bluuebunny/crossref_metadata_2025_split huggingface dataset:
Was ein Pilz über das Altern verrät: Podospora anserina – ein altes Modell mit neuen Perspektiven
Authors: Osiewacz Heinz D. 
Published: June 2007

AbstractUntersuchungen zur Erarbeitung der molekularen Mechanismen des Alterns und der Kontrolle der Lebensspanne bei dem Modellorganismus Podospora anserina haben zur Herausarbeitung einer zentralen Bedeutung der Mitochondrien geführt. Bei der Generierung von ATP in diesen Organellen kommt es zur Bildung von ROS, die zu Schädigungen der verschiedenen Zellbestandteile führen. Trotz der Existenz verschiedener zellulärer Schutzsysteme häufen sich solche Schäden im Laufe des Alterns an und es kommt zum Zelltod. Eingriffe in diese Maschinerie führen zu einer Lebensverlängerung. Allerdings ist der Preis in vielen Fällen eine verminderte “Fitness” der entsprechenden Individuen. Hauptziel der Forschung muss es sein, Bedingungen zu finden, die zu einer Form “gesunden” Alterns führen, d.h. des Alterns möglichst ohne Funktionsbeeinträchtigungen in späteren Lebensabschnitten.
Die Grenzen der Lebensdauer. Von welchen zellulären Faktoren wird das Altern bestimmt?
Authors: Rensing Ludger 
Published: June 2007

AbstractAltern ist in der Regel ein langsamer Prozess, der wesentlich durch eine Akkumulation von zellulären Schäden verursacht wird. Diese Schäden werden zu einem großen Teil durch reaktive Sauerstoff‐ und Stickstoffspezies (ROS und RNS) erzeugt, die bei der Atmung, durch Hormone und durch äußere Stressfaktoren entstehen. Hinzu kommt bei mitotischem Gewebe eine altersabhängig zunehmende replikative Seneszenz, die ebenfalls zu Erkrankungen (Arteriosklerose, Immunschwäche u.a.) führt. Die replikative Seneszenz beruht wesentlich auf der Erosion der Telomere sowie auf der Blockierung des Zellzyklus durch inhibitorische Proteine (p21 u.a.). Eine Restriktion der Nahrungsaufnahme verzögert die Seneszenz durch eine Verminderung der Aktivität des Insulinsignalwegs und Förderung von Transkriptionsfaktoren (FOXO, PHA‐4). Allgemein sind eine gesunde (nicht zu reichliche!) Ernährung verbunden mit körperlicher und geistiger Aktivität sowie Strategien zur Stressbewältigung Mittel gegen frühzeitiges Altern, während pharmakotherapeutische Manipulationen aller dieser Faktoren mit dem Ziel einer drastischen Verlängerung der Lebensdauer mit großer Skepsis betrachtet werden müssen.
Science Bridge wird “Ort der Ideen 2007”
Authors: Junk Susanne , Nellen Wolfgang 
Published: June 2007

AbstractNormalerweise macht Science Bridge für Schüler die eigenen Klassenräume zum Ort der Ideen, indem spannende molekularbiologische Experimente direkt in den Unterricht gebracht werden. Am 11. Dezember holt “Science Bridge” als “Ort der Ideen 2007” die Schule stattdessen zum Aktionstag in die Labore und Hörsäle der Universität Kassel. Da Science Bridge die Brücke zwischen Wissenschaft und Schule erfolgreich schlägt, hat die Gesellschaft für Biochemie und Molekularbiologie (GBM) das Kasseler Schülerlabor als Ausrichter für diesen Aktionstag ausgesucht.
DNA – für die Forschung schmilzt sie dahin
Authors: Schrödel Andrea 
Published: June 2007

AbstractBegonnen hat alles an einem Samstag Ende Februar 1953, als die Struktur der DNA von James D. Watson und Francis Crick durch die Fertigstellung ihres berühmten, aus Draht, Pappe und Klammern zusammengestückelten DNA‐Modells endgültig enträtselt wurde. Heute befasst man sich im Labor eher mit Verfahren zur Zerstörung der DNA, um diese untersuchen zu können. Eines davon ist die Schmelzpunktanalyse.
Schildkrötenfossilien als paläoklimatische Marker
Authors: Karl Hans‐Volker , Hein Juliane 
Published: June 2007

