bluuebunny/crossref_metadata_2025 huggingface dataset:
The Impact of Worksite-Based Safety Belt Programs: A Review of the Literature
Authors: Eddy James M. , Fitzhugh Eugene C. , Wojtowicz G. Greg , Wang Min Qi
Published: December 2011

Purpose.

The purpose of this paper is to provide a literature review of the research that examines the effectiveness of worksite intervention programs designed to increase the use of safety belts by employees.

Search methods.

The literature search, which identified 14 research studies on worksite safety belt programs conducted between 1968 and 1994, originated as part of a larger review on the health impact of worksite health promotion programs that was conducted by the Centers for Disease Control and Prevention (CDC). In addition, the authors conducted an additional search in an effort to validate the CDC search, but found no additional research articles.

Summary of Important Findings.

The literature specific to the effectiveness of safety belt programs is limited to only 14 studies. The safety belt intervention most commonly evaluated used behavioral modification principles involving incentives. These and other interventions demonstrated effective increases in seat belt utilization that, upon withdrawal of the intervention, achieved a recidivism rate above baseline levels. However, the vast majority of studies failed to incorporate control groups into their research design, which caused significant threats to internal validity. Thus, a summary of findings is only suggestive at best.

Major conclusions.

Based on the literature, there appears to be an insufficient number of quality research studies from which to derive a clear view of the impact of worksite safety belt programs. While the evidence is suggestive of a positive impact on safety belt use, there is a clear need for new, well-designed research initiatives on the effectiveness of theory-based safety belt intervention programs.
Application of Karasek's Demand/Control Model in a Canadian Occupational Setting Including Shift Workers during a Period of Reorganization and Downsizing
Authors: Schechter Janet , Green Lawrence W. , Olsen Lise , Kruse Karen , Cargo Margaret
Published: December 2011

Purpose.

To apply Karasek's Job Content Model to an analysis of the relationships between job type and perceived stress and stress behaviors in a large company during a period of reorganization and downsizing.

Design.

Cross-sectional mail-out, mail-back survey.

Setting.

A large Canadian telephone/telecommunications company.

Subjects.

Stratified random sample (stratified by job category) of 2200 out of 13,000 employees with a response rate of 48.8%.

Measures.

Responses to 25 of Karasek's core questions were utilized to define four job types: low demand and high control = “relaxed”; high demand and high control = “active”; low demand and low control = “passive”, and high demand with low control = “high strain.” These job types were compared against self-reported stress levels, perceived general level of health, absenteeism, alcohol use, exercise level, and use of medications and drugs. Similar analyses were performed to assess the influence of shift work.

Results.

Employees with “passive” or “high strain” job types reported higher levels of stress (trend test p <.0001); poorer health (trend test p = .006); and higher levels of absenteeism (trend test p >.0001). More shift workers reported themselves in poor or fair health (chi-square p = .018) and reported high levels of stress at home (chi-square p = .002) than nonshift workers. The relationships between job type and levels of stress, health, and absenteeism, however, held for nonshift workers as well.

Conclusions.

Job types with high demand and low control were associated with increased stress, increased absenteeism, and poorer self-concept of health. The demand/control model of Karasek and Theorell was validated in this setting with respect to stress and some stress-associated attitudes and behaviors.
A study on the aerosol optical properties over East Asia using a combination of CMAQ-simulated aerosol optical properties and remote-sensing data via a data assimilation technique
Authors: Park R. S. , Song C. H. , Han K. M. , Park M. E. , Lee S.-S. , Kim S.-B. , Shimizu A.
Published: December 2011

Abstract. To more accurately estimate direct radiative forcing (DRF) by aerosols, and better investigate particulate pollution over East Asia, precise calculations of the optical properties of aerosols, such as aerosol optical depth (AOD), single scattering albedo (SSA) and aerosol extinction coefficient (σext), are of primary importance. The aerosol optical properties over East Asia were investigated in this study, based on US EPA Models-3/CMAQ v4.5.1 model simulations. The CMAQ model simulations in this study were improved in several ways compared to those in a previous study (Song et al., 2008). Although the details of the improvements were described in the manuscript, the following points should be emphasized: (1) two data assimilation techniques were employed for producing more accurate AOD products and meteorological fields over East Asia; (2) updated/upgraded emission inventories were used in the CMAQ model simulations with a fine grid resolution of 30 × 30 km2; and (3) the 4-D particulate composition calculated from the CMAQ model simulations was converted into 3-D or 4-D aerosol optical products, using the Malm and Hand (2007) algorithm with significant further modifications. The results from the CMAQ model simulations (without assimilation) showed great improvements compared to those from a previous study. For example, in terms of the regression coefficients (R), R values were increased from 0.48–0.68 (previous study) to 0.62–0.79 (this study). The monthly-averaged CMAQ-simulated single scattering albedo (SSA) also agreed well with the AERONET SSA, with the exceptions of the Hong Kong and Taipei sites, where the air qualities were strongly influenced by active biomass burning events from January to April. There were also excellent matches between the vertical profiles of the CMAQ-simulated σext and LIDAR-retrieved σext. It was also found that the contributions of (NH4)2SO4 during summer, NH4NO3 during winter, sea-salt particles during winter and dust particles during spring to the total AOD were large over East Asia. In particular, the largest contribution of NH4NO3 to the total AOD was found over East Asia during winter. Therefore, it was suggested that this contribution of NH4NO3 should not be neglected. In order to produce more accurate AOD products, the CMAQ-simulated AODs were further assimilated with the MODIS-retrieved AODs. Both of the assimilated and AERONET AODs were better correlated with each other than the CMAQ-simulated and AERONET AODs. The obvious benefits from this study would be that with these improved aerosol optical properties, the particulate pollution (e.g. AOD can be served as a proxy to PM2.5 or PM10) and DRF by aerosols over East Asia can be more satisfactorily investigated in future.
Interaction of chemical and transport processes during the formation of the Arctic stratospheric polar vortex
Authors: Blessmann D. , Wohltmann I. , Lehmann R. , Rex M.
Published: December 2011

