bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photochemical Modulation of DNA Conformation by Organic Dications
Authors: Zinchenko Anatoly A. , Tanahashi Mao , Murata Shizuaki 
Published: November 2011

AbstractA group of azobenzene derivatives containing two quaternary ammonium groups with various intercharge distances between them was synthesised and used to control photochemically the conformation of genomic DNA by switching the distance between cationic ammonium groups in the dications. It was found that isomerisation of either dication from the trans form to cis resulted in an increase in the dication's efficiency for DNA compaction; this is associated with a decrease in intercharge distance between ammonium groups and leads to a better match of the binder's cationic groups to adjacent phosphate groups of DNA. Ammonium dications have several important advantages over the photosensitive surfactant type of diazobenzene reported earlier: they can be used at significantly lower (>100‐fold) concentrations than photosensitive surfactants, and DNA conformation control can be performed over a broader concentration range of dications. The influence of intercharge distance in photosensitive dications on photo‐induced DNA binding discrimination is discussed, and the molecular mechanism is proposed.
Giant Deuteron Migration During the Isosymmetric Phase Transition in Deuterated 3,5‐Pyridinedicarboxylic Acid
Authors: Ford Samantha J. , Delamore Oliver J. , Evans John S. O. , McIntyre Garry J. , Johnson Mark R. , Radosavljević Evans Ivana 
Published: November 2011

AbstractDeuterated 3,5‐pyridinedicarboxylic acid exhibits reversible temperature‐induced deuteron migration of a magnitude unprecedented in this class of compounds. We used a combination of variable‐temperature powder and single‐crystal neutron diffraction and density functional theory (DFT)‐based computational methods to elucidate the origin of this remarkable behaviour. Single‐crystal neutron diffraction shows that between 15 and 300 K, the deuteron moves by 0.32(1) Å and the structure changes from a low‐temperature ND⋅⋅⋅O form to a high‐temperature N⋅⋅⋅DO form. Variable‐temperature powder neutron‐diffraction data, which was fitted by using parametric Rietveld refinement, show that this deuteron migration is due to an isosymmetric, first‐order phase transition that occurs by growth of the daughter phase in the parent‐phase matrix. Similar phase transitions are observed in two selectively deuterated forms of the material. DFT calculations demonstrate the role of phonons and show that vibrational free‐energy stabilisation, which plays a key role in the observed structural phase transitions, is more pronounced in the fully deuterated material and proportional to the mass of the molecule, that is, the level of deuteration. This is consistent with our experimental work, for which distinct crystallographic phase transitions were clearly observed for the three deuterated systems, but not for the fully protonated material.
Highly Selective Electrosynthesis of Biphenols on Graphite Electrodes in Fluorinated Media
Authors: Kirste Axel , Hayashi Shotaro , Schnakenburg Gregor , Malkowsky Itamar M. , Stecker Florian , Fischer Andreas , Fuchigami Toshio , Waldvogel Siegfried R. 
Published: November 2011

AbstractThe direct and selective phenol coupling reaction that provides biphenols still represents a challenge in organic synthesis. The recently developed electrosynthesis on boron‐doped diamond anodes with fluorinated additives was developed further to allow the application to less‐expensive electrodes and fluorinated media. This advanced protocol allows the highly selective anodic phenol coupling reaction on graphite with a broad scope.
Intramolecular [2+2+2] Cycloaddition Reactions of Yne‐ene‐yne and Yne‐yne‐ene Enediynes Catalysed by RhI: Experimental and Theoretical Mechanistic Studies
Authors: Dachs Anna , Pla‐Quintana Anna , Parella Teodor , Solà Miquel , Roglans Anna 
Published: November 2011

AbstractN‐Tosyl‐linked open‐chain yne‐ene‐yne enediynes 1 and 2 and yne‐yne‐ene enediynes 3 and 4 have been satisfactorily synthesised. The [2+2+2] cycloaddition process catalysed by the Wilkinson catalyst [RhCl(PPh3)3] was tested with the above‐mentioned substrates resulting in the production of high yields of the cycloadducts. Enediynes 1 and 2 gave standard [2+2+2] cycloaddition reactions whereas enediynes 3 and 4 suffered β‐hydride elimination followed by reductive elimination of the Wilkinson catalyst to give cycloadducts, which are isomers of those that would be obtained by standard [2+2+2] cycloaddition reactions. The different reactivities of these two types of enediyne have been rationalised by density functional theory calculations.
Formal Homo‐Nazarov and Other Cyclization Reactions of Activated Cyclopropanes
Authors: De Simone Filippo , Saget Tanguy , Benfatti Fides , Almeida Sofia , Waser Jérôme 
Published: November 2011