AbstractDie Klima‐Problematik wird in zunehmendem Maße nationalstaatlich, kontinental und weltpolitisch thematisiert. Dies zeigt ihre fundamentale Bedeutung. Notwendig, um überhaupt gesicherte Aussagen über Umweltveränderungen treffen zu können, sind daher geeignete Paläoklima‐Modelle als Referenzmatrizen. Hierbei spielen die Klimaarchive aus dem von Eiszeiten geprägten Pleistozän eine Schlüsselrolle. Die Korrelation dieser Daten mit rezenten Verhältnissen ermöglicht Prognosen über einen Faunen‐ und Florenwandel.
Maintenance of binge eating through negative mood: A naturalistic comparison of binge eating disorder and bulimia nervosa
Authors: Hilbert Anja , Tuschen‐Caffier Brunna 
Published: June 2007

AbstractObjective:To examine negative mood as a proximal antecedent and reinforcing condition of binge eating in binge eating disorder (BED) and bulimia nervosa (BN).Method:Using an ecological momentary assessment design, 20 women with BED, 20 women with BN, and 20 nonclinical control women were recruited from the community, provided with a portable minicomputer, and asked to rate their mood and list their thoughts at randomly‐generated beep sounds and before, during, and after episodes of eating.Results:In both eating disorder groups mood before binge eating was more negative than before regular eating and at random assessment. Binge eating was followed by a deterioration of mood. The BED group revealed less antecedent negative mood than the BN group and less concomitant negative cognitions about food/eating and stress.Conclusion:Affect regulation difficulties likely lead to binge eating in both disorders, but binge eating may not be effective for regulating overall mood. © 2007 by Wiley Periodicals, Inc. Int J Eat Disord 2007.
Pathways to help‐seeking in bulimia nervosa and binge eating problems: A concept mapping approach
Authors: Hepworth Natasha , Paxton Susan J. 
Published: June 2007

AbstractObjective:To conduct an in‐depth study, using concept mapping, of three factors related to help‐seeking for bulimia nervosa and binge eating: problem recognition, barriers to help‐seeking, and prompts to help‐seeking.Method:Semistructured interviews were conducted to elicit information about help‐seeking with 63 women (18–62 years) with past or present bulimic behaviors.Results:Using Leximancer software, factors identified as associated with problem recognition were Changes in Behavior, Interference with Life Roles, Comments about Changes and Psychological Problems. Salient barriers to help‐seeking were Fear of Stigma, Low Mental Health Literacy/Perception of Need, Shame, Fear of Change and Cost. Prompts to help‐seeking were increased Symptom Severity, Psychological Distress, Interference with Life Roles, Health Problems, and Desire to Get Better.Conclusion:Results highlighted the need for awareness campaigns to reduce both self and perceived stigma by others towards bulimic behaviors, and the need to enhance awareness of available interventions for people ready to engage in treatment, to increase help‐seeking. © 2007 by Wiley Periodicals, Inc.
A comparison of surface and free‐air temperature variability and trends at radiosonde sites and nearby high elevation surface stations
Authors: Pepin N. C. , Duane W. 
Published: June 2007

AbstractPrevious research has illustrated differences in temperature trends as measured by high elevation surface stations versus free‐air temperatures interpolated to the same locations from the National Centers for Environmental Prediction (NCEP)/National Center for Atmospheric Research's (NCAR) Re‐analysis R1. This paper examines the extent to which the decision to use R1 rather than radiosonde data influenced these results. Temperatures at selected high elevation surface sites (1948–998) are paired with nearby homogeneity adjusted radiosonde data from Lanzante, Klein and Seidel (LKS). For each station pair, four mean monthly temperature anomaly time series are examined, consisting of (1) surface Global Historical Climate Network (GHCNv2)/Climate Research Unit (CRUv2) station anomalies (SF), (2) LKS radiosonde anomalies, and R1 anomalies interpolated to (3) the surface (RNSF) and (4) radiosonde (RNLKS) locations respectively. Analyses demonstrate the extent of common variance, the mean climatology of each of the four series, and differences or similarities in trends. The surface record is decoupled from the other three series especially in locations of incised topography. In 15 out of 18 pairs RNSF shows greater affinity with LKS than with SF and there is a high degree of common variance between LKS and RNSF. There is a high degree of correlation between secular trends in the two R1 series, both of which are much more similar to radiosonde than to surface trends. Trends in raw temperature and in ΔT (the surface/free‐air temperature difference) both therefore show limited sensitivity to the choice of LKS radiosonde versus R1 (RNSF), apart from in a few locations in the Eurasian continent. Copyright © 2007 Royal Meteorological Society
Erosion predictions with the Wind Erosion Equation (WEQ) using different climatic factors
Authors: Panebianco J. E. , Buschiazzo D. E. 
Published: June 2007

