bluuebunny/crossref_metadata_2025 huggingface dataset:
Secondary new particle formation in Northern Finland Pallas site between the years 2000 and 2010
Authors: Asmi E. , Kivekäs N. , Kerminen V.-M. , Komppula M. , Hyvärinen A.-P. , Hatakka J. , Viisanen Y. , Lihavainen H.
Published: September 2011

Abstract. Secondary new particle formation affects atmospheric aerosol and cloud droplet numbers and thereby, the aerosol effects on climate. In this paper, the frequency of nucleation events and the associated particle formation and growth rates, along with their seasonal variation, was analysed based on over ten years of aerosol measurements conducted at the Pallas GAW station in northern Finland. The long-term measurements also allowed a detailed examination of factors possibly favouring or suppressing particle formation. Effects of meteorological parameters and air mass properties as well as vapour sources and sinks for particle formation frequency and event parameters were inspected. In addition, the potential of secondary particle formation to increase the concentration of cloud condensation nuclei (CCN) sized particles was examined. Findings from these long-term measurements confirmed previous observations: event frequency peaked in spring and the highest growth rates were observed in summer, affiliated with increased biogenic activity. Events were almost exclusively observed in marine air masses on sunny cloud-free days. A low vapour sink by the background particle population as well as an elevated sulphuric acid concentration were found to favour particle formation. These were also conditions taking place most likely in marine air masses. Inter-annual trend showed a minimum in event frequency in 2003, when also the smallest annual median of growth rate was observed. This gives further evidence of the importance and sensitivity of particle formation for the condensing vapour concentrations at Pallas site. The particle formation was observed to increase CCN80 (>80 nm particle number) concentrations especially in summer and autumn seasons when the growth rates were the highest. When the growing mode exceeded the selected 80 nm limit, on average in those cases, 211 ± 114 % increase of CCN80 concentrations was observed.
Field inter-comparison of two high-accuracy fast-response spectroscopic sensors of carbon dioxide
Authors: Flowers B. A. , Powers H. H. , Dubey M. K. , McDowell N. G.
Published: September 2011

Abstract. Tunable diode laser absorption (TDL) and cavity ring-down spectroscopic (CRDS) sensors for atmospheric carbon dioxide were co-deployed during summer and fall of 2010 in the field at Los Alamos National Laboratory. Both sensors were characterized for accuracy and precision for ambient carbon dioxide measurements at ground level and are compared using both laboratory and atmospheric data. After a four point laboratory cross calibration, the mean [12C16O2]TDL = 392.05 ± 8.92 ppm and [12C16O2]CRDS' = 392.22 ± 9.05 ppm between 29 July and 16 August 2010 (mean difference = 0.04 ± 0.04 ppm). The slope of the cross-calibrated linear regression analysis between the two sensors is 1.000. The CRDS sensor is capable of measuring ambient [12C16O2] to a relative precision of 23 ppb Hz−1/2 for a 1-min time constant and this decreases to 6.5 ppb Hz−1/2 for a 58-min time constant. At one and 58-min time constants, the TDL exhibits precisions of 29 ppb Hz−1/2 and 53 ppb Hz−1/2. The CRDS is compact, fast, and stable. The TDL is larger and requires frequent calibrations that limit its time resolution. Field observations show that 1-min averaged data measured by the two instruments agree almost perfectly, for the 19-day period the CRDS/TDL ratio is a Gaussian distribution at x0 = 1.000 ± 3.38 × 10−5. The sensors also exhibit consistent hourly averaged diurnal values underscoring the interplay of biological, anthropogenic, and transport processes regulating CO2 at the site.
Modeling of stability of gas hydrates under permafrost in an environment of surface climatic change – terrestrial case, Beaufort-Mackenzie basin, Canada
Authors: Majorowicz J. , Šafanda J. , Osadetz K.
Published: September 2011

Abstract. Modeling of the onset of permafrost formation and succeeding gas hydrate formation in the changing surface temperature environment has been done for the Beaufort-Mackenzie Basin (BMB). Numerical 1-D modeling is constrained by deep heat flow from deep well bottom hole temperatures, deep conductivity, present permafrost thickness and thickness of Type I gas hydrates. Latent heat effects were applied to the model for the entire ice bearing permafrost and Type I hydrate intervals. Modeling for a set of surface temperature forcing during the glacial-interglacial history including the last 14 Myr was performed. Two scenarios of gas formation were considered; case 1: formation of gas hydrate from gas entrapped under deep geological seals and case 2: formation of gas hydrate from gas in a free pore space simultaneously with permafrost formation. In case 1, gas hydrates could have formed at a depth of about 0.9 km only some 1 Myr ago. In case 2, the first gas hydrate formed in the depth range of 290–300 m shortly after 6 Myr ago when the GST dropped from −4.5 °C to −5.5. °C. The gas hydrate layer started to expand both downward and upward subsequently. These models show that the gas hydrate zone, while thinning persists under the thick body of BMB permafrost through the current interglacial warming periods.
Climate sensitivity in the Anthropocene
Authors: Previdi M. , Liepert B. G. , Peteet D. T , Hansen J. , Beerling D. J , Broccoli A. J. , Frolking S. , Galloway J. N , Heimann M. , Le Quéré C. , Levitus S. , Ramaswamy V.
Published: September 2011