Abstract. Dynamical processes during the formation phase of the Arctic polar vortex can introduce considerable interannual variability in the amount of ozone that is incorporated into the vortex. Chemistry in autumn and early winter tends to remove part of that variability because ozone relaxes towards equilibrium. As a quantitative measure of how relevant variable dynamical processes during vortex formation are for the winter ozone abundances above the Arctic we analyze which fraction of an ozone anomaly induced dynamically during vortex formation persists until mid-winter. The work is based on the Lagrangian Chemistry Transport Model ATLAS. Model runs for the winter 1999–2000 are used to assess the fate of an ozone anomaly artificially introduced during the vortex formation phase. From these runs we get detailed information about the persistence of the induced ozone variability over time, height and latitude. Induced ozone variability survives longer inside the polar vortex compared to outside. At 540 K inside the polar vortex half of the initial perturbation survives until mid-winter (3 January) with a rapid fall off towards higher levels, mainly due to NOx induced chemistry. At 660 K 10% of the initial perturbation survives. Above 750 K the signal falls to values below 0.5%. Hence, dynamically induced ozone variability from the vortex formation phase can not significantly contribute to mid-winter variability at levels above 750 K. At lower levels increasingly larger fractions of the initial perturbation survive, reaching 90% at 450 K. In this vertical range dynamical processes during the vortex formation phase are crucial for the ozone abundance in mid-winter.
Remote sensing of coccolithophore blooms in selected oceanic regions using the PhytoDOAS method applied to hyper-spectral satellite data
Authors: Sadeghi A. , Dinter T. , Vountas M. , Taylor B. , Altenburg-Soppa M. , Bracher A.
Published: December 2011

Abstract. In this study temporal variations of coccolithophore blooms are investigated using satellite data. Eight years, from 2003 to 2010, of data of SCIAMACHY, a hyper-spectral satellite sensor on-board ENVISAT, were processed by the PhytoDOAS method to monitor the biomass of coccolithophores in three selected regions. These regions are characterized by frequent occurrence of large coccolithophore blooms. The retrieval results, shown as monthly mean time-series, were compared to related satellite products, including the total surface phytoplankton, i.e., total chlorophyll-a (from GlobColour merged data) and the particulate inorganic carbon (from MODIS-Aqua). The inter-annual variations of the phytoplankton bloom cycles and their maximum monthly mean values have been compared in the three selected regions to the variations of the geophysical parameters: sea-surface temperature (SST), mixed-layer depth (MLD) and surface wind speed, which are known to affect phytoplankton dynamics. For each region the anomalies and linear trends of the monitored parameters over the period of this study have been computed. The patterns of total phytoplankton biomass and specific dynamics of coccolithophores chlorophyll-a in the selected regions are discussed in relation to other studies. The PhytoDOAS results are consistent with the two other ocean color products and support the reported dependencies of coccolithophore biomass' dynamics to the compared geophysical variables. This suggests, that PhytoDOAS is a valid method for retrieving coccolithophore biomass and for monitoring its bloom developments in the global oceans. Future applications of time-series studies using the PhytoDOAS data set are proposed, also using the new upcoming generations of hyper-spectral satellite sensors with improved spatial resolution.
Extreme pointer years in tree-ring records of Central Spain as evidence of volcanic eruptions (Huaynaputina, Peru, 1600 AC) and other climatic events
Authors: Génova M.
Published: December 2011

Abstract. The study of pointer years based on the numerous tree-ring chronologies of the central Iberian Peninsula (Sierra de Guadarrama) could provide complementary information about climate variability over the last 405 years. In total, 64 pointer years have been identified: 30 negative (representing minimum growths) and 34 positive (representing maximum growths), the most significant of these being 1601, 1963 and 1996 for the negative ones, and 1734 and 1737 for the positive ones. Given that summer precipitation has been the most incident factor in the general variability of growth of Pinus in the Sierra de Guadarrama in the second half of the 20th century, it is also an explanatory factor in almost 50% of the extreme growths. Furthermore, the data show that there has been variability over the centuries in the distribution of the frequencies of pointer years and intervals. The first half of the 17th century, together with the second half of the 20th century, constitute the two most notable periods for the frequency of negative pointer years in Central Spain. This variability was sufficiently notable to affirm that, both in the 17th and 20th centuries, the macroclimatic anomalies that affected growth were more frequent and more extreme than in the other two centuries analysed. The period 1600–1602 is of special significance, being one of the most unfavourable for tree growth in the centre of Spain, with 1601 representing the minimum index in the regional chronology. It is possible to infer that these phenomena are the effect of the eruption of Huaynaputina, which occurred in Peru at the beginning of 1600 AD. This is the first time that the effects of this eruption in the tree-ring records of central and southern Europe have been demonstrated.
King George Island ice cap geometry updated with airborne GPR measurements
Authors: Rückamp M. , Blindow N.
Published: December 2011

