bluuebunny/crossref_metadata_2025 huggingface dataset:
Left ventricular noncompaction in patients with β‐thalassemia: Uncovering a previously unrecognized abnormality
Authors: Piga Antonio , Longo Filomena , Musallam Khaled M. , Veltri Andrea , Ferroni Francesca , Chiribiri Amedeo , Bonamini Rodolfo
Published: September 2012

Left ventricular noncompaction (LVNC) is a rare cardiomyopathy with potentially serious outcomes. It results in multiple and excessive trabeculations, deep intertrabecular recesses, and a thickened ventricular myocardium with two distinct layers, compacted and noncompacted. The condition is most commonly congenital; however, acquired forms have also been described. A recent report of LVNC detected in a β‐thalassemia twin suggested an association with cardiac siderosis. In a cross‐sectional study of 135 transfusion‐dependent patients with β‐thalassemia (130 major and 5 intermedia, mean age 29.6 ± 7.7 years, 49.6% males) presenting for cardiac iron assessment by magnetic resonance imaging (MRI), we evaluated the prevalence and risk factors for LVNC. None of the patients had neuromuscular or congenital heart disease. Eighteen patients (13.3%; 95% confidence interval [CI] = 8.6–20.1) fulfilled the preassigned strict criteria for LVNC on cardiac MRI. There were no statistically significant differences between patients with and without LVNC with respect to demographics; hemoglobin levels; splenectomy status; systemic, hepatic, and cardiac iron overload indices; hepatic disease and infection studies; or iron chelator type. Patients with LVNC were more likely to have heart failure (adjusted odds ratio = 1.77; 95% CI = 0.29–10.89); although with high uncertainty. Patients with β‐thalassemia have a higher prevalence of LVNC than normal individuals. As this finding could not be explained by conventional risk factors in this patient population, further investigation of the underlying mechanisms of LVNC is warranted. This remains crucial for an entity with adverse cardiac outcomes, especially in patients with β‐thalassemia where cardiac disease remains a primary cause of mortality. Am. J. Hematol., 2012. © 2012 Wiley Periodicals, Inc.
Long‐term safety and efficacy of imatinib mesylate (Gleevec®) in elderly patients with chronic phase chronic myelogenous leukemia: Results of the AFR04 study
Authors: Rousselot Philippe , Cony‐Makhoul Pascale , Nicolini Franck , Mahon François Xavier , Berthou Christian , Réa Delphine , Reiffers Josy , Bornand Anne , Saint‐Jean Olivier , Guilhot Joelle , Guilhot François ,   on behalf of the French Intergroup For Chronic Myelogenous Leukemia (Fi‐LMC)
Published: September 2012

Data from registries suggest that the median age of chronic myelogenous leukemia (CML) patients is 10–15 years older than that of clinical trials. We conducted a prospective phase II study to evaluate imatinib mesylate (IM, 400 mg daily) in newly diagnosed chronic phase CML (CP‐CML) patients. Patients aged 70 years and over diagnosed with CP‐CML within 12 months were eligible. Thirty patients were enrolled from April 2002 to October 2004. Median age was 74.8 years (range, 70–90). Male/female ratio was 1.72. At inclusion, comorbidities were reported in all but one patient, Cumulative Illness Rating Scale for Geriatrics comorbidity mean index was 1.47, and 66% of patients had cardiovascular disease. The median daily IM dose was 392 mg (range, 256–445). IM was interrupted in patients with severe comorbidities. Treatment discontinuation was observed in 36.6% of patients. Cumulative incidence of complete cytogenetic response was 71.4 and 78.5% at 12 and 24 months, respectively. A high level of sustained responses was observed in patients with mild or moderate comorbidities. Seven‐year estimated overall survival was 80.8% (95% CI: 59.0–91.7). Two‐thirds of the patients were still on long‐term therapy at cut‐off, and no patients had died from progression. This trial was registered at http://www.clinicaltrials.gov as # NCT00219765. Am. J. Hematol. 2013. © 2012 Wiley Periodicals, Inc.
The Synthesis of Aromatic Heterocycles from Propargylic Compounds
Authors: Jia‐Jie Wen , Zhu Yu , Zhan Zhuang‐Ping
Published: September 2012

It is well known that the aromatic heterocyclic compounds are the most ubiquitous motifs and are found in many natural products and pharmaceuticals that exhibit remarkable biological activities. Significant effort continues to be given to the development of new methods for their construction. Although a number of methods have been established to construct these compounds, the development of novel methods that allow the facile assembly of substituted heterocycles from readily available starting materials remains an important objective. In recent years, propargylic compounds that contain many reactive centers have attracted a lot of attention for their various transformations. Chemists have conducted a detailed investigation of their cyclization with nucleophiles. The cyclization of propargylic compounds with a variety of nucleophiles is a very efficient method for producing furans, pyrroles, thiazoles, indoles, imidazoles, indolizines, oxazoles, pyridines, quinolines, thiophenes, and so on. In this review, we highlight the substantial progress that has been made in this area between 2000 and mid‐2012, and give examples of the reactions of propargylic compounds with a variety of substrates to produce heterocycles.
Rescaling of aerial survey data with information from small numbers of telemetry tags to estimate the size of a declining harbour seal population
Authors: Lonergan Mike , Duck Callan , Moss Simon , Morris Chris , Thompson Dave
Published: September 2012

Estimates of both absolute abundance and trends in abundance are among the most basic pieces of information required for planning the conservation and management of wildlife populations. They are important for understanding both the current situation of species and potential risks to them.

This study presents estimates of the size of the harbour seal (Phoca vitulina) population associated with the Orkney Islands, a part of northern Scotland that used to contain one of the largest concentrations of this species in Europe.

The numbers of animals counted during aerial surveys of this area have decreased substantially over the period 2001–2010. ARGOS transmitters attached to flipper tags were used to rescale the counts into estimates of abundance and to confirm the rate of decline of this population.

