bluuebunny/crossref_metadata_2025 huggingface dataset:
ChemInform Abstract: Glycerol Carbonate as a Versatile Building Block for Tomorrow: Synthesis, Reactivity, Properties and Applications
Authors: Sonnati Matthieu O. , Amigoni Sonia , Taffin de Givenchy Elisabeth P. , Darmanin Thierry , Choulet Olivier , Guittard Frederic
Published: March 2013

Review: 275 refs.
ChemInform Abstract: Case Studies of the Synthesis of Bioactive Cyclodepsipeptide Natural Products
Authors: Stolze Sara C. , Kaiser Markus
Published: March 2013

Review: 73 refs.
ChemInform Abstract: Preparation and Application of Cyclodextrin Immobilized Polysaccharides
Authors: Yang Ji Sheng , Yang Li
Published: March 2013

Review: 94 refs.
ChemInform Abstract: Total Synthesis of Biologically Active Lipoteichoic Acids
Authors: Pedersen Christian Marcus , Bols Mikael , Qiao Yan
Published: March 2013

Review: 46 refs.
ChemInform Abstract: The Renaissance of Zinc Carbenoid in Stereoselective Synthesis in Acyclic Systems
Authors: Pasco Morgane , Gilboa Noga , Mejuch Tom , Marek Ilan
Published: March 2013

Review: 106 refs.
ChemInform Abstract: Total Synthesis of Aspergillides Using a Transannular Oxy‐Michael Strategy
Authors: Kanematsu Makoto , Shishido Kozo
Published: March 2013

Review: 72 refs.
ChemInform Abstract: Convergent Method via α‐Cyano Ethers: A Powerful Strategy for Synthesizing Ladder‐Shaped Polyethers
Authors: Oishi Tohru
Published: March 2013

Review: 81 refs.
ChemInform Abstract: Distinguishing Between the Homogeneous and Heterogeneous Mechanisms of Catalysis in the Mizoroki—Heck and Suzuki—Miyaura Reactions: Problems and Prospects
Authors: Schmidt A. F. , Kurokhtina A. A.
Published: March 2013

Review: 124 refs.
ChemInform Abstract: Fluorinated Liquid Crystals: Design of Soft Nanostructures and Increased Complexicity of Self‐Assembly by Perfluorinated Segments
Authors: Tschierske Carsten
Published: March 2013

Review: 440 refs.
ChemInform Abstract: Pentavalent Organobismuth Reagents in Organic Synthesis: Alkylation, Alcohol Oxidation and Cationic Photopolymerization
Authors: Matano Yoshihiro
Published: March 2013

Review: 102 refs.
ChemInform Abstract: Hydrogen Atom Donors: Recent Developments
Authors: Gansaeuer Andreas , Shi Lei , Otte Matthias , Huth Inga , Rosales Antonio , Sancho‐Sanz Iris , Padial Natalia M. , Oltra J. Enrique
Published: March 2013

Review: 90 refs.
ChemInform Abstract: Synthesis Without Protecting Groups
Authors: Hoffmann Reinhard W.
Published: March 2013

Review: 73 refs.
ChemInform Abstract: Dynamic Combinatorial Self‐Replicating Systems
Authors: Moulin Emilie , Giuseppone Nicolas
Published: March 2013

Review: 58 refs.
ChemInform Abstract: Supramolecular Chemistry of Donor—Acceptor Interactions
Authors: Tambara Koujiro , Pantos G. Dan
Published: March 2013

Review: 35 refs.
ChemInform Abstract: Metathesis Reactions
Authors: Thiel Oliver R.
Published: March 2013

Review: 151 refs.
ChemInform Abstract: Gas‐Phase Ion/Ion Reactions of Peptides and Proteins: Acid/Base, Redox, and Covalent Chemistries
Authors: Prentice Boone M. , McLuckey Scott A.
Published: March 2013

Review: 169 refs.
ChemInform Abstract: Nanomaterials Design and Tests for Neutral Tissue Engineering
Authors: Saracino Gloria A. A. , Cigognini Daniela , Silva Diego , Caprini Andrea , Gelain Fabrizio
Published: March 2013

Review: 326 refs.
ChemInform Abstract: Nucleotide, c‐di‐GMP, c‐di‐AMP, cGMP, cAMP, (p)ppGpp Signaling in Bacteria and Implications in Pathogenesis
Authors: Kalia Dimpy , Merey Goekce , Nakayama Shizuka , Zheng Yue , Zhou Jie , Luo Yiling , Guo Min , Roembke Benjamin T. , Sintim Herman O.
Published: March 2013

Review: 318 refs.
ChemInform Abstract: Anticancer Potential of Selenium‐ and Tellurium‐Containing Species: Opportunities Abound!
Authors: Seng Hoi‐Ling , Tiekink Edward R. T.
Published: March 2013

Review: 161 refs.
ChemInform Abstract: Porphyrin‐Sensitized Solar Cells
Authors: Li Lu‐Lin , Diau Eric Wei‐Guang
Published: March 2013

Review: 144 refs.
ChemInform Abstract: Energy Transfer Cassettes Based on Organic Fluorophores: Construction and Applications in Ratiometric Sensing
Authors: Fan Jiangli , Hu Mingming , Zhan Peng , Peng Xiaojun
Published: March 2013

Review: 68 refs.
Elevated Rho‐Kinase Activity as a Marker Indicating Atherosclerosis and Inflammation Burden in Polyvascular Disease Patients With Concomitant Coronary and Peripheral Arterial Disease
Authors: Dong Ming , Jiang Xin , Liao James K. , Yan Bryan P.
Published: March 2013

Background

Recent evidence suggests that Rho‐kinase (ROCK) plays an important role in the pathogenesis of atherosclerosis and a marker of atherosclerotic burden. Polyvascular disease with concomitant peripheral arterial disease (PAD) and coronary artery disease (CAD) is common and associated with a worse prognosis. The aim of this study was to evaluate ROCK activity as a marker of polyvascular disease.

