bluuebunny/crossref_metadata_2025 huggingface dataset:
Phase 2 trial of mifepristone (RU‐486) in advanced or recurrent endometrioid adenocarcinoma or low‐grade endometrial stromal sarcoma
Authors: Ramondetta Lois M. , Johnson Alaina J. , Sun Charlotte C. , Atkinson Neely , Smith Judith A. , Jung Maria S. , Broaddus Russel , Iyer Revathy B. , Burke Thomas
Published: February 2009

BACKGROUND:

The objective of this study was to determine the efficacy of mifepristone (RU‐486) in women with advanced or recurrent endometrioid adenocarcinoma or low‐grade endometrial stromal sarcoma (LGESS).

METHODS:

Mifepristone (RU‐486; 200 mg orally) was given daily to patients with progesterone receptor‐positive advanced or recurrent endometrioid adenocarcinoma or LGESS. Patients were evaluated every 4 weeks for toxicity and response. Quality‐of‐life data were obtained using the Memorial Symptom Assessment Scale and Functional Assessment for Cancer Therapy.

RESULTS:

Twelve of 13 enrolled patients were evaluable in the first phase of accrual. Stable disease was noted in 3 of 12 patients (at 8 weeks, 12 weeks, and ≥77 weeks, respectively), and the median time to disease progression was 48 days. Among the patients who had stable disease, 2 women had endometrioid endometrial cancer, and 1 woman had LGESS. No partial or complete responses were observed. The most frequent grade 1 and 2 toxicities were anorexia, fatigue, and mood alterations observed in 50%, 50%, and 58% of patients, respectively. The most common grade 3 toxicities were fatigue and dyspnea observed in 25% and 17% of patients, respectively. One patient experienced grade 4 dyspnea. Thirty‐three percent of patients had asymptomatic elevations of corticotropin. No serious treatment‐related adverse events occurred. There were no significant changes in quality of life.

CONCLUSIONS:

Single‐agent mifepristone used in the treatment of recurrent endometrioid adenocarcinoma or LGESS resulted in a stable disease rate of 25%. One patient who had a biopsy‐positive disease recurrence remained stable at 77 weeks. Although mifepristone was tolerated well, as a single agent, it provided limited response as a single agent in women with progesterone receptor‐positive uterine tumors. Recently, was been recognized that biologic agents used as single agents may result only in stable disease unless they are combined with cytotoxic agents. The authors concluded that further research into the best mode of application for mifepristone in the treatment of endometrial cancer is needed. Cancer 2009. © 2009 American Cancer Society.
The Quest for Cold and Ultracold Molecules
Authors: Chandler David W. , Strecker Kevin E.
Published: February 2009

Cool molecules: The cooling of molecules to sub‐Kelvin temperatures promises to have a great impact in chemistry and physics. Recently, the first experimental realizations of samples of deeply bound molecules that are approaching the ultracold regime were reported. In this contribution, these interesting results are briefly discussed.
Cdx1::Cre allele for gene analysis in the extraembryonic ectoderm and the three germ layers of mice at mid‐gastrulation
Authors: Hierholzer Andreas , Kemler Rolf
Published: February 2009

Transgenic mice with a defined cell‐ or tissues‐specific expression of Cre‐recombinase are essential tools to study gene function. Here we report the generation and analysis of a transgenic mouse line (Cdx1::Cre) with restricted Cre‐expression from Cdx1 regulatory elements. The expression of Cre‐recombinase mimicked the endogenous expression pattern of Cdx1 at midgastrulation (from E7.5 to early headfold stage) inducing recombination in the three germlayers of the primitive streak region throughout the posterior embryo and caudal to the heart. This enables gene modifications to investigate patterning of the caudal embryo during and after gastrulation. Interestingly, we identified Cdx1 expression in the trophectoderm (TE) of blastocyst stage embryos. Concordantly, we detected extensive Cre‐mediated recombination in the polar TE and, although to lesser extent, in the mural TE. In E7.5 postimplantation embryos, almost all cells of the extraembryonic ectoderm (ExE), which are derived from the polar TE, are recombined although the ExE itself is negative for Cdx1 and Cre at this stage. These results indicate that Cdx1::Cre mice are also a valuable tool to study gene function in tissues essential for placental development. genesis 47:204–209, 2009. © 2009 Wiley‐Liss, Inc.
Tet system in the brain: Transgenic rats and lentiviral vectors approach
Authors: Konopka Witold , Duniec Kamila , Klejman Agata , Wawrzyniak Marcin , Owczarek Dorota , Gawrys Ludwika , Maleszewski Marek , Mallet Jacques , Kaczmarek Leszek
Published: February 2009

Local and regulated expression of exogenous genes in the central nervous system is one of the major challenges of modern neuroscience. We have approached this issue by applying the inducible tetracycline system to regulate the expression of EGFP reporter gene in double transgenic rats. We have obtained a strong induction of EGFP only in male testes, which correlated with a high level of rtTA expression only in this organ. To overcome the problem of lack of rtTA protein in the transgenic rat brain, we have delivered this Tet system activator with lentiviral vectors into the dentate gyrus of hippocampus of transgenic EGFP rats. As a result, after systemic application of doxycycline we have obtained inducible, stable and restricted to the desired brain region expression of EGFP. An advantage of this strategy is that the transgene is located in the same genetic milieu in every cell of the transgenic organism. This is crucial to obtain uniform expression of the regulated gene within the target brain structure. Combination of rat transgenesis and lentiviral vectors is a novel approach enabling precise spatiotemporal regulation of genes of interest strictly in the brain structure of choice or in other tissues. genesis 47:274–280, 2009. © 2009 Wiley‐Liss, Inc.
‘Quantifying the effects of forest canopy cover on net snow accumulation at a continental, mid‐latitude site’
Authors: Veatch W. , Brooks P. D. , Gustafson J. R. , Molotch N. P.
Published: February 2009