Females hauled out for more of the survey window (0.84; bootstrap 95% CI: 0.63–0.99) than males (0.61; bootstrap 95% CI: 0.34–0.86). The animals hauled out less during weekends (0.57; bootstrap 95% CI: 0.40–0.74) than during the week (0.76; bootstrap 95% CI: 0.58–0.91).

The sex‐ratios of this population is unknown. Assuming it was close to 1:1, then there were around 3586 (bootstrap 95% CI: 2970–4542) harbour seals in Orkney in 2010. A female‐skewed sex‐ratio would reduce the population estimate, and a changing sex‐ratio might mean the counts understate the real decline.

The mean annual rate of decline in the Orkney population of harbour seals, over the period 2001–2010, is estimated at 13% (95% CI: 10.8–14.8). Similar data for Arisaig, on the west coast of Scotland, shows an increase of around 2% (95% CI: 1.5–2.4) and, assuming an equal sex‐ratio, 923 animals (95% CI: 765–1169) in 2007. Copyright © 2012 John Wiley & Sons, Ltd.
Hydrogen‐Bonding Interactions and Properties of Energetic Nitroamino[1,3,5]triazine‐Based Guanidinium Salts: DFT‐D and QTAIM Studies
Authors: Wang Fang , Du Hongchen , Liu Hui , Gong Xuedong
Published: September 2012

The intramolecular hydrogen‐bonding interactions and properties of a series of nitroamino[1,3,5]triazine‐based guanidinium salts were studied by using the dispersion‐corrected density functional theory method (DFT‐D). Results show that there are evident LP(N or O; LP=lone pair)→σ*(NH) orbital interactions related to O⋅⋅⋅HN or N⋅⋅⋅HN hydrogen bonds. Quantum theory of atoms in molecules (QTAIM) was applied to characterize the intramolecular hydrogen bonds. For the guanidinium salts studied, the intramolecular hydrogen bonds are associated with a seven‐ or eight‐membered pseudo‐ring. The guanylurea cation is more helpful for improving the thermal stabilities of the ionic salts than other guanidinium cations. The contributions of different substituents on the triazine ring to the thermal stability increase in the order of NO2<NF2<N3(ONO2)<NH2. Energy decomposition analysis shows that the salts are stable owing to electrostatic and orbital interactions between the ions, whereas the dispersion energy has very small contributions. Moreover, the salts exhibit relatively high densities in the range of 1.62–1.89 g cm−3. The detonation velocities and pressures lie in the range of 6.49–8.85 km s−1and 17.79–35.59 GPa, respectively, which makes most of them promising explosives.
One‐Step Synthesis of Graphitic Nanoplatelets that are Decorated with Luminescent Carbon Nanoparticles as New Optical‐Limiting Materials
Authors: Hu Shengliang , Dong Yingge , Yang Jinlong , Liu Jun , Tian Fei , Cao Shirui
Published: September 2012

Graphitic nanoplatelets (GNPs) and luminescent carbon nanoparticles (CNPs) are simultaneously synthesized by controlling the laser parameters and the size of the graphite flakes. Because luminescent CNPs are attached onto GNPs, a new carbon nanostructure is obtained. Compared with carbon black, GNPs, and luminescent CNPs alone, this nanostructure shows better optical‐limiting (OL) effects. The OL mechanism of GNPs that are decorated with luminescent CNPs can mainly be attributed to nonlinear scattering. The role of luminescent CNPs is to promote the formation and growth of nonlinear scattering bubbles, thereby enhancing their optical‐limiting effects.
Synthesis and Properties of Bisphosphole‐Bridged Ladder Oligophenylenes
Authors: Hanifi David , Pun Andrew , Liu Yi
Published: September 2012

Ladder‐type oligophenylenes (LOPP) with bridging heteroatoms are interesting systems as they offer novel electronic and photophysical properties on account of the rigid structural features, more efficient electron delocalization on the coplanar aromatic framework, and strong intermolecular interactions. LOPPs incorporating multiple phosphorous centers combine the excellent electronic properties of phospholes and rigidified conjugated framework of LOPPs, thus positioning themselves as an attractive class of organic semiconductors. To date, there still lacks an effective synthetic methodology towards LOPPs with multiple phosphorous bridges. Herein, we describe the synthesis and properties of a new class of bisphosphole‐bridged ladder oligo(p‐phenylene)s and the related phosphoxides. The synthesis of phospholes was achieved by a four‐fold free‐radical phosphanylation reaction of a tetrabromo p‐terphenylene or biphenyl‐thiophene. Sequential trapping of four highly reactive aryl radicals occurred effectively to give the desired phosphorous‐containing ladder compound. The oxides of the phospholes are shown to be strong fluorophores that can be used as potential n‐type building blocks for organic semiconducting materials.
Methode zur empirischen Prognose der Verformungen von sackungsanfälligen Lössböden
Authors: Meier Claas , Boley Conrad
Published: September 2012

Forschungstätigkeiten auf dem Gebiet der Sackungsanfälligkeit von Lössböden waren insbesondere zwischen den 30er und 80er Jahren des 20. Jahrhunderts von nationaler Individualität gekennzeichnet. Erst seit Anfang der 80er Jahre, mit Aufstellung der Arbeitsgruppe “Geotechnical Properties of Loess” der International Union for Quarternary Research (INQUA), ist eine international referenzierende Forschung auf dem Gebiet der Erfassung bodenmechanischer Eigenschaften von Lössböden zu verzeichnen. Der Schwerpunkt bisheriger Forschungsarbeiten lag auf der Erarbeitung sogenannter Kollapskriterien zur qualitativen Abschätzung des Sackungspotenzials bei einem Anstieg des Wassergehalts. Bisher durchgeführte geochemische Untersuchungen von Lössböden beschreiben zwar die mineralische Zusammensetzung, geben jedoch nur eingeschränkt Aufschluss über die Löslichkeit dieser Bestandteile in Wasser oder deren Einfluss auf das Sackungsverhalten.