Hypothesis

Methods

We retrospectively analyzed patients undergoing coronary angiography at our institution between February 2009 and May 2009. Patients with only CAD (n = 40) defined by coronary artery stenosis of ≥50% by angiography, only PAD (n = 40) defined by an ankle brachial index (ABI) <0.9, and combined CAD/PAD (n = 40) were matched by age and sex to control patients (n = 40) without CAD or PAD. ROCK activity was determined by phosphorylation of the myosin binding subunit in leukocytes and then compared between each group. Multivariate analysis was used to determine independent predictors of polyvascular disease. Discriminative ability of elevated ROCK activity was assessed using receiver operator characteristics (ROC) curves.

Results

Patients (age 68 ± 12 years, 79% male) with CAD, PAD, and CAD/PAD had a mean ABI of 1.08, 0.62, and 0.65, respectively, compared to 1.08 in the control group. There was an incremental increase in ROCK activity in patients with CAD (4.61 ± 2.11), PAD (4.27 ± 1.39), and CAD/PAD (5.96 ± 1.94) compared to control (2.40 ± 0.43) (all P < 0.05). ROCK activity (odds ratio: 4.53, 95% confidence interval: 1.26‐6.30) was an independent predictor of polyvascular disease. The ROCK cutoff value of 4.85 had a sensitivity of 72.7% and a specificity of 65.7%, with an area under ROC curve of 0.71 for polyvascular disease.

Conclusions

Patients with concomitant peripheral and coronary arterial disease are associated with increased Rho‐kinase activity. Rho‐kinase activity may be a potential marker of atherosclerotic burden for patients with polyvascular disease.
A Comprehensive Microscopic Picture of the Benzhydryl Radical and Cation Photogeneration and Interconversion through Electron Transfer
Authors: Sailer Christian F. , Thallmair Sebastian , Fingerhut Benjamin P. , Nolte Christoph , Ammer Johannes , Mayr Herbert , Pugliesi Igor , de Vivie‐Riedle Regina , Riedle Eberhard
Published: March 2013

Bond cleavage and bond formation are central to organic chemistry. Carbocations play a key role in our understanding of nucleophilic substitution reactions that involve both processes. The precise understanding of the mechanism and dynamics of the photogeneration of carbocations and carbon radicals is therefore an important quest. In particular, the role of electron transfer for the generation of carbocations from the radical pair is still unclear. A quantitative femtosecond absorption study is presented, with ultrabroad probing on selected donor and acceptor substituted benzhydryl chlorides irradiated with 270 nm (35 fs) pulses. The ultrafast bond cleavage within 300 fs is almost exclusively homolytic, thus leading to a radical pair. The carbocations observable in the nanosecond regime are generated from these radicals by electron transfer from the benzhydryl to the chlorine radical within the first tens of picoseconds. Their concentration is reduced by geminate recombination within hundreds of picoseconds. In moderately polar solvents this depletion almost extinguishes the cation population; in highly polar solvents free ions are still observable on the nanosecond timescale. The explanation of the experimental findings requires the microscopic realm of the intermediates to be accounted for, including their spatial and environmental distributions. The distance dependent electron transfer described by Marcus theory is combined with Smoluchowski diffusion. The depletion of the radical pair distribution at small distances causes a temporal increase of the mean distance and the observed stretched exponential electron transfer. A close accord with experiment can only be reached for a broad distribution of the nascent radical pairs. The increase in the inter‐radical and inter‐ion pair distance is measured directly as a shift of the UV/Vis absorption of the products. The results demonstrate that, at least for aprotic solvents, traditional descriptions of reaction mechanisms based on the concept of contact and solvent‐separated pairs have to be reassessed.
Hydrodesulfurization of Thiophene over Few‐Layer MoS2 Covered with Cobalt and Nickel Nanoparticles
Authors: Rao Bolla Govinda , Matte H. S. S. Ramakrishna , Chaturbedy Piyush , Rao C. N. R.
Published: March 2013

The hydrodesulfurization reaction of thiophene has been investigated over graphene‐like few‐layer MoS2 as well as over Co‐ and Ni‐nanoparticle‐covered few‐layer MoS2. Conversion of thiophene to n‐butane over few‐layer MoS2 is superior to that over bulk MoS2; the percent conversion is approximately 64 % at 450 °C. However, over few‐layer MoS2 covered with Co or Ni nanoparticles the conversion increases to approximately 98 % at around 375 °C as a result of the smaller nanoparticles being more effective.
Lanthanide(III) Complexes of Diethylenetriaminepentaacetic Acid (DTPA)–Bisamide Derivatives as Potential Agents for Bimodal (Optical/Magnetic Resonance) Imaging
Authors: Debroye Elke , Eliseeva Svetlana V. , Laurent Sophie , Vander Elst Luce , Petoud Stéphane , Muller Robert N. , Parac‐Vogt Tatjana N.
Published: March 2013