Abstract. Understanding the sensitivity of Earth's climate to an imposed external forcing is one of the great challenges in science and a critical component of efforts to avoid dangerous anthropogenic interference with the climate system. Climate sensitivity (or equilibrium global surface warming) to a doubling of atmospheric CO2 has long been estimated to be about 3 °C, considering only fast climate feedbacks associated with increases in water vapor, decreases in sea ice, and changes in clouds. However, evidence from Earth's history suggests that slower surface albedo feedbacks due to vegetation change and melting of Greenland and Antarctica can come into play on the timescales of interest to humans, which could increase the sensitivity to significantly higher values, as much as 6 °C. Even higher sensitivity may result as present-day land and ocean carbon sinks begin to lose their ability to sequester anthropogenic CO2 in the coming decades. The evolving view of climate sensitivity in the Anthropocene is therefore one in which a wider array of Earth system feedbacks are recognized as important. Since these feedbacks are overwhelmingly positive, the sensitivity is likely to be higher than has traditionally been assumed.
Modelling the extreme precipitation event over Madeira Island on 20 February 2010
Authors: Luna T. , Rocha A. , Carvalho A. C. , Ferreira J. A. , Sousa J.
Published: September 2011

Abstract. In the morning of the 20 February of 2010 an extreme precipitation event occurred over Madeira Island. This event triggered several flash floods and mudslides in the southern parts of the island, resulting in 42 confirmed deaths, 100 injured, and at least 8 people still missing. These extreme weather conditions were associated to a weather frontal system moving northeastwards embedded in a low pressure area centered in the Azores archipelago. This storm was one in a series of such storms that affected Portugal, Spain, Morocco and the Canary islands causing flooding and strong winds. These storms were bolstered by an unusually strong sea surface temperature gradient across the Atlantic Ocean. In this study, the WRF model is used to evaluate the intensity and predictability of this precipitation extreme event over the island. The synoptic/orographic nature of the precipitation is also evaluated, as well as the sensitivity of the model to horizontal resolution and cumulus parameterization. Orography was found to be the main factor explaining the occurrence, amplitude and phase of precipitation over the Island.
A Comparative Study of Optical Anisotropies of BC3 and B3C Systems by Density Functional Theory
Authors: Jana Debnarayan , Chen Li-Chyong , Chen Chun Wei , Chen Kuei-Hsien
Published: September 2011

The optical properties of (8,0) BC3 and B3C single-wall carbon nanotubes (SWCNTs) are computed using ab initio density functional theory (DFT). The electronic band structure reveals that the Fermi energy of B3C system is reduced compared to BC3. The static dielectric constant in the long wavelength limit for B3C system is 9 times larger than that of BC3 in unpolarized electromagnetic field. Within 10 eV frequency (energy) range, the absorption coefficient of B3C is higher compared to BC3, while, above 10 eV, it is less than that of BC3. In parallel polarization, the peak of the loss function for B3C is shifted to higher frequency (energy) region with significantly six orders of magnitude compared to BC3 system. The analysis of this study indicates that the optical anisotropies can be gained easily in these boron-doped systems by appropriately choosing the direction of the polarization of the electromagnetic field. Besides, the results of the loss functions may throw some light on the nature of collective excitations of these two systems.
Assessment of Panoramic Radiomorphometric Indices of the Mandible in a Brazilian Population
Authors: Alonso Maria Beatriz C. C. , Cortes Arthur R. G. , Camargo Angela J. , Arita Emiko S. , Haiter-Neto Francisco , Watanabe Plauto Christopher A.
Published: September 2011

The aim of this study was to evaluate radiomorphometric indices in dental panoramic radiographs in order to identify possible interrelationships between these indices and the sex and age of the patients analyzed. The study included 1287 digital panoramic radiographic images of patients that were grouped into five age groups (1 = age 17–20; 2 = age 21–35; 3 = age 36–55; 4 = age 56–69; 5 = over age 70). Two indices—cortical width at the gonion (GI) and below the mental foramen (MI)—were measured bilaterally in all panoramic radiographs. Statistical analysis was performed with Kruskal-Wallis and Mann-Whitney tests (alpha = 0.05). Results for the indices measurements showed significant differences among patient age groups of both sexes, considering that groups 4 and 5 presented lower values for the cortical width of both indices. The present paper supports the role of sex- and age-related changes in mandibular radiomorphometric indices in identifying skeletal osteopenia.
Study on Sodium Modification of Inferior Ca-Based Bentonite by Suspension Method
Authors: Zhang Yuanbo , Jiang Tao , Chen Liyong , Li Guanghui
Published: September 2011

Hunyuan Ca-based bentonite is one of large-type bentonite deposits in China, the reserve of which is more than 0.15 billion tons. However, they are not completely utilized in the pellet production. Process mineralogy investigation shows that the bentonite is a kind of typical Ca-bentonite (Ca-Bent). The sodium modification of the sample is studied by suspension method in this study. Results present the alkali coefficient K of modified Na-bentonite that is increased from 0.34 to 1.33, and the 2HWA, dilation, and colloid index are, respectively, increased to 601%, 32.4 mL/g and 87.6 mL/(3 g) under optimal conditions of Na2CO3 dosage 3.0%, pulp density 20%, sodium temperature 55°C, and sodium time 0.5 h. The XRD patterns show that d(001) of the sample bentonite is reduced from 1.5539 nm down to 1.2467 nm, and 2θ(001) of the sample bentonite is increased from 5.6875° to 7.0907°, indicating that the sample Ca-Bent is effectively modified into Na-Bent.
Chromatography of Membrane Proteins and Lipoproteins
Authors: Zolla Lello , D'Alessandro Angelo
Published: September 2011