Am Institut für Bodenmechanik und Grundbau der Universität der Bundeswehr in München wurde erstmals der Anteil leicht wasserlöslicher mineralischer Bestandteile eines afghanischen Lössbodens ermittelt und anhand von Parameterstudien der Einfluss des Ton‐ und Kalkgehalts auf das Hydrokonsolidationsverhalten untersucht.

Die gewonnenen Erkenntnisse dienten als Grundlage für die Formulierung einer neuen, empirisch abgeleiteten Prognosemethode zur qualitativen Abschätzung der infolge Hydrokonsolidation zu erwartenden kollapsartigen Verformung (Kollapsverformung).

Method for the empirical prediction of the collapse deformations of loess soils

Research into the liability of loess ground to collapse was historically carried out at the level of individual nations, particularly between the 30s and 80s of the last century. Internationally linked research in the area of the identification of the characteristics of the soil mechanics of loess ground is only taking place since the beginning of the 80s with the formation of the Geotechnical Properties of Loess working group. The main effort of research work in the past has been in the derivation of so called Collapse Criteria for the qualitative estimation of collapse potential in relation to increasing water content. While geochemical examinations of loess soils carried out so far have described their mineral compositions, they have, however, only produced limited amounts of data about the water solubility of soil components and its influence on collapse liability.

An initial examination of water soluble components of Afghan loess soils and of the influence of their clay and chalk contents on hydroconsolidation – on the basis of parameter studies – has been carried out at the Institute for Soil Mechanics and Geotechnical Engineering at the University of the Bundeswehr in Munich.

The resultant findings served as the basis for the formulation of a new, empirically derived prognosis method for the qualitative estimation of collapse‐type deformations which can be expected as a consequence of hydroconsolidation.
Flachgründung einer 400‐kV‐Schaltanlage am Kaspischen Meer
Authors: Gödecke Heinz‐Joachim , Viedenz Ulrich , Gödecke Jörg‐Henrik
Published: September 2012

Erdbebenerschütterungen können in sandigen im Grundwasser stehenden Gründungsböden zur Bodenverflüssigung mit einem erheblichen Porenwasserdruckaufbau führen. Dies ist weitläufig als Liquefaction bekannt. Durch den Aufbau des Porenwasserdruckes können die wirksamen Korn‐zu‐Korn‐Spannungen maßgeblich abgebaut und dadurch die Scherfestigkeiten im Untergrund vermindert werden. Im ungünstigsten Fall kann dies bis zum Grundbruchversagen der gesamten Bauwerksgründung führen, oder der Porenwasserdruck kann je nach Gründungstiefe und Sohlpressung die in den Untergrund eingebetteten Baukörper aufschwimmen lassen. Nachfolgend wird vom Bau einer 400‐kV‐ Hochspannungsanlage zur Stromversorgung des stark von Erdbeben beanspruchten Südwestens am Kaspischen Meer berichtet und vom geotechnischen Entwurf der dort flach gegründet ausgeführten Einzelfundamente, die für den Lastfall der Bodenverflüssigung beim Bemessungerdbeben auszulegen waren.

Shallow foundation of a 400‐kV‐substation at the Caspian Sea with shear failure analysis at liquefaction

Earthquakes in case of high ground water tables in sandy foundation soils could lead to liquefaction with remarkable pore water pressure. By this pore water pressure the effective grain‐to‐grain‐stresses and thus the shear strength of the subsoil could be reduced significantly. As a worst case scenario this may result in a shear failure of the entire building foundation, or depending on the foundation depth and pressure the foundation structures due to the pore water pressure may be damaged by uplift. Subsequently it will be reported about the construction of a 400 kV substation for the power supply in the southwest of the Caspian Sea. For this area heavily exposed by earthquakes the geotechnical conceptual design for the foundation with shallow single footings will be highlighted, which had to be designed for the load case of liquefaction due to the design earthquake.
Die 5. Auflage der Empfehlungen des Arbeitskreises Baugruben
Authors: Hettler Achim
Published: September 2012

Mit der Einführung des Eurocode 7 einschließlich Nationalem Anhang und ergänzenden Regeln der DIN 1054 wurde eine Anpassung der 4. Auflage der Empfehlungen des Arbeitskreises “Baugruben” (EAB) der Deutschen Gesellschaft für Geotechnik erforderlich. Im vorliegenden Beitrag werden die wesentlichen Änderungen der 5. Auflage vorgestellt und kommentiert.

The fifth edition of the “Recommendations on excavations”

Introducing Eurocode 7 including the national rules it was necessary to revise the fourth edition of the “Recommendations on excavations” of the German Committee for excavations. In the contribution the essential modifications of the fifth edition are discussed and commented.
Neural tube defects on the Texas‐Mexico border: What we've learned in the 20 years since the Brownsville cluster
Authors: Suarez Lucina , Felkner Marilyn , Brender Jean D. , Canfield Mark , Zhu Huiping , Hendricks Katherine A.
Published: September 2012

