bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and Crystallochromy of 1,4,7,10‐Tetraalkyltetracenes: Tuning of Solid‐State Optical Properties of Tetracenes by Alkyl Side‐Chain Length
Authors: Kitamura Chitoshi , Abe Yasushi , Ohara Takuya , Yoneda Akio , Kawase Takeshi , Kobayashi Takashi , Naito Hiroyoshi , Komatsu Toshiki 
Published: November 2009

AbstractWe synthesized a series of 1,4,7,10‐tetraalkyltetracenes using a new 2,6‐naphthodiyne precursor and 2,5‐dialkylfurans as starting materials (alkyl=methyl to hexyl). Surprisingly, the solid‐state color of the tetracenes ranges through yellow, orange, and red. Both yellow and red solids are obtained for the butyl derivative. Optical properties in solution show no marked differences; however, those in the solid state show characteristics that vary with alkyl side‐chain length: methyl, propyl, and pentyl derivatives are orange; ethyl and butyl derivatives are yellow; and another butyl and hexyl derivative are red. X‐ray analyses reveal that the molecular structures are planar, semi‐chair, or chair forms; the chair form takes a herringbone‐like arrangement and the other forms take slipped parallel arrangements. The mechanism of crystallochromy is discussed in terms of molecular structure, crystal packing, and calculations that take account of exciton coupling.
Supramolecular Chirality in Solvent‐Promoted Aggregation of Amphiphilic Porphyrin Derivatives: Kinetic Studies and Comparison between Solution Behavior and Solid‐State Morphology by AFM Topography
Authors: Monti Donato , De Rossi Massimo , Sorrenti Alessandro , Laguzzi Giuseppe , Gatto Emanuela , Stefanelli Manuela , Venanzi Mariano , Luvidi Loredana , Mancini Giovanna , Paolesse Roberto 
Published: November 2009

AbstractThe solvent‐promoted aggregation behavior of some amphiphilic porphyrin derivatives bearing chiral functionality in the form of a charged L‐proline group has been investigated by UV/Vis, resonance light scattering, fluorescence and circular dichroism spectroscopy. The investigated macrocycles give rise to aggregates featuring supramolecular chirality with high ellipticity. Kinetic studies reveal peculiar differences in the fashion of aggregation, depending on the intimate nature of the chiral functionality, namely, cationic (nitrogen‐quaternized L‐proline, 3H2) or anionic (carboxylate residue, 6H2) group. Formation of anionic 6H2 aggregates shows a diffusion‐limited kinetic behavior. AFM topography studies show formation of tighter globular structures. On the other hand, the corresponding 3H2 aggregates are formed by a cooperative, fractal‐type decay, and appear as long‐fibrous, looser structures. In the templated aggregation of 3H2 over preformed 6H2 aggregates, AFM images show formation of globular structures with reduced sizes, as a likely consequence of shorter interchromophore distances, due to favorable Coulombic interactions. The results obtained show an interesting parallelism between the solution behavior and the solid‐state aggregate structures, corroborating the sergeant–soldier effect observed in the templated aggregation. The results presented give important insights for understanding the complex mechanisms involved in these issues, which are of key importance for the development of chiral supramolecular materials and stereoselective sensors and devices.
Silicon‐ and Tin‐Based Cuprates: Now Catalytic in Copper!
Authors: Weickgenannt Andreas , Oestreich Martin 
Published: November 2009

AbstractSilicon‐ and tin‐containing molecules are versatile building blocks in organic synthesis. A stalwart method for their preparation relies on the stoichiometric use of silicon‐ and tin‐based cuprates, although a few copper(I)‐catalyzed or even copper‐free protocols have been known for decades. In this Concept, we describe our efforts towards copper(I)‐catalyzed carbonsilicon and also carbontin bond formations using soft bis(triorganosilyl) and bis(triorganostannyl) zinc reagents as powerful sources of nucleophilic silicon and tin. Conjugate addition, allylic substitution, and carboncarbon multiple bond functionalization is now catalytic in copper!
Einsatzmöglichkeiten thermophysikalischer Methoden zur Lösung biochemischer und biotechnologischer Fragestellungen
Authors: Hüttl R. , Frank DC N. , Harmel J. , Lißner DC A. , Winkelmann M. 
Published: November 2009