AbstractLittle information is available on the performance of the Wind Erosion Equation (WEQ) for estimating wind erosion under differing climatic conditions. The objective of this study was to assess the fitting of measured and WEQ‐estimated wind erosion with different climatic C factors. Results showed that WEQ underestimated the annual wind erosion by 45 per cent when loaded with the historic C, obtained with climatic data records between 1981 and 1990. The monthly averaged C factor (monthly C, n = 12) underestimated the erosion by 29 per cent, the C factors of each one of the six studied years (annual C, n = 6) underestimated the erosion by 19 per cent, and the C factors of each one of the evaluated months (monthly C, n = 72) overestimated the erosion by 31 per cent. Precipitation explained most of C factors variability. C factors corresponding to high precipitation periods predicted low erosion amounts in no‐till (NT) and conventional tillage (CT). C factors corresponding to low precipitation periods calculated high erosion rates in CT (143 t ha−1 y−1) and low in NT (2·4 t ha−1 y−1). The historical C factor predicted no erosion in NT and 7·1 t ha−1 y−1 in CT. These results indicated that the WEQ should be used with variable C factors in order to assess different climatic scenarios of the semiarid Argentina. Copyright © 2007 John Wiley & Sons, Ltd.
Land rights regimes in southwest Nigeria: implications for land access and livelihoods security of settled Fulani agropastoralists
Authors: Fabusoro E. , Matsumoto T. , Taeb M. 
Published: June 2007

AbstractThe need of Fulanis for secured access to land is a long time policy challenge in Nigeria but progress in achieving this is far from being made. Meanwhile, access to land, of Fulanis that are settled among the Yorubas in southwest Nigeria, is dependent on land rights regimes operating in Yoruba communities. The study examines the nature of land rights in southwest Nigeria and how these provide access to Fulanis for their livelihoods activities. The study hypothesised that land access and land rights relate significantly to livelihood security of the Fulanis. The study was conducted in three States, namely, Ogun, Oyo and Ekiti States. Two major settlements of the Fulanis were selected from each of the States and 20 Fulani households were sampled purposively from each settlement. Forty‐two Yoruba farmers were also interviewed to understand the land rights regimes operating in their communities. Non‐parametric Chi‐square analysis was conducted to test the hypotheses. The study revealed that communal land right regime operates in most communities in the region and designates use rights to Fulanis. Fulanis in Oyo State had management rights which gave them secured access to land in their host communities than their counterparts in other States. The hypotheses tested show significant relationship between land rights and livelihood security of the Fulanis (α < 0·05). The rehabilitation of existing grazing reserves in the region is therefore recommended to grant the Fulanis ownership rights and secured access to land for the security of their livelihoods. Copyright © 2007 John Wiley & Sons, Ltd.
The transient equations of viscous quantum hydrodynamics
Authors: Dreher Michael 
Published: June 2007

AbstractWe study the viscous model of quantum hydrodynamics in a bounded domain of space dimension 1, 2, or 3, and in the full one‐dimensional space. This model is a mixed‐order partial differential system with nonlocal and nonlinear terms for the particle density, current density, and electric potential. By a viscous regularization approach, we show existence and uniqueness of local in time solutions. We propose a reformulation as an equation of Schrödinger type, and we prove the inviscid limit. Copyright © 2007 John Wiley & Sons, Ltd.
Efficient handling of stability problems in shell optimization by asymmetric ‘worst‐case’ shape imperfection
Authors: Kegl M. , Brank B. , Harl B. , Oblak M. M. 
Published: June 2007

AbstractThe paper presents an approach to shape optimization of proportionally loaded elastic shell structures under stability constraints. To reduce the stability‐related problems, a special technique is utilized, by which the response analysis is always terminated before the first critical point is reached. In this way, the optimization is always related to a precritical structural state. The necessary load‐carrying capability of the optimal structure is assured by extending the usual formulation of the optimization problem by a constraint on an estimated critical load factor. Since limit points are easier to handle, the possible presence of bifurcation points is avoided by introducing imperfection parameters. They are related to an asymmetric shape perturbation of the structure. During the optimization, the imperfection parameters are updated to get automatically the ‘worst‐case’ pattern and amplitude of the imperfection. Both, the imperfection parameters and the design variables are related to the structural shape via the design element technique. A gradient‐based optimizer is employed to solve the optimization problem. Three examples illustrate the proposed approach. Copyright © 2007 John Wiley & Sons, Ltd.
Synthesis, characterization, and mechanical properties evaluation of thermally stable apophyllite vinyl ester nanocomposites
Authors: Chen Chenggang , Yebassa D. , Raghavan D. 
Published: June 2007