The available methods for the separation of membrane proteins and lipoproteins are sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS/PAGE), followed by immunoblotting, isoelectric focusing (IEF), and capillary electrophoresis (CE), along with the recently introduced gel‐based native techniques (blue native (BN) and clear native (CN)), and high‐performance liquid chromatography (HPLC). In this article, it is shown that HPLC techniques, given their wide versatility, relative ease of use, and high resolution, may be considered the most valuable tool for the characterization of virtually any hydrophobic protein. Application examples are described, and comparisons with other methods are discussed. Moreover, HPLC is not a destructive technique, and therefore, proteins, once separated, are available for further analytical investigations. Among these techniques, quantitative and qualitative analyses of the separated fractions can be obtained through other biophysical approaches, such as crystallography or structural spectroscopy. Most of these approaches require preliminary protein purification (90% or higher), which could be rapidly obtained through preliminary HPLC.
Quantitative and Qualitative Analysis of Posttranslationally Modified Proteins
Authors: Sharp Joshua S.
Published: September 2011

The majority of proteins are posttranslationally modified. Posttranslational modifications (PTMs) have been found to modify a wide variety of biological and biophysical properties, including structure, biophysical stability and dynamics, enzymatic activity, protein‐protein interactions, protein‐ligand interactions, and protein half‐life within the cell. Virtually every analytical technique that can be used to analyze proteins in general can and has been used to analyze posttranslationally modified proteins. A vast array of both enzymatic and nonenzymatic protein modifications have been identified and characterized, which can make comprehensive analyses of all possible modifications difficult. Owing to the enormous scope of this topic, this article focuses on the analytical techniques that are probably most broadly applicable and widely used for wide‐scale analyses of posttranslationally modified proteins, namely mass spectrometry (MS) coupled to various separations technologies. Some technical and experimental details on the analyses of three heavily studied classes of PTM have been provided — phosphorylation, N‐linked glycosylation, and nonenzymatic oxidation. While we will be using these three classes of modifications in order to provide focus to our discussion, we will attempt to use these specific examples to illustrate broadly applicable techniques, as well as issues that often lead to difficulties and conflict between the experimental designs required for thorough quantitative and qualitative analyses of posttranslationally modified proteins.
Hydrogen Exchange Mass Spectrometry for Conformational Analysis of Proteins
Authors: Engen John R. , Wales Thomas E. , Shi Xiaomeng
Published: September 2011

Proteins contain labile hydrogen atoms at the backbone amide positions. These hydrogens are in continuous exchange with hydrogen in surrounding solvent. By incubating proteins with an isotope of hydrogen, usually deuterium, this exchange process can be monitored experimentally. Because hydrogen exchange (HX) is a function of protein conformation and dynamics, the rate of HX reports on aspects of protein structure. One method for detection of exchange is mass spectrometry (MS), as proteins will increase in mass as deuteration proceeds. This article provides background on how and why hydrogens exchange, how the exchange is controlled by several parameters, and what measuring exchange is good for, and then gives a general overview of how to make these measurements with MS.
Introduction to Modeling High‐resolution Spectra
Authors: Western Colin M.
Published: September 2011

The basic ideas involved in the application of model Hamiltonians involving angular momentum operators to predict energy levels and transition intensities of various molecular systems are introduced. Such methods are essential for understanding many molecular systems, and are illustrated here with a few selected examples. These include two interacting nuclear spins, “forbidden” singlet–triplet transitions and the energy‐level patterns associated with Hund's cases (a)–(c) in a diatomic molecule.
High Accuracy Rotation — Vibration Calculations on Small Molecules
Authors: Tennyson Jonathan
Published: September 2011

The first‐principles calculation of the spectra of triatomic and increasingly tetratomic molecules is beginning to make a significant impact on high‐resolution spectroscopy as well as astrophysics and atmospheric physics. The variational nuclear motion methods combined with high accuracy ab initio electronic structure calculations can be used to make spectral predictions of increasing accuracy with very few a priori assumptions. This work is important for spectral analysis and is becoming particularly so for dipole transition intensities, which are often very difficult to obtain reliably from experiment but are essential for modeling and remote sensing. In addition, demands for very extended linelists covering several millions of transitions that are required to reproduce spectra of hot sources are best met using high‐quality theoretical models. High accuracy can only be obtained by explicitly considering the so‐called minor effects such as relativistic effects on the electronic motion and failure of the Born–Oppenheimer approximation. H3+and its isotopologues are discussed as a benchmark system for high‐accuracy calculations.
Rotational Spectroscopy of Complexes Containing Free Radicals
Authors: Endo Yasuki , Sumiyoshi Yoshihiro
Published: September 2011

The recent developments in rotational spectroscopy especially for studies of open‐shell complexes are discussed in this article. Fourier‐transform microwave (FTMW) spectroscopy and FTMW‐cm/mm‐wave double‐resonance spectroscopy were used for the studies reviewed in the article. The systems reviewed are simple atom–diatom systems with open‐shell diatom, such as OH, SH, and NO, and more complex atom–triatom and molecule–radical systems. Detailed intermolecular potential surfaces have been obtained for the atom–diatom systems, with analyses using a hindered‐free‐rotor model. On the other hand, it was found that analyses for normal rigid molecules could be used for other more complicated systems.
New Techniques in Microwave Spectroscopy
Authors: Shipman Steven T. , Pate Brooks H.
Published: September 2011