AbstractFür thermophysikalische Methoden auf den Gebieten der Biotechnologie bzw. Mikrobiologie gibt es vielfältige Anwendungsfelder. Beispiele reichen von der kalorimetrischen Ermittlung mikrobieller Aktivität über die Aufstellung von Stoffbilanzen bis hin zu Untersuchungen zum mikrobiellen Schadstoffabbau. Die vorgestellten Ergebnisse belegen die Leistungsfähigkeit thermischer Methoden zur Echtzeitdetektion mikrobieller Prozesse. Die Kombination der Universalität der kalorimetrischen Messung mit spezifischen Erkennungseinheiten im Sensor‐Kalorimeter eröffnet weiterhin die Möglichkeit der Analyse metabolischer Veränderungen. Das große Potential der thermischen Detektion liegt damit in der Überwachung, Optimierung und Kontrolle biotechnologischer Prozessabläufe.
Disruption of the blood brain barrier by brain metastases of triple‐negative and basal‐type breast cancer but not HER2/neu‐positive breast cancer
Authors: Yonemori Kan , Tsuta Koji , Ono Makiko , Shimizu Chikako , Hirakawa Akihiro , Hasegawa Tadashi , Hatanaka Yutaka , Narita Yoshitaka , Shibui Soichiro , Fujiwara Yasuhiro 
Published: November 2009

AbstractBACKGROUND:Generally, the blood‐brain barrier (BBB) of brain metastasis was thought to be disrupted.METHODS:We retrospectively performed immunohistochemical staining for glucose transporter 1 (GLUT1) and breast cancer resistance protein (BCRP) to evaluate the status of the BBB in resected brain metastases. Associations between expression of GLUT1 and/or BCRP and the immunohistochemical profiles of breast cancers, such as the statuses of hormone receptors, human epidermal growth factor receptor 2 (HER2/neu), and a basal‐type marker (cytokeratin 5/6, HER1), were also analyzed.RESULTS:The study included 29 breast cancer patients with brain metastasis who had undergone brain tumor resections. Among the 29 patients, there was no expression of GLUT1 and BCRP in the intratumor microvessels of 9 (32%) and 11 (38%) patients, respectively. There was no expression of both GLUT1 and BCRP in 8 patients (28%). The expression of GLUT1 was significantly associated with that of BCRP (P < .001). A positive correlation was observed between the expression of GLUT1 and/or BCRP and brain metastases of HER2/neu‐positive breast cancer (P = .012), while a negative correlation was observed between the expression of GLUT1 and/or BCRP and brain metastases of triple negative or basal‐type breast cancer (P = .014 and P = .003 for triple negative and basal‐type, respectively).CONCLUSIONS:Brain metastases of triple negative or basal‐type breast cancers may often disrupt the BBB, whereas brain metastases of HER2/neu‐positive breast cancer tend to preserve the BBB. Cancer 2010. © 2010 American Cancer Society.
Role of the cytoplasmic domain of the L1 cell adhesion molecule in brain development
Authors: Nakamura Yukiko , Lee Suni , Haddox Candace L. , Weaver Eli J. , Lemmon Vance P. 
Published: November 2009

AbstractMutations in the human L1CAM gene cause X‐linked hydrocephalus and MASA (Mental retardation, Aphasia, Shuffling gait, Adducted thumbs) syndrome. In vitro studies have shown that the L1 cytoplasmic domain (L1CD) is involved in L1 trafficking, neurite branching, signaling, and interactions with the cytoskeleton. L1cam knockout (L1KO) mice have hydrocephalus, a small cerebellum, hyperfasciculation of corticothalamic tracts, and abnormal peripheral nerves. To explore the function of the L1CD, we made three new mice lines in which different parts of the L1CD have been altered. In all mutant lines L1 protein is expressed and transported into the axon. Interestingly, these new L1CD mutant lines display normal brain morphology. However, the expression of L1 protein in the adult is dramatically reduced in the two L1CD mutant lines that lack the ankyrin‐binding region and they show defects in motor function. Therefore, the L1CD is not responsible for the major defects observed in L1KO mice, yet it is required for continued L1 protein expression and motor function in the adult. J. Comp. Neurol. 518:1113–1132, 2010. © 2009 Wiley‐Liss, Inc.
Three subdivisions of the auditory midbrain in chicks (Gallus gallus) identified by their afferent and commissural projections
Authors: Wang Yuan , Karten Harvey J. 
Published: November 2009

