bluuebunny/crossref_metadata_2025_split huggingface dataset:
Postfunctionalization of Luminescent Bipyridine PtII Bisacetylides by Click Chemistry
Authors: Stengel Ilona , Strassert Cristian A. , Plummer Edward A. , Chien Chen‐Han , De Cola Luisa , Bäuerle Peter 
Published: March 2012

AbstractThe synthesis of a family of differently substituted 5‐ and 4,4′‐ethynyl‐bpy PtII bisacetylide complexes (bpy = 2,2′‐bipyridine) and their postfunctionalization using click chemistry is described. CuI‐catalyzed azide–alkyne [3+2] cycloaddition was an efficient method to decorate the PtII complexes with a manifold of moieties in high yields. The absorption and emission properties and the electrochemical behaviour of all of the complexes have been investigated. The studied compounds emit at room temperature between 598 and 660 nm, reaching photoluminescence quantum yields of 0.33 in solution. The bright luminescent properties of the unsubstituted bpy PtII bisacetylide complex remained unaffected upon click‐functionalization as the resulting triazole substituent has no significant influence on the nonradiative decay rate constant. This route opens new possibilities for to control the bulk of the complexes, their solubility, and their further extension or immobilization on macromolecules, polymers and surfaces without affecting their intrinsic properties. Two derivatives were selected as triplet emitter molecules in solution‐processed polymer‐based organic light‐emitting devices.
Platinum‐Catalyzed Cyclization of N‐Allyl Carbamates for the Synthesis of 5‐Vinyloxazolidinones
Authors: Yoon Hyo‐Sang , Kim Ju‐Hye , Kang Eun Joo , Jang Hye‐Young 
Published: March 2012

AbstractPlatinum‐catalyzed addition of the oxygen nucleophile of a carbamate to an allyl bromide was carried out to afford a range of biologically active 5‐vinyl‐substituted oxazolidinones in good yields. Over the course of the reaction, a platinum complex, SnCl2, and the allyl bromide are assumed to generate an electrophilic allyl‐platinum intermediate in the presence of carbamate oxygen nucleophiles. This method provides a wide range of 5‐vinyloxazolidinones regardless of the substitution at the nitrogen and oxygen atoms.
Beurteilung der Setzungen bei EPB‐Vortrieben der Metro L9 Barcelona
Authors: Ruse Nico Michael , Schwarz Henning 
Published: March 2012

AbstractFür den Bau der insgesamt 50 km langen Metro Linie 9 in Barcelona werden zeitgleich bis zu fünf EPB‐Schilde eingesetzt; davon werden 13,6 km mit einem Ausbruchdurchmeser von 9,4 m und 27 km mit 12 m Durchmesser aufgefahren. Weitere Abschnitte führen über einen 4 km langen Viadukt sowie auf 6 km durch Tunnel in offener Bauweise und Tunnel in Spritzbetonbauweise. Seit Dezember 2009 sind bereits erste Teilstrecken dem automatischen U‐Bahnbetrieb übergeben.Der Vortrieb von Tunneln im innerstädtischen Bereich erfordert eine äußerst intensive Vorbereitung und Kontrolle der Vortriebsparameter der Tunnelbohrmaschinen sowie ein intensives geodätisches und geotechnisches Messprogramm. Im vorliegenden Artikel werden Verfahren zur Vorbereitung und Kontrolle der Vortriebe mittels Erddruckschilden dargestellt. Hierbei wird insbesondere auf die Arbeitsdrücke der EPB‐Schilde und die auftretenden Setzungen eingegangen, wobei der positive Effekt einer aktiven Kontrolle der Arbeitsdrücke im Steuerspalt zur Setzungsminimierung aufgezeigt wird. Zur detaillierten Analyse und Bewertung der Setzungen wird die “Effizienz” als Bewertungskriterium eingeführt.Assessment of settlements at EPB drives of Barcelona's metro line 9. For the construction of the 50 km long Metro Line 9 in Barcelona up to five earth pressure balanced shields have been used at the same time. Along 13.6 km the tunnel is excavated with an excavation diameter of 9.4 m and on a length of 27 km with a diameter of 12 m. Further sections are a 4 km long viaduct and 6 km of tunnels in cut and cover or conventionally excavated tunnels. First sub‐sections of the new metro line are in service since December 2009. The advance of tunnels below urban areas requires an intensive preparation and control of the machine advance parameters as well as an intensive topographical and geotechnical monitoring programme. In the present article procedures for the preparation and control of an EPB advance are shown. Main focus is set on the machines working pressures and the resulting ground movements. The positive influence of the shield gap injection will be pointed out. For the analysis and evaluation of the settlements for the advance in soil, the so called “efficiency” will be introduced.
Säulenherstellung mit Tiefenrüttlern in Böden mit einer undränierten Kohäsion cu < 15 kN/m2
Authors: Wehr Jimmy , Maihold Katja 
Published: March 2012