Diethylenetriaminepentaacetic acid (DTPA)–bisamide derivatives functionalized with p‐toluidine, 6‐aminocoumarin, 1‐naphthalene methylamine and 4‐ethynylaniline were synthesized and fully characterized by mass spectrometry, NMR spectroscopy, FTIR spectroscopy and elemental analysis. LnIII complexes (Ln = Gd, Eu, Tb, Y) of the ligands DTPA–bis‐p‐toluidineamide (DTPA–BTolA), DTPA–bis‐6‐coumarinamide (DTPA–BCoumA), DTPA–bis‐1‐naphthylmethylamide (DTPA–BNaphA) and DTPA–bis‐4‐ethynylphenylamide (DTPA–BEthA) were prepared and studied for their bimodal magnetic resonance imaging/optical properties. EuIII and TbIII derivatives in aqueous solutions exhibit characteristic red and green emission, respectively, with quantum yields of 0.73 % for EuIII–DTPA–BNaphA and 2.5 % for TbIII–DTPA–BEthA. Ligand‐centred photophysical properties of the GdIII complexes were investigated to gain insight into energy‐transfer processes that take place in these systems. The GdIII complexes were also analyzed by nuclear magnetic relaxation dispersion (NMRD) techniques. The relaxivity (r1) at 20 MHz and 310 K equals 4.1 s–1 mM–1 for Gd–DTPA–BTolA, 5.1 s–1 mM–1 for Gd–DTPA–BCoumA, 6.4 s–1 mM–1 for Gd–DTPA–BNaphA and 5.7 s–1 mM–1 for Gd–DTPA–BEthA. These values are higher than the value of 3.8 s–1 mM–1 for Gd–DTPA (Magnevist). The improved relaxivity is due to the increase in the rotational tumbling time τR with a factor of 1.6 for Gd–DTPA–BTolA, 2.1 for Gd–DTPA–BCoumA, 3.1 for Gd–DTPA–BNaphA and 6.5 for Gd–DTPA–BEthA. In a 4 % human serum albumin solution, the apparent relaxivity at 20 MHz increases to values of 13.9 and 19.1 s–1 mM–1 for Gd–DTPA–BNaphA and Gd–DTPA–BEthA, respectively. All these features assist the search for optimal bimodal optical and magnetic resonance imaging probes.
Synthesis and Characterization of β‐Trifluoromethyl‐Substituted Pyrrolidines
Authors: Yarmolchuk Vladimir S. , Shishkin Oleg V. , Starova Viktoriia S. , Zaporozhets Olga A. , Kravchuk Olga , Zozulya Sergey , Komarov Igor V. , Mykhailiuk Pavel K.
Published: March 2013

A practical synthetic approach to the construction of a library of three isomeric/homologous β‐trifluoromethyl‐substituted pyrrolidines is disclosed. All products were prepared in multigram quantities from a common precursor. The key synthetic step was a [3+2] cycloaddition reaction. The influence of the trifluoromethyl group on the physicochemical characteristics of the pyrrolidine fragment was studied.
Development of glutaraldehyde‐crosslinked chymotrypsin and an in situ immobilized enzyme microreactor with peptide mapping by capillary electrophoresis
Authors: Ghafourifar Golfam , Fleitz Antoine , Waldron Karen C.
Published: March 2013

Immobilized proteolytic enzymes present several advantages over their soluble form, not the least of which is suppression of autoproteolysis peaks even at high enzyme‐to‐substrate ratios. We have made immobilized chymotrypsin by directly crosslinking it with glutaraldehyde to produce polymeric particles. Digestion of two model substrates using the particles was followed by CE peptide mapping with detection by UV absorbance or LIF. Results showed that autoproteolysis was highly suppressed and that different storage conditions of the particles in the short term (24 h) did not affect digestion of denatured BSA. As well, the chymotrypsin particles were indifferent to the presence of fluorescein groups on a casein substrate. Glutaraldehyde crosslinking of chymotrypsin inside a fused silica capillary column to make an immobilized enzyme reactor (IMER) was achieved in a series of reagent addition and washing steps, entirely automated using a commercial CE instrument. Digestion of myoglobin in the IMER for 30 min at 37°C followed by peptide mapping by CE‐MS of the collected digest allowed identification of 17 chymotryptic peptides of myoglobin, or 83% primary sequence coverage.
Precise, fast and flexible determination of protein interactions by affinity capillary electrophoresis. Part 2: Cations
Authors: Redweik Sabine , Cianciulli Claudia , Hara Masakazu , Xu Yuanhong , Wätzig Hermann
Published: March 2013

The influence of various cations as metal ions (barium, calcium, copper, magnesia, manganese, and nickel), pharmaceuticals (ephedrine, ethambutol, pilocarpine, and pirenzepine), arginine, and guanidine has been tested on BSA, β‐lactoglobulin, and ovalbumin. Influences on proteins regarding changes in size, charge, or mass were of particular interest. ACE proved to be a suitable method to investigate these effects. ACE is able to observe slight but significant changes on proteins due to the excellent precision of the measurements. Therefore, some unexpected behaviors of protein–ligand interactions were found. The protein charge becomes more negative under metal ion influence and some pharmaceutical cations. Probably metal ions bound to the proteins form additional complexes with anions from the surrounding solution. Furthermore, already bound cations could be displaced at the protein surface. Both effects would change the overall charge of the ligand–protein complexes. In all studied cases, multiple‐binding stoichiometries have been observed.
Novel Ag–Glass Composite Interconnect Materials for Anode‐Supported Flat‐Tubular Solid Oxide Fuel Cells Operated at an Intermediate Temperature
Authors: Pi S.‐H. , Lee S.‐B. , Song R.‐H. , Lee J.‐W. , Lim T.‐H. , Park S.‐J. , Shin D.‐R. , Park C.‐O.
Published: March 2013

We developed novel Ag–glass composite interconnect materials for anode‐supported flat‐tubular solid oxide fuel cells (SOFCs) operated at 700 °C by optimization of the glass content. For this purpose, the variations of phase stability, area specific resistance (ASR), microstructure, gas leak rate, cell performance, and open circuit voltage (OCV) were determined for the Ag–glass composite materials with respect to the glass content. The Ag–glass composite materials maintain phase stability without chemical reactions. The ASR increased as the glass content increases due to glass existing as an insulator between the Ag phases. All the composite materials showed dense coating layers on the anode support and had a low gas leak. The cell performance and OCV were measured to identify the optimum composition of the Ag–glass composites. Our results confirm that Ag–glass composites are suitable for high performance interconnects in anode‐supported flat‐tubular fuel cells operated below 700 °C.
Using hydroacoustic stations as water column seismometers
Authors: Yildiz Selda , Sabra Karim , Dorman LeRoy M. , Kuperman W. A.
Published: March 2013