We reviewed the published findings from the Texas Neural Tube Defect Project, a 6‐year case‐control study (1995–2000) of neural tube defects (NTDs) on the Texas‐Mexico border. In this review, we highlight what was learned about environmental, genetic, and nutritional factors (i.e., those related to the folate and other metabolic pathways) and the novel putative risk factors that emerged from this study of Mexican American women living on the Texas‐Mexico border. Our investigations of the micronutrients and metabolic pathways involved confirmed the findings of other researchers that increased folate intake has a protective effect and that low serum B12, high serum homocysteine levels, and obesity independently contribute to risk. Studies of this population also have implicated hyperinsulinemia and low ferritin, metabolic risk factors, which require additional study to elucidate their physiologic mechanism. Environmental contaminants such as heavy metals, pesticides, and polychlorinated biphenyls (PCBs), which were of community concern, did little to explain NTD risk. Studies in this folic acid deficit‐population also revealed several novel risk factors, namely, diarrhea, stress, fumonisins, and the combination of nitrosatable drug exposure with high nitrate/nitrite intake. In conclusion, the 23 studies among the Mexican American women living along the Texas‐Mexico border have demonstrated the multifactorial nature of NTDs and that a population deficient in folic acid will be vulnerable to a variety of insults whether brought on by individual behaviors (e.g., obesity) or through the surrounding environment (e.g., fumonisins). Birth Defects Research (Part A), 2012. © 2012 Wiley Periodicals, Inc.
Maternal occupational exposure to polycyclic aromatic hydrocarbons and congenital heart defects among offspring in the national birth defects prevention study
Authors: Lupo Philip J. , Symanski Elaine , Langlois Peter H. , Lawson Christina C. , Malik Sadia , Gilboa Suzanne M. , Lee Laura J. , Agopian A. J. , Desrosiers Tania A. , Waters Martha A. , Romitti Paul A. , Correa Adolfo , Shaw Gary M. , Mitchell, Laura E. ,   and the National Birth Defects Prevention Study
Published: September 2012

BACKGROUND:There is evidence in experimental model systems that exposure to polycyclic aromatic hydrocarbons (PAHs) results in congenital heart defects (CHDs); however, to our knowledge, this relationship has not been examined in humans. Therefore, we conducted a case‐control study assessing the association between estimated maternal occupational exposure to PAHs and CHDs in offspring. METHODS:Data on CHD cases and control infants were obtained from the National Birth Defects Prevention Study for the period of 1997 to 2002. Exposure to PAHs was assigned by industrial hygienist consensus, based on self‐reported maternal occupational histories from 1 month before conception through the third month of pregnancy. Logistic regression was used to evaluate the association between maternal occupational PAH exposure and specific CHD phenotypic subtypes among offspring. RESULTS:The prevalence of occupational PAH exposure was 4.0% in CHD case mothers (76/1907) and 3.6% in control mothers (104/2853). After adjusting for maternal age, race or ethnicity, education, smoking, folic acid supplementation, and study center, exposure was not associated with conotruncal defects (adjusted odds ratio [AOR], 0.98; 95% confidence interval [CI], 0.58–1.67), septal defects (AOR, 1.28; 95% CI, 0.86–1.90), or with any isolated CHD subtype. CONCLUSIONS:Our findings do not support an association between potential maternal occupational exposure to PAHs and various CHDs in a large, population‐based study. For CHD phenotypic subtypes in which modest nonsignificant associations were observed, future investigations could be improved by studying populations with a higher prevalence of PAH exposure and by incorporating information on maternal and fetal genotypes related to PAH metabolism. Birth Defects Research (Part A), 2012. © 2012 Wiley Periodicals, Inc.
Epithelial fusion during neural tube morphogenesis
Authors: Pai Yun‐Jin , Abdullah N.L. , Mohd.‐Zin S.W. , Mohammed R.S. , Rolo Ana , Greene Nicholas D.E. , Abdul‐Aziz Noraishah M. , Copp Andrew J.
Published: September 2012

Adhesion and fusion of epithelial sheets marks the completion of many morphogenetic events during embryogenesis. Neural tube closure involves an epithelial fusion sequence in which the apposing neural folds adhere initially via cellular protrusions, proceed to a more stable union, and subsequently undergo remodeling of the epithelial structures to yield a separate neural tube roof plate and overlying nonneural ectoderm. Cellular protrusions comprise lamellipodia and filopodia, and studies in several different systems emphasize the critical role of RhoGTPases in their regulation. How epithelia establish initial adhesion is poorly understood but, in neurulation, may involve interactions between EphA receptors and their ephrinA ligands. Epithelial remodeling is spatially and temporally correlated with apoptosis in the dorsal neural tube midline, but experimental inhibition of this cell death does not prevent fusion and remodeling. A variety of molecular signaling systems have been implicated in the late events of morphogenesis, but genetic redundancy, for example among the integrins and laminins, makes identification of the critical players challenging. An improved understanding of epithelial fusion can provide insights into normal developmental processes and may also indicate the mode of origin of clinically important birth defects. Birth Defects Research (Part A), 2012. © 2012 Wiley Periodicals, Inc.
Bemessung und Konstruktion von zweiachsig gespannten Stahlbetondecken mit abgeflachten rotationssymmetrischen Hohlkörpern
Authors: Albrecht Christian , Albert Andrej , Pfeffer Karsten , Schnell Jürgen
Published: September 2012

Zur Realisierung von leichten, zweiachsig gespannten Decken werden Hohlkörpersysteme vermehrt eingesetzt, was zu einer wirtschaftlichen und ressourcenschonenden Bauweise führt. Bei der Bemessung und Konstruktion muss das besondere Tragverhalten dieser Systeme berücksichtigt werden. Es werden experimentelle Untersuchungen notwendig, um ein abgesichertes Bemessungsmodell aufstellen zu können. Mittels numerischer Untersuchungen können die Versuche nachgerechnet und Parameterstudien durchgeführt werden. Vereinfachungen und Bemessungshilfen ermöglichen den Tragwerksplanern eine einfache Bemessung und Konstruktion analog der massiven Flachdecke. Bei Berücksichtigung der Bemessungs‐ und Konstruktionsregeln können zweiachsig gespannte Stahlbetondecken mit abgeflachten rotationssymmetrischen Hohlkörpern auf dem bauaufsichtlich geforderten Sicherheitsniveau hergestellt werden.