AbstractBaustellenerfahrungen und systematische Modellversuche zeigen, dass eine Säulenherstellung von Rüttelstopfsäulen (RSV) mit dem Tiefenrüttler auch in sehr weichen Böden ab einem Grenzwert der undränierten Kohäsion von cu = 4 kN/m2 möglich ist. Der alte Grenzwert cu = 15 kN/m2 von 1979 verliert damit seine Gültigkeit. In der aktuellen allgemeinen bauaufsichtlichen Zulassung Z‐34.2‐3 für “Vermörtelte Stopfsäulen (VSS), Fertigmörtel‐Stopfsäulen (FSS) und Betonstopfsäulen (BSS)” der Keller Grundbau GmbH wurde diesen neuen Erkenntnissen mit der Anpassung der Anwendbarkeitsgrenzen und der Herstellung einer Kiesvergütung nun Rechnung getragen.Installation of columns with depth vibrators in soils with undrained cohesion cu < 15 kN/m2. Site experiences and systematic model tests show that the installation of vibro stone columns and vibro mortar columns is possible with a depth vibrator even in a very soft soil with an undrained cohesion of cu = 4 kN/m2. The old limit value of cu = 15 kN/m2 is no longer valid. The DIBt (“Deutsches Institut für Bautechnik”, German federal institute for construction technique, Berlin) accommodates this fact in the actual version of the general technical approval Nr. Z‐34.2‐3 for vibro concrete columns (VCC) and ready‐mixed vibro mortar columns (VMC).
Post‐combustion CO2 capture: chemical absorption processes in coal‐fired steam power plants
Authors: Oexmann Jochen , Kather Alfons , Linnenberg Sebastian , Liebenthal Ulrich 
Published: March 2012

AbstractThe integration of a post‐combustion CO2 capture unit in a coal‐fired steam power plant leads to a reduction in net power output, where the largest contributors to the power loss are the heat requirement for the regeneration of the chemical solvent in the desorber of the CO2 capture unit (approx. 2/3) and the auxiliary power demand of the CO2 compressor (approx. 1/4). In this review, the layout of the overall process is explained and the interaction of the three sub‐processes power plant, CO2 capture process and CO2 compressor is discussed. The optimization of process parameters of the CO2 capture unit – such as solution flow rate and reboiler temperature – is intricate due to the complex interaction of the sub‐processes. It is shown that although the heat requirement for solvent regeneration has the largest impact on the power output of the overall process, the optimal process parameters that lead to the lowest possible heat requirement of the capture unit do not necessarily coincide with the optimal process parameters that make for the most energy efficient operation of the overall process. Therefore, when optimizing process parameters of CO2 absorption processes in power plants, one should focus on the minimization of the overall power loss instead of solely reducing the heat requirement for solvent regeneration. The described coherences are illustrated by the results of process simulations based on detailed models of a post‐combustion CO2 capture unit using 7 m (30 wt.‐%) monoethanolamine (MEA), of a supercritical, hard‐coal‐fired steam power plant and of a six‐stage, intercooled CO2 compressor. © 2012 Society of Chemical Industry and John Wiley & Sons, Ltd
Assessment of dementia risk in aging adults using both FDG‐PET and FDDNP‐PET imaging
Authors: Ercoli L. M. , Small G. W. , Siddarth P. , Kepe V. , Huang S.‐C. , Miller K. J. , Lavretsky H. , Bookheimer S. Y. , Barrio J. R. , Silverman D. H. S. 
Published: March 2012