Getting seismic data from the deep oceans usually involves ocean‐bottom seismometers, but hydrophone arrays may provide a practical alternative means of obtaining vector data. We here explore this possibility using hydrophone stations of the International Monitoring System, which have been used to study icebergs and T‐wave propagation among others. These stations consist of three hydrophones at about the depth of the deep sound channel in a horizontal triangle array with 2 km sides. We use data from these stations in the very low‐frequency regime (0.01–0.05 Hz band) to demonstrate that these stations can also be used as water column seismometers. By differencing the acoustic pressure, we obtain vector quantities analogous to what a seismometer would record. Comparing processed hydrophone station records of the 2004 Great Sumatra‐Andaman Earthquake with broadband seismograms from a nearby island station, we find that the differenced hydrophones are indeed a practical surrogate for seismometers.
The importance of pickup oxygen ion precipitation to the Mars upper atmosphere under extreme solar wind conditions
Authors: Fang Xiaohua , Bougher Stephen W. , Johnson Robert E. , Luhmann Janet G. , Ma Yingjuan , Wang Yung‐Ching , Liemohn Michael W.
Published: March 2013

While the Mars upper atmosphere is continuously bombarded by charged particles of solar and planetary origins, the energy flux carried is often not sufficient to significantly affect the neutral atmosphere. However, we show that this is not the case during major space weather events. By applying two Mars global models—a Monte Carlo model for simulating pickup O+ precipitation at the exobase and a thermosphere‐ionosphere model for assessing its global impact, we find that the thermospheric effects of reentering ions can change from negligible to very important when upstream solar wind conditions vary from normal to extreme. The atmospheric response under the most extreme conditions includes dramatic neutral temperature enhancement, significant neutral composition and wind changes, and increased importance of sputtering loss and possibly even thermal escape of heavy species.
Tectonic overpressure in weak crustal‐scale shear zones and implications for the exhumation of high‐pressure rocks
Authors: Schmalholz Stefan M. , Podladchikov Yuri Y.
Published: March 2013

A two‐dimensional numerical simulation of lithospheric shortening shows the formation of a stable crustal‐scale shear zone due to viscous heating. The shear zone thickness is controlled by thermomechanical coupling that is resolved numerically inside the shear zone. Away from the shear zone, lithospheric deformation is dominated by pure shear, and tectonic overpressure (i.e., pressure larger than the lithostatic pressure) is proportional to the deviatoric stress. Inside the shear zone, deformation is dominated by simple shear, and the deviatoric stress decreases due to thermal weakening of the viscosity. To maintain a constant horizontal total stress across the weak shear zone (i.e., horizontal force balance), the pressure in the shear zone increases to compensate the decrease of the deviatoric stress. Tectonic overpressure in the weak shear zone can be significantly larger than the deviatoric stress at the same location. Implications for the geodynamic history of tectonic nappes including high‐pressure/ultrahigh‐pressure rocks are discussed.
An Alpaca Nanobody Inhibits Hepatitis C Virus Entry And Cell-To-Cell Transmission
Authors: Tarr Alexander W. , Lafaye Pierre , Meredith Luke , Damier-Piolle Laurence , Urbanowicz Richard A. , Meola Annalisa , Jestin Jean-Luc , Brown Richard J. P. , McKeating Jane A. , Rey Felix A. , Ball Jonathan K. , Krey Thomas
Published: March 2013

Severe liver disease caused by chronic hepatitis C virus is the major indication for liver transplantation. Despite recent advances in antiviral therapy, drug toxicity and unwanted side effects render effective treatment in liver-transplanted patients a challenging task. Virus-specific therapeutic antibodies are generally safe and well-tolerated, but their potential in preventing and treating hepatitis C virus (HCV) infection has not yet been realized due to a variety of issues, not least high production costs and virus variability. Heavy-chain antibodies or nanobodies, produced by camelids, represent an exciting antiviral approach; they can target novel highly conserved epitopes that are inaccessible to normal antibodies, and they are also easy to manipulate and produce. We isolated four distinct nanobodies from a phage-display library generated from an alpaca immunized with HCV E2 glycoprotein. One of them, nanobody D03, recognized a novel epitope overlapping with the epitopes of several broadly neutralizing human monoclonal antibodies. Its crystal structure revealed a long complementarity determining region (CD3) folding over part of the framework that, in conventional antibodies, forms the interface between heavy and light chain. D03 neutralized a panel of retroviral particles pseudotyped with HCV glycoproteins from six genotypes and authentic cell culture–derived particles by interfering with the E2-CD81 interaction. In contrast to some of the most broadly neutralizing human anti-E2 monoclonal antibodies, D03 efficiently inhibited HCV cell-to-cell transmission. Conclusion: This is the first description of a potent and broadly neutralizing HCV-specific nanobody representing a significant advance that will lead to future development of novel entry inhibitors for the treatment and prevention of HCV infection and help our understanding of HCV cell-to-cell transmission. (Hepatology 2013;53:932–939)
INFORMAL SOCIAL SUPPORT AND DEPRESSION AMONG AFRICAN AMERICAN MEN WHO HAVE SEX WITH MEN
Authors: Yang Cui , Latkin Carl , Tobin Karin , Patterson Jocelyn , Spikes Pilgrim
Published: March 2013

Men who have sex with men (MSM) experience greater mental health problems as compared with heterosexual populations. Informal social support plays a critical role in emotional well‐being. The primary goal of this article is to examine the relationship between depressive symptoms and received social support from family, friends, and sex partners within the social network from a sample of 188 African American MSM in Baltimore, Maryland. We found that receiving emotional support from a family member or a sex partner was associated with reduced odds of having depressive symptoms. Receiving financial support from a family member or a friend was associated with increased odds of having depressive symptoms. The results suggest the importance of emotional support provided by family and sex partner in mental health and the potential value of training African American MSM in skills to enhance the quality of the relationships.
THE CARROT AND THE STICK: A CROSS‐SECTIONAL STUDY OF THE INFLUENCES ON RESPONSIBLE MERCHANT PRACTICES TO REDUCE UNDERAGE DRINKING
Authors: Chinman Matthew , Ebener Patricia , Malone Patrick S. , Chan Karen , Imm Pamela , Wright Patricia Ann
Published: March 2013