Abstract. Ice geometry is a mandatory requirement for numerical modelling purposes. In this paper we present a consistent data set for the ice thickness, the bedrock topography and the ice surface topography of the King George Island ice cap (Arctowski Icefield and the adjacent central part). The newly data set is composed of groundbased and airborne Ground Penetrating Radar (GPR) and differential GPS (DGPS) measurements, obtained during several field campaigns. Blindow et al. (2010) already provided a comprehensive overview of the groundbased measurements carried out in the safely accessible area of the ice cap. The updated data set incorporates airborne measurements in the heavily crevassed coastal areas. Therefore, in this paper special attention is paid to the airborne measurements by addressing the used instrument, survey, and data processing in more detail. In particular, the inclusion of airborne GPR measurements with the 30 MHz BGR-P30-System developed at the Institute of Geophysics (University of Münster) completes the picture of the ice geometry substantially. The compiled digital elevation model of the bedrock shows a rough, highly variable topography with pronounced valleys, ridges, and troughs. Mean ice thickness is ~240 m, with a maximum value of ~400 m in the surveyed area. Noticeable are bounded areas in the bedrock topography below sea level where marine based ice exists. The provided data set is required as a basis for future monitoring attempts or as input for numerical modelling experiments. The data set is available from the PANGAEA database at doi:10.1594/PANGAEA.770567.
Self-sustained vibrations in volcanic areas extracted by Independent Component Analysis: a review and new results
Authors: De Lauro E. , De Martino S. , Falanga M. , Palo M.
Published: December 2011

Abstract. We investigate the physical processes associated with volcanic tremor and explosions. A volcano is a complex system where a fluid source interacts with the solid edifice so generating seismic waves in a regime of low turbulence. Although the complex behavior escapes a simple universal description, the phases of activity generate stable (self-sustained) oscillations that can be described as a non-linear dynamical system of low dimensionality. So, the system requires to be investigated with non-linear methods able to individuate, decompose, and extract the main characteristics of the phenomenon. Independent Component Analysis (ICA), an entropy-based technique is a good candidate for this purpose. Here, we review the results of ICA applied to seismic signals acquired in some volcanic areas. We emphasize analogies and differences among the self-oscillations individuated in three cases: Stromboli (Italy), Erebus (Antarctica) and Volcán de Colima (Mexico). The waveforms of the extracted independent components are specific for each volcano, whereas the similarity can be ascribed to a very general common source mechanism involving the interaction between gas/magma flow and solid structures (the volcanic edifice). Indeed, chocking phenomena or inhomogeneities in the volcanic cavity can play the same role in generating self-oscillations as the languid and the reed do in musical instruments. The understanding of these background oscillations is relevant not only for explaining the volcanic source process and to make a forecast into the future, but sheds light on the physics of complex systems developing low turbulence.
Developing a Four-Year Integrated Core Curriculum:
Authors: M. Mirabella Roseanne , M. Balkun Mary
Published: December 2011

Seton Hall University’s new core curriculum includes a pair of Signature Courses and a third-year Signature Course developed within departments, two composition classes, a university life course, and five proficiencies. This article describes the process leading to the development of this new curriculum and provides advice on general education reform.
Evolution‐Based Design of an Injectable Hydrogel
Authors: Geisler Iris M. , Schneider Joel P.
Published: December 2011

A new class of simple, linear, amphiphilic peptides are developed that have the ability to undergo triggered self‐assembly into self‐supporting hydrogels. Under non‐gelling aqueous conditions, these peptides exist in a random coil conformation and peptide solutions have the viscosity of water. On the addition of a buffered saline solution, the peptides assemble into a β‐sheet rich network of fibrils, ultimately leading to hydrogelation. A family of nine peptides is prepared to study the influence of peptide length and amino acid composition on the rate of self‐assembly and hydrogel material properties. The amino acid composition is modulated by varying residue hydrophobicity and hydrophilicity on the two opposing faces of the amphiphile. The conformation of peptides in their soluble and gel state is studied by circular dichroism (CD), while the resultant material properties of their gels is investigated using oscillatory sheer rheology. One weight percent gels formed under physiological conditions have storage modulus (G′) values that vary from ≈20 to ≈800 Pa, with sequence length and hydrophobic character playing a dominant roll in defining hydrogel rigidity. Based on the structural and functional data provided by the nine‐peptide family members, an optimal sequence, namely LK13, is evolved. LK13 (LKLKLKLKLKLKL‐NH2) undergoes triggered self‐assembly, affording the most rigid gel of those studied (G′=797 ± 105). It displays shear thin‐recovery behavior, allowing its delivery by syringe and is cytocompatibile as assessed with murine C3H10t1/2 mesenchymal stem cells.
Graphene‐supported nickel ferrite: A magnetically separable photocatalyst with high activity under visible light
Authors: Fu Yongsheng , Chen Haiqun , Sun Xiaoqiang , Wang Xin
Published: December 2011

A straightforward strategy is designed for the fabrication of a magnetically separable NiFe2O4‐graphene photocatalyst with different graphene content. It is very interesting that the combination of NiFe2O4 nanoparticles with graphene sheets results in a dramatic conversion of the inert NiFe2O4 into a highly active catalyst for the degradation of methylene blue (MB) under visible light irradiation. The significant enhancement in photoactivity under visible light irradiation can be ascribed to the reduction of GO, because the photogenerated electrons of NiFe2O4 can transfer easily from the conduction band to the reduced GO, effectively preventing a direct recombination of electrons and holes. The results of the kinetic study indicated that the rate‐determining stage is the adsorption process of MB molecules. NiFe2O4 nanoparticles themselves have a strong magnetic property, which can be used for magnetic separation in a suspension system, and, therefore, the introduction of additional magnetic supports is no longer necessary. © 2011 American Institute of Chemical Engineers AIChE J, 2012
12‐ to 22‐Membered Bridged β‐Lactams as Potential Penicillin‐Binding Protein Inhibitors
Authors: Sliwa Aline , Dive Georges , Marchand‐Brynaert Jacqueline
Published: December 2011

