bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bis(pyrazol‐1‐yl)methane as Non‐Chromophoric Ancillary Ligand for Charged Bis‐Cyclometalated Iridium(III) Complexes
Authors: Meng Sheng , Jung Il , Feng Jie , Scopelliti Rosario , Di Censo Davide , Grätzel Michael , Nazeeruddin M. Khaja , Baranoff Etienne 
Published: May 2012

AbstractNew charged cyclometalated iridium(III) complexes [Ir(ppy)2(L)](PF6) [ppy = 2‐phenylpyridine; L = bis(pyrazol‐1‐yl)methane (for 1); L = bis(3,5‐dimethylpyrazol‐1‐yl)methane (for 2)] were synthesized and their electrochemical and photophysical properties studied. These complexes with non‐π‐electron‐conjugated ancillary chelates exhibit significantly blueshifted emission relative to those of commonly used derivatives with NN ancillary ligands such as bipyridine or phenanthroline. Both X‐ray and theoretical analysis based on time‐dependent density functional theory (TD‐DFT) reveal that the binding of Ir to the bis(pyrazol‐1‐yl)methane ancillary ligand is much weaker than that to the phenylpyridine main ligand; the effect is enhanced in the excited state. As a result, the ancillary ligand does not participate in low‐energy excitations and triplet emission, and the electronic transitions are concentrated on the main chromophoric ligands. The blueshift feature is attributed to emission originating from the main cyclometalated ligands, in contrast to emitters with the NN chromophoric ancillary ligand. In addition, complex 2 exhibits a one order of magnitude higher non‐radiative decay rate than complex 1, which is attributed to the steric hindrance of the methyl groups that leads to a more loosely bound ancillary ligand.
Diphosphastannylenes: Precursors for Phosphorus–Phosphorus Coupling?
Authors: Řezníček Tomáš , Dostál Libor , Růžička Aleš , Jambor Roman 
Published: May 2012

AbstractThe preparation of the secondary phosphane (Ph){C6H3‐2,6‐(CH2NMe2)2}PH (1), a potentially base‐stabilized ligand, and the sterically protected carbaborane‐based phosphane (o‐CH3C2B10H10)2PH (2) is reported. Reaction of Sn{N(SiMe3)}2 with 1 gives the diphosphastannylene [(Ph){(C6H3‐2,6‐CH2NMe2)2}P]2Sn (3) in high yield. In contrast, the room‐temperature reaction of 2 with Sn{N(SiMe2)}2 does not proceed. By applying elevated temperatures, the heteroleptic amidophosphastannylene {(o‐CH3C2B10H10)2P}{(SiMe3)2N}Sn (4) was formed, instead of the expected diphosphastannylene {(o‐CH3C2B10H10)2P}2Sn. The thermal decomposition of compounds 3 and 4 was also studied. The thermal decomposition of 3 produced the new phosphorus–phosphorus‐bonded compound 5, an unprecedented 1,2‐diphosphol‐type molecule.
Reaction Mechanism of Phosphane‐Catalyzed [4+2] Annulations between α‐Alkylallenoates and Activated Alkenes: A Computational Study
Authors: Zhao Lili , Wen Mingwei , Wang Zhi‐Xiang 
Published: May 2012