We discuss the design principles and performance of a true broadband chirped‐pulse Fourier transform microwave spectrometer capable of operation from 800 MHz to 18.5 GHz. This spectrometer utilizes recent advances in high‐speed digital electronics to both directly generate linear frequency sweeps spanning more than 10 GHz and to directly digitize the molecular free induction decay (FID). Signal averaging is performed in the time domain to improve the signal‐to‐noise ratio. This spectrometer has a number of capabilities that are well suited for studies on large‐molecule systems, including the ability to perform multiplexed Stark effect measurements and selective‐excitation microwave double‐resonance measurements. These characteristics are demonstrated using the molecule 1,2,2,2‐tetrafluoroethyl difluoromethyl ether (C
3
H
2
F
6
O, molecular weight 168 g mol
−1
, also known by its trade names of
suprane
or
desflurane
) as an example. The simultaneous use of multiple‐pulsed nozzles as well as the acquisition of multiple FIDs per valve pulse is also demonstrated in the context of strategies for increasing spectrometer sensitivity by 2 orders of magnitude.
High‐resolution Inner‐shell Photoionization, Photoelectron and Coincidence Spectroscopy
Authors: Miron Catalin , Morin Paul
Published: September 2011

This article gives an overview of high‐resolution photoionization, photoelectron, and coincidence spectroscopies of inner‐shell excited species of increasing complexity ranging from atoms to nanoparticles. The development and the routine use of soft X‐ray techniques is intimately related to the spectacular advances in instrumentation in the last twenty years. These concern not only the construction and operation of high‐performance soft X‐ray beamlines at several synchrotron radiation laboratories around the world but also the remarkable improvement in charged particle analyzers and detectors (detection efficiency, resolution) and the extensive use of multidimensional coincidence techniques that allows simultaneous acquisition and further correlation of several physical parameters. From the examples we have chosen to present, it is apparent that inner‐shell ionization studies are not limited anymore by the lifetime broadening effects and that a deep and unique insight into ultrafast dynamics is possible. Various examples are shown of both pure high‐resolution photoionization and electron spectroscopies together with more sophisticated techniques such as the electron–ion coincidence measurements with energy and angle resolution. A prospective view of the field is given in the end. In particular, the expectations from the next‐generation ultrahigh brilliance X‐ray sources such as energy recovery linacs or free electron lasers are briefly tackled.
Experimental Methods in Cation Spectroscopy
Authors: Willitsch Stefan
Published: September 2011

The spectroscopic study of molecular cations in the gas phase poses a range of challenges which are generally associated with their high chemical reactivity, the difficulties in producing sufficiently high number densities of the desired ion species in a spectrometer, and the limits on the particle densities imposed by the space‐charge effect. The present article provides an overview of different experimental techniques that have been developed over the past years to overcome these problems. The topics discussed include highly sensitive laser‐based spectroscopic methods (cavity ring‐down spectroscopy, frequency‐, velocity‐ and concentration‐modulation schemes, and various types of action spectroscopy), the production of internally cold samples of ions and the use of mass‐spectrometric methods to select the species of interest out of a mixed sample. Owing to these developments, the range of molecular cations amenable to a spectroscopic characterization has been extended considerably over the past years and now includes various types of cluster ions, protonated biomolecules, ionic carbon chains, and the ions of polycyclic aromatic hydrocarbons.
Doppler‐free Laser Spectroscopy
Authors: Demtröder Wolfgang
Published: September 2011

This article discusses several experimental techniques with Doppler‐free spectral resolution such as linear spectroscopy in collimated molecular beams and nonlinear spectroscopy in gas or vapor cells, using saturation spectroscopy, polarization spectroscopy, or multiphoton absorption. Optical cooling of atoms and molecules down to extremely low temperatures brings the Doppler width below the natural linewidth. Special double‐resonance schemes enable stabilization of atomic collision pairs and sub‐Doppler spectroscopy of molecules in very high‐vibrational levels. Finally, some techniques with a resolution below the natural linewidth are discussed.
2
D
‐Infrared Spectroscopy
Authors: Hamm Peter
Published: September 2011

The basic concepts of 2D spectroscopy are summarized from both the theoretical and the experimental points of view. The Feynman diagram formalism is introduced and applied to calculate 2D spectra. Spectroscopic Hamiltonians are used to describe intramolecular couplings such as excitonic coupling and Fermi resonances, and to predict their appearance in a 2D spectrum. Furthermore, Kubo's lineshape theory is applied to 2D spectroscopy to explain dephasing in the presence of solvent fluctuations. Finally, various experimental realizations of 2D spectroscopy are discussed with their advantages and disadvantages.
High‐resolution Photofragment Translational Spectroscopy using Rydberg Tagging Methods
Authors: Ashfold Michael N. R. , King Graeme A. , Nix Michael G. D. , Oliver Thomas A. A.
Published: September 2011

Photofragment translational spectroscopy (PTS) is a general and versatile technique for exploring the dynamics of gas‐phase molecular photodissociation processes, through measurement of the speeds and directions of the resulting atomic and molecular products. This article describes recent enhancements in the achievable kinetic energy resolution and then focuses on applications employing one particular high‐resolution variant of the technique, wherein H(D) atom photofragments are monitored by Rydberg tagging methods. Systems described range from small hydrides such as H
2
O, NH
3
, and C
2
H
2
to larger heteroaromatic molecules such as pyrrole and phenol. In the former cases, the achievable resolution allows observation of individual rovibrational quantum states of the radical partner, providing detailed insights into the forces acting during the dissociation process. This allows intimate contact with complementary ab initio and wave packet modeling studies, and accurate determination of bond strengths and related thermodynamic quantities. The density of possible product states increases rapidly for larger radical cofragments. PTS studies of several heteroaromatics point to the generality of prompt dissociation from
1
πσ* excited states, which manifests itself in remarkably mode specific fragmentation dynamics. The article concludes with a summary of complementary photofragmentation studies of hydride radicals and an anticipation of future activities in this field.
Design Guidelines For Conjugated Polymers With Light‐Activated Anticancer Activity
Authors: Xing Chengfen , Liu Libing , Tang Hongwei , Feng Xuli , Yang Qiong , Wang Shu , Bazan Guillermo C.
Published: September 2011

