bluuebunny/crossref_metadata_2025_split huggingface dataset:
Carbene Complexes Based on Dilithium Methandiides
Authors: Gessner Viktoria H. , Becker Julia , Feichtner Kai‐Stephan 
Published: March 2015

AbstractIn the last 15 years, methandiide ligands have given access to a new class of carbene complexes with unique electronic properties. The metal–carbon interactions in these complexes cover a range of bonding situations, from highly polar interactions to metal–carbon double bonds. This flexibility has allowed the isolation of complexes with metals covering the whole periodic table, including metals that had long been reluctant to form multiple bonds with carbon atoms. Thus, recent years have seen the revelation of many unusual carbene species with interesting reactivities. In this microreview, we focus on the latest developments in the chemistry of methandiides and their use as ligands in carbene complexes. We give an overview of the geminal dianionic compounds, their properties, and molecular and electronic structures, with special focus on those compounds that are applied in transition metal chemistry. The second part of the article deals with the preparation and electronic structures of methandiide‐derived carbene complexes, and we highlight important examples that display the unique properties and efficiency of the ligands. The last section gives an overview of the reactivity and the non‐innocent behavior of these methandiide ligands.
Germanium(II) and Tin(II) Halide Complexes Containing the Triimido Sulfur(VI) Phosphanyl Ligand
Authors: Carl Elena , Stalke Dietmar 
Published: March 2015

AbstractThe monomeric compounds [GeCl{(NtBu)3SCH2PPh2}] (1) and [SnBr{(NtBu)3SCH2PPh2}] (2) have been synthesized from equimolar reactions of [(tmeda)Li{(NtBu)3SCH2PPh2}] and GeCl2·dioxane or SnBr2, respectively, to introduce the N,N′‐chelating triimidosulfonate anion Ph2PCH2S(NtBu)3–. The complexes were fully characterized by single‐crystal X‐ray structural analysis, NMR spectroscopy, and mass spectrometry.
Oxide‐Bridged Heterobimetallic Aluminum/Zirconium Catalysts for Ethylene Polymerization
Authors: Boulho Cédric , Zijlstra Harmen S. , Harder Sjoerd 
Published: March 2015

AbstractA bimetallic aluminum/zirconium complex Cp*2Zr(Me)OAl(DIPH) [DIPH‐H2 = 3,3′‐bis(2‐methylallyl)‐(1,1′‐biphenyl)‐2,2′‐diol; Cp* = C5Me5] was prepared in good yield by the reaction of (DIPH)AlMe with Cp*2Zr(Me)OH. In contrast to Roesky's catalyst, Cp2Zr(Me)O(Me)Al(DIPP‐nacnac) {DIPP‐nacnac = CH[(CMe)(2,6‐iPr2C6H3N)]2}, it contains no Al–Me functionality and has increased Lewis acidity at Al. Crystal structures and the NMR spectra of the aluminum complex (DIPH)AlMe and the bimetallic Al/Zr species reveal in both cases dimeric complexes. The crystal structure of [Cp*2Zr(Me)OAl(DIPH)]2 shows a planar Al2O2 core and a terminal Cp*2Zr(Me)O group. Ethylene polymerization in toluene was studied for the bimetallic complex with a variety of scavengers. Under comparable polymerization conditions, the methylalumoxane‐activated species show high activities that are similar to those obtained with Cp*2ZrCl2 and Roesky's bimetallic complex Cp2Zr(Me)OAl(Me)(DIPP‐nacnac), with a relatively narrow polydispersity index (2.47).
Silver‐Mediated Decarboxylative Fluorination of Paraconic Acids: A Direct Entry to β‐Fluorinated γ‐Butyrolactones
Authors: Phae‐nok Supasorn , Soorukram Darunee , Kuhakarn Chutima , Reutrakul Vichai , Pohmakotr Manat 
Published: March 2015