Although many studies have investigated the effects of forest cover on streamflow and runoff, and several have examined the effects of canopy density on snowpack accumulation, the impacts of forest canopy density on spatial patterns of snowmelt input to catchments remain relatively underquantified. We performed an intensive snow depth and density survey during maximum accumulation in a mid‐latitude montane environment in northern New Mexico, taking 900 snow depth measurements and excavating six snow pits across a continuum of canopy densities. Snow water equivalent (SWE) data are correlated with forest canopy density (R2 = 0·21, p < 0·0001), with maximum snow accumulation in forests with density between 25 and 40%. Forest edges are shown to be highly influential on patterns of snow depth, with unforested areas shaded by forest to their immediate south holding approximately 25% deeper snow than either large open areas or densely forested areas. This indicates that the combination of canopy influences on throughfall and snowpack shading are key processes underlying snow distribution in the high solar load environments typical of mountainous, mid‐latitude areas. We further show that statistical models of snow distribution are improved with the addition of remotely sensed forest canopy information (R2 increased in 10 of 11 cases, deviance lowered in 9 of 11 cases), making these findings broadly relevant for improving estimation of water resources, predicting the ecohydrological implications of vegetation and climate change, and informing integrated forest and water resources management. Copyright © 2009 John Wiley & Sons, Ltd.
Metal‐Catalyzed Olefin Cyclopropanation with Ethyl Diazoacetate: Control of the Diastereoselectivity
Authors: Caballero Ana , Prieto Auxiliadora , Díaz‐Requejo M. Mar , Pérez Pedro J.
Published: February 2009

The control of the cis/trans diastereoselectivity by catalyst design in the olefin cyclopropanation reaction with ethyl diazoacetate is reviewed. Catalysts based on ruthenium, copper, rhodium, iron, osmium and cobalt are discussed. The degree of stereocontrol achieved for styrene and related aryl‐containing olefins is higher than that for terminal alkenes with no aryl substituents.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Dual‐plastic hinge design concept for reducing higher‐mode effects on high‐rise cantilever wall buildings
Authors: Panagiotou Marios , Restrepo José I.
Published: February 2009

This paper explores the notion of detailing reinforced concrete structural walls to develop base and mid‐height plastic hinges to better control the seismic response of tall cantilever wall buildings to strong shaking. This concept, termed here dual‐plastic hinge (DPH) concept, is used to reduce the effects of higher modes of response in high‐rise buildings. Higher modes can significantly increase the flexural demands in tall cantilever wall buildings. Lumped‐mass Euler–Bernoulli cantilevers are used to model the case‐study buildings examined in this paper. Buildings with 10, 20 and 40 stories are designed according to three different approaches: ACI‐318, Eurocode 8 and the proposed DPH concept. The buildings are designed and subjected to three‐specific historical strong near‐fault ground motions. The investigation clearly shows the dual‐hinge design concept is effective at reducing the effects of the second mode of response. An advantage of the concept is that, when combined with capacity design, it can result in relaxation of special reinforcing detailing in large portions of the walls. Copyright © 2009 John Wiley & Sons, Ltd.
Exact analysis of different detector algorithms for NDA carrier phase recovery of 16/32‐APSK signals
Authors: Gappmair Wilfried , Cioni Stefano , Vanelli‐Coralli Alessandro , Koudelka Otto
Published: February 2009

In the new digital video broadcasting standard for satellite communications (DVB‐S2), 16‐ and 32‐ary amplitude‐phase shift keying (APSK) are recommended as complementary modulation schemes to 4‐PSK and 8‐PSK. For carrier phase recovery with feedback loops, decision‐directed (DD) and non‐data‐aided (NDA) detector algorithms are basically applicable. In some recent papers, however, a hybrid NDA/DD solution has been suggested for this purpose, although not analysed in detail. Motivated by this observation, the hybrid algorithms are investigated in this paper in terms of detector characteristic (S‐curve) and jitter variance as the main figures of merit in this respect, with an additional design parameter introduced for optimisation. For comparison reasons, results for power‐law and monomial‐based Viterbi and Viterbi (V & V) trackers, as classical NDA solutions, are derived as well. Copyright © 2009 John Wiley & Sons, Ltd.
North Atlantic Oscillation influences on Turkish lake levels
Authors: Küçük Murat , Kahya Ercan , Cengiz Taner M. , Karaca Mehmet
Published: February 2009

The North Atlantic Oscillation (NAO) is a large‐scale mode of natural climate variability governing the path of Atlantic mid‐latitude storm tracks and precipitation regimes in the Atlantic and Mediterranean sectors. The primary focus of this study is to investigate the variability of lake levels in seven lakes scattered across Turkey using the method of continuous wavelet transforms and global spectra. The long winter (December, January, February and March) lake‐level series and the NAO index (NAOI) series were subjected to wavelet transform. The global wavelet spectrum (energy spectrum of periodicities) of lake levels and winter NAOI anomalies, in most cases, revealed a significant correlation. It was shown that the Tuz, Sapanca, and Uluabat lakes reflect much stronger influences of the NAO than the other four lakes. In contrast, weak correlations were found in the coastal areas of the Mediterranean and eastern Turkey. The periodic structures of Turkish lake levels in relation to the NAO revealed a spectrum between the 1‐year and 10‐year scale level. Although the periodicities of more than 10‐year scale levels were detected, explaining significant relations between the NAO and these long‐term periodicities remains a challenging task. The results of this study are consistent with the earlier studies concerning the teleconnection between the NAO and climate variables in Turkey. Copyright © 2009 John Wiley & Sons, Ltd.
Comments on ‘Jointness of growth determinants’
Authors: Ley Eduardo , Steel Mark F. J.
Published: February 2009