AbstractA DFT study has been performed to understand the [4+2] annulation reaction between α‐methylallenoate (2) and benzylidenemalononitrile (3), catalyzed by P(NMe2)3 (1). For the reaction channel to produce cyclohexene 4a as the predominated product, the catalytic cycle can be characterized by three stages: in situ generation of the 1,3‐dipole IM2 between 1 and 2 (stage I); the addition of 3 to IM2 giving six‐membered‐ring intermediate IM8 (stage II); and catalyst 1 liberation from IM8 to produce 4a (stage III). For stage II, the pathway through direct [4+2] addition, followed by [1,3]‐H transfer, enabled by the alkene carbon bearing nitrile groups, is feasible, but less favorable than the [3+2] addition pathway followed by water‐aided [1,3]‐H transfer. The pathway leading to the regioisomer of 4a (i.e., 4b) is substantially less favorable, which accounts for the exclusive regioselectivity (4a/4b = 100:0) of the reaction. The [4+2] annulations are different from the conventional [3+2] cycloadditions of allenoates and activated alkenes. For the latter, a trace of water was demonstrated to be critical, even though the reactions are carried out in so‐called “anhydrous” solvents, because water is the only available hydrogen transfer mediator. In other words, the traditional [3+2] cycloadditions would not occur if the solvent were absolutely free of water. In contrast, [4+2] annulations can take place, even though water is completely absent, because the carbon (CCN of alkene 3) bearing the nitrile groups can serve as the hydrogen transfer mediator. The substitution effects of alkenes on the addition step of alkenes to IM2 have been further investigated.
Efficient Method for Varying the Anions in Quaternary Onium Halides
Authors: Jeon Jong Yeob , Varghese Jobi Kodiyan , Park Ji Hae , Lee Suck‐Hyun , Lee Bun Yeoul 
Published: May 2012

AbstractQuaternary onium salts of halides can be efficiently converted into the corresponding quaternary onium salts of various anions [NO3–, BF4–, PF6–, CF3SO3–, CH3SO3–, ClO4–, p‐CH3C6H4SO3–, CF3CO2–, 2,4‐(NO2)2C6H3O–] by treating the onium halide with trimethyl phosphate under neat condition in the presence of an equivalent amount of conjugate acid of the desired anion.
Modelling decomposition and fire behaviour of small samples of a glass‐fibre‐reinforced polyester/balsa‐cored sandwich material
Authors: Marquis Damien M. , Pavageau Michel , Guillaume Eric , Chivas‐Joly Carine 
Published: May 2012

ABSTRACTThis publication presents the experimental and numerical methods to model the devolatilization process of a glass‐fibre‐reinforced polyester/balsa‐cored sandwich material on small scale. The fundamental modelling of the source term in pyrolysis‐based fire simulations requires as input data the thermochemical properties of solid fuel and the kinetic parameters of the devolatilization process. First, the thermal decomposition of both elements composing the sandwich structure was studied by thermogravimetry coupled with gas analysis, in air and pure nitrogen atmospheres at several heating rates, in order to define a comprehensive multi‐step reaction pathway. A differential equation system is defined to model these decomposition processes. The kinetic parameters were then estimated by solving the system of equations by an inverse problem. Second, the fire behaviour of each element was studied separately and then combined in the sandwich structure on the cone calorimeter. In addition, numerical simulations with Fire Dynamics Simulator were performed to gradually assess the ability of the model(s) to reproduce each element composing the sandwich structure. Numerical and experimental results are compared and then discussed. Overall, the model provides a good agreement with the experimental data and encourages to model higher scales. Copyright © 2012 John Wiley & Sons, Ltd.
Decreased hospital stay and significant cost savings after routine use of prophylactic gastrostomy for high‐risk patients with head and neck cancer receiving chemoradiotherapy at a tertiary cancer institution
Authors: Hughes Brett G. M. , Jain Vikram K. , Brown Teresa , Spurgin Ann‐Louise , Hartnett Gemma , Keller Jacqui , Tripcony Lee , Appleyard Mark , Hodge Robert 
Published: May 2012