BackgroundIn a previous study, positron emission tomography (PET) with 2‐(1‐{6‐[(2‐[F‐18]fluoroethyl)(methyl)amino]‐2‐naphthyl}ethylidene)malononitrile (FDDNP), a molecule that binds to plaques and tangles in vitro, identified three subgroups of non‐demented subjects according to FDDNP binding patterns: low global (LG) binding; high frontal, parietal, medial temporal binding (HF/PA); and high medial and lateral temporal and posterior cingulate (HT/PC) binding. In this follow‐up investigation, we compared 2‐deoxy‐2‐[F‐18]fluoro‐ d‐glucose (FDG)‐PET cerebral metabolic patterns in the three FDDNP‐PET binding subgroups.MethodsFifty‐four subjects with normal aging (N = 28) or amnestic forms of mild cognitive impairment (N = 26) underwent FDDNP‐PET and FDG‐PET scanning. Subjects in the LG, HF/PA, and HT/PC FDDNP subgroups were compared according to visual ratings, statistical parametric mapping, and automated region of interest analyses of their FDG‐PET data.ResultsThe FDDNP‐PET subgroups demonstrated different glucose metabolic patterns according to visual ratings, region of interest, and statistical parametric mapping analyses of FDG‐PET data. The LG FDDNP subgroup showed no areas of significant hypometabolism relative to the other subgroups and had low Alzheimer's disease risk by FDG‐PET standards. The HF/PA FDDNP subgroup demonstrated hypometabolism in bilateral inferior parietal/parietotemporal, bilateral posterior cingulate, perisylvian, mid‐temporal gyrus, and dorsolateral prefrontal regions, which is a pattern suggestive of high Alzheimer's disease risk. The HT/PC FDDNP subgroup demonstrated heterogeneous FDG‐PET patterns with predominant anterior frontal and anterior temporal hypometabolism, suggestive of mixed etiologies, including fronto‐temporal dementia risk.ConclusionsThe FDG‐PET data provided independent validation that different patterns of FDDNP‐PET binding in non‐demented individuals may be associated with differential dementia risk. Copyright © 2012 John Wiley & Sons, Ltd.
Falling through the cracks: gaps in depression treatment among older Mexican‐origin and white men
Authors: Hinton Ladson , Apesoa‐Varano Ester Carolina , González Hector M. , Aguilar‐Gaxiola Sergio , Dwight‐Johnson Megan , Barker Judith C. , Tran Cindy , Zuniga Ramiro , Unützer Jürgen 
Published: March 2012

ObjectivesThis study aims (i) to compare depression frequency and self‐reported depression treatment in Mexican‐origin and white men; (ii) to examine ethnic differences in self‐reported prior depression diagnosis and types of treatment; and (iii) to determine whether Mexican‐origin men (both English and Spanish language preferring) are less likely than white men to report receiving depression treatment after controlling for potential confounders.MethodsThis is a cross‐sectional, observational study of Mexican‐origin and white men (60 years old and over) presenting for primary care visits at six outpatient clinics in California's Central Valley. Clinical depression was assessed with the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM‐IV), module for past‐year major depression and questions for chronic depression. Past year, self‐reported prior depression diagnosis and treatment (i.e., medication, psychotherapy, mental health referral) were assessed through a structured questionnaire.ResultsThe frequency of past‐year clinical depression was similar for both ethnic groups, yet Mexican‐origin men were significantly less likely than whites to report receiving a prior diagnosis of depression or prior depression treatment. Compared with whites, the odds of untreated depression in Mexican‐origin men was 4.35 (95% CI 1.35–14.08) for those interviewed in English and 10.40 (95% CI 2.11–51.25) for those interviewed in Spanish. For both ethnic groups, the majority (i.e., approximately two‐thirds) of men receiving depression treatment also met criteria for past‐year clinical depression.ConclusionsMexican‐origin older men in primary care suffer from significant gaps in depression care (i.e., diagnosis and treatment) compared with whites. Delivering effective depression treatment (i.e., so that depression remits) remains elusive for both ethnic groups. Copyright © 2012 John Wiley & Sons, Ltd.
CYCLICAL ABSENTEEISM AMONG PRIVATE SECTOR, PUBLIC SECTOR AND SELF‐EMPLOYED WORKERS
Authors: Pfeifer Christian 
Published: March 2012