As potential inhibitors of penicillin‐binding proteins (PBPs), we focused our research on the synthesis of non‐traditional 1,3‐bridged β‐lactams embedded into macrocycles. We synthesized 12‐ to 22‐membered bicyclic β‐lactams by the ring‐closing metathesis (RCM) of bis‐ω‐alkenyl‐3(S)‐aminoazetidinone precursors. The reactivity of 1,3‐bridged β‐lactams was estimated by the determination of the energy barrier of a concerted nucleophilic attack and lactam ring‐opening process by using ab initio calculations. The results predicted that 16‐membered cycles should be more reactive. Biochemical evaluations against R39 DD‐peptidase and two resistant PBPs, namely, PBP2a and PBP5, revealed the inhibition effect of compound 4d, which featured a 16‐membered bridge and the N‐tert‐butyloxycarbonyl chain at the C3 position of the β‐lactam ring. Surprisingly, the corresponding bicycle, 12d, with the PhOCH2CO side chain at C3 was inactive. Reaction models of the R39 active site gave a new insight into the geometric requirements of the conformation of potential ligands and their steric hindrance; this could help in the design of new compounds.
Usutu‐Virus verursacht Vogelsterben
Authors: Jöst Hanna , Schmidt‐Chanasit Jonas , Bosch Stefan , Becker Norbert
Published: December 2011

In Südwestdeutschland wurden im Sommer 2011 hunderte tote Vögel, insbesondere Amseln, aufgefunden. Forscher der Kommunalen Aktionsgemeinschaft zur Bekämpfung der Schnakenplage (KABS), der Universität Heidelberg, des Bernhard‐Nocht‐Instituts (BNI), des NABU und des Friedrich‐Loeffler‐Instituts (FLI) sammelten die toten Vögel ein und untersuchten ihre Organe auf verschiedene Erreger. Im Jahr 2001 traten ähnliche Vorfälle in Österreich auf, wo das tropische Usutu‐Virus (USUV) für ein Vogelsterben verantwortlich war. Bereits im Jahr 2010 konnte das USUV in der Hausmücke (Culex pipiens pipiens) nachgewiesen werden. Der Verdacht der Forscher bestätigte sich nun: Auch die toten Vögel aus Südwestdeutschland waren mit dem USUV infiziert.
Ritterliche Grillenmännchen
Authors: Wendler Silke
Published: December 2011

Männliche Feldgrillen (Gryllus campestris) zeigen ein ritterliches Verhalten gegenüber den Weibchen, mit denen sie sich gepaart haben. Ist Gefahr im Verzug, lassen die Männchen die Weibchen sogar dann zuerst in den Bau, wenn diese sich gerade weiter entfernt befinden als das Männchen.
Foldit, das Protein‐Origami
Authors: Kronberg Max , Kronberg Inge
Published: December 2011

“Solve puzzles for science” – so heißt es in der Ankündigung von “Foldit”. In diesem experimentellen Onlinespiel mit wissenschaftlichem Anspruch werden Aminosäureketten durch verschiedene Werkzeuge in die optimale dreidimensionale Proteinform gefaltet, gerüttelt, gedreht und gebunden. Im Wettbewerb mit anderen Internet‐Spielern kann das “Daddeln” auch der Wissenschaft nützen, sobald alternative Proteinformen entdeckt oder Falt‐Algorithmen in den Datenbanken verbessert werden.
Die ältesten Seehunde der Welt
Authors: Diedrich Cajus
Published: December 2011

Fundstellen im norddeutschen Tiefland bei Fürstenau im UNESCO‐Geopark TERRA.vita liefern derzeit viele interessante Fossilien von marinen Wirbeltieren. Diese Meeresfauna ergänzt die Landtier‐ und Pflanzenwelt sowie die schnelle Artbildung der Haifische im Eozän und ermöglicht ein besseres Verständnis der vollständigen Biodiversität und Ökologie einer tropischen Zeit inmitten von Europa.
Eine neue Waffe gegen pathogene Bakterien?
Authors: Schumann Wolfgang
Published: December 2011

Gentechnisch‐veränderte Escherichia coli‐Zellen detektieren den aggressiven Krankheitskeim Pseudomonas aeruginosa und töten ihn ab. Dabei macht sich das neue Verfahren zwei besondere Fähigkeiten von Bakterien zu Nutze: das Quorum Sensing und die Sekretion von Bacteriocinen.
Antifungal Metabolites from the Roots of Diospyros virginiana by Overpressure Layer Chromatography
Authors: Wang Xiaoning , Habib Eman , León Francisco , Radwan Mohamed M. , Tabanca Nurhayat , Gao Jiangtao , Wedge David E. , Cutler Stephen J.
Published: December 2011

A preparative overpressure layer chromatography (OPLC) method was successfully used for the separation of two new natural compounds, 4‐hydroxy‐5,6‐dimethoxynaphthalene‐2‐carbaldehyde (1) and 12,13‐didehydro‐20,29‐dihydrobetulin (2) together with nine known compounds, including 7‐methyljuglone (3), diospyrin (4), isodiospyrin (5), shinanolone (6), lupeol (7), betulin (8), betulinic acid (9), betulinaldehyde (10), and ursolic acid (11) from the acetone extract of the roots of Diospyros virginiana. Their identification was accomplished by 1D‐ and 2D‐NMR spectroscopy and HR‐ESI‐MS methods. All the isolated compounds were evaluated for their antifungal activities against Colletotrichum fragariae, C. gloeosporioides, C. acutatum, Botrytis cinerea, Fusarium oxysporum, Phomopsis obscurans, and P. viticola using in vitro micro‐dilution broth assay. The results indicated that compounds 3 and 5 showed high antifungal activity against P. obscurans at 30 μM with 97.0 and 81.4% growth inhibition, and moderate activity against P. viticola (54.3 and 36.6%). It appears that an optimized OPLC system offers a rapid and efficient method of exploiting bioactive natural products.
Novel use of a pericardium‐covered stent graft to treat bulky coronary artery thrombus
Authors: Gunn Julian , Siotia Anjan , Malkin Christopher J. , Iqbal Javaid , Raina Tushar , Morton Allison C.
Published: December 2011