AbstractThe silver(I)‐mediated decarboxylative fluorination of paraconic acids using Selectfluor® as a fluorine source is reported. Readily available paraconic acids undergo decarboxylative fluorination with Selectfluor® mediated by AgNO3 to give the corresponding β‐fluorinated γ‐butyrolactones in moderate to good yields. This approach serves as a direct and site‐selective strategy for the introduction of a fluorine atom at the β position of γ‐butyrolactone cores. The fluorinated products are synthetically useful scaffolds for organic synthesis.
A DFT Study of Inter‐ and Intramolecular Aryne Ene Reactions
Authors: Pérez Patricia , Domingo Luis R. 
Published: March 2015

AbstractThe molecular mechanisms of inter‐ and intramolecular aryne‐ene reactions have been theoretically studied by DFT methods at the MPWB1K/6‐311G(d,p) level. These reactions proceed through a one‐step mechanism via nearly asynchronous transition states (TSs), in which the C–C single bond formation is slightly more advanced than the hydrogen transfer process. These ene reactions show very low activation enthalpies (<1 kcal/mol) and are strongly exothermic by more than 73 kcal/mol. An electron localisation function (ELF) topological analysis of the changes of electron density during these ene reactions indicates that the bonding changes are nonconcerted. ELF topological analysis of the electron density in the C1–C2 bonding region of benzyne indicates that the 1,2‐pseudodiradical vinyl structure, rather than a structure with a C≡C triple bond, is responsible for the very high reactivity of these species.
Hetero‐Click Conjugation of Oligonucleotides with Glycosides Using Bifunctional Phosphoramidites
Authors: Meyer Albert , Noël Mathieu , Vasseur Jean‐Jacques , Morvan François 
Published: March 2015

AbstractTwo phosphoramidite derivatives, 1 and 2, each bearing two orthogonal functions: alkyne/thioacetyl or alkyne/tosyl, respectively, were synthesized and used to generate heteroglyco 5′‐oligonucleotide conjugates. After coupling, the first conjugation was performed using CuAAC on solid support with an azide‐bearing carbohydrate. For 1, the second conjugation was performed in solution by a thiol “click” reaction using a bromoacetamide galactoside, whereas for 2, the tosyl group was converted into an azide and a second CuAAC was applied on solid support. Accordingly, a deoxycholic‐centered heteroglycocluster exhibiting two D‐galactose and two L‐fucose motifs, conjugated to an oligonucleotide, was successfully synthesized.
The Dynamic Assembly of Covalent Organic Polygons: Finding the Optimal Balance of Solubility, Functionality, and Stability
Authors: Smith Merry K. , Goldberg Alexander R. , Northrop Brian H. 
Published: March 2015

AbstractSix variably functionalized phenanthrene‐based bis(catechol) derivatives have been synthesized and their ability to undergo dynamic covalent assembly with 1,4‐benzenediboronic acid (BDBA) to give discrete, shape‐persistent [2+2] assemblies has been investigated. Systematically varying the functionality of the bis(catechol) derivatives is found to influence both the reaction conditions necessary to promote their self‐assembly with BDBA as well as the stability of the resulting assemblies in the presence of protic solvents. A model is proposed to describe how solvent choice and starting material functionality must be carefully balanced in order to shift many competing equilibria toward the formation of discrete, soluble covalent organic polygons. The results are expected to provide additional insight into optimizing the synthesis of other boronate ester polygons/polyhedra as well as related, “infinite” covalent organic frameworks (COFs).
Structure and Absolute Configuration of Auriculamide, a Natural Product from the Predatory Bacterium Herpetosiphon aurantiacus
Authors: Schieferdecker Sebastian , Domin Nicole , Hoffmeier Christine , Bryant Donald A. , Roth Martin , Nett Markus 
Published: March 2015