We consider the measures of jointness proposed by Doppelhofer and Weeks (2009) and Strachan (2009) in the context of variable selection. Using the general criteria suggested in Ley and Steel (2007), we identify some shortcomings of these measures, which are illustrated with empirically relevant example cases. We argue that careful examination of the properties of any jointness measure is critical before using it to inform decisions, and favour the use of the measures proposed in Ley and Steel (2007). Copyright © 2009 John Wiley & Sons, Ltd.
OECD validation of phase 3 Hershberger assay in Korea using surgically castrated male rats with coded chemicals
Authors: Moon Hyun‐Ju , Kang Tae Seok , Kim Tae Sung , Kang Il Hyun , Ki Ho Youn , Kim Seung Hee , Han Soon Young
Published: February 2009

As a participating laboratory for the OECD Hershberger validation program, we conducted a phase 3 trial to test the reliability of the Hershberger assay using coded substances. Male Sprague–Dawley rats were castrated at 6 weeks of age and allowed to recover for 8 days. All the coded substances were administered orally once daily for 10 consecutive days. In the antagonist version of the assay, 0.4 mg kg−1 of testosterone propionate (TP), a reference androgen, was co‐administered with the coded compounds C, D, H, I or K, by a subcutaneous injection. As anticipated, TP alone produced statistically significant increases in the five mandatory accessory sex organ weights. The coded substance L (trenbolone 40 mg kg−1), the test agonist, caused significant increases in the weights of the androgen‐dependent tissues. The five coded compounds, p,p′‐DDE at two doses (codes C and I), linuron at two doses (codes D and K) and flutamide (code H), all significantly decreased the weights of the TP‐stimulated sex organs. These results suggest the OECD Hershberger assay to be a reliable screening method for detecting androgen agonists and antagonists. Copyright © 2009 John Wiley & Sons, Ltd.
PI3K Acts in synergy with loss of PKC to elicit apoptosis via the UPR
Authors: Guo Jinjin , Zhu Tongbo , Luo Ling‐Yu , Huang Yi , Sunkavalli Raja G. , Chen Chang Yan
Published: February 2009

It is known that Ras mutations, together with loss of PKC, are apoptotic in various types of mammalian cells. The mechanism of how aberrant Ras transmits this apoptotic signaling remains unclear. Using three V12‐Ha‐ras loop mutants that preferentially bind to and activate one of Ras effectors, we tested the role of Ras downstream pathways in the induction of apoptosis in rat lung epithelia, human lung or prostate cancer cells. After PKC inhibition, the activation of PI3K/Akt renders the susceptibility of cells to apoptosis. We also demonstrate that the amount of ROS is moderately increased in the cells ectopically expressing V12C40 and dramatically elevated by suppression of PKC, which leads to apoptosis through the activation of UPR. Thus, our study suggests that after PKC abrogation, PI3K functions downstream of Ras to perturb the state of cellular redox and signals to ER stress‐regulated apoptotic machinery. J. Cell. Biochem. 107: 76–85, 2009. © 2009 Wiley‐Liss, Inc.
Evodiamine and rutaecarpine inhibit migration by LIGHT via suppression of NADPH oxidase activation
Authors: Heo Sook‐Kyoung , Yun Hyun‐Jeong , Yi Hyo‐Seung , Noh Eui‐Kyu , Park Sun‐Dong
Published: February 2009

LIGHT acted as a new player in the atherogenesis. The dried, unripe fruit of Evodia Fructus (EF) has long been used as a traditional Chinese herbal medicine, and is currently widely used for the treatment of headache, abdominal pain, vomiting, colds and reduced blood circulation. Evodiamine and rutaecarpine are active components of EF. In this study, we investigated the inhibitory effect of evodiamine and rutaecarpine on LIGHT‐induced migration in human monocytes. Evodiamine and rutaecarpine decreased the LIGHT‐induced production of ROS, IL‐8, monocyte chemoattractant protein‐1 (MCP‐1), TNF‐α, and IL‐6, as well as the expression of chemokine receptor (CCR) 1, CCR2 and ICAM‐1 and the phosphorylation of the ERK 1/2 and p38 MAPK. Furthermore, NADPH oxidase assembly inhibitor, AEBSF, blocked LIGHT‐induced migration and activation of CCR1, CCR2, ICAM‐1, and MAPK such as ERK and p38 in a manner similar to evodiamine and rutaecarpine. These findings indicate that the inhibitory effects of evodiamine and rutaecarpine on LIGHT‐induced migration and the activation of CCR1, CCR2, ICAM‐1, ERK, and p38 MAPK occurs via decreased ROS production and NADPH oxidase activation. Taken together, these results indicate that evodiamine and rutaecarpine have the potential for use as an anti‐atherosclerosis agent. J. Cell. Biochem. 107: 123–133, 2009. © 2009 Wiley‐Liss, Inc.
Evaluation of different scan methods for the urinary detection of corticosteroid metabolites by liquid chromatography tandem mass spectrometry
Authors: Pozo Oscar J. , Ventura Rosa , Monfort Núria , Segura Jordi , Delbeke Frans T.
Published: February 2009