Objectives: We studied the acute safety and feasibility of a pericardium‐covered stent (PCS) in the obliteration of massive coronary thrombus. Background: Thrombus is frequently encountered in the setting of acute myocardial infarction, and conventional pharmacological and aspiration approaches are not always successful in dispersing or removing it, especially when it is very substantial. Methods: We treated nine patients (10 lesions) in the setting of an acute coronary syndrome characterized by the presence of substantial (TIMI grade 3–4) thrombus in a large caliber native coronary artery, persisting after conventional treatment, with percutaneous implantation of an equine PCS graft. Nine of 10 lesions were in large right coronary arteries. Results: Deployment was successful in nine of 10 lesions. In all nine cases, the filling defect was immediately eliminated and there was restoration or maintenance of TIMI grade 3 blood flow. There was one in‐hospital stent thrombosis in a 56‐year‐old male, who had only received aspirin due to a coexistent stroke. This patient underwent successful repeat percutaneous intervention but died later of complications of the stroke. There were no 30‐day events, and medium‐term follow‐up continues. Conclusions: A PCS graft is a potentially useful device to treat massive thrombus burden in the setting of acute coronary syndrome. A larger study is warranted. © 2011 Wiley Periodicals, Inc.
Double‐vessel coronary stenting via 5 french diagnostic catheters
Authors: Khattab Ahmed A. , Shrestha Nikesh Raj , Meier Bernhard
Published: December 2011

The authors report on the use of 5 French diagnostic catheters to deliver a stent‐on‐a‐wire system during a double vessel coronary intervention. © 2011 Wiley Periodicals, Inc.
Rhodium Carbene Complexes as Versatile Catalyst Precursors for SiH Bond Activation
Authors: Krüger Anneke , Albrecht Martin
Published: December 2011

Rhodium(III) complexes comprising monoanionic C,C,C‐tridentate dicarbene ligands activate SiH bonds and catalyse the hydrolysis of hydrosilanes to form silanols and siloxanes with concomitant release of H2. In dry MeNO2, selective formation of siloxanes takes place, while changing conditions to wet THF produces silanols exclusively. Silyl ethers are formed when ROH is used as substrate, thus providing a mild route towards the protection of alcohols with H2 as the only by‐product. With alkynes, comparably fast hydrosilylation takes place, while carbonyl groups are unaffected. Further expansion of the SiH bond activation to dihydrosilanes afforded silicones and polysilyl ethers. Mechanistic investigations using deuterated silane revealed deuterium incorporation into the abnormal carbene ligand and thus suggests a ligand‐assisted mechanism involving heterolytic SiH bond cleavage.
Design, Synthesis, Evaluation, and Structure of Vitamin D Analogues with Furan Side Chains
Authors: Fraga Ramón , Zacconi Flavia , Sussman Fredy , Ordóñez‐Morán Paloma , Muñoz Alberto , Huet Tiphaine , Molnár Ferdinand , Moras Dino , Rochel Natacha , Maestro Miguel , Mouriño Antonio
Published: December 2011

Based on the crystal structures of human vitamin D receptor (hVDR) bound to 1α,25‐dihydroxy‐vitamin D3 (1,25 D) and superagonist ligands, we previously designed new superagonist ligands with a tetrahydrofuran ring at the side chain that optimize the aliphatic side‐chain conformation through an entropy benefit. Following a similar strategy, four novel vitamin D analogues with aromatic furan side chains (3 a, 3 b, 4 a, 4 b) have now been developed. The triene system has been constructed by an efficient stereoselective intramolecular cyclization of an enol triflate (A‐ring precursor) followed by a Suzuki–Miyaura coupling of the resulting intermediate with an alkenyl boronic ester (CD‐side chain, upper fragment). The furan side chains have been constructed by gold chemistry. These analogues exhibit significant pro‐differentiation effects and transactivation potency. The crystal structure of 3 a in a complex with the ligand‐binding domain of hVDR revealed that the side‐chain furanic ring adopts two conformations.
Electrochemical “Signal‐On” Reporter for Amyloid Aggregates
Authors: Beheshti Samaneh , Martić Sanela , Kraatz Heinz‐Bernhard
Published: December 2011