AbstractThe auditory midbrain is a site of convergence of multiple auditory channels from the brainstem. In birds, two separate ascending channels have been identified, through which time and intensity information is sent to the nucleus mesencephalicus lateralis, pars dorsalis (MLd), the homologue of the central nucleus of the mammalian inferior colliculus. Using in vivo anterograde and retrograde tracing techniques, the current study provides two lines of anatomical evidence supporting the presence of a third ascending channel to the chick MLd. First, three non‐overlapping zones of the MLd receive inputs from three distinct cell groups in the caudodorsal brainstem. The projections from the nucleus angularis (NA) and nucleus laminaris (NL) are predominantly contralateral and may correspond to the time and intensity channels. A rostromedial portion of the MLd receives bilateral projections mainly from the regio intermedius, an interposed region of cells lying at a caudal level between the NL and NA, as well as scattered neurons embedded in the 8th nerve tract, and probably a very ventral region of the NA. Second, the bilateral zones of the MLd on two sides of the brain are reciprocally connected and do not interact with other zones of the MLd via commissural connections. In contrast, the NL‐recipient zone projects contralaterally upon the NA‐recipient zone. The structural separation of the third pathway from the NA and NL projections suggests a third information‐processing channel, in parallel with the time and intensity channels. Neurons in the third channel appear to process very low frequency information including infrasound, probably utilizing different mechanisms than that underlying higher frequency processing. J. Comp. Neurol. 518:1199–1219, 2010. © 2009 Wiley‐Liss, Inc.
Morphology of dopaminergic amacrine cells in the mouse retina: Independence from homotypic interactions
Authors: Keeley Patrick W. , Reese Benjamin E. 
Published: November 2009

AbstractTo determine the role of homotypic interactions between neighboring dopaminergic amacrine (DA) cells upon dendritic morphogenesis, the morphology of single cells was examined relative to the positioning of all neighboring homotypic cells. For each labeled cell, the dendritic field was reconstructed, its Voronoi domain was calculated, and the two were related. The dendritic fields of DA cells were observed to be large, sparse, and highly irregular. Dendrites readily overlapped those of neighboring cells, showing no evidence for dendritic tiling or inter‐digitation consistent with homotypic repulsion or avoidance. Furthermore, a direct comparison of dendritic field area with the Voronoi domain area of the same cell showed no evidence for dendritic growth being constrained or biased by the local distribution of homotypic neighbors in wild‐type retinas. A comparison of the processes of adjacent filled cells confirmed their immediate proximity to one another within the inner plexiform layer, indicating that they do not engage in mutual avoidance by coursing at different depths. Together, these results suggest that the morphogenesis of DA cells is independent of homotypic interactions. However, in the absence of the pro‐apoptotic Bax gene, which yields a fourfold increase in DA cell number, a small but significant reduction in dendritic field size was obtained, although not so great as would be predicted by the increase in density. The present results are considered in light of recent studies on the role of cell adhesion molecules expressed by developing DA cells. J. Comp. Neurol. 518:1220–1231, 2010. © 2009 Wiley‐Liss, Inc.
Quantitative analysis of pre‐ and postsynaptic sex differences in the nucleus accumbens
Authors: Forlano Paul M. , Woolley Catherine S. 
Published: November 2009

AbstractThe nucleus accumbens (NAc) plays a central role in motivation and reward. While there is ample evidence for sex differences in addiction‐related behaviors, little is known about the neuroanatomical substrates that underlie these sexual dimorphisms. We investigated sex differences in synaptic connectivity of the NAc by evaluating pre‐ and postsynaptic measures in gonadally intact male and proestrous female rats. We used DiI labeling and confocal microscopy to measure dendritic spine density, spine head size, dendritic length, and branching of medium spiny neurons (MSNs) in the NAc, and quantitative immunofluorescence to measure glutamatergic innervation using pre‐ (vesicular glutamate transporter 1 and 2) and postsynaptic (postsynaptic density 95) markers, as well as dopaminergic innervation of the NAc. We also utilized electron microscopy to complement the above measures. Clear but subtle sex differences were identified, namely, in distal dendritic spine density and the proportion of large spines on MSNs, both of which are greater in females. Sex differences in spine density and spine head size are evident in both the core and shell subregions, but are stronger in the core. This study is the first demonstration of neuroanatomical sex differences in the NAc and provides evidence that structural differences in synaptic connectivity and glutamatergic input may contribute to behavioral sex differences in reward and addiction. J. Comp. Neurol. 518:1330–1348, 2010. © 2009 Wiley‐Liss, Inc.
From prejudice to discrimination: The legitimizing role of perceived threat in discrimination against immigrants
Authors: Pereira Cícero , Vala Jorge , Costa‐Lopes Rui 
Published: November 2009