Design and construction of two‐way spanning reinforced concrete slabs with flattened rotationally symmetrical void formers

For the realization of lightweight, two‐way spanning concrete slabs, hollow body systems are increasingly used, resulting in economic and resource‐efficient constructions. In the design and construction, the special structural behavior of these systems must be considered. In order to establish a safe design model, experimental investigations are required. By numerical investigations, the tests can be modeled and parametric studies can be carried out. Simplifications and design tools allow a simple design and construction similar to the conventional reinforced concrete slabs. By considering the design and detailing rules of two‐way spanning concrete slabs with flattened rotationally symmetrical void formers, the safety level required by the building authority is met.
Tiefgaragen mit unbeschichteten Stahlbeton‐Bodenplatten – ein Erfahrungsbericht
Authors: Dauberschmidt Christoph , Vestner Stephan , von Thermann Edmund
Published: September 2012

Die Ausführung von unbeschichteten, direkt befahrenen Bodenplatten ist eine nach den aktuellen Normen und Merkblättern anerkannte Bauweise, wenn zum einen ein möglichst chloriddichter Beton bei ausreichend hoher Betondeckung verwendet wird. Zum anderen sollten Maßnahmen ergriffen werden, um die Rissbildung zu vermeiden bzw. sollte eine “begleitende Rissbehandlung” im Rahmen der Wartung durchgeführt werden. Die Erfahrungen an insgesamt vier durch einen Fachplaner gutachterlich begleiteten Bauvorhaben zeigen, dass sowohl die Chloriddichtheit nachweisbar erreicht werden kann, als auch eine weitestgehende Rissfreiheit, selbst nach mehreren Wintern, eingehalten ist. Entscheidend für den Erfolg der rissfreien Konstruktion ist, dass bereits in den frühen Planungsphasen eine zwängungsarme Auflagerung berücksichtigt wird. Zudem sind auch ein ausreichendes Gefälle sowie die Konzeption von Entwässerungseinrichtungen frühzeitig planerisch zu berücksichtigen. Die Ausführungsqualität der Bodenplatte kann mittels zerstörungsfreier Betondeckungsmessungen und durch Bestimmung der Chloridbelastung überprüft werden. Letztlich konnte mit den hier beschriebenen, unbeschichteten Tiefgaragen‐Bodenplatten eine dauerhafte und wirtschaftliche Konstruktion gefunden werden, deren Instandhaltungsaufwand im Vergleich zu beschichteten Bodenplatten deutlich geringer sein wird.

Uncoated and directly driven RC‐ground slabs in underground car parks – a field report

The construction of an uncoated and directly driven RC‐ground slab is proven and acknowledged by standards and bulletins, if on one hand a concrete is used, which is chloride dense as possible in combination with a sufficient thick concrete cover. On the other hand actions should be taken to avoid crack initiation or an accompanied crack treatment within the scope of the maintenance should be carried out. The experience of four building projects, which were supervised by concrete technology consultants, show, that as well the chloride impermeability is verifiable achievable as hardly any cracks have been determined – even after several winter periods. Important to achieve a crack‐free construction is the consideration of a bearing with reduced restraints already in early stages of the design. Also the planning of a sufficient gradient of the surface and a drainage concept has to be considered early within design. The quality of the execution of the ground slab can be checked by using non destructive concrete cover measurement and by determining the chloride contamination. Finally a durable and cost‐effective construction could be achieved with the described uncoated subterranean garage ground slabs leading to a reduced maintenance expense compared to coated ground slabs.
H2O2‐ and pH‐sensitive CdTe quantum dots as fluorescence probes for the detection of glucose
Authors: Li Yinping , Li Baoxin , Zhang Junli
Published: September 2012

A novel fluorescence assay system for glucose was developed with thioglycollic acid (TGA)‐capped CdTe quantum dots (QDs) as probes. The luminescence quantum yield of the TGA‐capped CdTe QDs was highly sensitive to H2O2 and pH. In the presence of glucose oxidase, glucose is oxidized to yield, gluconic acid and H2O2. H2O2 and H+ (dissociated from gluconic acid) intensively quenched the fluorescence of QDs. The experimental results showed that the quenched fluorescence was proportional to the glucose concentration within the range of 0.01–5.0 mm under optimized experimental conditions. Compared with most of the existing methods, this newly developed system possesses many advantages, including simplicity, low cost, high flexibility, and good sensitivity. Furthermore, no complicated chemical modification of QDs and enzyme immobilization was needed in this system. Copyright © 2012 John Wiley & Sons, Ltd.
Dark‐red‐emitting CdTe/Cd1‐xZnxS core/shell quantum dots: preparation and properties
Authors: Yang Ping , Murase Norio
Published: September 2012

CdTe nanocrystals (NCs) were fabricated through an organic synthesis. The growth and properties of CdTe NCs depended strongly on the preparation conditions. In a reaction system of octadecene and tetradecylphosphonic acid (TDPA), the growth was slow. CdTe NCs with cubic‐like morphology were created in trioctylamine (TOA) using octadecylphosphonic acid (ODPA)‐CdO or TDPA‐CdO as precursors. The TOA and ODPA system gives rise to NCs with high photoluminescence (PL) efficiencies (12%). A CdxZn1‐xS shell coating on the CdTe core, gave rise to tunable dark red PL (630–670 nm). The morphology and PL properties of the CdTe cores were drastically affected by shell coating and this determined the properties of CdTe/CdxZn1‐xS NCs. Small CdTe NCs were easily coated with CdxZn1‐xS shells. The resulting core/shell NCs revealed a spherical morphology. However, shell growth became slow when large CdTe cores were used. This is ascribed to the cores with a cubic‐like morphology. CdS interlayer plays an important role for the formation of the CdTe/CdxZn1‐xS NCs because the experimental result indicated it is difficult to coat CdTe NCs with a ZnS shell. The core/shell NCs benefited from a CdxZn1‐xS composite shell because CdTe/CdS NCs created via a similar procedure revealed a low PL efficiency. Copyright © 2012 John Wiley & Sons, Ltd.
Genetic Encoding of a Bicyclo[6.1.0]nonyne‐Charged Amino Acid Enables Fast Cellular Protein Imaging by Metal‐Free Ligation
Authors: Borrmann Annika , Milles Sigrid , Plass Tilman , Dommerholt Jan , Verkade Jorge M. M. , Wießler Manfred , Schultz Carsten , van Hest Jan C. M. , van Delft Floris L. , Lemke Edward A.
Published: September 2012