AbstractThe genome of the filamentous, predatory bacterium Herpetosiphon aurantiacus harbors a plethora of genes that are predicted to be involved in natural product biosynthesis. Until now, however, no secondary metabolites have been described from this microorganism. Analysis of H. aurantiacus culture extracts by 1H NMR spectroscopy now led to the discovery of a chlorinated amide, which we termed auriculamide. The configuration of the three chiral centers in auriculamide was solved by chromatographic comparison with stereospecifically prepared reference compounds following chemical degradation. Furthermore, a putative gene cluster for the biosynthesis of auriculamide was identified by genome mining.
Cu(OAc)2‐Catalysed Oxidative Dual C–H/N–H Activation of Terminal Alkynes and N‐Deprotected Sulfonimidamides: An Easy Access to N‐Alkynylated Sulfonimidamides
Authors: Nandi Ganesh Chandra , Kota Sudhakar Rao , Naicker Tricia , Govender Thavendran , Kruger Hendrick G. , Arvidsson Per I. 
Published: March 2015

AbstractWe report a mild and efficient Cu(OAc)2‐catalysed protocol for the oxidative C–N cross‐coupling of terminal alkynes and N‐deprotected sulfonimidamides. The reaction leads to hitherto unknown N‐alkynylated sulfonimidamides. Furthermore, we found that the synthesised N‐alkynylated sulfonimidamides could undergo silica‐gel‐mediated hydrolysis to give the corresponding N‐acyl‐sulfonimidamides, as well as borane–dimethyl sulfide‐mediated reduction to give the corresponding N‐alkylated sulfonimidamides.
Food Addiction in Overweight and Obese Adolescents Seeking Weight‐loss Treatment
Authors: Meule Adrian , Hermann Tina , Kübler Andrea 
Published: March 2015

AbstractSome forms of overeating closely resemble addictive behaviour. The Yale Food Addiction Scale (YFAS) was developed to measure such addiction‐like eating in humans and has been employed in numerous studies for examining food addiction in adults. Yet, little is known about food addiction in children and adolescents. Fifty adolescents were recruited at the beginning of treatment in a weight‐loss hospital and completed the YFAS among other questionnaires. Nineteen participants (38%) received a YFAS diagnosis, who did not differ in age, body mass and gender distribution from those not receiving a diagnosis. However, those with food addiction reported more binge days, more frequent food cravings, higher eating, weight and shape concerns, more symptoms of depression and higher attentional and motor impulsivity. Eating restraint and nonplanning impulsivity did not differ between groups. Results replicate findings from studies in obese adults such that food addiction is not related to age, gender, body mass or eating restraint, but to higher eating pathology, more symptoms of depression and higher impulsivity. Furthermore, results highlight that particularly attentional impulsivity is related to ‘food addiction’. Addiction‐like eating appears to be a valid phenotype in a substantial subset of treatment‐seeking, obese adolescents. Copyright © 2015 John Wiley & Sons, Ltd and Eating Disorders Association.
Competencies for Program Evaluators in Light of Adaptive Action: What? So What? Now What?
Authors: King Jean A. , Stevahn Laurie 
Published: March 2015

AbstractThis chapter considers next steps in the development and use of evaluator competencies in the United States and globally. It begins with a brief grounding in definitions, then applies the framework of adaptive action (Eoyang & Holladay, 2013), asking “What?” to first describe the current status of evaluator competencies, “So what?” to discuss the implications of that status, and finally “Now what?” to identify potential actions that might attend to the complexity of change in the field of evaluation. © Wiley Periodicals, Inc., and the American Evaluation Association.
How Does Accreditation Fit Into the Picture?
Authors: McDavid James C. , Huse Irene 
Published: March 2015