Different approaches for the non‐target detection of corticosteroids in urine have been evaluated. As a result of previous studies about the ionization (positive/negative) and fragmentation of corticosteroids, several methods based on both precursor ion (PI) and neutral loss (NL) scans are proposed. The applicability of these methods was checked by the injection of a standard solution containing 19 model compounds. Five of the studied methods (NL of 76 Da; PI of 77, 91 and 105; PI of 237; PI of 121, 147 and 171; and NL of 38 Da) exhibited satisfactory results at the concentration level checked (corresponding to 20 ng/ml in sample). Some other methods in negative ionization mode such as the NL of 104 Da were found to lack sufficient sensitivity. Some of the applied methods were found to be specific for a concrete structure (NL of 38 Da for fluorine containing corticosteroids) while others showed a wide range applicability (PI of 77, 91 and 105 showed response in all model compounds). Interference by endogenous compounds was also tested by the analysis of negative urines and urines spiked with different corticosteroids. The suitability of these methods for the detection of corticosteroid metabolites was checked by the analysis of urine samples collected after the administration of methylprednisolone and triamcinolone. A combination of the reported methods seems to be the approach of choice in order to have a global overview about the excreted corticosteroid metabolites. Copyright © 2009 John Wiley & Sons, Ltd.
Dynamics and mechanism of the Crystal II → smecticG phase transition in TB7A by a temperature‐dependent micro‐Raman study and DFT calculations
Authors: Vikram K. , Srivastava Sunil K. , Ojha Animesh K. , Schlücker S. , Kiefer W. , Singh Ranjan K.
Published: February 2009

The solid to smecticG (SmG) phase transition in a Schiff base liquid crystalline compound, terepthal‐bis‐heptylaniline (TB7A), is monitored in situ by temperature‐dependent Raman microspectroscopy, using the band of a CH in‐plane bending mode as a marker. Contrary to the earlier report of a sudden wavenumber shift, the in situ measurement shows very clearly that a new Raman band at ∼1160 cm−1 appears at the Crystal II → SmG transition. The dynamics of this phase transition is discussed in terms of a triple well potential below 210 K and a double well potential above 210 K. The phase transition essentially takes place as a result of intra‐molecular rotation about the long molecular axis. The optimization energy at various fixed dihedral angles, (CCCN) are calculated using density functional theory (DFT) at the B3LYP/6‐31G* level of theory. The relative energy at each dihedral angle is calculated relative to optimization energy obtained without any constraints and plotted as a function of dihedral angle (Φ) between the adjacent phenyl ring planes, which also shows a double well potential at room temperature. Copyright © 2009 John Wiley & Sons, Ltd.
Has the experience economy arrived? The views of destination managers in three visitor‐dependent areas
Authors: Morgan Michael , Elbe Jörgen , de Esteban Curiel Javier
Published: February 2009

This paper explores the concept of the experience economy as a basis for management and marketing strategies in tourism destination regions. It identifies the key elements of the concept as being a view of consumer behaviour which stress the emotional, aspirational and participative over the functional and rational; an approach to services management through theatrical metaphors of staging, casting and performance; and strategies which see the delivery, or co‐creation, of unique and memorable experiences as a source of competitive advantage. It investigates the extent to which these have been accepted and acted upon by destination managers, using case studies from three contrasting visitor‐dependent economies. Copyright © 2009 John Wiley & Sons, Ltd.
The comfort of strangers: tourists in the Australian Outback
Authors: White Naomi Rosh , White Peter B.
Published: February 2009

Interviews with tourists in the remote regions of Outback Australia reveal that interactions with others are integral to their experience as tourists and an important mechanism for dealing with their occupation of a landscape whose mythical status in the Australian imagination renders it simultaneously culturally familiar and alien. The role, significance and characteristics of relationships forged with people encountered while travelling in this environment were examined. Because of the rigours of the travel in this setting, tourists were found to be keen to be in the company of others. Their relationships and interactions were bounded, free of the obligation of ongoing attachment and consisting, for the most part, of ritualised interchanges. Interactions between tourists enriched their understanding of this ambivalently perceived cultural and physical environment, offering comfort and companionship. Copyright © 2009 John Wiley & Sons, Ltd.
Comparison of health insurance claims and patient interviews in assessing drug use: data from the Three‐City (3C) Study
Authors: Noize Pernelle , Bazin Fabienne , Dufouil Carole , Lechevallier‐Michel Nathalie , Ancelin Marie‐Laure , Dartigues Jean‐François , Tzourio Christophe , Moore Nicholas , Fourrier‐Réglat Annie
Published: February 2009

Purpose

Precise determination of drug exposure is fundamental in pharmacoepidemiology. Drug exposure is often presumed from health insurance claims but this may not correspond exactly to what subjects actually take. This study was designed to investigate French reimbursement databases in assessing drug use.

Methods

Between 1999 and 2001, 9294 subjects were included in the Three‐City (3C) Study, a French cohort studying the relationship between vascular risk factors and dementia. Of these, 4112 subjects had data available from both clinical interviews and the reimbursement databases of the French national health insurance system. Agreement between drugs reported as used at interview and drugs reimbursed during the previous 30 or 60 days was measured with κ coefficients. Using calculations of sensitivity (Se), specificity (Sp), positive predictive values (PPVs) and negative predictive values (NPVs), the validity of reimbursement data for the 30 or 60 days preceding the interview was investigated taking drugs reported at interview as the ‘gold standard’.

Results

Declared drug use at interview was less well predicted by 30‐day than by 60‐day reimbursement data. Agreement between reimbursement data and interviews as well as validity of reimbursement data with reference to interviews were substantial for drugs used in cardiovascular diseases, diabetes, rheumatic disorders or neuropsychiatric conditions and were poor for laxatives, vitamins, vasculoprotectives, first and second line analgesics, anti‐infective products or dermatologicals.

Conclusions

Reimbursement data with an appropriate time frame and interviews estimate exposure to chronically used drugs similarly. Self‐medication was better described with interviews whereas reimbursement data seem more useful for drugs used topically or intermittently. Copyright © 2009 John Wiley & Sons, Ltd.
Risk of cataract among idiopathic thrombocytopenic purpura patients in the UK general practice research database
Authors: Feudjo‐Tepie Maurille A. , Hall Susan A. , Logie John , Robinson Noah J.
Published: February 2009

Purpose

To estimate the incidence of cataracts in an adult idiopathic thrombocytopenic purpura (ITP) and in a comparable non‐ITP population, stratified by age, gender and medication use in order to determine whether the risk of cataracts is greater in ITP patients.