Alcohol merchants (N = 331) completed a cross‐sectional survey assessing their attitudes and beliefs about underage drinking, its likely consequences, requirements for responsible beverage service (RBS) training, and performance of RBS practices and checking IDs. Merchants requiring more rigorous RBS training (i.e., state‐approved vs. in‐house or none) have stronger beliefs that outlets who sell to minors will get cited and that their employees know RBS practices. Also, merchants who engage in more RBS practices require more rigorous RBS training, and believe more strongly that outlets who sell to minors are more likely to face, and deserve, stricter sanctions. Merchants who check IDs more strictly conduct more RBS practices and believe more strongly that underage drinking is serious and will result in stronger consequences if caught selling to minors. These findings about the attitudes, practices, and enforcement of alcohol merchants suggests ways communities can better target their limited resources to prevent underage drinking.
SPOTTING THE SIGNS: FIRST‐YEAR COLLEGE STUDENTS' RESPONSES TO BYSTANDER‐THEMED RAPE PREVENTION POSTERS
Authors: Katz Jennifer , Olin Rachel , Herman Catherine , DuBois Melinda
Published: March 2013

This research evaluated whether exposure to “Know Your Power” posters promotes willingness to help others at risk, alone or in interaction with social self‐identification. At the start of the academic year, posters were hung in two randomly selected residence halls. No posters were hung in a control hall. After 6 weeks, first‐year undergraduate students (N = 95) reported their willingness to help others and their perceptions of the posters via an anonymous online survey. More students from the experimental than control halls noticed the posters; there were no other differences between students who did and did not notice the posters. Willingness to help others at risk was elevated among students exposed to posters at least once. This effect was marginally enhanced among students who perceived the posters as depicting familiar people and situations. Overall, results suggest that bystander‐themed educational posters help promote community safety by encouraging bystander intervention.
Characterization and intercomparison of global moderate resolution leaf area index (LAI) products: Analysis of climatologies and theoretical uncertainties
Authors: Fang Hongliang , Jiang Chongya , Li Wenjuan , Wei Shanshan , Baret Frédéric , Chen Jing M. , Garcia‐Haro Javier , Liang Shunlin , Liu Ronggao , Myneni Ranga B. , Pinty Bernard , Xiao Zhiqiang , Zhu Zaichun
Published: March 2013

Leaf area index (LAI) is a critical variable for land surface and climate modeling studies. Several global LAI products exist, and it is important to know how these products perform and what their uncertainties are. Five major global LAI products—MODIS, GEOV1, GLASS, GLOBMAP, and JRC‐TIP—were compared between 2003 and 2010 at a 0.01° spatial resolution and with a monthly time step. The daily Land‐SAF product was used as a regional reference in order to evaluate the performance of other global products in Africa. Cross‐sensor LAI conversion equations were derived for different biome types. Product uncertainties were assessed by looking into the product quantitative quality indicators (QQIs) attached to MODIS, GEOV1, and JRC‐TIP. MODIS, GEOV1, GLASS, and GLOBMAP are generally consistent and show strong linear relationships between the products (R2 > 0.74), with typical deviations of < 0.5 for nonforest and < 1.0 for forest biomes. JRC‐TIP, the only effective LAI product, is about half the values of the other LAI products. The average uncertainties and relative uncertainties are in the following order: MODIS (0.17, 11.5%) < GEOV1 (0.24, 26.6%) < Land‐SAF (0.36, 37.8%) < JRC‐TIP (0.43, 114.3%). The highest relative uncertainties usually appear in ecological transition zones. More than 75% of MODIS, GEOV1, JRC‐TIP, and Land‐SAF pixels are within the absolute uncertainty requirements (± 0.5) set by the Global Climate Observing System (GCOS), whereas more than 78.5% of MODIS and 44.6% of GEOV1 pixels are within the threshold for relative uncertainty (20%). This study reveals the discrepancies mainly due to differences between definitions, retrieval algorithms, and input data. Future product development and validation studies should focus on areas (e.g., sparsely vegetated and savanna areas) and periods (e.g., winter time) with higher uncertainties.
K‐t GRAPPA accelerated phase contrast MRI: Improved assessment of blood flow and 3‐directional myocardial motion during breath‐hold
Authors: Bauer Simon , Markl Michael , Föll Daniela , Russe Maximilian , Stankovic Zoran , Jung Bernd
Published: March 2013

Purpose

To evaluate spatiotemporal parallel imaging with R = 5 in comparison to conventional parallel imaging with R = 2 applied to phase contrast (PC) magnetic resonance imaging (MRI). This was motivated by the fact that scan times for PC imaging often exceed breath‐hold capabilities of patients even with standard parallel imaging using typical reduction factors of R = 2.

Materials and Methods

K‐t generalized autocalibrating partially parallel acquisition (GRAPPA) acquisition was validated in phantom measurements and then applied in 10 volunteer and three patient examinations. Due to the higher reduction factor compared to conventional GRAPPA, k‐t GRAPPA measurements could be performed during breath‐hold with high spatial and temporal resolution. K‐t GRAPPA scans were compared to GRAPPA acquired during free‐breathing with navigator respiration control. In addition, spatiotemporally accelerated PC imaging was acquired during free‐breathing for comparison of k‐t‐accelerated breath‐held scans.

Results

Substantial improvements in image quality for the breath‐hold measurements were observed. Significantly reduced peak velocities were found for the GRAPPA protocol compared to the k‐t‐accelerated breath‐hold scans for both flow (8%) and myocardial motion (up to 30%) measurements.