ABSTRACTThis research note analyzes differences in the number of absent working days and doctor visits and in their cyclicality between private sector, public sector and self‐employed workers. For this purpose, I used large‐scale German survey data for the years 1995 to 2007 to estimate random effects negative binomial (count data) models. The main findings are as follows. (i) Public sector workers have on average more absent working days than private sector and self‐employed workers. Self‐employed workers have fewer absent working days and doctor visits than dependent employed workers. (ii) The regional unemployment rate is on average negatively correlated with the number of absent working days among private and public sector workers as well as among self‐employed men. The correlations between regional unemployment rate and doctor visits are only significantly negative among private sector workers. Copyright © 2012 John Wiley & Sons, Ltd.
Do clinical and experimental investigations support an antiatherogenic role for dietary phytosterols/stanols?
Authors: Lottenberg Ana Maria , Bombo Renata P.A. , Ilha Angela , Nunes Valeria Sutti , Nakandakare Edna R. , Quintão Eder C.R. 
Published: March 2012

AbstractThe plasma cholesterol‐reducing effect of phytosterols (PS) has been recognized in several studies, but the usefulness of PS in preventing coronary heart disease remains controversial, as some investigations claim that the high PS concentrations found in plasma and specific tissues are related to an increased risk of cardiovascular events. It has also been demonstrated that PS may induce inflammation and reduce cholesterol efflux from macrophages, conditions that are directly implicated in the development of atherosclerosis. As to arterial dysfunction and atherosclerosis, some studies have concluded that plasma PS concentrations are unrelated or only weakly related or that PS intake or plasma PS concentrations are harmful. Thus, in light of the National Cholesterol Education Program‐ATPIII report, it is necessary to evaluate the relevance of their findings. To this end, we have evaluated the studies conducted on cells, animal models, and humans regarding the influence of PS on the development of atherosclerosis. © 2012 IUBMB Life, 64(4): 296–306, 2012
Highly efficient synthesis of 5‐cyanovaleramide by Rhodococcus ruber CGMCC3090 resting cells
Authors: Shen Yanbing , Wang Min , Li Xiaodan , Zhang Jinli , Sun Hua , Luo Jianmei 
Published: March 2012

AbstractBACKGROUND: The chemo‐selective biocatalytic hydrolysis of nitriles presents a valuable alternative to chemical hydrolysis, a procedure in which harsh conditions are applied. In this study, Rhodococcus ruber CGMCC3090 is used for 5‐cyanovaleramide (5‐CVAM) production by means of adiponitrile (ADN) hydration. Several parameters that affect the biocatalyzation process are investigated.RESULTS: The effective production of 5‐CVAM from ADN with good regioselectivity was successfully achieved using the resting cells of Rhodococcus ruber CGMCC3090. The reaction parameters for 5‐CVAM production were investigated during the experiment, and it was found that resting cells were effective in converting ADN at high concentrations (up to 2.0 mol L−1) and the hydration reaction was slightly inhibited by different concentrations of 5‐CVAM. After 100 min of incubation, more than 99.2% of the added adiponitrile was converted to 5‐CVAM when the cell concentration was 1.05 g dry cell weight (DCW) L−1.CONCLUSION: The study provides a facile and feasible way of achieving high 5‐CVAM production levels while maintaining high purity of the product obtained. Copyright © 2012 Society of Chemical Industry
Metabolome analysis reveals ethanolamine as potential marker for improving lipid accumulation of model photosynthetic organisms
Authors: Cheng Jing‐Sheng , Niu Yan‐Hong , Lu Shu‐Huan , Yuan Ying‐Jin 
Published: March 2012