AbstractBackgroundEvidence‐based nutritional and swallowing guidelines were developed to identify patients at high risk of developing malnutrition during chemoradiation for head and neck cancer. These guidelines recommended a prophylactic gastrostomy and were actively implemented at our institution in January 2007. This study assesses the effect of this policy change on patient outcomes.MethodsThis retrospective cohort study was carried out for the years before (2005) and after (2007) implementation of these guidelines.ResultsIn all, 165 patients were treated with radical chemoradiation for head and neck cancer at our institution in the years 2005 and 2007. Gastrostomy tube complications were low. Patients in 2007 had significantly fewer hospital admissions, unexpected admissions, and a shorter mean duration of hospital stay in comparison with those in 2005.ConclusionsProphylactic gastrostomy tubes in patients with high‐risk head and neck cancer resulted in a significant decrease in hospital admissions and length of stay, and led to increased bed availability. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
Head and neck squamous cell carcinoma: Differentiation of histologic grade with standard‐ and high‐b‐value diffusion‐weighted MRI
Authors: Yun Tae Jin , Kim Ji‐hoon , Kim Kwang Hyun , Sohn Chul‐Ho , Park Sun‐Won 
Published: May 2012

AbstractBackgroundThe correlation between the histologic grades and the apparent diffusion coefficient (ADC) in head and neck squamous cell carcinomas (HNSCCs) remains unclear. This study aimed to evaluate the potential of diffusion‐weighted MRI (DW‐MRI) at both standard and high b values to differentiate the histologic grades of HNSCC.MethodsIn all, 54 consecutive patients with HNSCCs (34 well‐differentiated, 10 moderately differentiated, and 10 poorly differentiated) performed DW‐MRIs at both b = 1000 and 2000 s/mm2 prior to biopsy or surgery. The ADC values were compared among the different histologic grades.ResultsThe ADC values of well‐differentiated and poorly differentiated HNSCC were significantly different at both b values (p < .001 in both). However, significant difference between moderately differentiated and poorly differentiated HNSCC was revealed at only b = 2000 s/mm2 (p = .014).ConclusionsDW‐MRIs at standard and high b values are helpful for differentiating histologic grades in HNSCC with better differentiation at a high b‐value. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
Prospective study of prognostic value of Raf kinase inhibitory protein and pretreatment plasma Epstein–Barr virus DNA for distant metastasis in locoregionally advanced nasopharyngeal carcinoma
Authors: Li Si‐Wei , Wang Hua , Xiang Yan‐Qun , Zhang Hai‐bo , Lv Xing , Xia Wei‐Xiong , Zeng Mu‐Sheng , Mai Hai‐Qiang , Hong Ming‐Huang , Guo Xiang 
Published: May 2012

AbstractBackgroundThe purpose of this prospective study was to investigate the predictive significance of Raf kinase inhibitory protein (RKIP) in locoregionally advanced nasopharyngeal carcinoma (NPC) and its effect on distant metastasis.MethodsThe usual immunohistochemical stainings were performed to detect RKIP expression of cancer tissues from 210 patients with advanced NPC. After DNA samples from pretreatment plasma from these patients were extracted, real‐time polymerase chain reaction (PCR) was performed to quantitatively analyze plasma Epstein–Barr virus (EBV) DNA.ResultsRKIP expression was significantly different for different N classifications and WHO pathologic grades, respectively (p < .05). Cox regression confirmed RKIP and EBV DNA were independent prognostic markers for 5‐year distant metastasis‐free survival (DMFS). In the high RKIP expression group, chemotherapy had a positive effect on improved DMFS, but not in the low RKIP expression group.ConclusionsRKIP could be identified as an independent prognostic factor on DMFS. For each combined treatment modality, the different impact of chemotherapy on distant metastasis might be related to the RKIP expression level. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
Conventional transoral surgery for stage I–II squamous cell carcinoma of the tonsillar region
Authors: Laccourreye Ollivier , Malinvaud David , Alzahrani Hatem , Ménard Madeleine , Garcia Dominique , Bonfils Pierre , Holsinger F. Christopher 
Published: May 2012