Conclusion

Spatiotemporal acceleration allows the performance of high temporal or spatial resolution PC imaging during breath‐hold while providing high image quality and robust acquisition of functional information that cannot be achieved during breath‐hold with standard techniques. J. Magn. Reson. Imaging 2013;38:1054–1062. © 2013 Wiley Periodicals, Inc.
Low‐molecular contrast agent dynamic contrast‐enhanced (DCE)‐MRI and diffusion‐weighted (DW)‐MRI in early assessment of bevacizumab treatment in breast cancer xenografts
Authors: Moestue Siver A. , Huuse Else M. , Lindholm Evita M. , Bofin Anna , Engebraaten Olav , Mælandsmo Gunhild M. , Akslen Lars A. , Gribbestad Ingrid S.
Published: March 2013

Purpose

To investigate the effect of bevacizumab treatment on vascular architecture and function in two xenograft models with different angiogenic properties using diffusion‐weighted magnetic resonance imaging (DW‐MRI) and dynamic contrast‐enhanced MRI (DCE‐MRI).

Materials and Methods

Mice carrying basal‐like (MAS98.12) or luminal‐like (MAS98.06) orthotopic breast cancer xenografts were treated with bevacizumab (5 mg/kg), doxorubicin (8 mg/kg), or both drugs in combination. DW‐MRI and DCE‐MRI were performed before and 3 days after treatment using a Bruker 7T preclinical scanner. Mean microvessel density (MVD) and proliferating microvessel density (pMVD) in the tumors were determined for evaluation of vascular response to bevacizumab treatment.

Results

No changes in DCE‐MRI or DW‐MRI parameters were observed in untreated controls during the experiment period. DW‐MRI showed increased apparent diffusion coefficient (ADC) values in all treatment groups in both basal‐like and luminal‐like xenografts. DCE‐MRI showed increased contrast agent uptake, particularly in central regions of the tumors, after bevacizumab/combination treatment in both xenograft models. This was accompanied by decreased MVD and pMVD in basal‐like xenografts. Doxorubicin treatment had no effect on DCE‐MRI parameters in any of the xenograft models.

Conclusion

Both DW‐MRI and DCE‐MRI demonstrated an early response to bevacizumab treatment in the xenograft tumors. Increased contrast agent uptake and reduced MVD/pMVD is consistent with a normalization of vascular function. J. Magn. Reson. Imaging 2013;38:1043–1053. © 2013 Wiley Periodicals, Inc.
Masters athletes exhibit larger regional brain volume and better cognitive performance than sedentary older adults
Authors: Tseng Benjamin Y. , Uh Jinsoo , Rossetti Heidi C. , Cullum C. Munro , Diaz‐Arrastia Ramon F. , Levine Benjamin D. , Lu Hanzhang , Zhang Rong
Published: March 2013

Purpose

To investigate differences in the age‐related decline in brain tissue concentration between Masters athletes and sedentary older adults.

Materials and Methods

Twelve Masters athletes (MA) (three females, age = 72.4 ± 5.6 years, endurance training >15 years), 12 sedentary elderly (SE) similar in age and educational level (four females, age = 74.6 ± 4.3 years), and nine young controls (YC) (four females, age = 27.2 ± 3.6 years) participated. T1‐weighted high‐resolution (1 × 1 × 1mm3) images were acquired. Voxel‐based analysis was conducted to identify clusters showing tissue concentration differences with t‐tests. Cognitive function was assessed using a standard clinical battery focused on executive function and memory.

Results

Two MA and two SE were unable to complete the magnetic resonance imaging (MRI) study. Both SE and MA showed lower gray matter (GM) concentrations than YC in the superior, inferior and middle frontal gyrus, superior temporal gyrus, postcentral gyrus, and the cingulate gyrus (PFDR‐corrected < 0.001) and lower white matter (WM) concentrations in the inferior frontal gyrus and precentral gyrus (PFDR‐corrected < 0.005). Notably, MA showed higher GM and WM concentrations than SE in the subgyral, cuneus, and precuneus regions related to visuospatial function, motor control, and working memory (PFDR‐corrected < 0.005). After controlling for estimated intelligence, MA outperformed SE on tasks of letter (P < 0.01) and category (P < 0.05) fluency.

Conclusion

Life‐long exercise may confer benefits to some aspects of executive function and age‐related brain tissue loss in the regions related to visuospatial function, motor control, and working memory in older adults. J. Magn. Reson. Imaging 2013;38:1169–1176. © 2013 Wiley Periodicals, Inc.
Bioactive lipids in the butter production chain from Parmigiano Reggiano cheese area
Authors: Verardo Vito , Gómez‐Caravaca Ana M , Gori Alessandro , Losi Giuseppe , Caboni Maria F
Published: March 2013

BACKGROUND

Bovine milk contains hundreds of diverse components, including proteins, peptides, amino acids, lipids, lactose, vitamins and minerals. Specifically, the lipid composition is influenced by different variables such as breed, feed and technological process. In this study the fatty acid and phospholipid compositions of different samples of butter and its by‐products from the Parmigiano Reggiano cheese area, produced by industrial and traditional churning processes, were determined.

RESULTS

The fatty acid composition of samples manufactured by the traditional method showed higher levels of monounsaturated and polyunsaturated fatty acids compared with industrial samples. In particular, the contents of n‐3 fatty acids and conjugated linoleic acids were higher in samples produced by the traditional method than in samples produced industrially. Sample phospholipid composition also varied between the two technological processes. Phosphatidylethanolamine was the major phospholipid in cream, butter and buttermilk samples obtained by the industrial process as well as in cream and buttermilk samples from the traditional process, while phosphatidylcholine was the major phospholipid in traditionally produced butter. This result may be explained by the different churning processes causing different types of membrane disruption. Generally, samples produced traditionally had higher contents of total phospholipids; in particular, butter produced by the traditional method had a total phospholipid content 33% higher than that of industrially produced butter.