Methods

Retrospective cohort of 745 newly diagnosed ITP patients and 3725 non‐ITP subjects who were 18 years of age or older. The study population included patients registered on the General Practice Research Database (GPRD) during the period 1992–2005. ITP patients, identified using Read/Oxmis codes, were matched to five non‐ITP patients. The exposure of interest was oral systemic steroid use and the primary outcome was cataracts.

Results

The overall incidence rate of cataracts in males was 11.8 per 1000 PY (95%CI: 6.3–20.2) and in females 9.0 per 1000 PY (95%CI: 5.2–14.4). In the non‐ITP population these rates were 14.0 per 1000 PY (95%CI: 11.0–17.4) and 8.1 per 1000 PY (95%CI: 6.4–10.1), respectively. In the ITP population, users of oral steroids (OS) had a cataract incidence rate of 14.0 per 1000 PY (95%CI: 8.7–21.4) and non‐users 6.0 per 1000 PY (95%CI: 2.8–11.4). In the non‐ITP population, these rates were 16.9 per 1000 PY (95%CI: 11.9–23.3) and 9.2 per 1000 PY (95%CI: 7.6–11.0), respectively. OS were associated with an increased risk for cataracts.

Conclusions

The rates of cataract in an adult ITP population are comparable to that in a non‐ITP population. Copyright © 2009 John Wiley & Sons, Ltd.
Die dunkle Seite des Kosmos. Dunkle Materie
Authors: Bartelmann Matthias
Published: February 2009

Auf die Existenz von Dunkler Materie wurden Astronomen aufmerksam, weil ohne sie die Geschwindigkeiten der Sterne in Galaxien und die der Galaxien in Galaxienhaufen viel zu hoch wären, als dass diese Objekte stabil bleiben könnten. Der Gravitationslinseneffekt erlaubt es, dass wir unsichtbare Materie und deren räumliche Verteilung indirekt kartieren können. Wäre die Dunkle Materie ebenso baryonisch wie die, aus der wir bestehen, hätten die Temperaturschwankungen im kosmischen Mikrowellenhintergrund eine Amplitude im Millistatt im Mikrokelvin‐Bereich. Die Häufigkeiten leichter Elemente im Universum zeigen, dass die Baryonendichte nur etwa 4 % der kritischen Dichte beitragen kann, während die Strukturen im Mikrowellenhintergrund auf eine Gesamtdichte der Materie von etwa 30 % schließen lassen. Aus diesen Befunden schließen wir, dass der dominierende Teil der Materie im Universum dunkel ist, nicht aus Baryonen besteht und vermutlich nur schwach wechselwirkt, jedenfalls aber nicht elektromagnetisch.
Neutronenhalos in neuem Licht. Kernphysik mit exotischen Isotopen
Authors: Nörtershäuser Wilfried , Müller Peter
Published: February 2009

Laserspektroskopie an den neutronenreichen kurzlebigen Isotopen von Helium und Lithium erlaubt detaillierte Aussagen zur Kernstruktur von exotischen Halokernen. Mit speziell entwickelten Methoden, die eine hohe Präzision in der Bestimmung der atomaren Übergangsfrequenzen mit einer sehr hohen Empfindlichkeit verbinden, ließen sich die Ladungsradien der Atomkerne von He‐6, He‐8 und Li‐11 erstmalig bestimmen. Aus diesen Daten können die mittleren Entfernungen der Haloneutronen vom Rumpfkern extrahiert werden.
Schwarze Löcher im Labor. Künstliche Ereignishorizonte und Quantenphysik
Authors: Leonhardt Ulf
Published: February 2009

Der Raum um ein Schwarzes Loch verhält sich wie eine strömende Flüssigkeit, die im Strudel der Singularität verschwindet. Wo die Fließgeschwindigkeit die Lichtgeschwindigkeit übersteigt, kann nichts mehr dem Schwarzen Loch entweichen. Die Fläche, auf der die Lichtgeschwindigkeit erreicht wird, ist der Ereignishorizont. Ereignishorizonte lassen sich künstlich erzeugen: Für Wasserwellen entstehen sie, wenn fließendes Wasser die Wellengeschwindigkeit übersteigt; für Licht, wenn ein Lichtpuls sich schneller bewegt als die Lichtgeschwindigkeit im Material. Wir haben ungewöhnliche physikalische Effekte an Wasserhorizonten beobachtet und optische Horizonte in Glasfasern erzeugt und untersucht. Das Ziel ist, die Quantenphysik von Ereignishorizonten im Labor zu studieren.
Achterbahn fahren im Physikunterricht. Physikdidaktik
Authors: Heintz Verena , Martensson Pendrill Ann‐Marie , Schmitt Annette , Wendt Klaus
Published: February 2009

Das Messen von Beschleunigungen und Höhen während einer Achterbahnfahrt bietet die Möglichkeit, den Physikunterricht anwendungsbezogen zu gestalten. Dieser Ansatz erlaubt einen erlebnisorientierten Zugang speziell im Bereich der oftmals als langweilig empfundenen Mechanik. Das Beispiel der Achterbahn Kanonen in Göteborg demonstriert die vielen Möglichkeiten der Datenauswertung. Außerdem generiert das eigenständige Experimentieren mit einem modernen Messsystem und die Datenauswertung mit Analyse am Computer einen zusätzlichen Lerneffekt.
Das Zentrum der Milchstraße
Authors: Gillessen Stefan
Published: February 2009