AbstractSince evaluation does not currently accredit preparation programs, the content of this chapter was virtually a blank slate for the authors. Fittingly, they began by reviewing some background literature as to basic terms, what accreditation might entail, and critically parsing out the benefits of doing so. From there they proceeded to examine fields with a kinship to evaluation (accounting, business management, and human resource development) that have implemented systems to provide accredited status for their educational programs. The results have been questionable and led to perhaps unanticipated recommendations for what evaluation should be considering. © Wiley Periodicals, Inc., and the American Evaluation Association.
Using temporal orientation, category fluency, and word recall for detecting cognitive impairment: the 10‐point cognitive screener (10‐CS)
Authors: Apolinario Daniel , Lichtenthaler Daniel Gomes , Magaldi Regina Miksian , Soares Aline Thomaz , Busse Alexandre Leopold , das Gracas Amaral Jose Renato , Jacob‐Filho Wilson , Brucki Sonia Maria Dozzi 
Published: March 2015

ObjectivesA screening strategy composed of three‐item temporal orientation and three‐word recall has been increasingly used for detecting cognitive impairment. However, the intervening task administered between presentation and recall has varied. We evaluated six brief tasks that could be useful as intervening distractors and possibly provide incremental accuracy: serial subtraction, clock drawing, category fluency, letter fluency, timed visual detection, and digits backwards.MethodsOlder adults (n = 230) consecutively referred for suspected cognitive impairment underwent a comprehensive assessment for gold‐standard diagnosis, of whom 56 (24%) presented cognitive impairment not dementia and 68 (30%) presented dementia. Among those with dementia, 87% presented very mild or mild stages (Clinical Dementia Rating 0.5 or 1). The incremental value of each candidate intervening task in a model already containing orientation and word recall was assessed.ResultsCategory fluency (animal naming) presented the highest incremental value among the six candidate intervening tasks. Reclassification analyses revealed a net gain of 12% among cognitively impaired and 17% among normal participants. A four‐point scaled score of the animal naming task was added to three‐item temporal orientation and three‐word recall to compose the 10‐point Cognitive Screener. The education‐adjusted 10‐point Cognitive Screener outperformed the longer Mini‐Mental State Examination for detecting both cognitive impairment (area under the curve 0.85 vs 0.77; p = 0.027) and dementia (area under the curve 0.90 vs 0.83; p = 0.015).ConclusionsBased on empirical data, we have developed a brief and easy‐to‐use screening strategy with higher accuracy and some practical advantages compared with commonly used tools. Copyright © 2015 John Wiley & Sons, Ltd.
Detection of subclinical recurrence or second primary cancer using 18F‐FDG PET/CT in patients treated curatively for head and neck squamous cell carcinoma
Authors: Kikuchi Masahiro , Shinohara Shogo , Hino Megumu , Itoh Kyo , Tona Risa , Kishimoto Ippei , Harada Hiroyuki , Fujiwara Keizo , Suehiro Atsushi , Naito Yasushi 
Published: March 2015

BackgroundThe efficacy of posttreatment surveillance 18F‐fluorodeoxyglucose positron emission tomography (18F‐FDG PET)/CT was evaluated in patients with head and neck squamous cell carcinoma (HNSCC).MethodsThe subjects were 158 patients with HNSCC who underwent PET/CT after definitive treatment. PET/CT detection of subclinical recurrence or a second primary cancer and the effect of timing of PET/CT scans on survival were analyzed.ResultsRecurrence or a second primary cancer occurred in 70 patients, and 67% of these cases were detected by PET/CT. Detection rates were 17%, 9%, 5%, and 5% in the first, second, third, and fourth scans at 4, 9, 15, and 21 months, respectively. In multivariate analysis, patients who underwent early first scans had significantly better disease‐specific (hazard ratio [HR] = 0.37; p = .031) and overall (HR = 0.45; p = .040) survival compared with those who underwent late first scans.ConclusionEarlier detection of subclinical lesions by surveillance PET/CT within 4 months after treatment may improve survival in patients with HNSCC. © 2015 Wiley Periodicals, Inc. Head Neck 38: E511–E518, 2016
Synchronous reconstruction of bilateral osteoradionecrosis of the mandible using a single fibular osteocutaneous flap in patients with nasopharyngeal carcinoma
Authors: Fan Song , Wang You‐yuan , Lin Zhao‐yu , Zhang Da‐ming , Yu Xin , Chen Wei‐xiong , Zhong Jiang‐long , Li Qun‐xing , Feng Yu‐huan , Chen Wei‐liang , Pan Chao‐bin , Dias–Ribeiro Eduardo , Sonoda Celso Koogi , Ye Jian‐tao , Li Jin‐song 
Published: March 2015