AbstractBACKGROUND: Many researchers focus on exploring approaches to improve lipid productivity by photosynthetic organisms. Metabolomic analysis provides a new way to globally explore metabolic changes. To elevate lipid yields in the process of biodiesel production using photosynthetic organisms as feedstock, metabolomics combined with orthogonal partial least‐squares discriminant analysis (OPLS‐DA) is being applied widely to seek potential markers in regulation of lipid production. Herein, metabolic differences among three photosynthetic organisms Scenedesmus obliquus, Synechocystis sp. PCC6803 and Anabaena sp. PCC7120 were analyzed by gas chromatography coupled with time‐of‐flight mass spectrometry (GC‐TOF‐MS).RESULTS: In total, 74 metabolites were identified by GC‐TOF‐MS. The OPLS‐DA model revealed good correlation between metabolites and lipid content (R2 = 0.9916). Nine compounds including ethanolamine were selected as potential markers affecting lipid accumulation. Herein, the highest level of C18:3 revealed its roles in regulation of the unsaturated degree of fatty acids. Further study revealed that exogenous ethanolamine (2 mmol L−1) significantly increased the lipid content (22%) in Scenedesmus obliquus. In particular, ethanolamine significantly elevated the levels of C16:2, C18:1, and C18:2.CONCLUSION: Metabolomic analysis is a useful tool to search for potential markers to improve lipid accumulation of photosynthetic organisms. Ethanolamine can be regarded as an alternative compound to improve lipid content and fatty acid levels for biodiesel production. Copyright © 2012 Society of Chemical Industry
Sodium imaging of human brain at 7 T with 15‐channel array coil
Authors: Qian Yongxian , Zhao Tiejun , Wiggins Graham C. , Wald Lawrence L. , Zheng Hai , Weimer Jonathan , Boada Fernando E. 
Published: March 2012

AbstractSignal‐to‐noise ratio (SNR) is a major challenge to sodium magnetic resonance imaging. Phased array coils have been shown significantly improving SNR in proton imaging over volume coils. This study investigates SNR advantage of a 15‐channel array head coil (birdcage volume coil for transmit/receive and 15‐channel array insert for receive‐only) in sodium imaging at 7 T. Phantoms and healthy human brains were scanned on a whole‐body 7 T magnetic resonance imaging scanner using a customer‐developed pulse sequence with the twisted projection imaging trajectory. Noise‐only images were acquired with blanked radiofrequency excitations for noise measurement on a pixel basis. SNR was calculated on the root of sum‐of‐squares images. When compared with the volume coil, the 15‐channel array produced SNR more than doubled at the periphery and slightly increased at the center of the phantoms and human brains. Decorrelation of noise across channels of the array coil extended the SNR‐doubled region into deep area of the brain. The spatial modulation of element sensitivities on the sum‐of‐squares combined image was removed by performing self‐calibrated sensitivity encoding parallel image reconstruction and uniform image intensity across entire field of view was attained. The 15‐channel array coil is an efficient tool to substantially improve SNR in sodium imaging on human brain. Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc.
Probiotika: Quo Vadis....?
Authors: von Schillde Marie‐Anne , Haller Dirk 
Published: March 2012

AbstractDie Rechtfertigung für den Einsatz von probiotischen Mikroorganismen beruht bisher auf den Ergebnissen rein deskriptiver Studien in Mensch oder Tier. Die ursächlichen Mechanismen sind allerdings häufig nicht bekannt. Um neue, wissenschaftlich fundierte Indikationsgebiete und Applikationswege für Probiotika zu bestimmen und neue probiotische Stämme sowie Probiotika‐Mischungen gezielt einsetzen zu können, bedarf es der Kenntnis zugrunde liegender Wirkmechanismen bzw. Struktur‐Funktions‐Beziehungen. Ergebnisse, die mit einem bestimmten Stamm in einem Indikationsgebiet erzielt wurden, können nicht per se auf andere Stämme übertragen werden. Nur solch ein rationaler Einsatz von Probiotika wird letztlich zu abschätzbaren Wirkungen von probiotischen Therapien führen und sie zukünftig unter Einhaltung pharmakologischer Sicherheitsstandards als ernst zu nehmende Begleittherapie oder Alternative zu pharmakologischen Therapien etablieren.
Trichuris suis ova bei chronisch‐entzündlichen Darmerkrankungen
Authors: Dignaß Axel , Hartmann Franz , Schulze Hermann , Stein Jürgen 
Published: March 2012