Es gilt heute als unbestritten, dass sich im Zentrum der Milchstraße ein superschweres Schwarzes Loch befindet. Rund 17 Jahre decken die Beobachtungen von Astronomen des Max‐Planck‐Instituts für extraterrestrische Physik (MPE) in Garching an diesem Objekt inzwischen ab. Diese Kontinuität erlaubt es, das galaktische Zentrum als astronomisches Präzisionslabor zu verwenden. So lässt sich die Entfernung zum Milchstraßenzentrum mit unerreichter Genauigkeit bestimmen oder das Leben der Sterne nahe am Schwarzen Loch untersuchen.
Modeling excitation properties of iridium complexes
Authors: Świderek Katarzyna , Paneth Piotr
Published: February 2009

Five iridium Ir(III) complexes have been studied using B3P86, B3LYP, M05, M06, M05‐2X, and M06‐2X functionals within configuration interaction singles (CIS) and time dependent density functional theory (TDDFT) formalisms with the aim of finding theory level that would allow for reliable prediction of emission properties. Knowledge of these properties prior to synthesis may significantly facilitate rational design of organic light‐emitting diodes (OLEDs). Our results indicate that the M05‐2X functional gives excellent results in this respect for the class of complexes studied here with the exception of the (bsn)2Ir(acac) complex. We have shown that the discrepancy between the theoretical and experimental values for this complex is due to the presence of the sulfur atom. Copyright © 2009 John Wiley & Sons, Ltd.
Chiral polymers for resolution of enantiomers
Authors: Okamoto Yoshio
Published: February 2009

In 1979, the formation of one‐handed helical poly(triphenylmethyl methacrylate) (PTrMA) was found through the helix‐sense‐selective polymerization of methacrylate using chiral anionic initiators, and the existence of a stable helical polymer without chiral side chains was proved. The chiral polymer exhibited unexpected high chiral recognition of various racemic compounds when used as the chiral packing material (CPM) for HPLC, which was commercialized in 1982 as the first chiral column based on an optically active polymer. This success encouraged us to develop further useful commercial chiral packing materials (CPMs) based on polysaccharides, cellulose, and amylose. By using these polysaccharide‐based CPMs, particularly phenylcarbamate derivatives, nearly 90% of chiral compounds can be resolved not only analytically but also preparatively, and several chiral drugs have been produced using the CPMs. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1731–1739, 2009
Synthesis and characterization of novel electroactive polyamides and polyimides with bulky 4‐(1‐adamantoxy)triphenylamine moieties
Authors: Kung Yi‐Chun , Liou Guey‐Sheng , Hsiao Sheng‐Huei
Published: February 2009

A novel adamantoxytriphenylamine‐containing diamine monomer, 4‐(1‐adamantoxy)‐4′,4″‐diaminotriphenylamine, was synthesized from readily available reagents. Two series of novel electroactive aromatic polyamides and polyimides with bulky 4‐(1‐adamantoxy)triphenylamine moieties were prepared from the newly synthesized diamine monomer with various aromatic dicarboxylic acids and tetracarboxylic dianhydrides, respectively. All the resulting polyamides and most of the polyimides were readily soluble in polar organic solvents and could be solution cast into tough and flexible films. These polymers showed moderate to high glass transition temperatures in the range of 263–311 °C, and they were fairly stable up to a temperature above 480 °C (for polyamides) or 500 °C (for polyimides). Cyclic voltammograms of the polyamides and polyimides showed one pair of reversible redox waves with oxidation half‐wave potentials (E1/2) in the range of 0.78–0.81 and 0.97–1.05 V, respectively, versus Ag/AgCl in an acetonitrile solution. In addition, the polymers were found to display stable electrochromic properties by repeated cyclic scans between 0.0 and 1.1–1.2 V, with coloration change from a colorless or pale yellowish neutral form to a dark blue or bluish green oxidized form. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1740–1755, 2009
Highly soluble fluorinated polyimides based on an asymmetric bis(ether amine): 1,7‐bis(4‐amino‐2‐trifluoromethylphenoxy)naphthalene
Authors: Chung Cheng‐Lin , Lee Wen‐Fu , Lin Chun‐Hung , Hsiao Sheng‐Huei
Published: February 2009

A novel structurally asymmetric bis(ether amine) monomer containing trifluoromethyl groups, 1,7‐bis(4‐amino‐2‐trifluoromethylphenoxy)naphthalene, was prepared through the nucleophilic substitution reaction of 2‐chloro‐5‐nitrobenzotrifluoride and 1,7‐dihydroxynaphthalene in the presence of potassium carbonate in N‐methyl‐2‐pyrrolidone (NMP), followed by catalytic reduction with hydrazine and Pd/C in ethanol. A series of new fluorine‐containing polyimides were synthesized from the diamine with various commercially available aromatic tetracarboxylic dianhydrides using a two‐stage process with thermal or chemical imidization method. The intermediate poly(amic acid)s had inherent viscosities between 0.93 and 1.93 dL/g. Most of the polyimides obtained from both routes were readily soluble in many organic solvents such as NMP and N,N‐dimethylacetamide (DMAc). All the polyimides could afford transparent, flexible, and strong films with low moisture absorptions of 0.29–0.69%, low dielectric constants of 2.81–3.23 at 10 kHz, and an ultraviolet‐visible absorption cutoff wavelength at 358–423 nm. The glass‐transition temperatures (Tgs) (by DSC) and softening temperatures (by thermomechanical analysis) of the polyimides were recorded in the range of 222–271 °C and 210–266 °C, respectively. Decomposition temperatures for 10% weight loss all occurred above 500 °C in both nitrogen and air atmospheres. For a comparative study, some properties of the present polyimides will be compared with those of structurally related ones derived from 1,7‐bis(4‐aminophenoxy)naphthalene and 1,5‐bis(4‐amino‐2‐trifluoromethylphenoxy)naphthalene. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1756–1770, 2009
AGET ATRP in water and inverse miniemulsion: A facile route for preparation of high‐molecular‐weight biocompatible brush‐like polymers
Authors: Oh Jung Kwon , Perineau Fabien , Charleux Bernadette , Matyjaszewski Krzysztof
Published: February 2009