AbstractBackgroundThe reconstruction of bilateral osteoradionecrosis (ORN) of mandibular defects using a single free bone flap is rarely performed because extensively radiated neck tissue with severe fibrosis is usually unsuitable for vascularized reconstruction.MethodsThirty‐one patients with nasopharyngeal carcinoma (NPC) underwent bilateral reconstruction of advanced ORN in the mandible using a single fibular osteocutaneous flap. Clinical factors associated with the operation were assessed, including classification of mandible defects, types of recipient vessels, perioperative complications, and postoperative outcomes.ResultsAll of the fibular osteocutaneous flaps survived completely, with the exception of 1 inner skin paddle that presented partial necrosis in a reconstruction of through‐and‐through defects. All patients experienced an improvement in cosmetic results 6 months after the reconstruction, whereas 23 patients experienced improved mouth opening compared to the preoperative condition.ConclusionAdvanced bilateral ORN in patients with NPC could be synchronously reconstructed with a single fibular osteocutaneous flap. © 2015 Wiley Periodicals, Inc. Head Neck 38: E–E, 2016
CDC42 Gtpase Activation Affects Hela Cell DNA Repair and Proliferation Following UV Radiation‐Induced Genotoxic Stress
Authors: Ascer Liv G. , Magalhaes Yuli T. , Espinha Gisele , Osaki Juliana H. , Souza Renan C. , Forti Fabio L. 
Published: March 2015

ABSTRACTCell division control protein 42 (CDC42) homolog is a small Rho GTPase enzyme that participates in such processes as cell cycle progression, migration, polarity, adhesion, and transcription. Recent studies suggest that CDC42 is a potent tumor suppressor in different tissues and is related to aging processes. Although DNA damage is crucial in aging, a potential role for CDC42 in genotoxic stress remains to be explored. Migration, survival/proliferation and DNA damage/repair experiments were performed to demonstrate CDC42 involvement in the recovery of HeLa cells exposed to ultraviolet radiation‐induced stress. Sub‐lines of HeLa cells ectopically expressing the constitutively active CDC42‐V12 mutant were generated to examine whether different CDC42‐GTP backgrounds might reflect different sensitivities to UV radiation. Our results show that CDC42 constitutive activation does not interfere with HeLa cell migration after UV radiation. However, the minor DNA damage exhibited by the CDC42‐V12 mutant exposed to UV radiation most likely results in cell cycle arrest at the G2/M checkpoint and reduced proliferation and survival. HeLa cells and Mock clones, which express endogenous wild‐type CDC42 and show normal activity, are more resistant to UV radiation. None of these effects are altered by pharmacological CDC42 inhibition. Finally, the phosphorylation status of the DNA damage response proteins γ‐H2AX and p‐Chk1 was found to be delayed and attenuated, respectively, in CDC42‐V12 clones. In conclusion, the sensitivity of HeLa cells to ultraviolet radiation increases with CDC42 over‐activation due to inadequate DNA repair signaling, culminating in G2/M cell accumulation, which is translated into reduced cellular proliferation and survival. J. Cell. Biochem. 116: 2086–2097, 2015. © 2015 Wiley Periodicals, Inc.
The Electrochemical Behavior of a N‐containing Calix[4]arene Derivative
Authors: Wu Yanju , Zhai Shengguo , Gao Lin , Wang Fei 
Published: March 2015