AbstractBackgroundThe purpose of this study was to review the results of conventional transoral resection and neck dissection for stage I to II squamous carcinoma of the tonsillar region.MethodsWe conducted a retrospective review of 65 patients (stage I, 21 patients; stage II, 44 patients). Induction chemotherapy and postoperative radiation therapy (RT) were administered in 76.9% and 12.3%, respectively, of these cases.ResultsThe postoperative course was uneventful in 96.9% of patients. Five‐year actuarial estimates for local recurrence, nodal recurrence, distant metastasis, and survival were 0% to 7.6%, 0% to 7.8%, 0% to 7.3%, and 70.8% to 71.5% for patients with T1 to T2 carcinoma, respectively. Contralateral and retropharyngeal recurrence occurred in only 1 patient.ConclusionConventional transoral resection with ipsilateral neck dissection provides an alternative approach for patients with stage I to II squamous cell carcinoma (SCC) of the tonsillar region. A primary surgical approach spares the use of radiotherapy to eliminate late effects and to permit its use for subsequent management of metachronous head and neck second primary cancer. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
Prenatal stress changes learning strategies in adulthood
Authors: Schwabe Lars , Bohbot Veronique D. , Wolf Oliver T. 
Published: May 2012

AbstractIt is well known that stressful experiences may shape hippocampus‐dependent learning and memory processes. However, although most studies focused on the impact of stress at the time of learning or memory testing, very little is known about how stress during critical periods of brain development affects learning and memory later in life. In this study, we asked whether prenatal stress exposure may influence the engagement of hippocampus‐dependent spatial learning strategies and caudate nucleus‐dependent response learning strategies in later life. To this end, we tested healthy participants whose mothers had experienced major negative life events during their pregnancy in a virtual navigation task that can be solved by spatial and response strategies. We found that young adults with prenatal stress used rigid response learning strategies more often than flexible spatial learning strategies compared with participants whose mothers did not experience major negative life events during pregnancy. Individual differences in acute or chronic stress do not account for these findings. Our data suggest that the engagement of hippocampal and nonhippocampal learning strategies may be influenced by stress very early in life. © 2012 Wiley Periodicals, Inc.
Isolated central nervous system relapses in primary mediastinal large B‐cell lymphoma after CHOP‐like chemotherapy with or without Rituximab
Authors: Papageorgiou Sotirios G. , Diamantopoulos Panayiotis , Levidou Georgia , Angelopoulou Maria K. , Economopoulou Panagiota , Efthimiou Anna , Constantinou Nikos , Katsigiannis Andreas , Korkolopoulou Penelope , Pappa Vassiliki , Economopoulou Christina , Georgiou George , Dimou Maria , Tsirigotis Panagiotis , Kyrtsonis Marie‐Christine , Kotsianidis Ioannis , Kalpadakis Christina , Dimopoulos Meletios‐Athanassios , Beris Photis , Meletis John , Pangalis Gerassimos A. , Dervenoulas John , Panayiotidis Panayiotis , Vassilakopoulos Theodoros P. 
Published: May 2012

AbstractCentral nervous system (CNS) involvement in patients with primary mediastinal large B‐cell (PMLBCL) lymphoma is a rare event, occurring in approximately 6% of patients, on the basis of the review of the literature prior to induction of Rituximab. The aim of this retrospective study was to describe the incidence of CNS relapse among 100 consecutive patients with PMLBCL who were treated with R‐CHOP ± RT in comparison to patients treated with CHOP ± RT (n = 45) in 11 hospitals in Greece. Two patients experienced a CNS relapse, representing an overall frequency of 2.0% in R‐CHOP treated patients and a 2‐year actuarial incidence of 2.3%. Both patients had isolated CNS relapses. The incidence of CNS relapse after CHOP without Rituximab was 2/45 (4.4%) for a 2‐year actuarial incidence of 7.5% (p = 0.29). Again, both patients had isolated CNS relapses. Parenchymal‐only localizations accounted for 3/4 cases. Risk factors for CNS involvement could include leukocytosis, poor performance status and higher age‐adjusted International Prognostic Index, although their impact was weakened by competing risk survival analysis. Both patients relapsing after R‐CHOP required CNS radiotherapy to achieve a complete remission and be forwarded to high‐dose therapy and autologous stem cell transplantation: They are both alive and disease‐free 18 and 23 months after CNS relapse. Both cases relapsing after CHOP without Rituximab were salvaged by CNS radiotherapy (one also received intrathecal chemotherapy) entering long‐term remissions. In conclusion, CNS relapses are rare in PMLBCL tending to be isolated in the CNS, probably reflecting the persistence of latent CNS disease than dissemination of resistant disease. The impact of Rituximab in reducing CNS relapses remains unknown. Established risk factors for CNS involvement in aggressive lymphomas may not be helpful in assessing the risk of CNS recurrence in this disease. Routine CNS prophylaxis is not probably required in PMLBCL. Copyright © 2012 John Wiley & Sons, Ltd.
Determination of bare surface soil moisture from combined temporal evolution of land surface temperature and net surface shortwave radiation
Authors: Zhao Wei , Li Zhao‐Liang , Wu Hua , Tang Bo‐Hui , Zhang Xiaoyu , Song Xiaoning , Zhou Guoqing 
Published: May 2012