Visualizing biomolecules by fluorescent tagging is a powerful method for studying their behaviour and function inside cells. We prepared and genetically encoded an unnatural amino acid (UAA) that features a bicyclononyne moiety. This UAA offered exceptional reactivity in strain‐promoted azide–alkyne cycloadditions. Kinetic measurements revealed that the UAA reacted also remarkably fast in the inverse‐electron‐demand Diels–Alder cycloaddition with tetrazine‐conjugated dyes. Genetic encoding of the new UAA inside mammalian cells and its subsequent selective labeling at low dye concentrations demonstrate the usefulness of the new amino acid for future imaging studies.
Methods in Molecular Biology, Vol. 812: Two Hybrid Technologies: Methods and Protocols. Edited by Bernhard Suter and Erich E. Wanker.
Authors: Colas Pierre
Published: September 2012

Humana Press, Totowa 2012, XI+329 pp., hardcover, $ 139.00.—ISBN 978‐1‐617‐79454‐4
Transition‐Metal Complexes of Tetrylones [(CO)5W‐E(PPh3)2] and Tetrylenes [(CO)5W‐NHE] (E=C–Pb): A Theoretical Study
Authors: Nguyen Thi Ai Nhung , Frenking Gernot
Published: September 2012

Quantum chemical calculations at the BP86/TZVPP//BP86/SVP level are performed for the tetrylone complexes [W(CO)5‐E(PPh3)2] (W‐1 E) and the tetrylene complexes [W(CO)5‐NHE] (W‐2 E) with E=C–Pb. The bonding is analyzed using charge and energy decomposition methods. The carbone ligand C(PPh3) is bonded head‐on to the metal in W‐1 C, but the tetrylone ligands E(PPh3)2 are bonded side‐on in the heavier homologues W‐1 Si to W‐1 Pb. The WE bond dissociation energies (BDEs) increase from the lighter to the heavier homologues (W‐1 C: De=25.1 kcal mol−1; W‐1 Pb: De=44.6 kcal mol−1). The W(CO)5←C(PPh3)2 donation in W‐1 C comes from the σ lone‐pair orbital of C(PPh3)2, whereas the W(CO)5←E(PPh3)2 donation in the side‐on bonded complexes with E=Si–Pb arises from the π lone‐pair orbital of E(PPh3)2 (the HOMO of the free ligand). The π‐HOMO energy level rises continuously for the heavier homologues, and the hybridization has greater p character, making the heavier tetrylones stronger donors than the lighter systems, because tetrylones have two lone‐pair orbitals available for donation. Energy decomposition analysis (EDA) in conjunction with natural orbital for chemical valence (NOCV) suggests that the WE BDE trend in W‐1 E comes from the increase in W(CO)5←E(PPh3)2 donation and from stronger electrostatic attraction, and that the E(PPh3)2 ligands are strong σ‐donors and weak π‐donors. The NHE ligands in the W‐2 E complexes are bonded end‐on for E=C, Si, and Ge, but side‐on for E=Sn and Pb. The WE BDE trend is opposite to that of the W‐1 E complexes. The NHE ligands are strong σ‐donors and weak π‐acceptors. The observed trend arises because the hybridization of the donor orbital at atom E in W‐2 E has much greater s character than that in W‐1 E, and even increases for heavier atoms, because the tetrylenes have only one lone‐pair orbital available for donation. In addition, the WE bonds of the heavier systems W‐2 E are strongly polarized toward atom E, so the electrostatic attraction with the tungsten atom is weak. The BDEs calculated for the WE bonds in W‐1 E, W‐2 E and the less bulky tetrylone complexes [W(CO)5‐E(PH3)2] (W‐3 E) show that the effect of bulky ligands may obscure the intrinsic WE bond strength.
Cyclometalated Iridium(III)–Polyamine Complexes with Intense and Long‐Lived Multicolor Phosphorescence: Synthesis, Crystal Structure, Photophysical Behavior, Cellular Uptake, and Transfection Properties
Authors: Li Steve Po‐Yam , Tang Tommy Siu‐Ming , Yiu Ken Shek‐Man , Lo Kenneth Kam‐Wing
Published: September 2012