Activators generated by electron transfer for atom transfer radical polymerization (AGET ATRP) of oligo(ethylene glycol) monomethyl ether methacrylate (OEOMA) was investigated in homogeneous aqueous solution targeting DP = 1000, and in inverse miniemulsion targeting DP = 600, at 30 °C. Several reaction parameters were examined in the preparation of biocompatible, brush‐like, high‐molecular‐weight, water‐soluble polymers. They include concentration of ascorbic acid (AscA), ratio of water to OEOMA, mode of addition of AscA, and ratio of initiator to Cu(II) complex. The results obtained in these studies indicate that AGET ATRP retains all of the benefits of normal ATRP and, additionally, provides a facile route for the preparation of well‐controlled high‐molecular‐weight polymers because of the use of oxidatively stable catalyst precursors. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1771–1781, 2009
Synthesis and characterization of pH sensitive poly(glycidol)‐b‐poly(4‐vinylpyridine) block copolymers
Authors: Mendrek Sebastian , Mendrek Aleksandra , Adler Hans‐Juergen , Dworak Andrzej , Kuckling Dirk
Published: February 2009

Block copolymers of poly(glycidol)‐b‐poly(4‐vinylpyridine) were obtained by ATRP of 4‐vinylpyridine initiated by ω‐(2‐chloropropionyl) poly(glycidol) macroinitiators. By changing the monomer/macroinitiator ratio in the synthesis polymers with varied P4VP/PGl molar ratio were obtained. The obtained block copolymers showed pH sensitive solubility. It was found that the linkage of a hydrophilic poly(glycidol) block to a P4VP influenced the pKa value of P4VP. DLS measurements showed the formation of fully collapsed aggregates exceeding pH 4.7. Above this pH values the collapsed P4VP core of the aggregates was stabilized by a surrounding hydrophilic poly(glycidol) corona. The size of the aggregates depended significantly upon the composition of the block copolymers. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1782–1794, 2009
PNIPAM‐b‐(PEA‐g‐PDMAEA) double‐hydrophilic graft copolymer: Synthesis and its application for preparation of gold nanoparticles in aqueous media
Authors: Feng Chun , Shen Zhong , Li Yongjun , Gu Lina , Zhang Yaqin , Lu Guolin , Huang Xiaoyu
Published: February 2009

A series of well‐defined double‐hydrophilic graft copolymers, consisting of poly(N‐isopropylacrylamide)‐b‐poly(ethyl acrylate) (PNIPAM‐b‐PEA) backbone and poly(2‐(dimethylamino)ethyl acrylate) (PDMAEA) side chains, were synthesized by the combination of single‐electron‐transfer living radical polymerization (SET‐LRP) and atom‐transfer radical polymerization (ATRP). PNIPAM‐b‐PEA backbone was first prepared by sequential SET‐LRP of N‐isopropylacrylamide and 2‐hydroxyethyl acrylate at 25 °C using CuCl/tris(2‐(dimethylamino)ethyl)amine as catalytic system followed by the transformation into the macroinitiator by treating the pendant hydroxyls with 2‐chloropropionyl chloride. The final graft copolymers with narrow molecular weight distributions were synthesized by ATRP of 2‐(dimethylamino)ethyl acrylate initiated by the macroinitiator at 40 °C using CuCl/tris(2‐(dimethylamino)ethyl)amine as catalytic system via the grafting‐from strategy. These copolymers were employed to prepare stable colloidal gold nanoparticles with controlled size in aqueous solution without any external reducing agent. The morphology and size of the nanoparticles were affected by the length of PDMAEA side chains, pH value, and the feed ratio of the graft copolymer to HAuCl4. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1811–1824, 2009
Preparation and incorporation of microcapsules in functional coatings for self‐healing of packaging board
Authors: Andersson Caisa , Järnström Lars , Fogden Andrew , Mira Isabel , Voit Wolfgang , Zywicki Sebastian , Bartkowiak Artur
Published: February 2009

The replacement of flexible polyolefin barrier layers with novel, thin, functional polymer coatings in the production of paperboard packaging involves the risk of deteriorated barrier and mechanical properties during the converting process. Local defects or cracks in the protective barrier layer can arise because of the stress induced in creasing and folding operations. In this study, the incorporation of microencapsulated self‐healing agents in coating formulations applied both by spot‐ and uniform‐coating techniques was studied. The preparation process of microcapsules with a hydrophobic core surrounded by a hydrophobically modified polysaccharide membrane in aqueous suspension was developed to obtain capsules fulfilling both the criteria of small capsule size and reasonably high solids content to match the requirements set on surface treatment of paperboard for enhancement of packaging functionality. The survival of the microcapsules during application and their effectiveness as self‐healing agents were investigated. The results showed a reduced tendency for deteriorated barrier properties and local termination of cracks formed upon creasing. The self‐healing mechanism involves the rupture of microcapsules local to the applied stress, with subsequent release of the core material. Crack propagation is hindered by plasticization of the underlying coating layer, while the increased hydrophobicity helps to maintain the barrier properties. Copyright © 2009 John Wiley & Sons, Ltd.
Simplified batch equilibration for D/H determination of non‐exchangeable hydrogen in solid organic material
Authors: Sauer Peter E. , Schimmelmann Arndt , Sessions Alex L. , Topalov Katarina
Published: February 2009

Hydrogen isotopic analysis of organic materials has been widely applied in studies of paleoclimate, animal migration, forensics, food and flavor authentication, and the origin and diagenesis of organic matter. Hydrogen bound to carbon (C‐H) generally retains isotopic information about the water present during organic matter synthesis and associated biosynthetic fractionations, but hydrogen bound to other elements (O, S, or N) can readily exchange with atmospheric water vapor and reflects recent exposure to water or vapor. These two pools must be separated to obtain meaningful information from isotope ratios of organic materials. Previously published analytical methods either replace exchangeable H chemically or control its isotopic composition, usually by equilibration with water or waters of known isotopic composition. In addition, the fraction of H that is exchangeable can vary among samples and is itself of scientific interest. Here we report an improved and automated double‐equilibration approach.