Multifunctional materials that simultaneously provide therapeutic action and image the results provide new strategies for the treatment of various diseases. Here, it is shown that water soluble conjugated polymers with a molecular design centered on the polythiophene−porphyrin dyad are effective for killing neighboring cells. Following photoexcitation, energy is efficiently transferred from the polythiophene backbone to the porphyrin units, which readily produce singlet oxygen (1O2) that is toxic for the cells. Due to the light‐harvesting ability of the electronically delocalized backbone and the efficient energy transfer amongst optical partners, the polythiophene−porphyrin dyad shows a higher 1O2 generation efficiency than a small molecule analog. The fluorescent properties of these polymers can also serve to distinguish amongst living and dead cells. Polymers can be designed with folic acid grafted onto the polymer side chain that can specifically kill folate receptor‐overexpressed cells, thereby providing an important demonstration of anticancer specificity through molecular design.
Interphases in Graphene Polymer‐based Nanocomposites: Achievements and Challenges
Authors: Terrones Mauricio , Martín Olga , González María , Pozuelo Javier , Serrano Berna , Cabanelas Juan C. , Vega‐Díaz Sofía M. , Baselga Juan
Published: September 2011

Graphene constitutes a two dimensional sp2 hybridized carbon material with outstanding electrical and mechanical properties. To date, novel methods for producing large quantities of graphene and its derivatives (doped or functionalized graphenes, nanoribbons and nanoplatelets) are emerging, and research dedicated to the fabrication of polymer nanocomposites using graphenes has started. In this Research News, we summarize the synthesis and properties of graphene and its derivatives, and provide an overview of the latest research dedicated to the fabrication of polymer composites for different applications, including mechanical, electrical, optical and thermal. Some of the recently fabricated composites exhibit outstanding properties, however, it is vital to understand the chemistry and physics of the interphases established between the polymer and the graphene surfaces. The challenges in the fabrication of super robust and highly conducting composites using graphenes are also discussed. It is believed that graphene‐based polymer composites will result in commercial products if their interphases and reactivity are carefully controlled.
Embryo developmental disruption during organogenesis produced by CF‐1 murine periconceptional alcohol consumption
Authors: Coll Tamara A. , Tito Leticia Perez , Sobarzo Cristian M.A. , Cebral Elisa
Published: September 2011

The aim was to study the control females (CF)‐1 mouse embryo differentiation, growth, morphology on embryonic E‐ and N‐cadherin expression at midgestation after periconceptional moderate alcohol ingestion. Adult female mice were exposed to 10% ethanol in drinking water for 17 days previous to and up to day 10 of gestation (ethanol‐exposed females, EF) and were compared with nonexposed CF. EF presented reduced quantities of E10 to E10.5 embryos, greater percentage of embryos at stages less than E7.5, reduced implantation site numbers/female, and increased resorptions compared with CF. EF‐embryo growth was significantly affected as evidenced by reduced cephalic and body sizes of E10 and E10.5 embryos (scanning electron microscopy) and decreased protein content of E10.5 embryos vs. CF embryos. A significantly higher percentage of EF‐E10‐10.5 embryos presented abnormal neural tube (NT) closure vs. the percentage of CF. E10 embryos from EF presented elevated tissue disorganization, pyknosis and nuclear condensation in somites, mesenchymal and neuroepithelial tissue. Immunohistochemical E‐ and N‐cadherin distribution patterns were similar in organic structures of E10 embryos between groups. However, western blot revealed that E‐ and N‐cadherin expression levels were significantly increased in EF‐derived embryos vs. controls. Perigestational ethanol consumption by CF‐1 mice induced significant damage in the organogenic embryogenesis by producing delayed differentiation, growth deficiencies, and increasing the frequency of NT defects. Ethanol exposure may disrupt cell–cell adhesion leading to upregulation of E‐ and N‐cadherin expression suggesting that deregulation of cell adhesion molecules could be involved in the disruption of embryo development at organogenesis in CF‐1 mouse. Birth Defects Res (Part B) 92:560–574, 2011.© 2011 Wiley Periodicals, Inc.
Flavanone Glycosides from Viscum coloratum and Their Inhibitory Effects on Osteoclast Formation
Authors: Han Na , Huang Ting , Wang Yi‐Chun , Yin Jun , Kadota Shigetoshi
Published: September 2011