A new class of phosphorescent cyclometalated iridium(III)–polyamine complexes [{Ir(N^C)2}n(bPEI)](PF6)n (bPEI=branched poly(ethyleneimine), average Mw=25 kDa, n=15.6–27.4; HN^C=2‐phenylpyridine Hppy (1 a), 2‐((1,1′‐biphenyl)‐4‐yl)pyridine Hpppy (2 a), 2‐phenylquinoline Hpq (3 a), 2‐phenylbenzothiazole Hbt (4 a), 2‐(1‐naphthyl)benzothiazole Hbsn (5 a)) and [Ir(N^C)2(en)](PF6) (en=ethylenediamine; HN^C=Hppy (1 b), Hpppy (2 b), Hpq (3 b), Hbt (4 b), Hbsn (5 b)) have been synthesized and characterized. The X‐ray crystal structure of complex 5 b was also determined. All of these complexes showed a reversible iridium(IV/III) oxidation couple at +1.01 to +1.26 V and a quasi‐reversible ligand‐based reduction couple at −1.54 to −2.08 V (versus SCE). Upon photoexcitation, the complexes displayed intense and long‐lived green to orange–red emission in fluid solutions at room temperature and in low‐temperature glass. Lipophilicity measurements indicated that bPEI played a dominant role in the polar nature of complexes 1 a–5 a, thus rendering them very soluble in aqueous solutions. Inductively coupled plasma–mass spectrometry (ICP‐MS) and confocal laser scanning microscopy (CLSM) data indicated that an energy‐requiring process, such as endocytosis, was involved in the cellular uptake of all of the complexes. In addition, the cytotoxicity of the complexes toward human cervix epithelioid carcinoma (HeLa) and human embryonic kidney 293T (HEK293T) cell‐lines has been evaluated by the 3‐(4,5‐dimethyl‐2‐thiazolyl)‐2,5‐diphenyltetrazolium bromide (MTT) assay. The DNA‐binding properties of complex 5 a have been investigated by gel‐retardation assays and the polyplexes that were formed from this complex with plasmid DNA (pDNA) were studied by zeta‐potential measurements and particle‐size estimation. Furthermore, complex 5 a was grafted with poly(ethylene glycol) (PEG, average Mw=2 kDa) to different extents, thereby yielding the phosphorescent copolymers PEG12.3‐g‐5 a, PEG25.4‐g‐5 a, and PEG62.1‐g‐5 a. Interestingly, these copolymers showed enhanced transfection activity, as revealed by in vitro transfection experiments with tissue‐culture‐based luciferase assays.
Hierarchical Supramolecular Spinning of Nanofibers in a Microfluidic Channel: Tuning Nanostructures at a Dynamic Interface
Authors: Numata Munenori , Takigami Yusuke , Takayama Momoko , Kozawa Tomohiro , Hirose Naoya
Published: September 2012

One of the fundamental problems in supramolecular chemistry, as well as in material sciences, is how to control the self‐assembly of polymers on the nanometer scale and how to spontaneously organize them towards the macroscopic scale. To overcome this problem, inspired by the self‐assembly systems in nature, which feature the dynamically controlled self‐assembly of biopolymers, we have previously proposed a self‐assembly system that uses a dynamic liquid/liquid interface with dimensions in the micrometer regime, thereby allowing polymers to self‐assemble under precisely controlled nonequilibrium conditions. Herein, we further extend this system to the creation of hierarchical self‐assembled architectures of polysaccharides. A natural polysaccharide, β‐1,3‐glucan (SPG), and water were injected into opposite “legs” of microfluidic devices that had a Y‐shape junction, so that two solvents would gradually mix in the down stem, thereby causing SPG to spontaneously self‐assemble along the flow in a head‐to‐tail fashion, mainly through hydrophobic interactions. In the initial stage, several SPG nanofibers would self‐assemble at the Y‐junction owing to the shearing force, thereby creating oligomers with a three‐way junction point. This unique structure, which could not be created through conventional mixing procedures, has a divergent self‐assembly capability. The dynamic flow allows the oligomers to interact continuously with SPG nanofibers that are fed into the Y‐junction, thus amplifying the nanostructure along the flow to form SPG networks. Consequently, we were able to create stable, centimeter‐length macroscopic polysaccharide strands under the selected flow conditions, which implies that SPG nanofibers were assembled hierarchically in a supramolecular fashion in the dynamic flow. Microscopic observations, including SEM and AFM analysis, revealed the existence of clear hierarchical structures inside the obtained strand. The network structures self‐assembled to form sub‐micrometer‐sized fibers. The long fibers further entangled with each other to give stable micrometer‐sized fibers, which finally assembled to form the macroscopic strands, in which the final stabilities in the macroscopic regime were governed by that of the network structures in the nanometer regime. Thus, we have exploited this new supramolecular system to create hierarchical polymeric architectures under precisely controlled flow conditions, by combining the conventional supramolecular strategy with microfluidic science.
Characterization of Zn‐Containing Metal–Organic Frameworks by Solid‐State 67Zn NMR Spectroscopy and Computational Modeling
Authors: Sutrisno Andre , Terskikh Victor V. , Shi Qi , Song Zhengwei , Dong Jinxiang , Ding San Yuan , Wang Wei , Provost Bianca R. , Daff Thomas D. , Woo Tom K. , Huang Yining
Published: September 2012

Metal–organic frameworks (MOFs) are an extremely important class of porous materials with many applications. The metal centers in many important MOFs are zinc cations. However, their Zn environments have not been characterized directly by 67Zn solid‐state NMR (SSNMR) spectroscopy. This is because 67Zn (I=5/2) is unreceptive with many unfavorable NMR characteristics, leading to very low sensitivity. In this work, we report, for the first time, a 67Zn natural abundance SSNMR spectroscopic study of several representative zeolitic imidazolate frameworks (ZIFs) and MOFs at an ultrahigh magnetic field of 21.1 T. Our work demonstrates that 67Zn magic‐angle spinning (MAS) NMR spectra are highly sensitive to the local Zn environment and can differentiate non‐equivalent Zn sites. The 67Zn NMR parameters can be predicted by theoretical calculations. Through the study of MOF‐5 desolvation, we show that with the aid of computational modeling, 67Zn NMR spectroscopy can provide valuable structural information on the MOF systems with structures that are not well described. Using ZIF‐8 as an example, we further demonstrate that 67Zn NMR spectroscopy is highly sensitive to the guest molecules present inside the cavities. Our work also shows that a combination of 67Zn NMR data and molecular dynamics simulation can reveal detailed information on the distribution and the dynamics of the guest species. The present work establishes 67Zn SSNMR spectroscopy as a new tool complementary to X‐ray diffraction for solving outstanding structural problems and for determining the structures of many new MOFs yet to come.
Gold Nanoparticles Grown on Ionic Liquid‐Functionalized Single‐Walled Carbon Nanotubes: New Materials for Photothermal Therapy
Authors: Meng Lingjie , Niu Lvye , Li Ling , Lu Qinghua , Fei Zhaofu , Dyson Paul J.
Published: September 2012