AbstractThe electrochemical behavior of 5,11,17,23‐Tetrakis‐dimethylaminomethylcalix[4]arene (DCA) has been investigated by cyclic voltammetry (CV). The results show that there is an irreversible electrochemical oxidative wave with peak potential of 1.35 V in chloroform at a glassy carbon electrode. The kinetic parameters of the andic wave, such as α, n and ks, were discussed. In addition, a new pair of quasi‐reversible redox peaks with peak potentials of 0.72 V and 0.94 V was found. It can result in DCA electrodeposition at the electrode surface. This film modified electrode was characterized by CV and electrochemical impedance spectroscopy (EIS). Moreover, the possible mechanism of electrodeposition was also discussed
Improved Synthesis of 2,2‐Arylmethylene Bis(3‐hydroxy‐5,5‐dimethyl‐2‐cyclohexene‐1‐one) and 1,8‐Dioxo‐octahydroxanthene Derivatives Catalyzed by Electrogenerated Base and Sulfuric Acid
Authors: Kazemi‐Rad Reyhaneh , Azizian Javad , Kefayati Hassan 
Published: March 2015

AbstractAn efficient method has been developed for the synthesis of 1,8‐dioxo‐octahydroxanthene derivatives in two‐step. In the first step, the electrogenerated base (EGB) catalyzed multicomponent transformation of dimedone and aromatic aldehydes in an undivided cell in the presence of sodium bromide as an electrolyte into 2,2′‐arylmethylene bis(3‐hydroxy‐5,5‐dimethyl‐2‐cyclohexene‐1‐one) at room temperature. In the second step, H2SO4 was employed as a dehydrating reagent for the cyclization process to give symmetrical heterocycles 1,8‐dioxo‐octahydroxanthene derivatives. Short reaction time, convenient work up, and using of inexpensive reagents, simple equipment, novel and eco‐friendly procedure make this strategy more useful for the preparation of xanthene derivatives.
Anharmonic Effect of the Unimolecular Isomerization/Decomposition of Benzyne
Authors: Li Qian , Yao Li , Lin S. H. 
Published: March 2015

AbstractThe anharmonic and harmonic rate constants were calculated for the unimolecular decomposition of o‐benzyne, the isomerization of o‐benzyne to m‐benzyne, the isomerization of m‐benzyne to p‐benzyne and unimolecular decomposition of p‐benzyne by using the Rice–Ramsperger–Kassel–Marcus (RRKM) theory respectively, in the canonical and microcanonical systems. The geometry and the vibrational frequencies were calculated by MP2 and B3LYP methods with 6‐311G(d,p) basis set and the barrier energies were corrected using CBS‐QB3 theory. The anharmonic effect on the reactions was also examined. Comparison of results for the decompositions of benzyne indicate that both in microcanonical and canonical cases, the anharmonic effect on the decomposition of the o‐C6H4 and p‐C6H4 are significant, while the anharmonic effect on the two isomerizations are not pronounced.
The Substituent Effect of 1‐Arylazonaphthen‐2‐ols on Azo‐hydrazone Tautomerization According to NMR Analysis
Authors: Lin Yi‐Cang , Chen Chien‐Chih , Ding Mei‐Fan , Lin Shaw‐Tao 
Published: March 2015

AbstractThe substituent effect on azo‐hydrazone tautomerization of 1‐arylazonaphthen‐ols is studied by means of NMR analysis. Among the 13C chemical shifts, the C(2) of this series compound is the most sensitive to the variation in the nature of substituent on the phenyl ring. Therefore, the variation in the chemical shifts of C(2) is used to probe the substituent effect by using the substituent chemical shifts and free energy vs. Hammett’s constant (χρ+). Both methods give a negative correlation slope, indicating the electron‐with‐ drawing groups favor the hydrazone tautomer form. The effect on the chemical shifts of C(2) of compound 8 in ten solvents can be classified as the solvent with a proton‐donor, proton‐acceptor and arenes system. The substituent with electron‐donating character is more sensitive to the nature of solvent and it favors the hydrazone form. Free energy obtained from the dynamic NMR technique indicates the tautomerization favors the hydrazone‐form for the substituent with electron‐withdrawing character.