AbstractThe objective of this study is to prepare layered organosilicates with enhanced thermal stability that can be used to formulate high‐temperature polymer nanocomposites. Fourier transform infrared (FTIR) spectroscopy, wide‐angle X‐ray diffraction (WAXD), and thermal gravimetric analysis (TGA) characterization results of the modified silicates indicate that the organic pendant group has been chemically grafted on to the backbone of layered silicate and the organically modified apophyllite is thermally stable up to approximately 430°C. The organically modified apophyllite was mixed along with vinyl ester resin and styrene diluent in a sonic dismembrator and the mixture cured to form a nanocomposite specimen. Transmission electron microscopy (TEM) results of the nanocomposites showed mixed morphology with predominant fraction of organosilicates exhibiting an intercalated structure. Tapping mode atomic force microscopy (TMAFM) observation of the nanocomposite showed striated layered silicates dispersed in the resin matrix. The nanocomposites formulated with organosilicates containing reactive terminal pendant group were found to have a higher tensile strain than the nanocomposites formulated with organosilicates containing inert pendant group. Copyright © 2007 John Wiley & Sons, Ltd.
Development of noninvasive fetal DNA diagnosis from nucleated erythrocytes circulating in maternal blood
Authors: Sekizawa Akihiko , Purwosunu Yuditiya , Farina Antonio , Okai Takashi , Takabayashi Haruo , Kita Mikiko , Yura Hirofumi , Kitagawa Michihiro 
Published: June 2007

AbstractBackgroundA considerable effort is being spent in developing noninvasive prenatal DNA diagnostic procedures. We recently reported that nucleated erythrocytes (NRBCs) can be enriched from maternal blood by a galactose‐specific lectin method. In the present study, to prove that fetal NRBCs are definitely present in maternal blood and are a good source for fetal genetic diagnosis, we evaluated methods for lectin enrichment and subsequent fluorescence in situ hybridization (FISH) analysis through fetal gender determination.MethodsPeripheral blood samples were collected from pregnant women (median 15, range: 10–18 weeks). From the blood samples, NRBCs were enriched based on galactose‐specific lectin method. After detecting them by their morphology, NRBCs are separated and taken in a new glass slide by micromanipulator. We analyzed fetal gender using X and Y‐chromosome‐specific FISH probes. The results were compared with fetal gender analysis using Y‐chromosomal sequences in maternal plasma.ResultsThe fetal gender analyses by FISH in 20 pregnant women were all in accordance with the results from maternal plasma analyses. It is confirmed that fetal NRBCs were present in maternal blood and that 30.4% of NRBCs in maternal blood were fetal in origin.ConclusionWe have successfully carried out a noninvasive prenatal DNA diagnosis of fetal gender by using galactose‐specific lectin method and subsequent FISH analysis. Copyright © 2007 John Wiley & Sons, Ltd.
Synthesis of dendronized polymer brushes containing metallo‐supramolecular polymer side chains
Authors: Zhang Yanhong , Xu Zizhen , Li Xiaokai , Chen Yongming 
Published: June 2007

AbstractA new kind of dendronized polymer brush with metallo‐supramolecular polymer side chains was fabricated by a combination of macromonomer and graft‐to approach. The alternating copolymers of maleic anhydride and styryl macromonomers pendant with Fréchet‐type dendrons of three generations were reported previously. In this article, terpyridine groups were introduced along the backbone of the dendronized polymers through the amidolysis of anhydride groups. The terpyridine functionalized PEO linear chains were then incorporated through the complexation of terpyridine and Ru(II) ion. Thus, dendronized polymer brushes with amphiphilic properties were synthesized. AFM analysis showed worm‐like single molecular morphologies of the polymers of three generations, and 1H NMR analysis indicated that such molecular brushes had an amphiphilic nature in solution. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3303–3310, 2007
Nanostructured polymetallaynes of controlled length: Synthesis and characterization of oligomers and polymers from 1,1′‐bis‐(ethynyl)4,4′‐biphenyl bridging Pt(II) or Pd(II) centers
Authors: Fratoddi Ilaria , Battocchio Chiara , Groia Alessandra L. , Russo Maria V. 
Published: June 2007