CONCLUSION

The samples studied represent the two types of products present in the Parmigiano Reggiano cheese area, where the industrial churning process is widespread compared with the traditional processing of Reggiana cow's milk. This is because Reggiana cow's milk production is lower than that of other breeds and the traditional churning process is time‐consuming and economically disadvantageous. However, its products have been demonstrated to contain more bioactive lipids compared with products obtained from other breeds and by the industrial process. © 2013 Society of Chemical Industry
A new methodology for rain identiﬁcation from passive microwave data in the Tropics using neural networks
Authors: Kacimi Sahra , Viltard Nicolas , Kirstetter Pierre‐Emmanuel
Published: March 2013

The detection of rainfall remains a challenge for the monitoring of precipitation from space. A methodology is presented to identify rain events from spaceborne passive microwave data using neural networks. We focus on BRAIN, the algorithm that provides instantaneous quantitative precipitation estimates at the surface, based on the MADRAS radiometer onboard the Megha‐Tropiques satellite. A version of BRAIN using data from the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) has been used to compare several multilayer perceptrons (MLP) trained on different combinations of TMI brightness temperatures with the conventional GSCAT‐2 algorithm approach used for rainfall detection. These classiﬁers were compared at a global scale to reference values from the TRMM Precipitation Radar (PR). They were also compared to ground measurements using two 1° × 1° dense rain‐gauge networks from different climatic zones in West Africa to assess the inﬂuence of rainfall types. At the global scale the MLPs provide better Probability of Detection than the GSCAT‐2 decision tree but tend to have a higher False Alarm Rate. While no unique solution exists given the strong regional dependence of the classiﬁers' performances, the screen based on the 19, 21 and 85 GHz channels provides the best detection results at the instantaneous scales. As to accumulated rainfall, the screen that exhibits the lower bias relative to the PR makes use of the 37 and 85 GHz channels. The evaluation over West Africa using 10 years of TRMM overpasses shows that MLPs are in better agreement with both the PR and the gauges than GSCAT‐2. The MLP trained on the 37 and 85 GHz channels increases the Probability of Detection by nearly 35% compared to the former screening over the two studied regions. Better results are obtained in the case of organized systems. Copyright © 2013 Royal Meteorological Society
The geometric norm improves ensemble forecasting with the breeding method
Authors: Pazó D. , López J. M. , Rodríguez M. A.
Published: March 2013

Error breeding is a popular and simple method to generate flow‐adapted perturbations for use in ensemble forecasting. It has traditionally been believed that the norm type used in periodic normalizations of bred vectors (BVs) does not have an important effect on the performance of BVs within ensemble forecasting systems. However, we have recently reported that the geometric norm has nice properties (e.g. enhancement of the ensemble diversity) that in principle render it more adequate to construct ensembles than other norm types like the Euclidean one. These advantages are clearly demonstrated here in a simple experiment of ensemble forecasting for the Lorenz‐96 model with ensembles of BVs. Our simple numerical assimilation experiment shows how the increased statistical diversity of geometric BVs leads to improved scores regarding forecasting capabilities as compared with BVs constructed with the standard Euclidean norm. Moreover, we provide a theoretical basis for all these results by resorting to generic properties of spatially extended chaotic systems.
Using operational weather radar to assess high‐resolution numerical weather prediction over the British Isles for a cold air outbreak case‐study
Authors: McBeath K. , Field P. R. , Cotton R. J.
Published: March 2013

Examination of weather radar data from the Constrain field campaign during January 2010 is presented, and comparisons between the radar data and reflectivity data computed from the Met Office high‐resolution British Isles NWP model (UKV Δx = 1.5 km) are shown. Cluster analysis was used to identify and track cells of precipitation in the two datasets; this allowed characteristics of the cloud field to be examined. Cells of precipitation were identified in the data using a reflectivity threshold of 10 dBz which allowed these cells to be tracked as they moved through the region of interest. The mean cell area identified in the radar data was found to be 37.5±1.3 km2, while the mean area of cells identified in the model data was 63.5±2.0 km2. Significant differences between the model and radar data were seen in the shape of the cells, with the cells identified in the model found to be more circular than those seen in the radar data.
Parametrization of instantaneous global horizontal irradiance: clear‐sky component
Authors: Sun Zhian , Zeng Xianning , Liu Jingmiao , Liang Hong , Li J.
Published: March 2013

Based on an accurate atmospheric radiative transfer scheme, a parametrization of instantaneous global horizontal irradiance (GHI) at the Earth's surface has been developed. The scheme is named SUNFLUX and this article describes the development of the scheme for clear‐sky conditions. The work dealing with clouds has been published in a separate article. Unlike traditional methods, this study applies the band model idea used in radiative transfer theory to the development of the surface radiation scheme and, importantly, includes absorption and scattering in the parametrization. Thus the scheme is more accurate compared with those using simple empirical approaches and may be applied to any site without being tuned for local conditions. The parametrization of aerosol transmittance and albedo developed by Kokhanovskyet al.is adopted to account for the effects of aerosols. All variables used in the scheme are available in climate models or from satellite observations. Therefore, the parametrization can be used to determine the GHI at the surface under clear‐sky conditions

The scheme is evaluated using observations obtained from three US Atmospheric Radiation Measurement (ARM) stations and three stations on the Tibetan Plateau, and the results demonstrate that the scheme is accurate. The relative mean bias difference is less than 4.3% and the relative root‐mean‐squared difference is less than 0.09%.
Idealised simulations of sting‐jet cyclones
Authors: Baker L. H. , Gray S. L. , Clark P. A.
Published: March 2013

An idealised modelling study of sting‐jet cyclones is presented. Sting jets are descending mesoscale jets that occur in some extratropical cyclones and produce localised regions of strong low‐level winds in the frontal fracture region. Moist baroclinic lifecycle (LC1) simulations are performed with modifications to produce cyclones resembling observed sting‐jet cyclones.