The synthesis and characterization of four new Ferrocene (Fc) bioconjugates, bearing a podant (Lys)‐Leu‐Val‐Phe‐Phe motif, namely the hydrophobic sequence of amyloid‐β‐peptides (Aβ), is reported. The Fc‐peptide conjugates are characterized by a reversible redox activity and the ability to undergo hydrophobic and hydrogen bonding interactions. Biomolecular interactions between Fc‐bioconjugates with Aβ12–28 fragments were studied by circular dichroism (CD), transmission electron microscopy (TEM), and electrochemistry. All four Fc‐peptides interacted favourable with Aβ12–28 and prevented fibril formation, the extent of which depended on the length of the peptide and the nature of the C‐terminal group. The aggregates obtained for the Aβ12–28/Fc‐peptide mixtures range from short fibrils to spherical aggregates. We demonstrated that in solution the peptide sequence and peptide charge affect the biomolecular interactions. Fc‐peptide interactions with immobilized Aβ12–28‐Cys films on Au surfaces were detected by measuring the current response of the Fc redox process. The formal redox potential, E0, at ∼440 (10) mV and ipc/ipa at 0.9 were observed characteristic for the monosubstituted Fc‐derivative undergoing a one‐electron redox process. On the surface, methyl ester‐protected Fc‐peptides (1 and 3) interacted only weakly with Aβ12–28‐Cys films, giving rise to minimal redox activity. In contrast, charged Fc‐peptides (2 and 4) gave a significant electrochemical readout following the interaction with Aβ12−28‐Cys films. Interestingly, the Fc‐peptide charge dictates the surface‐assisted interactions, while hydrophobic and ionic effects contribute to the overall solution behaviour of the Fc‐bioconjugates with Aβ12–28.
Nachträgliche Horizontalabdichtung von Bruchsteinmauerwerk mittels Injektionsverfahren
Authors: Balak Michael
Published: December 2011

Im Rahmen des Forschungsprojektes “Hydrophobierende und/oder porenverschließende Injektionsmittel“ (gefördert durch die FFG Forschungsförderungsgesellschaft) wurden die Wirksamkeit und die Anwendungsgrenzen von hydrophobierenden und/oder porenverschließenden Injektionsmitteln zur nachträglichen Horizontalabdichtung von Bruchsteinmauerwerk unter besonderer Berücksichtigung der Einbringungsart untersucht.

In Abhängigkeit des Durchfeuchtungsgrades (gering, mittel, hoch) und der Einbringungsart (Hohldochtverfahren, Infusionsschlauchverfahren, Injektionscremeverfahren, Druckverfahren) wurde die Wirksamkeit von sieben Injektionsmitteln an vier unterschiedlichen in der Wiener Bausubstanz häufig vorkommenden Gesteinstypen (St. Margarethener Kalksandstein, Leithakalk, Rohrbacher Konglomerat, Quarzsandstein aus der Flyschzone) im Labor, an Versuchspfeilern und an zwei Objekten untersucht.

Die Untersuchungen haben hinsichtlich des Einsatzes von hydrophobierenden und/oder porenverschließenden Injektionsmitteln zur nachträglichen Horizontalabdichtung von Bruchsteinmauerwerk sehr unterschiedliche Ergebnisse gebracht, wodurch an jedem Objekt vor Durchführung der Injektionsarbeiten im Rahmen der Bauwerksdiagnostik eine Gesteinserkundung hinsichtlich der physikalischen Eigenschaften zur Auswahl objektspezifisch geeigneter Injektionsmittel erforderlich ist.

Post‐construction horizontal waterproofing of quarry stone masonry by means of injection technology. In the context of the research project Hydrophobic and/or capillary‐obstructing injection materials, subsidised by the Austrian Research Promotion Agency (FFG), hydrophobic and/or capillary‐obstructing injection materials for post‐construction horizontal waterproofing of quarry stone masonry were tested with regard to effectiveness and limitations of application, in consideration of the way in which the injection material is introduced.

The effectiveness of seven injection materials was tested on four different types of stone that are typical of masonry in Vienna (St. Margarethen sandy limestone, Leitha limestone, Rohrbach conglomerate, and quartz sandstone from the Flysch zone), for different degrees of dampness (low, medium, high) and different ways of introducing the sealing material (cardboard tube, flexible plastic tube, paste injection, pressure injection). The tests were carried out in the laboratory, on test pillars built for this purpose and two buildings.

Regarding the effects of hydrophobic and/or capillary‐obstructing injection materials for post‐construction horizontal waterproofing of quarry stone masonry, the tests performed have shown highly diverse results: therefore, before injections are applied, it is necessary in each case to analyse the physical properties of the masonry in question in the context of building diagnostics in order to be able to select an injection material that is suitable for this object.
Cellular properties of principal neurons in the rat entorhinal cortex. II. The medial entorhinal cortex
Authors: Canto Cathrin B. , Witter Menno P.
Published: December 2011

Principal neurons in different medial entorhinal cortex (MEC) layers show variations in spatial modulation that stabilize between 15 and 30 days postnatally. These in vivo variations are likely due to differences in intrinsic membrane properties and integrative capacities of neurons. The latter depends on inputs and thus potentially on the morphology of principal neurons. In this comprehensive study, we systematically compared the morphological and physiological characteristics of principal neurons in all MEC layers of newborn rats before and after weaning. We recorded simultaneously from up to four post‐hoc morphologically identified MEC principal neurons in vitro. Neurons in L(ayer) I‐LIII have dendritic and axonal arbors mainly in superficial layers, and LVI neurons mainly in deep layers. The dendritic and axonal trees of part of LV neurons diverge throughout all layers. Physiological properties of principal neurons differ between layers. In LII, most neurons have a prominent sag potential, resonance and membrane oscillations. Neurons in LIII and LVI fire relatively regular, and lack sag potentials and membrane oscillations. LV neurons show the most prominent spike‐frequency adaptation and highest input resistance. The data indicate that adult‐like principal neuron types can be differentiated early on during postnatal development. The results of the accompanying paper, in which principal neurons in the lateral entorhinal cortex (LEC) were described (Canto and Witter,2011), revealed that significant differences between LEC and MEC exist mainly in LII neurons. We therefore systematically analyzed changes in LII biophysical properties along the mediolateral axis of MEC and LEC. There is a gradient in properties typical for MEC LII neurons. These properties are most pronounced in medially located neurons and become less apparent in more laterally positioned ones. This gradient continues into LEC, such that in LEC medially positioned neurons share some properties with adjacent MEC cells. © 2011 Wiley Periodicals, Inc.
Synthesis of RingA‐Modified Baicalein Derivatives
Authors: Wang Jun‐Fei , Ding Ning , Zhang Wei , Wang Peng , Li Ying‐Xia
Published: December 2011