AbstractThe reactivity of square planar palladium(II) and platinum(II) complexes in trans or cis configuration, namely trans or cis‐[dichlorobis(tributylphosphine)platinum(II)] and trans‐[dichlorobis(tributylphosphine)palladium(II)] with 1,1′‐bis(ethynyl) 4,4′‐biphenyl, DEBP, leading to π‐conjugated organometallic oligomeric and polymeric metallaynes, was investigated by a systematic variation of the reaction conditions. The formation of polymers and oligomers with defined chain length [M(PBu3)2 (CCC6H4C6H4CC)]n (n = 3–10 for the oligomers, n = 20–50 for the polymers) depends on the configuration of the precursor Pt(II) and Pd(II) complexes, the presence/absence of the catalyst CuI, and the reaction time. A series of model reactions monitored by XPS, GPC, and NMR 31P spectroscopy showed the route to modulate the chain growth. As expected, the nature of the transition metal (Pt or Pd) and the molecular weight of the polymers markedly influence the photophysical characteristics of the polymetallaynes, such as optical absorption and emission behavior. Polymetallaynes with nanostructured morphology could be obtained by a simple casting procedure of polymer solutions. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3311–3329, 2007
Divergent synthesis of dendrimer‐like macromolecules through a combination of atom transfer radical polymerization and click reaction
Authors: Liu Qingchun , Zhao Peng , Chen Yongming 
Published: June 2007

AbstractThis article describes a divergent strategy to prepare dendrimer‐like macromolecules from vinyl monomers through a combination of atom transfer radical polymerization (ATRP) and click reaction. Firstly, star‐shaped polystyrene (PS) with three arms was prepared through ATRP of styrene starting from a three‐arm initiator. Next, the terminal bromides of the star‐shaped PS were substituted with azido groups. Afterwards, the azido‐terminated star‐shaped PS was reacted with propargyl 2,2‐bis((2′‐bromo‐2′‐methylpropanoyloxy)methyl)propionate (PBMP) via click reaction. Star‐shaped PS with six terminal bromide groups was afforded and served as the initiator for the polymerization of styrene to afford the second‐generation dendrimer‐like PS. Iterative process of the aforementioned sequence of reactions could allow the preparation of the third‐generation dendrimer‐like PS. When the second‐generation dendrimer‐like PS with 12 bromide groups used as an initiator for the polymerization of tert‐butyl acrylate, the third‐generation dendrimer‐like block copolymer with a PS core and a poly (tert‐butyl acrylate) (PtBA) corona was afforded. Subsequently PtBA segments were selectively hydrolyzed with hydrochloric acid, resulting an amphiphilic branched copolymer with inner dendritic PS and outer linear poly(acrylic acid) (PAA). Following the same polymerization procedures, the dendrimer‐like PS and PS‐block‐PtBA copolymers of second generation originating from six‐arm initiator were also synthesized. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3330–3341, 2007
Preparation and morphological, electrical, and mechanical properties of polyimide‐grafted MWCNT/polyimide composite
Authors: Yuen Siu‐Ming , Ma Chen‐Chi M. , Chiang Chin‐Lung , Lin Yao‐Yu , Teng Chih‐Chun 
Published: June 2007

AbstractPrecursor of polyimide, polyamic acid has been prepared sucessfully. Acid‐modified carbon nanotube (MWCNT) was grafted with soluble polyimide then was added to the polyamic acid and heated to 300 °C to form polyimide/carbon nanotube composite via imidation. Morphology, mechanical properties and electrical resistivity of the MWCNT/polyimide composites have been studied. Transmission electron microscope microphotographs show that the diameter of soluble polyimide‐grafted MWCNT was increased from 30–60 nm to 200 nm, that is a thickness of 70–85 nm of the soluble polyimide was grafted on the MWCNT surface. PI‐g‐MWCNT was well dispersed in the polymer matrix. Percolation threshold of MWCNT/polyimide composites has been investigated. PI‐g‐MWCNT/PI composites exhibit lower electrical resistivity than that of the acid‐modified MWCNT/PI composites. The surface resistivity of 5.0 phr MWCNT/polyimide composites was 2.82 × 108 Ω/cm2 (PI‐g‐MWCNT) and 2.53 × 109 Ω/cm2 (acid‐modified MWCNT). The volume resistivity of 5.0 phr MWCNT/polyimide composites was 8.77 × 106 Ω cm (PI‐g‐MWCNT) and 1.33 × 1013 Ω cm (acid‐modified MWCNT).Tensile strength and Young's modulus increased significantly with the increase of MWCNT content. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3349–3358, 2007