AbstractLand surface soil moisture (SSM) is an important variable for hydrological, ecological, and meteorological applications. A multi‐linear model has recently been proposed to determine the SSM content from the combined diurnal evolution of both land surface temperature (LST) and net surface shortwave radiation (NSSR) with the parameters TN (the LST mid‐morning rising rate divided by the NSSR rising rate during the same period) and td (the time of daily maximum temperature). However, in addition to the problem that all the coefficients of the multi‐linear model depend on the atmospheric conditions, the model also suffers from the problems of the nonlinearity of TN as a function of the SSM content and the uncertainty of determining the td from the diurnal evolution of the LST. To address these problems, a modified multi‐linear model was developed using the logarithm of TN and normalizing td by the mid‐morning temperature difference instead of using the TN and td. Except for the constant term, the coefficients of all other variables in the modified multi‐linear model proved to be independent of the atmospheric conditions. Using the relevant simulation data, results from the modified multi‐linear model show that the SSM content can be determined with a root mean square error (RMSE) of 0.030m3/m3, provided that the constant term is known or estimated day to day. The validation of the model was conducted using the field measurements at the Langfang site in 2008 in China. A higher correlation is achieved (coefficient of determination: R2 = 0.624, RMSE = 0.107m3/m3) between the measured SSM content and the SSM content estimated using the modified multi‐linear model with the coefficients determined from the simulation data. Another experiment is also conducted to estimate the SSM content using the modified model with the constant term calibrated each day by one‐spot measurements at the site. The estimation result has a relatively larger error (RMSE = 0.125m3/m3). Additionally, the uncertainty of the determination of the coefficients is analysed using the field measurements, and the results indicate that the SSM content obtained using the modified model accurately characterizes the surface soil moisture condition. Copyright © 2012 John Wiley & Sons, Ltd.
The APTIMA HPV assay versus the hybrid capture 2 test in triage of women with ASC‐US or LSIL cervical cytology: A meta‐analysis of the diagnostic accuracy
Authors: Arbyn Marc , Roelens Jolien , Cuschieri Kate , Cuzick Jack , Szarewski Ann , Ratnam Sam , Reuschenbach Miriam , Belinson Suzanne , Belinson Jerome L. , Monsonego Joseph 
Published: May 2012