AbstractThis research analyses the mediational role of threat perception in the relationship between prejudice and discrimination (opposition to immigration and opposition to naturalization of immigrants). In the first study, using representative samples in 21 European countries (N = 36 566) from European Social Survey (2002), we showed that the relationship between prejudice and opposition to immigration was more strongly mediated by realistic than by symbolic threat perceptions. In Study 2, using representative samples in two countries with different traditions of immigration (Switzerland, N = 940; Portugal, N = 1514), we showed that realistic threat more strongly mediated the relationship between prejudice and opposition to immigration, while only symbolic threat perception mediated the link between prejudice and opposition to naturalization. The theoretical implications of considering threat perceptions as factors that legitimize discrimination are discussed. Copyright © 2009 John Wiley & Sons, Ltd.
Perceived HRM practices, organizational commitment, and voluntary early retirement among late‐career managers
Authors: Herrbach Olivier , Mignonac Karim , Vandenberghe Christian , Negrini Alessia 
Published: November 2009

AbstractUsing a sample of 514 French late‐career managers representing a variety of occupations and organizations, we investigated the relations among perceived HRM practices, organizational commitment, and voluntary early retirement. We found that the provision of training opportunities was associated with the most favorable outcomes. It was related to higher affective and high‐sacrifice commitment, lower lack of alternatives commitment, and reduced voluntary early retirement. On the other hand, we found that flexible working conditions and the assignment of older workers to new roles (for example, mentor or coach) did not have the expected positive effects. In addition, our results highlight the importance of disentangling the components of continuance commitment, as high‐sacrifice commitment was associated with reduced likelihood of voluntary early retirement, while lack of alternatives commitment had the opposite effect. These findings suggest that voluntary early retirement should be incorporated as a major outcome in future organizational behavior research. © 2009 Wiley Periodicals, Inc.
Why some firms adopt telecommuting while others do not: A contingency perspective
Authors: Mayo Margarita , Pastor Juan‐Carlos , Gomez‐Mejia Luis , Cruz Cristina 
Published: November 2009

AbstractUsing a contingency perspective and data from 122 CEOs of Spanish firms, this paper examines what makes a firm likely to adopt telecommuting. We hypothesized that employer adoption of telecommuting would depend on organizational constraints (age and size of the firm), the international composition of the workforce, and the top executives' leadership style. In turn, we argue that firms adopting telecommuting would emphasize outcome‐based control systems. Our empirical evidence showed that telecommuting correlated with small organizational size, a high proportion of international employees, and variable compensation. A contingent reward leadership style at the top moderated the effects of firm age and internationalization on the adoption of telecommuting. © 2009 Wiley Periodicals, Inc.
Urbanization signature in the observed heavy rainfall climatology over India
Authors: Kishtawal C. M. , Niyogi Dev , Tewari Mukul , Pielke Roger A. , Shepherd J. Marshall 
Published: November 2009

AbstractWe assess the urbanization impacts on the heavy rainfall climatology during the Indian summer monsoon. While a number of studies have identified the impact of urbanization on local precipitation, a large‐scale assessment has been lacking. This relation between urbanization and Indian monsoon rainfall changes is investigated by analyzing in situ and satellite‐based precipitation and population datasets. Using a long‐term daily rainfall dataset and high‐resolution gridded analysis of human population, this study showed a significantly increasing trend in the frequency of heavy rainfall climatology over urban regions of India during the monsoon season. Urban regions experience less occurrences of light rainfall and significantly higher occurrences of intense precipitation compared to nonurban regions. Very heavy and extreme rainfall events showed increased trends over both urban and rural areas, but the trends over urban areas were larger and statistically more significant. Our analysis suggests that there is adequate statistical basis to conclude that the observed increasing trend in the frequency of heavy rainfall events over Indian monsoon region is more likely to be over regions where the pace of urbanization is faster. Moreover, rainfall measurements from satellites also indicate that urban areas are more (less) likely to experience heavier (lighter) precipitation rates compared to those in nonurban areas. While the mechanisms causing this enhancement in rainfall remain to be studied, the results provide the evidence that the increase in the heavy rainfall climatology over the Indian monsoon region is a signature of urban‐induced rainfall anomaly. Copyright © 2009 Royal Meteorological Society
Calculation of off‐resonance Raman scattering intensities with parametric models
Authors: Bougeard Daniel , Smirnov Konstantin S. 
Published: November 2009