Two novel flavanone glycosides, homoeriodictyol 7‐O‐β‐D‐[6‐(3‐hydroxybutanoyl)glucopyranoside] (viscumneoside IX; 1) and homoeriodictyol 7‐O‐β‐D‐[6‐(3‐hydroxybutanoyl)glucopyranosyl](1→2)‐β‐D‐glucopyranoside (viscumneoside X; 2), together with four known flavanoids, 2‐homoeriodictyol 7‐O‐β‐D‐glucopyranoside (3), viscumneoside I (4), viscumneoside III (5), and 4′,5‐dihydroxy‐3′‐methoxy‐7‐(2‐O‐α‐L‐rhamnopyranosyl‐β‐D‐glucopyranosyloxy)flavanone (6) were isolated from stems and leaves of Viscum coloratum. Their structures were elucidated on the basis of their NMR spectra, HR‐FAB‐MS data, and acid hydrolysis. Inhibitory effects of the four compounds 1–4 on the formation of osteoclast‐like multinucleated cells were investigated. As a result, all the four flavanoids showed significant inhibitory effects on the formation of osteoclast‐like multinuclear cells even at a low concentration of 2 μg/ml. The activities of 1–4 at such a concentration exceeded or approximated to that of elcitonin, the positive control drug at a concentration of 2 U/ml, suggesting that they may be of interest for the development of new anti‐osteoporosis drugs.
Pollen Aroma Fingerprint of two Sunflower (Helianthus annuus L.) Genotypes Characterized by Different Pollen Colors
Authors: Bertoli Alessandra , Fambrini Marco , Doveri Silvia , Leonardi Michele , Pugliesi Claudio , Pistelli Luisa
Published: September 2011

Samples of fresh pollen grains, collected from capitula in full bloom from two genotypes of sunflower (Helianthus annuus L.) and characterized by a different color, i.e., white‐cream (WC) and orange (O), were analyzed by the HS‐SPME (headspacesolid phase microextraction)/GC/MS technique. This study defined for the first time the fingerprint of the sunflower pollen, separated from the disc flowers, to define its contribution to the inflorescence aroma. In the GC/MS fingerprints of the WC and O genotypes, 61 and 62 volatile compounds were identified, respectively. Monoterpene hydrocarbons (34% in O vs. 28% in WC) and sesquiterpene hydrocarbons (37% in O vs. 31% in WC) were ubiquitous in all samples analyzed and represented the main chemical classes. α‐Pinene (21% in O vs. 20% in WC) and sabinene (11% in O vs. 6% in WC) were the dominant volatiles, but also a full range of aliphatic hydrocarbons and their oxygenated derivatives gave a decisive contribution to the aroma composition (10% in O vs. 12% in WC). In addition, dendrolasin (3% in O vs. 4% in WC) and some minor constituents such as (E)‐hex‐2‐en‐1‐ol (0.4% in O vs. 0.1% in WC) were pointed out not only for their contribution to the pollen scent, but also for their well‐known role in the plant ecological relationships. Having evaluated two pollen morphs with different carotenoid‐based colors, the study sought to highlight also the presence of some volatile precursors or derivatives of these pigments in the aroma. However, the pollen aroma of the two selected genotypes made a specific chemical contribution to the sunflower inflorescence scent without any influence on carotenoid derivatives.
Evaluation of Differences in the Aroma Composition of Free‐Run and Pressed Neutral Grape Juices Obtained from Emir (Vitis vinifera L.)
Authors: Selli Serkan , Bagatar Berfu , Sen Kemal , Kelebek Haşim
Published: September 2011

In this study, the differences in the aroma compounds released after the free‐run and pressed juices of cv. Emir grape (Vitis vinifera L.) were evaluated. Aroma compounds were obtained by liquid‐liquid extraction with CH2Cl2, and then analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). According to the results, pressing uniformly increased the levels of the aromatic constituents, but this treatment lowered the grape juice quality for winemaking by increasing the total phenolic compounds, browning index, and C6‐alcohol levels (green‐herbaceaous odor) as compared to the free‐run juice. From all the aroma compounds identified in both juices, hexan‐1‐ol, (E)‐hex‐2‐en‐1‐ol, isobutanol, isoamyl alcohol, and 2‐phenylethanol were the most abundant volatile compounds.
Climate Friendly Coal from Hydrothermal Carbonization of Biomass
Authors: Buttmann M.
Published: September 2011

Es wird das Verfahren der Hydrothermalen Karbonisierung (HTC) von biogenen Reststoffen und die Umsetzung in einer kontinuierlich laufenden, industriellen Anlage beschrieben. Die Vorteile des Verfahrens zur Verwertung der Biomasse und die Energiebilanz werden erläutert. Die Produkteigenschaften werden exemplarisch für HTC‐Kohle aus Klärschlamm aufgezeigt. Es wird dargelegt, dass das Verfahren eine gute Energieeffizienz aufweist und für die energetische Verwertung unterschiedlicher Eingangsstoffe gut geeignet ist.
Energetic Nitrogen‐Rich Salts of 1‐(2‐Hydroxyethyl)‐5‐nitriminotetrazole
Authors: Fischer Niko , Klapötke Thomas M. , Stierstorfer Jörg
Published: September 2011

1‐(2‐Hydroxyethyl)‐5‐nitriminotetrazole (2) was formed by the reaction of 5‐amino‐1‐(2‐hydroxyethyl)tetrazole (1) and 100 % HNO3. Compound 1 was obtained by alkylation of 5‐amino‐1H‐tetrazole with 2‐chloroethanol. Nitrogen‐rich salts such as the ammonium (3), hydroxylammonium (4), guanidinium (5), aminoguanidinium (6), diaminoguanidinium (7), triaminoguanidinium (8), azidoformamidinium (9), and diaminouronium (10) 1‐(2‐hydroxyethyl)‐5‐nitriminotetrazolate were prepared by deprotonation or metathesis reactions. Compounds 3–10 were fully characterized by single‐crystal X‐ray diffraction (except for 9 and 10), vibrational spectroscopy (IR and Raman), multinuclear NMR spectroscopy, elemental analysis, and differential scanning calorimetry (DSC) measurements. The heats of formation of 4–10 were calculated by the atomization method based on CBS‐4M enthalpies. With these values and the X‐ray densities, several detonation parameters such as the detonation pressure, velocity, energy, and temperature were computed using the EXPLO5 code. In addition their sensitivities towards impact, friction, and electrical discharge were tested using a BAM drophammer, a friction tester, and a small‐scale electrical discharge device.
Development of Decarboxylative Coupling Processes for the Synthesis of Azomethines and Ketones
Authors: Collet Florence , Song Bingrui , Rudolphi Felix , Gooßen Lukas J.
Published: September 2011