AbstractThe Nazarov cyclization of divinyl ketones gives access to cyclopentenones. Replacing one of the vinyl groups by a cyclopropane leads to a formal homo‐Nazarov process for the synthesis of cyclohexenones. In contrast to the Nazarov reaction, the cyclization of vinyl‐cyclopropyl ketones is a stepwise process, often requiring harsh conditions. Herein, we describe two different approaches for further polarization of the three‐membered ring of vinyl‐cyclopropyl ketones to allow the formal homo‐Nazarov reaction under mild catalytic conditions. In the first approach, the introduction of an ester group α to the carbonyl on the cyclopropane gave a more than tenfold increase in reaction rate, allowing us to extend the scope of the reaction to non‐electron‐rich aryl donor substituents in the β position to the carbonyl on the cyclopropane. In this case, a proof of principle for asymmetric induction could be achieved using chiral Lewis acid catalysts. In the second approach, heteroatoms, especially nitrogen, were introduced β to the carbonyl on the cyclopropane. In this case, the reaction was especially successful when the vinyl group was replaced by an indole heterocycle. With a free indole, the formal homo‐Nazarov cyclization on the C3 position of indole was observed using a copper catalyst. In contrast, a new cyclization reaction on the N1 position was observed with Brønsted acid catalysts. Both reactions were applied to the synthesis of natural alkaloids. Preliminary investigations on the rationalization of the observed regioselectivity are also reported.
Multilayered Supported Ionic Liquids as Catalysts for Chemical Fixation of Carbon Dioxide: A High‐Throughput Study in Supercritical Conditions
Authors: Aprile Carmela , Giacalone Francesco , Agrigento Paola , Liotta Leonarda F. , Martens Johan A. , Pescarmona Paolo P. , Gruttadauria Michelangelo 
Published: November 2011

AbstractMultilayered, covalently supported ionic liquid phase (mlc‐SILP) materials were synthesized by using a new approach based on the grafting of bis‐vinylimidazolium salts on different types of silica or polymeric supports. The obtained materials were characterized and tested as catalysts in the reaction of supercritical carbon dioxide with various epoxides to produce cyclic carbonates. The material prepared by supporting a bromide bis‐imidazolium salt on the ordered mesoporous silica SBA‐15 was identified as the most active catalyst for the synthesis of cyclic carbonates and displayed improved productivity compared with known supported ionic liquid catalysts. The catalyst retained its high activity upon reuse in consecutive catalytic runs. This is the first report of the application of mlc‐SILP materials as catalysts in a reaction for the fixation of carbon dioxide. Rapid, parallel screening and comparison of the catalysts was performed by means of high‐throughput experimentation.
Clinical profile of cyclosporine in dermatology
Authors: Colombo Delia , Poggi Susanna 
Published: November 2011

AbstractCyclosporine is one of the most effective agents available for the treatment of psoriasis. It is also widely used in atopic dermatitis and other dermatological disorders. Recent consensus guidelines for psoriasis recommend an initial dosage of 2.5–5 mg/kg/day (in one or two daily doses), with adjustments of 0.5–1 mg/kg/day every 1–2 weeks; the maximum daily dosage is 6 mg/kg/day. The most widely used cyclosporine schedule is intermittent short‐term therapy for 12–16 weeks; subsequently, when relapse occurs, treatment is restarted at the previously established, effective dosage. Short‐term cyclosporine therapy is also particularly useful as a “rescue” treatment for severe disease flares, and as a “bridging” treatment to other maintenance schedules. Hypertension and renal dysfunction are the major tolerability issues, but these are related to dose and treatment duration, and can be markedly reduced if appropriate dosage and monitoring guidelines are followed. Generally, if cyclosporine dosage is maintained at ≤5 mg/kg/day, and treatment duration at ≤2 years, these events are reversible after treatment is stopped. As definitive clinical experience continues to accrue for several cyclosporine monotherapy and combination regimens in various dermatological disorders, cyclosporine is likely to markedly extend its already integral therapeutic role in dermatology. Drug Dev Res 72:634–646, 2011. © 2011 Wiley Periodicals, Inc.
Stability of a 2′‐O‐(Carbamoylmethyl)adenosine‐Containing Dinucleotide
Authors: Milton Stefan , Ander Charlotte , Yeheskiely Esther , Strömberg Roger 
Published: November 2011