AbstractDie Pathogenese der chronisch‐entzündlichen Darmerkrankungen Morbus Crohn und Colitis ulcerosa ist trotz erheblicher Fortschritte in der Ätiopathogenese‐Forschung weiterhin ungeklärt. Verschiedene Faktoren, wie z.B. eine genetische Prädisposition oder Umweltfaktoren (u.a. bakterielle oder virale Infekte, Ernährungsbestandteile, Rauchen) führen vermutlich zu einer Barrierestörung und konsekutiver Fehlregulation des mukosalen Immunsystems, die in der Entwicklung einer chronisch‐entzündlichen Darmerkrankung (CED) resultiert.
Graphene based composites prepared through exfoliation of graphite platelets in methyl methacrylate/poly(methyl methacrylate)
Authors: Cardinali Marta , Valentini Luca , Kenny Josè M. , Mutlay İbrahim 
Published: March 2012

AbstractThe use of methyl methacrylate/poly(methyl methacrylate) as a medium for the exfoliation of graphite platelets without any chemical treatment is reported. The dispersions, characterized by transmission electron microscopy and Raman spectroscopy, confirmed the obtainment of graphene sheets a few layers thick. We found that the electrical conductivity of such nanocomposites can be activated at temperature by the application of an external electric field, this effect being reversible after removal of the thermal stimulus. This result provides an initial understanding of how electric field assisted thermal annealing can be used to control the bulk physical properties of such composites. Copyright © 2012 Society of Chemical Industry
Der große Wurf
Authors: Hofmann Jan , Klar Peter J. , von Aufschnaiter Claudia 
Published: March 2012

AbstractWurftechniken und Fallvorgänge im Judo lassen sich mit vergleichsweise einfachen technischen Hilfsmitteln physikalisch analysieren. Ein Wurf kann dabei in drei Phasen zerlegt werden: Brechen des Gleichgewichts, Niederwurf und Fallen. Videoanalyse und physikalische Analyse zeigen, dass sich die Philosophie des Judobegründers Kano “eines möglichst wirkungsvollen Gebrauchs von geistiger und körperlicher Energie” in der Tat in den Trajektorien der Bewegung wiederfindet. Eine Analyse des Kraftstoßes beim Fallen zeigt, dass das Abschlagen physikalisch sinnvoll ist. Die auf den Oberkörper wirkende Kraft, und damit die Verletzungsgefahr, wird verringert. Mit ähnlich geringem technischen Aufwand sollten sich auch aussagekräftige Ergebnisse zu anderen Sportarten wie Hochsprung oder Turnen erzielen lassen.
Aber bitte mit Sahne
Authors: Vilgis Thomas 
Published: March 2012

AbstractSchlichte Schlagsahne ist ein kleines physikalisches Wunder, lassen sich aus ihr luftige und dennoch feste Schäume schlagen. Geschlagene Sahne ist ein stabiles Gebilde aus Luftbläschen, festen, teilkristallinen Fettpartikeln und Proteinen. In ihr treffen alle drei Aggregatzustände aufeinander.
Ein Michelson‐Interferometer in der Schule
Authors: Hütz Benjamin , Wallkötter Sebastian , Heizenreder Martin 
Published: March 2012

AbstractIm Rahmen eines Physikprojekts haben wir am Hohenstaufen‐Gymnasium in Kaiserslautern mit geringem Kostenaufwand ein Michelson‐Interferometer gebaut. Der Einsatz in Schulversuchen eröffnet den Zugang zu einem vertieften Verständnis von Licht und dessen Eigenschaften.