Samples are loaded in a 50‐position autosampler carousel in an air‐tight aluminum equilibration chamber. Water vapor of known isotopic composition is pumped through the chamber at 115°C for at least 6 h. After flushing with dry N2 and being cooled, the carousel is rapidly transferred from the equilibration chamber to a He‐purged autosampler attached to a pyrolysis elemental analyzer connected to an isotope ratio mass spectrometer. By equilibrating two aliquots of each sample with two isotopically distinct waters, it is possible to calculate both (1) the D/H ratio of non‐exchangeable H, and (2) the fraction of H that is exchangeable. Relative to previous double‐equilibration techniques, this approach offers significant reductions in sample size and labor by allowing simultaneous equilibration of several tens of samples. Copyright © 2009 John Wiley & Sons, Ltd.
Simultaneous determination of morphine, codeine, 6‐acetylmorphine, cocaine and benzoylecgonine in hair by liquid chromatography/electrospray ionization tandem mass spectrometry
Authors: Huang Da‐Kong , Liu Chiareiy , Huang Min‐Kun , Chien Chun‐Sheng
Published: February 2009

A fast and sensitive liquid chromatography/triple quadrupole tandem mass spectrometry (LC/MS/MS) method was developed for the simultaneous determination of morphine, codeine, 6‐acetylmorphine (6‐AM), cocaine and benzoylecgonine (BE) in hair. Pulverized hair samples were extracted with methanol, and a 50 µL supernatant aliquot was injected into the LC/MS/MS system. Chromatography was performed with an XBridge™ phenyl column (3.5 µm particle size, 4.6 × 150 mm), and the mobile phase was composed of methanol and 10 mM ammonium acetate adjusted to pH 4.00 with 99% formic acid (95:5, v/v). A separation run with isocratic elution was completed in 10 min at a flow rate of 500 µL/min. Positive electrospray ionization and multiple reaction monitoring (MRM) with one precursor ion/product ion transition were used for the identification of each analyte. Deuterated analogues as internal standards were used for quantification and qualification. Linearity was established in the concentration range of 100–3000 pg/mg. The limits of detection were 10 pg/mg for morphine, codeine and 6‐AM; and 1 pg/mg for cocaine and BE. The precision and accuracy were determined by spiking hair samples at six concentration levels. For all analytes, the relative standard deviations of intra‐ and inter‐day precision were 0.1–6.3% and 1.5–10.6%, respectively. The accuracy ranged from 92.7 to 109.7%. The validated LC/MS/MS method was successfully applied to the analysis of 79 authentic hair samples. Copyright © 2009 John Wiley & Sons, Ltd.
Quantifying the behavioral response of spawning chum salmon to elevated discharges from Bonneville Dam, Columbia river, USA
Authors: Tiffan Kenneth F. , Haskell Craig A. , Kock Tobias J.
Published: February 2009

Chum salmon Oncorhynchus keta that spawn in main‐stem habitats below Bonneville Dam on the Columbia River, USA, are periodically subjected to elevated discharges that may alter spawning behaviour. We investigated behavioural responses of spawning chum salmon to increased water velocities associated with experimental increases in tailwater elevation using acoustic telemetry and a dual‐frequency identification sonar. Chum salmon primarily remained near their redds at base tailwater elevations (3.5 m above mean sea level), but displayed different movement and behavioural responses as elevations were increased to either 4.1 or 4.7 m for 8‐h periods. When velocities remained suitable (<0.8 m s−1) during elevated‐tailwater tests, female chum salmon remained near their redds but exhibited reduced digging activity as water velocities increased. However, when velocities exceeded 0.8 m s−1, the females that remained on their redds exhibited increased swimming activity and digging virtually ceased. Female and male chum salmon that left their redds when velocities became unsuitable moved mean distances ranging from 32 to 58 m to occupy suitable velocities, but returned to their redds after tailwaters returned to base levels. Spawning events (i.e. egg deposition) were observed for five of nine pairs of chum salmon following tests indicating any disruptions to normal behaviour caused by elevated tailwaters were likely temporary. We believe a chum salmon's decision to either remain on, or leave, its redd during periods of unsuitably high water velocities reflects time invested in the redd and the associated energetic costs it is willing to incur. Published in 2009 by John Wiley & Sons, Ltd.
Formation and characterisation of NiAl‐Ti coating on nickel‐based superalloy B1900
Authors: Shahriari F. , Ashrafizadeh F. , Saatchi A.
Published: February 2009

Alumina‐former coatings have been known as the best surface engineering approach to combat high temperature corrosion in gas turbine industry. In this investigation, attempts have been made to obtain a titanium‐modified aluminide coating with improved protective properties. Modification has been achieved by introducing titanium in the coating composition by a two‐stage coating treatment; titanium coating and subsequent aluminising. The modified coatings were characterised and compared with simple aluminides by means of electron metallography, depth elemental profiling and x‐ray diffraction techniques. Experimental results indicated that pre‐titanising diffusion treatment is an effective route to modify chemical composition of simple aluminide coating. The final microstructure of the coating was β‐NiAl matrix with titanium‐bearing precipitates mainly distributed in near surface layers. The mechanism of the coating formation is discussed. Copyright © 2009 John Wiley & Sons, Ltd.