AbstractIn the interest of pursuing the synthesis of 2′‐O‐carbamoylmethyl‐modified oligonucleotides from building blocks already containing the modification, we have performed studies on the chemical and enzymatic stability of a 2′‐O‐carbamoylmethyl‐modified dinucleotide. The dinucleotide was subjected to ammonolysis and other basic conditions such as treatment with ethylenediamine and sodium hydroxide at different temperatures. The amide of the carbamoylmethyl group partially hydrolyzed under standard deprotection conditions for oligonucleotide synthesis (conc. aq. NH3 at 55 °C). However, under several other conditions, including saturated NH3 in methanol, the amide remained intact. Treatment of the dinucleotide with Phosphodiesterase I from Crotalus adamanteus venom and Phosphodiesterase II from Bovine spleen, showed that the carbamoylmethyl moiety gives substantial protection of the phosphodiester towards enzymatic degradation.
Measuring extrastriatal dopamine release during a reward learning task
Authors: Vrieze Elske , Ceccarini Jenny , Pizzagalli Diego A. , Bormans Guy , Vandenbulcke Mathieu , Demyttenaere Koen , Van Laere Koen , Claes Stephan 
Published: November 2011

AbstractObjectives: Reward learning is critical for survival. Animal research emphasizes the role of dopaminergic (DA) mesocorticolimbic pathways in reward learning, but few studies have evaluated extrastriatal DA functioning in humans. The purpose of this study was to examine presynaptic DA release in extrastriatal regions of the reward circuit by measuring displacement of the high affinity D2/D3 radioligand [18F]Fallypride during a reward task. Design: Ten healthy volunteers underwent a [18F]Fallypride positron emission tomography protocol while performing a reward task, allowing us to assess participants' ability to modulate behavior as a function of reward. DA receptor ligand displacement was correlated with task performance and self‐reported anhedonia. Observations: Parametric t‐maps revealed significant decrease in [18F]Fallypride binding in the medial orbitofrontal cortex (mOFC), ventromedial prefrontal cortex (vmPFC), and dorsal anterior cingulate cortex (dACC), indicating endogenous DA release in these regions. Increasing anhedonic symptoms correlated with DA release in the left vmPFC, left dACC, and right dACC emerged (all r's > 0.65, P's < 0.05). Similarly, reduced reward learning correlated with higher DA release in left vmPFC, right vmPFC, and left dACC (all r's < −0.64, P's < 0.05). Left dACC (r = 0.66, P = 0.04) and left vmPFC (r = 0.74, P = 0.01) DA release showed a significant positive correlation with impaired tendency to modulate behavior as a function of prior positive reinforcements. Conclusions: These findings support the hypothesis that DA release in mOFC, vmPFC, and dACC regions plays an important role in reinforcement learning in the human brain. Hum Brain Mapp, 2013. © 2011 Wiley Periodicals, Inc.
Behavioral data and neural correlates for postural prioritization and flexible resource allocation in concurrent postural and motor tasks
Authors: Huang Cheng‐Ya , Hwang Ing‐Shiou 
Published: November 2011