A bimetallic catalyst system has been developed that allows the synthesis of azomethines by a one‐pot three‐component decarboxylative coupling, starting from simple, nontoxic precursors, i.e. potassium α‐oxo carboxylates, aryl halides and primary amines. In the presence of 15 mol‐% copper/phenanthroline and 1 mol‐% Pd/dppf, a wide range of valuable imines is conveniently accessible in high yields at 100 °C, an unprecedentedly low temperature for redox‐neutral decarboxylative cross‐coupling reactions. Hydrogenation of the azomethine products leads to secondary amines. Alternatively, they can be hydrolyzed in situ to aryl ketones. The resulting ketone synthesis via azomethine intermediates is also of interest as it gives higher yields at much lower temperatures than the direct decarboxylative coupling of α‐oxo carboxylates with aryl halides.
Interaction of Mitomycin C with DNA Immobilized onto Single‐walled Carbon Nanotube/Polymer Modified Pencil Graphite Electrode
Authors: Canavar Ece , Kuralay Filiz , Erdem Arzum
Published: September 2011

The electrochemical investigation of the interaction between the anticancer drug mitomycin C (MC) and DNA was described using a single‐walled carbon nanotube (SWCNT)/poly(vinylferrocenium) (PVF+) modified pencil graphite electrode (PGE). The electrochemical oxidation signals of guanine were monitored before and after the interaction between MC and DNA by using differential pulse voltammetry. The effects of DNA and MC concentration and MC interaction time were examined based on the electrode response. Cyclic voltammetry and electrochemical impedance spectroscopy were used for the characterization of SWCNT/PVF+ modified and PVF+ modified PGEs. The detection limit corresponded to 625 ng/mL for MC using calf thymus double‐stranded DNA immobilized SWCNT/PVF+ modified PGE.
A Third‐Generation Hydrogen Peroxide Biosensor Based on Horseradish Peroxidase Immobilized in Carbon Nanotubes/ SBA‐15 Film
Authors: Fang Zheng‐Hui , Lu Li‐Min , Zhang Xiao‐Bing , Li Hong‐Bo , Yang Bin , Shen Guo‐Li , Yu Ru‐Qin
Published: September 2011

A new third‐generation biosensor for H2O2 assay was developed on the basis of the immobilization of horseradish peroxidase (HRP) in a nanocomposite film of carbon nanotubes (CNTs)‐SBA‐15 modified gold electrode. The biological activity of HRP immobilizing in the composite film was characterized by UV‐vis spectra. The HRP immobilized in the nanocomposite matrix displayed excellent electrocatalytic activity to the reduction of H2O2. The effects of the experimental variables such as solution pH and working potential were investigated using steady‐state amperometry. Under the optimal conditions, the resulting biosensor showed a linear range from 1 µM to 7 mM and a detection limit of 0.5 µM (S/N=3). Moreover, the stability and reproducibility of this biosensor were evaluated with satisfactory results.
In Situ Self Assembly of Thiolated ortho‐Quinone Capped Electrocatalysts for Bioanalytical Applications
Authors: Wendland Tom R. , Muntean Brian S. , Kaur Jaskiran , Mukherjee Jhindan , Chen Jie , Tan Xinxuan , Attygalle Dinesh , Collins Robert W. , Kirchhoff Jon R. , Tillekeratne L. M. Viranga
Published: September 2011

Thiolated o‐quinone‐capped electrocatalysts modeled on the naturally occurring o‐quinone cofactor pyrroloquinoline quinone (PQQ) were designed and synthesized for the development of biosensor devices. The o‐quinone‐capped electrocatalysts self assembled on gold electrodes through a thiolated phenyleneethynylene linkage to form a monolayer less than 2 nm in thickness. Cyclic voltammetric measurements demonstrated reversible electrochemical properties between the quinone and hydroquinone forms of the head group. In an amperometric sensing mode, the modified electrodes reproducibly detected ethanethiol at micromolar levels demonstrating their robust electrocatalytic activity toward thiols. Their redox cycling and electrocatalytic properties show promise for detection of biologically important thiols and other nucleophiles.
Stage-dependent susceptibility to copper in Rhinella arenarum embryos and larvae
Authors: Aronzon Carolina M , Sandoval Maria Teresa , Herkovits Jorge , PérezColl Cristina S
Published: September 2011