AbstractThe paper reviews applications of parametric models for calculations of the Raman scattering intensity of materials with the main emphasis on the performance of the bond polarizability model. The use of the model in studies of polymers, aluminosilicates, and nanostructures is discussed and the existing sets of electro‐optical parameters as well as their transferability are analyzed. The paper highlights the interplay between the first‐principles and parametric approaches to the Raman intensity calculations and suggests further developments in this field. Copyright © 2009 John Wiley & Sons, Ltd.
Temperature‐dependent Raman scattering study of multiferroic MnWO4
Authors: Hoang Luc Huy , Hien Nguyen T. M. , Choi W. S. , Lee Y. S. , Taniguchi K. , Arima T. , Yoon S. , Chen X. B. , Yang In‐Sang 
Published: November 2009

AbstractWe have measured polarized Raman spectra of MnWO4 single crystals at low temperatures, and studied the temperature dependence of the various phonon modes. From our Raman studies of the MnWO4, a new transition temperature, ∼180 K, was found. We have completely assigned the symmetries of the 18 observed Raman modes of the MnWO4, as expected from a group theoretical analysis. These Raman modes have been classified into three groups according to weak, intermediate and strong temperature dependence of the modes in each group. Six internal modes have been identified by their weak temperature dependence of the Raman wavenumbers. The temperature dependence of the wavenumbers of the Bg modes in MgO bonds, modes of intermediate temperature dependence group, shows an anomalous behavior under 50 K. The phonon modes of strong temperature dependence show an anomalous change at ∼180 K in the linewidths. This is believed to be a new transition temperature which involves the changes in the inter‐WO6 octahedra structure. Copyright © 2009 John Wiley & Sons, Ltd.
Minocycline Block Copolymer Micelles and their Anti‐Inflammatory Effects on Microglia
Authors: Soliman Ghareb Mohamed , Choi Angela O. , Maysinger Dusica , Winnik Françoise M. 
Published: November 2009

AbstractMH, a semisynthetic tetracycline antibiotic with promising neuroprotective properties, was encapsulated into PIC micelles of CMD‐PEG as a potential new formulation of MH for the treatment of neuroinflammatory diseases. PIC micelles were prepared by mixing solutions of a Ca2+/MH chelate and CMD‐PEG copolymer in a Tris‐HCl buffer. Light scattering and1H NMR studies confirmed that Ca2+/MH/CMD‐PEG core‐corona micelles form at charge neutrality having a hydrodynamic radius ≈100 nm and incorporating ≈ 50 wt.‐% MH. MH entrapment in the micelles core sustained its release for up to 24 h under physiological conditions. The micelles protected the drug against degradation in aqueous solutions at room temperature and at 37 °C in the presence of FBS. The micelles were stable in aqueous solution for up to one month, after freeze drying and in the presence of FBS and BSA. CMD‐PEG copolymers did not induce cytotoxicity in human hepatocytes and murine microglia (N9) in concentrations as high as 15 mg·mL−1after incubation for 24 h. MH micelles were able to reduce the inflammation in murine microglia (N9) activated by LPS. These results strongly suggest that MH PIC micelles can be useful in the treatment of neuroinflammatory disorders.magnified image
Synthesis with Single Macromolecules: Covalent Connection between a Neutral Dendronized Polymer and Polyelectrolyte Chains as well as Graphene Edges
Authors: Barner Jörg , Al‐Hellani Rabie , Schlüter A. Dieter , Rabe Jürgen P. 
Published: November 2009

AbstractSingle chains of a neutral, dendronized polymer with peripheral azide groups (PG3A) are co‐deposited onto molecularly modified graphite substrates with a positively charged dendronized polymer (PG2) as well as with negatively charged plasmid dsDNA. PG3A is also prepared near graphite step‐edges. Single PG3A chains are moved with a scanning force microscope tip, into close contact with either of the two polyelectrolytes, as well as the step‐edge at predetermined positions. Treating these structures in situ with UV light leads to photochemically induced cross‐linking between the PG3A chains carrying azide groups and PG2, dsDNA, and graphite step‐edges, respectively, which is proven by mechanically challenging the “welding” points by pulling on the molecules with the SFM‐tip.magnified image