 
Published: July 2014

AbstractAn efficient synthesis of spirocyclic triazolooxazine nucleosides is described. This was achieved by the conversion of β‐D‐psicofuranose to the corresponding azido‐derivative, followed by alkylation of the primary alcohol with a range of propargyl bromides, obtained by Sonogashira chemistry. The products of these reactions underwent 1,3‐dipolar addition smoothly to generate the protected spirocyclic adducts. These were easily deprotected to give the corresponding ribose nucleosides. The library of compounds obtained was investigated for its antiviral activity using MHV (mouse hepatitis virus) as a model wherein derivative 3 f showed the most promising activity and tolerability.
An Experimental Study of Wave Velocity Anisotropy in Sandstone Bearing Differential Pore Fluids from the Yanchang Formation
Authors: Er‐Wei QIAO , Chang‐Xing LONG , Hong‐Tao MA 
Published: July 2014

AbstractThis work applied the AutoLab 2000 test system to investigate three kinds of core samples of sandstone from the Yanchang oilfield that were cut parallel and perpendicular to the bedding planes (named H and V, respectively), and obtained accurate P‐ and S‐wave velocities, and wave velocity anisotropy data at pressures up to 180 MPa in dry, water‐ and oil‐saturated states for those sandstone. The results show the wave velocities VP, VSH and VSV for all H and V samples cut from three kinds of samples of sandstone Y1, Y2 and Y3 change basically logarithmically with increasing confining pressure p, and for all VP, the slopes of the oil‐saturated curves are greater than that of the corresponding water‐saturated curves. For all H samples, in dry, water‐ and oil‐saturated conditions, the VP and VSH and VSV are larger than the corresponding ones for V samples. For two kinds of sandstones Y1 and Y2, the wave velocity anisotropy parameters ε, γ and ζ change exponentially or in a quadratic curve with increasing confining pressure, and Y2 has a greater correlation coefficient of anisotropy parameters than Y1, but there is no wave velocities anisotropy in Y3. In addition, in dry, water‐ and oil‐saturated conditions the relationships between ε, γ and p or γ, ζ and p are quite distinct from each other, that is, the anisotropy factors ε, γ and ζ of Y1 and Y2 exhibit a clear correlation with pressure and the fluid property, and ε and γ in oil‐saturated condition are larger than that in the corresponding water‐saturated condition at the experimental pressure. The experimental results can provide an important basis for the interpretation of seismic data, identifying oil and water zones and comparing with well log data in the study area.
Transfemoral Aortic Valve Implantation of Edwards SAPIEN XT Without Predilatation Is Feasible
Authors: Möllmann Helge , Kim Won‐Keun , Kempfert Jörg , Blumenstein Johannes , Liebetrau Christoph , Nef Holger , Van Linden Arnaud , Walther Thomas , Hamm Christian 
Published: July 2014

ABSTRACTBackgroundTranscatheter aortic valve implantation (TAVI) without predilatation has fewer procedural steps and thereby potentially fewer complications. This has been demonstrated for the antegrade transapical access; however, whether TAVI can be safely performed without predilatation using the retrograde transfemoral route is unknown.HypothesisWe postulated that TAVI is feasible with a balloon‐expandable device without predilatation using the retrograde transfemoral route.MethodsTwenty‐six consecutive patients with stenosis of the native aortic valve (AV) undergoing transfemoral TAVI with the Edwards SAPIEN XT prosthesis without predilatation were enrolled in this retrospective study and compared with 30 patients treated previously with predilatation.ResultsThe procedure was successfully performed in all 26 patients, irrespective of the AV area and the extent of AV calcification. At baseline mean AV area, mean AV gradient, and median left ventricular ejection fraction were 0.7 ± 0.2 cm2, 36.0 ± 17.3 mm Hg, and 55.0% (interquartile range [IQR], 35.0–60.0], respectively; prior to discharge these values were 1.7 ± 0.3 (P < 0.001), 9.8 ± 6.1 mm Hg (P < 0.001), and 57.5% (IQR, 38.7–60.0) (P = not significant). Postdilatation was required in 3 patients due to aortic regurgitation >2°; this was reduced by the procedure to <2° in all cases. Radiation dose and amount of contrast dye were significantly reduced in comparison with the predilatation group. No periprocedural neurological adverse events occurred. Mortality at 30 days was 0%.ConclusionsTAVI without predilatation using the transfemoral Edwards SAPIEN XT valve is feasible and safe. Larger studies are required to further evaluate this approach.
Impact of sex on the survival of patients with hepatocellular carcinoma: A Surveillance, Epidemiology, and End Results analysis
Authors: Yang Dongyun , Hanna Diana L. , Usher Josh , LoCoco Jordan , Chaudhari Pritesh , Lenz Heinz‐Josef , Setiawan V. Wendy , El‐Khoueiry Anthony 
Published: July 2014

BACKGROUNDMen are 4 to 8 times more likely to develop hepatocellular carcinoma (HCC) than women. Preclinical models have suggested a role for sex hormones in the development of HCC. In the current study, the authors investigated the impact of age, sex, race, and ethnicity on the survival of patients with HCC using the Surveillance, Epidemiology, and End Results (SEER) database.METHODSPatients diagnosed with HCC from 1988 through 2010 were identified from the SEER registry. Hazard ratios (HR) for overall survival (OS) were derived using the Cox regression model adjusted for race, year of diagnosis, marital status, treatment, birthplace, tumor differentiation, and tumor size.RESULTSA total of 39,345 patients were identified; 76% were men and 34% were women (50% white, 12% African American, 21% Asian, 16% Hispanic, and 1% Native American). The median age at the time of diagnosis was 61 years for men and 67 years for women. Approximately 84% of patients had liver‐limited disease and 16% had metastatic disease. Treatment information was available for patients diagnosed after 1998 (34,674 patients): 11% received liver‐directed therapy, 11% underwent surgical resection, and 7% underwent liver transplantation. The HR for the OS of women versus men was 0.83 (95% confidence interval [95% CI], 0.77‐0.88) for patients aged <55 years. The protective effect of sex on OS was found to be greatest in patients aged 18 to 44 years (HR, 0.75; 95% CI, 0.65‐0.86 [P<.001]), especially those with surgically resected tumors (HR, 0.68; 95% CI, 0.54‐0.86 [P = .001]) and those who were African American (HR, 0.85; 95% CI, 0.78‐0.92 [P<.001]). There was no survival difference between sexes noted among Hispanics or patients aged >65 years.CONCLUSIONSSex appears to be associated with survival in patients with HCC. The role of androgens and estrogens in the development and progression of HCC warrants further investigation. Cancer 2014;120:3707–3716. © 2014 American Cancer Society.