Copper toxicity in different embryonic and larval stages of the common South American toad Rhinella arenarum was evaluated by means of continuous and 24-h pulse treatments in 12 different developmental stages. Lethal concentrations (LC) of 10, 50, and 90% of continuous treatment with Cu from early blastula (S.4), complete operculum (S.25), and hind limb bud (S.28) stages were plotted from 24 to 168 h, resulting from S.4 in a 24-h LC50 of 137 µg Cu2+/L and a 168-h LC50 of 19.5 µg Cu2+/L. This result was in agreement with pulse treatments that showed a high resistance to Cu at blastula and gastrula stages, whereas the organogenic period, between muscular response (S.18) and open mouth (S.21), was very susceptible to this metal. Continuous treatments from S.25 showed no significant differences along exposure time (168-h LC50 = 51 µg Cu2+/L), but in the case of S.28 toxicity increased slightly from a 24-h LC50 of 138.6 µg Cu2+/L to a 168-h LC50 of 104 µg Cu2+/L, pointing out that, although the larval period was significantly more resistant to Cu, there was also a remarkable stage-dependent susceptibility to this metal. Copper teratogenic potential was approximately two, and main adverse effects were reduced body size, axial flexure, microcephaly, acephaly, mouth malformations, agenesis of or underdeveloped gills, agenesis of or underdeveloped tail, and hydropsy. The results are discussed considering Cu toxicity mechanisms, an evolutionary perspective, and environmental protection. Environ. Toxicol. Chem. 2011;30:2771–2777. © 2011 SETAC
Database of published retention factors for immobilized artificial membrane HPLC and an assessment of the effect of experimental variability
Authors: Ledbetter M.R , Gutsell S , Hodges G , Madden J.C , O'Connor S , Cronin M.T.D
Published: September 2011

A database was collated of published experimental logarithmic values for the relative retention factors (log kIAM) measured using an immobilized artificial membrane column and high-performance liquid chromatography (IAM HPLC). Log kIAM is an alternative measure of hydrophobicity to the octanol/water partition coefficient (log KOW). While there are several accepted methods to measure log KOW, no standardized method exists to determine log kIAM. The database of collated log kIAM values includes 13 key experimental parameters and contains 1,686 values for 555 compounds, which are predominantly polar organic compounds and include drug molecules and surfactants. These compounds are acidic, basic, and neutral and both ionized and un-ionized under the conditions of analysis. The data compiled demonstrated experimental variability for each experimental parameter considered, including column stationary phase, pH, temperature, and mobile phase. Reducing the experimental variability allowed for greater consistency in the datasets. Environ. Toxicol. Chem. 2011;30:2701–2708. © 2011 SETAC
Anisotropic mesh adaptation driven by a recovery‐based error estimator for shallow water flow modeling
Authors: Porta G. M. , Perotto S. , Ballio F.
Published: September 2011

The aim of this paper is to propose an effective anisotropic mesh adaptation procedure for the solution of the shallow water equations. The hyperbolic partial differential equation system is solved via the streamline diffusion FEM, suitably modified by a shock‐capturing correction. The proposed adaptation procedure relies on a recovery‐based error estimator. In particular, we look for an anisotropic error estimator able to select not only the size but also the shape and the orientation of the mesh elements, with the aim of optimizing the computational advantages yielded by a standard isotropic mesh adaptation strategy. The robustness of the proposed estimator is assessed when either a single physical quantity, meaningful for the problem at hand, or a combination of all the shallow water system components drives the adaptation procedure. For this purpose, steady shallow water problems as well as unsteady configurations are considered. Copyright © 2011 John Wiley & Sons, Ltd.
A one‐pot efficient four‐component reaction for the synthesis of 2‐(arylamino)‐2‐(5‐aryl‐1,3,4‐oxadiazol‐2‐yl)propyl benzoate (or acetate) derivatives
Authors: Ramazani Ali , Ahmadi Yavar , Malekzadeh Asemeh Mashhadi , Rezaei Aram
Published: September 2011

Reactions of (N‐isocyanimino) triphenylphosphorane with 2‐oxopropylbenzoate (or acetate) in the presence of aromatic carboxylic acids and primary amines proceed smoothly at room temperature and in neutral conditions to afford sterically congested 1,3,4‐oxadiazole derivatives in high yields. The reaction proceeds smoothly and cleanly under mild conditions, and no side reactions were observed. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 22:692–698, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20735
Multinational quality assurance
Authors: Kinser Kevin
Published: September 2011

This chapter highlights the dilemmas facing traditional models of quality assurance in a global environment where higher education institutions can and do cross geopolitical borders.
The cross‐border education policy context: Educational hubs, trade liberalization, and national sovereignty
Authors: Lane Jason E. , Kinser Kevin
Published: September 2011

Policies for importing and exporting international branch campuses are increasingly being formalized, with a number of countries explicitly encouraging educational trade as an economic development goal.
WHAT FACTORS INFLUENCE THE EARNINGS OF GENERAL PRACTITIONERS AND MEDICAL SPECIALISTS? EVIDENCE FROM THE MEDICINE IN AUSTRALIA: BALANCING EMPLOYMENT AND LIFE SURVEY
Authors: Cheng Terence Chai , Scott Anthony , Jeon Sung‐Hee , Kalb Guyonne , Humphreys John , Joyce Catherine
Published: September 2011

To date, there has been little data or empirical research on the determinants of doctors' earnings despite earnings having an important role in influencing the cost of health care, decisions on workforce participation and labour supply. This paper examines the determinants of annual earnings of general practitioners (GPs) and specialists using the first wave of the Medicine in Australia: Balancing Employment and Life, a new longitudinal survey of doctors. For both GPs and specialists, earnings are higher for men, for those who are self‐employed and for those who do after‐hours or on‐call work. GPs have higher earnings if they work in larger practices, in outer regional or rural areas, and in areas with lower GP density, whereas specialists earn more if they have more working experience, spend more time in clinical work and have less complex patients. Decomposition analysis shows that the mean earnings of GPs are lower than that of specialists because GPs work fewer hours, are more likely to be female, are less likely to undertake after‐hours or on‐call work, and have lower returns to experience. Roughly 50% of the income gap between GPs and specialists is explained by differences in unobserved characteristics and returns to those characteristics. Copyright © 2011 John Wiley & Sons, Ltd.