AbstractTesting for DNA of 13 high‐risk HPV types with the Hybrid Capture 2 (HC2) test has consistently been shown to perform better in triage of women with cervical cytology results showing atypical squamous cells of undetermined significance (ASC‐US) but often not in triage of low‐grade squamous intraepithelial lesions (LSIL) detected in cervical cancer screening. In a meta‐analysis, we compared the accuracy of the APTIMA HPV test, which identifies RNA of 14 high‐risk HPV types, to HC2 for the triage of women with ASC‐US or LSIL. Literature search‐targeted studies where the accuracy of APTIMA HPV and HC2 for detection of underlying CIN2/3+ was assessed concomitantly including verification of all cases of ASC‐US and LSIL. HSROC (Hierarchical Summary ROC) curve regression was used to compute the pooled absolute and relative sensitivity and specificity. Eight studies, comprising 1,839 ASC‐US and 1,887 LSIL cases, were retrieved. The pooled sensitivity and specificity of APTIMA to triage ASC‐US to detect underlying CIN3 or worse was 96.2% (95% CI = 91.7–98.3%) and 54.9% (95% CI = 43.5–65.9%), respectively. APTIMA and HC2 showed similar pooled sensitivity; however, the specificity of the former was significantly higher (ratio: 1.19; 95% CI = 1.08–1.31 for CIN2+). The pooled sensitivity and specificity of APTIMA to triage LSIL were 96.7% (95% CI = 91.4–98.9%) and 38.7% (95% CI = 30.5–47.6%) for CIN3+. APTIMA was as sensitive as HC2 but more specific (ratio: 1.35; 95% CI = 1.11–1.66). Results were similar for detection of CIN2 or worse. In both triage of ASC‐US and LSIL, APTIMA is as sensitive but more specific than HC2 for detecting cervical precancer.
Meat and fish consumption and risk of pancreatic cancer: Results from the European Prospective Investigation into Cancer and Nutrition
Authors: Rohrmann Sabine , Linseisen Jakob , Nöthlings Ute , Overvad Kim , Egeberg Rikke , Tjønneland Anne , Boutron‐Ruault Marie Christine , Clavel‐Chapelon Françoise , Cottet Vanessa , Pala Valeria , Tumino Rosario , Palli Domenico , Panico Salvatore , Vineis Paolo , Boeing Heiner , Pischon Tobias , Grote Verena , Teucher Birigit , Khaw Kay‐Tee , Wareham Nicholas J. , Crowe Francesca L. , Goufa Ioulia , Orfanos Philippos , Trichopoulou Antonia , Jeurnink Suzanne M. , Siersema Peter D. , Peeters Petra H.M. , Brustad Magritt , Engeset Dagrun , Skeie Guri , Duell Eric J. , Amiano Pilar , Barricarte Aurelio , Molina‐Montes Esther , Rodríguez Laudina , Tormo María‐José , Sund Malin , Ye Weimin , Lindkvist Björn , Johansen Dorthe , Ferrari Pietro , Jenab Mazda , Slimani Nadia , Ward Heather , Riboli Elio , Norat Teresa , Bueno‐de‐Mesquita H. Bas 
Published: May 2012

AbstractPancreatic cancer is the fourth most common cause of cancer death worldwide with large geographical variation, which implies the contribution of diet and lifestyle in its etiology. We examined the association of meat and fish consumption with risk of pancreatic cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC). A total of 477,202 EPIC participants from 10 European countries recruited between 1992 and 2000 were included in our analysis. Until 2008, 865 nonendocrine pancreatic cancer cases have been observed. Calibrated relative risks (RRs) and 95% confidence intervals (CIs) were computed using multivariable‐adjusted Cox hazard regression models. The consumption of red meat (RR per 50 g increase per day = 1.03, 95% CI = 0.93–1.14) and processed meat (RR per 50 g increase per day = 0.93, 95% CI = 0.71–1.23) were not associated with an increased pancreatic cancer risk. Poultry consumption tended to be associated with an increased pancreatic cancer risk (RR per 50 g increase per day = 1.72, 95% CI = 1.04–2.84); however, there was no association with fish consumption (RR per 50 g increase per day = 1.22, 95% CI = 0.92–1.62). Our results do not support the conclusion of the World Cancer Research Fund that red or processed meat consumption may possibly increase the risk of pancreatic cancer. The positive association of poultry consumption with pancreatic cancer might be a chance finding as it contradicts most previous findings.