AbstractThis study was undertaken to investigate the reciprocity effect between postural and suprapostural performances and its underlying neural mechanisms wherein subjects executed a perceptual‐motor suprapostural task and maintained steady upright postures. Fourteen healthy individuals conducted force‐matching maneuvers (static vs. dynamic) under two stance conditions (bipedal stance vs. unipedal stance); meanwhile, force‐matching error, center of pressure dynamics, event‐related potentials (ERPs), and the movement‐related potential (MRP) were monitored. The behavioral results showed that force‐matching error and postural sway were differently modulated by variations in stance pattern and force‐matching version. Increase in postural challenge undermined the precision of static force‐matching but facilitated a dynamic force‐matching task. Both static and dynamic force‐matching tasks improved postural control of unipedal stance but not of bipedal stance, in reference to the control conditions. ERP results revealed a stance‐dependent N1 response, which was greater around the parietal cortex in the unipedal stance conditions. Instead, P2 was modulated by the effect of the suprapostural motor task, with a smaller P2 in the right parietal cortex for dynamic force‐matching. Spatiotemporal evolution of the MRP commenced at the left frontal‐central area and spread bilaterally over the frontal‐central and parietal cortex. MRP onset was subject to an analogous interaction effect on force‐matching performance. Our findings suggest postural prioritization and a structural alternation effect of stance pattern on postural performance, relevant to implicit expansion and selective allocation of central resources for relative task‐loads of a postural‐suprapostural task. Hum Brain Mapp, 2013. © 2011 Wiley Periodicals, Inc.
Inferior frontal white matter asymmetry correlates with executive control of attention
Authors: Yin Xuntao , Han Yan , Ge Haitao , Xu Wenjian , Huang Ruiwang , Zhang Dong , Xu Junhai , Fan Lingzhong , Pang Zengchang , Liu Shuwei 
Published: November 2011

AbstractWhite matter (WM) asymmetries of the human brain have been well documented using diffusion tensor imaging (DTI). However, the relationship between WM asymmetry pattern and cognitive performance is poorly understood. By means of tract‐based spatial statistics (TBSS) and voxel‐based analyses of whole brain, this study examined the WM asymmetries and the correlations between WM integrity/asymmetries and three distinct components of attention, namely alerting, orienting, and executive control (EC), which were assessed by attention network test (ANT). We revealed a number of WM anisotropy asymmetries, including leftward asymmetry of cingulum, corticospinal tract and cerebral peduncle, rightward asymmetry of internal capsule, superior longitudinal fasciculus and posterior corona radiata, as well as heterogeneous asymmetries in anterior corpus callosum and anterior corona radiata (ACR). Moreover, specific correlation was found between asymmetric pattern of inferior frontal ACR and EC performance. Additionally, this study also proposed that there were no significant relationships of WM anisotropy asymmetries to alerting and orienting functions. Further clusters of interest analyses and probabilistic fiber tracking validated our findings. In conclusion, there are a number of differences in WM integrity between human brain hemispheres. Specially, the anisotropy asymmetry in inferior frontal ACR plays a crucial role in EC function. Our finding is supportive of the functional studies of inferior frontal regions and in keeping with the theory of the brain lateralization on human ventral attention system. Hum Brain Mapp, 2013. © 2011 Wiley Periodicals, Inc.
Reconstruction of lower lip with myomucosal advancement flap
Authors: Isik Daghan , Garca M. Fatih , Durucu Cengiz , Goktas Ugur , Atik Bekir 
Published: November 2011

AbstractBackgroundIn this article, a new surgical procedure that can be used for reconstruction of lower lip defects of any size is described.MethodsIn this prospective study, the surgical procedure was applied in 16 patients. In this procedure, the mucosa and the orbicularis oris muscle of the lower lip are repaired with a composite flap, and the skin defect is closed using local skin flaps. The patients were assessed in terms of complications, mouth opening, sphincter function of the mouth, and sensation in the lower lip.ResultsThe aesthetic results obtained in all patients were satisfactory. Sufficient oral sphincter function was achieved in all patients.ConclusionReconstruction of lower lip defects using the procedure described here can be performed in patients with lower lip defects of any size as long as the mucosal and skin repair lines are not superimposed. This procedure yielded good sphincter function and aesthetic results. © 2011 Wiley Periodicals, Inc. Head Neck, 2011
Survival study and treatment strategy for second primary tumors in the oral cavity in patients with nasopharyngeal carcinoma after definitive radiation
Authors: Song Ming , Zhuang Shi‐Min , Chen Shu‐Wei , Zhang Quan , Yang An‐Kui , Wang Li‐Ping , Guo Zhu‐Ming 
Published: November 2011