A sting jet exists in the idealised control cyclone with similar characteristics to the sting jet in a simulation of windstormGudrun(a confirmed sting‐jet case). Unlike in windstormGudrun, a low‐level layer of strong moist static stability prohibits the descent of the strong winds from above the boundary layer to the surface in the idealised case. Conditional symmetric instability (CSI) exists in the cloud head and dissipates as the sting jet leaves the cloud head and descends. The descending, initially moist, sting‐jet trajectories consistently have negative or near‐zero saturated moist potential vorticity but moist static stability and inertial stability, consistent with CSI release; the moist static stability becomes negative during the period of most rapid descent, by which time the air is relatively dry implying conditional instability release is unlikely.

Sensitivity experiments show that the existence of the sting jet is robust to changes in the initial state, and that the initial tropospheric static stability significantly impacts the descent rate of the sting jet. Inertial and conditional instability are probably being released in the experiment with the weakest initial static stability. This suggests that sting jets can arise through the release of all three instabilities associated with negative saturated moist potential vorticity. While evaporative cooling occurs along the sting‐jet trajectories, a sensitivity experiment with evaporation effects turned off shows no significant change to the wind strength or descent rate of the sting jet implying that instability release is the dominant sting‐jet driving mechanism.
Stahlkonstruktionen des Verwaltungs‐ und Leitungssystems der Südmährischen Gas‐AG. in Brno
Authors: Melcher J.
Published: March 2013

Im Beitrag wird über den Entwurf des Stahltragwerkes des Verwaltungs‐ und Leitungszentrums berichtet, das für die Südmährische Gas‐AG. in Brno realisiert wurde. Hier werden näher die Disposition, das Bemessungsmodell, die Konstruktionslösung und typische Details des mehrstöckigen zylinderförmigen Hauptgebäudes beschrieben. Es wird sowohl die Ästhetik als auch das Verhältnis von Detail und Übersicht der vor dem Außenmantel angeordneten Gitterstabstruktur dieses Gebäudes hervorgehoben.
Hängeseil‐ und Schrägseilkonstruktionen von Fußgänger‐ und Rohrleitungsbrücken
Authors: Agócs Z. , Chladny E. , Brodniansky J.
Published: March 2013

Im vorliegenden Beitrag werden einige realisierte Typen von Hängeseil‐ und Schrägseilkonstruktionen für Fußgänger‐ und Rohrleitungsbrücken auf dem Territorium der Slowakischen und Tschechischen Republik beschrieben. Weiter werden die Besonderheiten der Konzeption, Konstruktion und Technologie der Brücken für größere Spannweiten und mit kleiner Steifigkeit des Aussteifungsträgers erläutert.
Probabilistische Verfahren in der Bemessung von Stahltragwerken
Authors: Marek P. , Gustar M.
Published: March 2013

Die bisher angewendeten Konzeptionen zur Beurteilung der Zuverlässigkeit von Stahlkonstruktionen, welche in derzeitigen Normen zur Geltung kommen, sind während der Epoche des Rechenschiebers entstanden und schaffen kaum Voraussetzungen zur vollen Nutzung der Leistungsfähigkeit der sich schnell weiterentwickelnden Computertechnologie und des "Information Freeway". Der Beitrag bietet einen Blick darauf, wie sich die deterministischen und semi‐probabilistischen Methoden zu voll‐probabilistischen Konzeptionen auf dem Gebiet der Bemessung von Stahlkonstruktionen gewendet haben. Die Aufmerksamkeit ist speziell auf die SBRA‐Methode (Simulation‐Based Reliability Assessment) gerichtet, welche dem Prinzip der "Parameterbezogenen Histogramme" entspricht, wobei alle Variablen durch die entsprechenden Histogramme repräsentiert werden, die Analyse der Zuverlässigkeitsfunktion mit Hilfe der Monte‐Carlo‐Simulation durchgeführt wird und die Wahrscheinlichkeit des Versagens P Index f, verglichen mit dem Bemessungswert der Wahrscheinlichkeit P Index d, das Zuverlässigkeitskriterium darstellt. Der qualitative Unterschied zwischen dem Konzept der Teilsicherheitsfaktoren und der SBRA‐Methode wird diskutiert. Ein Stahlrahmen mit drei Pendelstützen und einer eingespannten Stütze dient als Beispiel für die Verwendung des SBRA‐Verfahrens.
Stabilitätsprobleme der nichtlinearen Baudynamik bei Systemen mit variabler Struktur
Authors: Vielsack P.
Published: March 2013

Systeme mit variabler Struktur gehören zum Problemkreis der nichtglatten Dynamik. Wegen ihrer strengen Nichtlinearität sind spezielle Lösungsmethoden erforderlich. Zwei Aufgabenstellungen werden betrachtet, die eine Analogie zu bekannten statischen Stabilitätsproblemen besitzen. Dies sind ein kinetisches Durchschlagproblem und ein kinetisches Verzweigungsproblem.
Stabilitätsverhalten von punktförmig gestützten Kreiszylinderschalen
Authors: Schulz U. , Ruff D. , Ummenhofer Th.
Published: March 2013

In der vorliegenden Arbeit wird über die Durchführung einer umfangreichen Versuchsreihe berichtet, bei der unter Verwendung einer neuartigen Versuchstechnik das Beulverhalten punktgestützter Zylinderschalen mit Endringsteifen untersucht wurde. Die gefundenen Versuchsdaten ermöglichen die Verifikation eines Nachweiskonzeptes, bei dem der Ort des zu führenden Stabilitätsnachweises durch einen fiktiven Lastausbreitungswinkel und den Horizont der einfallenden Beulen definiert wird. Es zeigt sich, daß bei Kenntnis des Lastausbreitungswinkels und des Beulhorizontes sowie nach Einführung eines einfachen Korrekturfaktors das in DIN 18800 Teil 4 beschriebene Nachweisverfahren auch für punktgestützte Zylinderschalen verwendbar ist.