Baicalein, an important active constituent of the traditional Chinese herbScutellaria baicalensis, exhibited antitumor activity and inhibitory activity against P‐gp 170. The syntheses of 25 baicalein derivatives,2–26(Table), are described here (Scheme 1). These compounds were systematically modified withO‐alkylation andO‐acylation at HOC(5), HOC(6), and HOC(7), singly or in combination, on the ringAof baicalein in order to evaluate the effects of such modifications on their inhibitory activities against multidrug‐resistant tumor cell lines and P‐gp 170. Highly selective and efficient alkylations at HOC(7) of peracetylated baicalein were the key to the distinction between HOC(6) and HOC(7) of baicalein.
Huangqiyenins G – J, Four New 9,10‐Secocycloartane (=9,19‐Cyclo‐9,10‐secolanostane) Triterpenoidal Saponins from Astragalus membranaceusBunge Leaves
Authors: Kuang Hai‐Xue , Wang Qiu‐Hong , Yang Bing‐You , Wang Zhi‐Bin , Okada Yoshihito , Okuyama Tohru
Published: December 2011

Four new 9,10‐secocycloartane (=9,19‐cyclo‐9,10‐secolanostane) triterpenoidal saponins, named huangqiyenins G–J (1–4, resp.), were isolated from Astragalus membranaceus Bunge leaves. The acid hydrolysis of 1–4 with 1M aqueous HCl yielded D‐glucose, which was identified by GC analysis after treatment with L‐cysteine methyl ester hydrochloride. The structures of 1–4 were established by detailed spectroscopic analysis as (3β,6α,10α,16β,24E)‐3,6‐bis(acetyloxy)‐10,16‐dihydroxy‐12‐oxo‐9,19‐cyclo‐9,10‐secolanosta‐9(11),24‐dien‐26‐yl β‐D‐glucopyranoside (1), (3β,6a,10α,24E)‐3,6‐bis(acetyloxy)‐10‐hydroxy‐12,16‐dioxo‐9,19‐cyclo‐9,10‐secolanosta‐9(11),24‐dien‐26‐yl β‐D‐glucopyranoside (2), (3β,6α,9α,10α,16β,24E)‐3,6‐bis(acetyloxy)‐9,10,16‐trihydroxy‐9,19‐cyclo‐9,10‐secolanosta‐11,24‐dien‐26‐yl β‐D‐glucopyranoside (3), and (3β,6α,10α,24E)‐3,6‐bis(acetyloxy)‐10‐hydroxy‐16‐oxo‐9,19‐cyclo‐9,10‐secolanosta‐9(11),24‐dien‐26‐yl β‐D‐glucopyranoside (4).
Exposure to oral bisphosphonates and risk of cancer
Authors: Cardwell Chris R. , Abnet Christian C. , Veal Philip , Hughes Carmel M. , Cantwell Marie M. , Murray Liam J.
Published: December 2011

Recently, oral bisphosphonate use has increased markedly in the United States and elsewhere. Little is known about cancer risks associated with these drugs. A few studies have observed associations between bisphosphonates and the risk of breast, colorectal and esophageal cancer. However, the risk of all cancer and the risk of other cancers have not been investigated. In our study, we examined the risk of all cancer and site specific cancers in individuals taking bisphosphonates. Data were extracted from the UK General Practice Research Database to compare site‐specific cancer incidence in a cohort of oral bisphosphonate users and a control cohort. Hazard ratios (HRs) were calculated using Cox regression modeling. The bisphosphonate and control cohort contained 41,826 participants (mean age 70, 81% female). Overall, the bisphosphonate cohort compared with the control cohort had a reduced risk of all cancer after any bisphosphonate usage [HR = 0.87, 95% confidence interval (CI) 0.82, 0.92]. In the bisphosphonate cohort, compared with the control cohort, there was no evidence of a difference in the risk of lung (HR = 1.03, 95% CI 0.88, 1.20) or prostate cancer (HR = 0.86, 95% CI 0.67, 1.09) but breast (HR = 0.71, 95% CI 0.62, 0.81) and colorectal cancer (HR = 0.74, 95% CI, 0.60–0.91) were both reduced. Our findings indicate that bisphosphonates do not appear to increase cancer risk. Although reductions in breast and colorectal cancer incidence were observed in bisphosphonate users it is unclear, particularly for breast cancer, to what extent confounding by low bone density may explain the association.
Diabetes and risk of esophageal and gastric adenocarcinomas
Authors: Jiang Xuejuan , Bernstein Leslie , Tseng Chiu‐Chen , Wu Anna H.
Published: December 2011