AbstractBackgroundThe purpose of this study was to investigate the clinicopathologic characteristics and prognostic factors of second primary tumors (SPTs) in the oral cavity in patients with nasopharyngeal carcinoma (NPC) after definitive radiation, and to determine an optimal treatment strategy for these patients.MethodsThis retrospective study enrolled consecutive patients who were admitted to the Sun Yat–Sen University Cancer Center between 1990 and 2005.ResultsThe key prognostic factors influencing the survival were age when NPC was diagnosed, TNM stage, and surgery treatment modality. Multivariate analysis revealed that the clinical TNM stage was an independent risk factor for patient survival.ConclusionClinical TNM stage was an independent prognostic factor that influenced the treatment outcome. Our data indicate that the survival of patients with SPTs in the oral cavity can be improved by modifying treatment strategy, and that surgery is preferred when SPTs are diagnosed at an earlier stage. © 2011 Wiley Periodicals, Inc. Head Neck, 2011
Extrahepatic metastases occur in a minority of hepatocellular carcinoma patients treated with locoregional therapies: Analyzing patterns of progression in 285 patients
Authors: Senthilnathan Seanthan , Memon Khairuddin , Lewandowski Robert J. , Kulik Laura , Mulcahy Mary F. , Riaz Ahsun , Miller Frank H. , Yaghmai Vahid , Nikolaidis Paul , Wang Edward , Baker Talia , Abecassis Michael , Benson Al B. , Omary Reed A. , Salem Riad 
Published: November 2011

Abstract

Although most cancers are considered predominantly systemic processes, this may not hold true for hepatocellular carcinoma (HCC). The literature regarding patterns of progression of HCC (local versus systemic) has been relatively sparse. Our objectives were to: (1) analyze patterns of progression in HCC patients presenting with intrahepatic disease from initial treatment until death, and (2) identify clinically relevant risk factors for the development of metastases. Over a 9-year period, 285 patients treated with transarterial locoregional therapies underwent scheduled imaging follow-up from treatment until death and were categorized by pattern of progression: (i) intrahepatic (increased tumor enhancement/size, development/progression of vascular invasion, new hepatic lesions) progression or (ii) extrahepatic (adrenal/bone/lung/lymph node) metastases. Uni/multivariate analyses assessing the risk factors for the development of metastases were performed. The median time from last scan to death was 2.4 months (interquartile range: 1.3-4.8 months). The time to development of metastases, vascular invasion, and/or new lesions was 13.8 months (confidence interval: 11.3-17.7 months). Of the 209 patients followed until death, only 50 developed extrahepatic metastases (24%). Multivariate analyses identified age <65 years (

P

= 0.038), alpha-fetoprotein >200 ng/mL (

P

= 0.04), and vascular invasion (

P

= 0.017) as significant predictors of metastases development.

Conclusion:

Knowledge of the risk factors associated with the development of metastases may help guide assessment of patient prognosis. Because 76% of patients presenting with local disease treated with locoregional therapies die without developing extrahepatic metastases, the notion of HCC as a systemic disease, as detected by imaging, may be reconsidered. (Hepatology 2011)
Knowledge workers' creativity and the role of the physical work environment
Authors: Dul Jan , Ceylan Canan , Jaspers Ferdinand 
Published: November 2011

AbstractThe present study examines the effect of the physical work environment on the creativity of knowledge workers, compared with the effects of creative personality and the social‐organizational work environment. Based on data from 274 knowledge workers in 27 small and medium‐sized enterprises, we conclude that creative personality, the social‐organizational work environment, and the physical work environment independently affect creative performance. The relative contribution of the physical work environment is smaller than that of the social‐organizational work environment, and both contributions are smaller than that of creative personality. The results give support for human resource practices that focus on the individual, the social‐organizational work environment, and the physical work environment in order to enhance knowledge workers' creativity. © 2011 Wiley Periodicals, Inc.
The diverse organization: Finding gold at the end of the rainbow
Authors: Scott Kristyn A. , Heathcote Joanna M. , Gruman Jamie A. 
Published: November 2011

AbstractThe breadth and depth of research on organizational diversity reveals the complex nature of diversity in organizations. Indeed, research in the realm of human resource management focuses on diversity applied to a variety of topics, including recruitment, retention, succession planning, and work‐life management, among others. In this article, we use Cox and Blake's (1991) advantages as a framework to review the diversity literature and suggest that organizational culture may be key to understanding when organizations will benefit from a diverse employee base. Specifically, organizations that emphasize inclusion and integrate diversity into all policies and practices may benefit to a greater extent compared with organizations focusing on diversity as a stand‐alone practice. Through an examination of academic research and the award‐winning diversity program of Campbell Soup Company (Catalyst, 2010), we make culturally based propositions to further diversity research in, and the practice of, human resource management. © 2011 Wiley Periodicals, Inc.