Gold nanoparticles were grown on single‐walled carbon nanotubes (SWNTs) coated with a thiol‐functionalized ionic liquid resulting in the formation of core‐shell structures referred to as SWNT‐IL‐Au nanohybrid materials. The nanohybrid materials were characterized by high‐resolution transmission electron microscopy (HR‐TEM), Raman‐, and UV/Vis absorption spectroscopy. The nanohybrid materials were found to enter lysosomes in HeLa cells and show negligible cytotoxicity. Interestingly, they have an enhanced NIR absorption that is effectively transferred into heat to cause localized hyperthermia, resulting in rapid cell death; overall, the material appears to have excellent properties for photothermal therapeutic applications.
Is the HO4− Anion a Key Species in the Aqueous‐Phase Decomposition of Ozone?
Authors: Anglada Josep M. , Torrent‐Sucarrat Miquel , Ruiz‐Lopez Manuel F. , Martins‐Costa Marilia
Published: September 2012

The role of the HO4− anion in atmospheric chemistry and biology is a matter of debate, because it can be formed from, or be in equilibrium with, key species such as O3 + HO− or HO2 + O2−. The determination of the stability of HO4− in water therefore has the greatest relevance for better understanding the mechanism associated with oxidative cascades in aqueous solution. However, experiments are difficult to perform because of the short‐lived character of this species, and in this work we have employed DFT, CCSD(T) complete basis set (CBS), MRCI/aug‐cc‐pVTZ, and combined quantum mechanics/molecular mechanics (QM/MM) calculations to investigate this topic. We show that the HO4− anion has a planar structure in the gas phase, with a very large HOOOO bond length (1.823 Å). In contrast, HO4− adopts a nonplanar configuration in aqueous solution, with huge geometrical changes (up to 0.232 Å for the HOOOO bond length) with a very small energy cost. The formation of the HO4− anion is predicted to be endergonic by 5.53±1.44 and 2.14±0.37 kcal mol−1 with respect to the O3 + HO− and HO2 + O2− channels, respectively. Moreover, the combination of theoretical calculations with experimental free energies of solvation has allowed us to obtain accurate free energies for the main reactions involved in the aqueous decomposition of ozone. Thus, the oxygen transfer reaction (O3 + OH− → HO2 + O2−) is endergonic by 3.39±1.80 kcal mol−1, the electron transfer process (O3 + O2− → O3− + O2) is exergonic by 31.53±1.05 kcal mol−1, supporting the chain‐carrier role of the superoxide ion, and the reaction O3 + HO2− → OH + O2− + O2 is exergonic by 12.78±1.15 kcal mol−1, which is consistent with the fact that the addition of small amounts of HO2− (through H2O2) accelerates ozone decomposition in water. The combination of our results with previously reported thermokinetic data provides some insights into the potentially important role of the HO4− anion as a key reaction intermediate.
Central‐Atom Size Effects on the Methyl Torsions of Group XIV Tetratolyls
Authors: Ng Maggie C. C. , Harper Jason B. , Stampfl Anton P. J. , Kearley Gordon J. , Rols Stéphane , Stride John A.
Published: September 2012

The Group XIV tetratolyl series X(C6H4‐CH3)4 (X=C, Si, Ge, Sn, Pb) were studied by using inelastic neutron scattering to measure the low‐energy phonon spectra to directly access the methyl‐group torsional modes. The effect of increased molecular radius as a function of the size of the central atom was shown to have direct influence on the methyl dynamics, reinforced with the findings of molecular dynamics and contact surface calculations, based upon the solid‐state structures. The torsional modes in the lightest analogue were found to be predominantly intramolecular: the Si and Ge analogues have a high degree of intermolecular methyl–methyl group interactions, whilst the heaviest analogues (Sn and Pb) showed pronounced intermolecular methyl interactions with the whole phonon bath of the lattice modes.
Synthesis and Characterization of Multiferrocenyl‐Substituted Group 4 Metallocene Complexes
Authors: Kaleta Katharina , Strehler Frank , Hildebrandt Alexander , Beweries Torsten , Arndt Perdita , Rüffer Tobias , Spannenberg Anke , Lang Heinrich , Rosenthal Uwe
Published: September 2012

The reaction of different metallocene fragments [Cp2M] (Cp=η5‐cyclopentadienyl, M=Ti, Zr) with diferrocenylacetylene and 1,4‐diferrocenylbuta‐1,3‐diyne is described. The titanocene complexes form the highly strained three‐ and five‐membered ring systems [Cp2Ti(η2‐FcC2Fc)] (1) and [Cp2Ti(η4‐FcC4Fc)] (2) (Fc=[Fe(η5‐C5H4)(η5‐C5H5)]) by addition of the appropriate alkyne or diyne to Cp2Ti. Zirconocene precursors react with diferrocenyl‐ and ferrocenylphenylacetylene under CC bond coupling to yield the metallacyclopentadienes [Cp2Zr(C4Fc4)] (3) and [Cp2Zr(C4Fc2Ph2)] (5), respectively. The exchange of the zirconocene unit in 3 by hydrogen atoms opens the route to the super‐crowded ferrocenyl‐substituted compound tetraferrocenylbutadiene (4). On the other hand, the reaction of 1,4‐diferrocenylbuta‐1,3‐diyne with zirconocene complexes afforded a cleavage of the central CC bond, and thus, dinuclear [{Cp2Zr(μ‐η1:η2‐CCFc)}2] (6) that consists of two zirconocene acetylide groups was formed. Most of the complexes were characterized by single‐crystal X‐ray crystallography, showing attractive multinuclear molecules. The redox properties of 3, 5, and 6 were studied by cyclic voltammetry. Upon oxidation to 3n+, 5n+, and 6n+ (n=1–3), decomposition occured with in situ formation of new species. The follow‐up products from 3 and 5 possess two or four reversible redox events pointing to butadiene‐based molecules. However, the dinuclear complex 6 afforded ethynylferrocene under the measurement conditions.