Diabetes has been consistently associated with an increased risk of liver, pancreas and endometrial cancer and has been implicated as a risk factor for esophageal and gastric cancers, although this association has been less well studied. We sought to determine the role of diabetes in the etiology of esophageal, gastric cardia and distal gastric adenocarcinomas (DGAs). This analysis included patients with esophageal adenocarcinoma (EA) (n = 209), gastric cardia adenocarcinoma (GCA) (n = 257) and DGA (n = 382), and 1,309 control participants from a population‐based case–control study conducted in Los Angeles County. The study included non‐Hispanic whites, African Americans, Hispanics and Asian Americans. The association of diabetes with the three tumor types was estimated using polytomous logistic regression. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were estimated. Nine percent of control participants and 13% of the case patients reported a history of diabetes. After adjustment for age, gender, race, birthplace, education, cigarette smoking status and body mass index, diabetes was associated with an increased risk of EA (OR, 1.48; 95% CI, 0.94–2.32; p = 0.089) and DGA (OR, 1.47; 95% CI, 1.01–2.15; p = 0.045), but was not associated with risk of GCA (OR, 0.96; 95% CI, 0.59–1.55; p = 0.87). However, the association between diabetes and risk of DGA was statistically significant only among patients for whom we interviewed their next of kin. Our study further investigated the association between diabetes and adenocarcinomas of the esophagus and distal stomach.
DNA methylation contributes to the regulation of sclerostin expression in human osteocytes
Authors: Delgado-Calle Jesús , Sañudo Carolina , Bolado Alfonso , Fernández Agustín F , Arozamena Jana , Pascual-Carra María A , Rodriguez-Rey José C , Fraga Mario F , Bonewald Lynda , Riancho José A
Published: December 2011

Sclerostin, encoded by the SOST gene, is a potent inhibitor of bone formation, produced by osteocytes, not by osteoblasts, but little is known about the molecular mechanisms controlling its expression. We aimed to test the hypothesis that epigenetic mechanisms, specifically DNA methylation, modulate SOST expression. We found two CpG-rich regions in SOST: region 1, located in the proximal promoter, and region 2, around exon 1. qMSP and pyrosequencing analysis of DNA methylation showed that region 2 was largely methylated in all samples analyzed. In contrast, marked differences were observed in region 1. Whereas the CpG-rich region 1 was hypermethylated in osteoblasts, this region was largely hypomethylated in microdissected human osteocytes. Bone lining cells showed a methylation profile between primary osteoblasts and osteocytes. Whereas SOST expression was detected at very low level or not at all by RT-qPCR in several human osteoblastic and nonosteoblastic cell lines, and human primary osteoblasts under basal conditions, it was dramatically upregulated (up to 1300-fold) by the demethylating agent AzadC. Experiments using reporter vectors demonstrated the functional importance of the region −581/+30 of the SOST gene, which contains the CpG-rich region 1. In vitro methylation of this CpG-island impaired nuclear protein binding and led to a 75 ± 12% inhibition of promoter activity. In addition, BMP-2-induced expression of SOST was markedly enhanced in cells demethylated by AzadC. Overall, these results strongly suggest that DNA methylation is involved in the regulation of SOST expression during osteoblast–osteocyte transition, presumably by preventing the binding of transcription factors to the proximal promoter. To our knowledge, our data provide first ever evidence of the involvement of DNA methylation in the regulation of SOST expression and may help to establish convenient experimental models for further studies of human sclerostin. © 2012 American Society for Bone and Mineral Research.
Evaluation of protein‐ligand binding free energy focused on its entropic components
Authors: Chiba Shuntaro , Harano Yuich , Roth Roland , Kinoshita Masahiro , Sakurai Minoru
Published: December 2011

The binding free energy for FK506‐binding protein‐ligand systems is evaluated as a sum of two entropic components, the water‐entropy gain, and the configurational‐entropy loss for the protein and ligand molecules upon the binding. The two entropic components are calculated using morphometric thermodynamics combined with a statistical‐mechanical theory for molecular liquids and the normal mode analysis, respectively. We find that there is an excellent correlation between the calculated and experimental values of the binding free energy. This result is compared with those of several other binding‐free energy calculation methods, including MM‐PB/SA. The binding can well be elucidated by competition of the two entropic components. Upon the protein‐ligand binding, the total volume available to the translational displacement of the coexisting water molecules increases, leading to an increase in the number of accessible configurations of the water. The water‐entropy gain, by which the binding is driven, originates primarily from this effect. This study sheds new light on the theoretical prediction of the protein‐ligand binding free energy. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
Predicting trabecular bone elastic properties from measures of bone volume fraction and fabric on the basis of micromagnetic resonance images
Authors: Wald Michael J. , Magland Jeremy F. , Rajapakse Chamith S. , Bhagat Yusuf A. , Wehrli Felix W.
Published: December 2011

The relationship between fabric (a measure of structural anisotropy) and elastic properties of trabecular bone was examined by invoking morphology and homogenization theory on the basis of micromagnetic resonance images from the distal tibia in specimens (N = 30) and human subjects (N = 16) acquired at a 160 × 160 × 160 μm3 voxel size. The fabric tensor was mapped in 7.5 × 7.5 × 7.5 mm3 cubic subvolumes by a three‐dimensional mean‐intercept‐length method. Elastic constants (three Young's and three shear moduli) were derived from linear microfinite element simulations of three‐dimensional grayscale bone volume fraction‐mapped images. In the specimen data, moduli fit power laws of bone volume fraction (bone volume/total volume) for all three test directions and subvolumes (R2 = 0.92–0.98) with exponents ranging from 1.3 to 1.8. Weaker linear relationships were found for the in vivo data because of a narrower range in bone volume/total volume. When pooling the data for all test directions and subvolumes, bone volume/total volume predicted elastic moduli less well in the specimens (mean R2 = 0.74) and not at all in vivo. A model of bone volume/total volume and fabric was highly predictive of microfinite element‐derived Young's moduli: mean R2s of 0.98 and 0.82 (in vivo). The results show that fabric, an important predictor of bone mechanical properties, can be assessed in the limited resolution and signal‐to‐noise ratio regime of micromagnetic resonance images. Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc.