bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of IASI tropospheric O3 data over Arctic during POLARCAT campaigns in 2008
Authors: Pommier M. , Clerbaux C. , Law K. S. , Ancellet G. , Bernath P. , Coheur P.-F. , Hadji-Lazaro J. , Hurtmans D. , Nédélec P. , Paris J.-D. , Ravetta F. , Ryerson T. B. , Schlager H. , Weinheimer A. J.
Published: December 2011

Abstract. Ozone data retrieved in the Arctic region from infrared radiance spectra recorded by the Infrared Atmospheric Sounding Interferometer (IASI) on board the MetOp-A European satellite are presented. They are compared with in situ and lidar observations obtained during a series of aircraft measurement campaigns as part of the International Polar Year (IPY) POLARCAT activities in spring and summer 2008. Different air masses were sampled during the campaigns including clean air, polluted plumes originating from anthropogenic sources, forest fire plumes from the three northern continents, and stratospheric-influenced air masses. The comparison between IASI O3 [0–8 km], [0–12 km] partial columns and profiles with collocated aircraft observations is achieved by taking into account the different sensitivity and geometry of the sounding instruments. A detailed analysis is provided and the agreement is discussed in terms of information content and surface properties at the location of the observations. Overall, IASI O3 profiles are found to be in relatively good agreement in the free troposphere with smoothed in situ and lidar profiles with differences less than 40% (25% over the sea for both seasons) and 10%, respectively. The correlation between IASI O3 retrieved partial columns and the smoothed aircraft partial columns is good with DC-8 in situ data in spring over North American forest fire regions (r = 0.68), and over Greenland with ATR-42 lidar measurements in summer (r = 0.67). Correlations with other data are less significant highlighting the difficulty with which IASI is able to capture O3 variability in the Arctic upper troposphere and lower stratosphere (UTLS) with sufficient precision as noted in comparison with the [0–12 km] partial columns. However the [0–8 km] partial columns show good results with IASI which displays a negative bias (maximum of 26% over snow) compared to columns derived from in situ measurements. Despite these difficulties in the Arctic UTLS, this work also shows that IASI can be used to study particular cases where stratospheric intrusions are present using a O3/CO ratio diagnostic.
Stable carbon isotope fractionation in the UV photolysis of CFC-11 and CFC-12
Authors: Zuiderweg A. , Kaiser J. , Laube J. C. , Röckmann T. , Holzinger R.
Published: December 2011

Abstract. The chlorofluorocarbons CFC-11 (CCl3F) and CFC-12 (CCl2F2) are stable atmospheric compounds that are produced at the earth's surface, but removed only at high altitudes in the stratosphere, where their removal liberates atomic chlorine that then catalytically destroys stratospheric ozone. For such long-lived compounds, isotope effects in the stratospheric removal reactions have a large effect on their global isotope budgets. We have determined the photolytic isotope fractionation for stable carbon isotopes of CFC-11 and CFC-12 in laboratory experiments. 13C/12C isotope fractionations (ϵ) range from (−23.7 ± 0.9) to (−17.5 ± 0.4)‰ for CFC-11 and (−69.2 ± 3.4) to (−49.4 ± 2.3)‰ for CFC-12 between 203 and 288 K, a temperature range relevant to conditions in the troposphere and stratosphere. These results suggest that CFCs should become strongly enriched in 13C with decreasing mixing ratio in the stratosphere, similar to what has been recently observed for CFC chlorine isotopes. In conjunction with the strong variations in CFC emissions before and after the Montréal Protocol, the stratospheric enrichments should also lead to a significant temporal increase in the 13C content of the CFCs at the surface over the past decades, which should be recorded in atmospheric air archives such as firn air.
Characterisation of corona-generated ions used in a Neutral cluster and Air Ion Spectrometer (NAIS)
Authors: Manninen H. E. , Franchin A. , Schobesberger S. , Hirsikko A. , Hakala J. , Skromulis A. , Kangasluoma J. , Ehn M. , Junninen H. , Mirme A. , Mirme S. , Sipilä M. , Petäjä T. , Worsnop D. R. , Kulmala M.
Published: December 2011

Abstract. We characterized size and chemical composition of ions generated by a corona-needle charger of a Neutral cluster and Air Ion Spectrometer (NAIS) by using a high resolution differential mobility analyzer and a time-of-flight mass spectrometer. Our study is crucial to verify the role of corona-generated ions in the particle size spectra measured with the NAIS, in which a corona charger is used to charge aerosol particles down to the size range overlapping with the size of generated ions. The size and concentration of ions produced by the corona discharging process depend both on corona voltage and on properties and composition of carrier gas. Negative ions were <1.6 nm (0.8 cm2 V−1 s−1 in mobility) in all tested gas mixtures (nitrogen, air with variable mixing ratios of water vapour), whereas positive ions were <1.7 nm (0.7 cm2 V−1 s−1). Electrical filtering of the corona generated ions and not removing all charged particles plays an important role in determining the lowest detection limit. Based on our experiments, the lowest detection limit for the NAIS in the particle mode is between 2 and 3 nm.
Characterization of atmospheric aerosol in the US Southeast from ground- and space-based measurements over the past decade
Authors: Alston E. J. , Sokolik I. N. , Kalashnikova O. V.
Published: December 2011

Abstract. This study examines how aerosols measured from the ground and space over the US Southeast change temporally over a regional scale during the past decade. PM2.5 data consist of two datasets that represent the measurements that are used for regulatory purposes by the US EPA and continuous measurements used for quickly disseminating air quality information. AOD data comes from three NASA sensors: the MODIS sensors onboard Terra and Aqua satellites and the MISR sensor onboard the Terra satellite. We analyze all available data over the state of Georgia from 2000–2009 of both types of aerosol data. The analysis reveals that during the summer the large metropolitan area of Atlanta has average PM2.5 concentrations that are 50% more than the remainder of the state. Strong seasonality is detected in both the AOD and PM2.5 datasets; as evidenced by a threefold increase of AOD from mean winter values to mean summer values, and the increase in PM2.5 concentrations is almost twofold from over the same period. Additionally, there is good agreement between MODIS and MISR onboard the Terra satellite during the spring and summer having correlation coefficients of 0.64 and 0.71, respectively. Monthly anomalies were used to determine the presence of a trend in all considered aerosol datasets. We found negative linear trends in both the monthly AOD anomalies from MODIS onboard Terra and the PM2.5 datasets, which are statistically significant for α = 0.05. Decreasing trends were also found for MISR onboard Terra and MODIS onboard Aqua, but those trends were not statistically significant.
Characteristics of gravity waves generated in a convective and a non-convective environment revealed from hourly radiosonde observation under CPEA-II campaign
Authors: Dhaka S. K. , Bhatnagar R. , Shibagaki Y. , Hashiguchi H. , Fukao S. , Kozu T. , Panwar V.
Published: December 2011

Abstract. Analyses of hourly radiosonde data of temperature, wind, and relative humidity during four days (two with convection and two with no convection) as a part of an intensive observation period in CPEA-2 campaign over Koto Tabang (100.32° E, 0.20° S), Indonesia, are presented. Characteristics of gravity waves in terms of dominant wave frequencies at different heights and their vertical wavelengths are shown in the lower stratosphere during a convective and non-convective period. Gravity waves with periods ~10 h and ~4–5 h were found dominant near tropopause (a region of high stability) on all days of observation. Vertical propagation of gravity waves were seen modified near heights of the three identified strong wind shears (at ~16, 20, and 25 km heights) due to wave-mean flow interaction. Between 17 and 21 km heights, meridional wind fluctuations dominated over zonal wind, whereas from 22 to 30 km heights, wave fluctuations with periods ~3–5 h and ~8–10 h in zonal wind and temperature were highly associated, suggesting zonal orientation of wave propagation. Gravity waves from tropopause region to 30 km heights were analyzed. In general, vertical wavelength of 2–5 km dominated in all the mean-removed (~ weekly mean) wind and temperature hourly profiles. Computed vertical wavelength spectra are similar, in most of the cases, to the source spectra (1–16 km height) except that of zonal wind spectra, which is broad during active convection. Interestingly, during and after convection, gravity waves with short vertical wavelength (~2 km) and short period (~2–3 h) emerged, which were confined in the close vicinity of tropopause, and were not identified on non-convective days, suggesting convection to be the source for them. Some wave features near strong wind shear (at 25 km height) were also observed with short vertical wavelengths in both convective and non-convective days, suggesting wind shear to be the sole cause of generation and seemingly not associated with deep convection below. A drop in the temperature up to ~4–5 K (after removal of diurnal component) was observed at ~16 km height near a strong wind shear (~45–55 m s−1 km−1) during active period of convection.
Ecosystem-scale compensation points of formic and acetic acid in the central Amazon
Authors: Jardine K. , Yañez Serrano A. , Arneth A. , Abrell L. , Jardine A. , Artaxo P. , Alves E. , Kesselmeier J. , Taylor T. , Saleska S. , Huxman T.
Published: December 2011

Abstract. Organic acids, central to terrestrial carbon metabolism and atmospheric photochemistry, are ubiquitous in the troposphere in the gas, particle, and aqueous phases. As the dominant organic acids in the atmosphere, formic acid (FA, HCOOH) and acetic acid (AA, CH3COOH) control precipitation acidity in remote regions and may represent a critical link between the terrestrial carbon and water cycles by acting as key intermediates in plant carbon and energy metabolism and aerosol-cloud-precipitation interactions. However, our understanding of the exchange of these acids between terrestrial ecosystems and the atmosphere is limited by a lack of field observations, the existence of biogenic and anthropogenic primary and secondary sources whose relative importance is unclear, and the fact that vegetation can act as both a source and a sink. Here, we first present data obtained from the tropical rainforest mesocosm at Biosphere 2 which isolates primary vegetation sources. Strong light and temperature dependent emissions enriched in FA relative to AA were simultaneously observed from individual branches (FA/AA = 3.0 ± 0.7) and mesocosm ambient air (FA/AA = 1.4 ± 0.3). We also present long-term observations of vertical concentration gradients of FA and AA within and above a primary rainforest canopy in the central Amazon during the 2010 dry and 2011 wet seasons. We observed a seasonal switch from net ecosystem-scale deposition during the dry season to net emissions during the wet season. This switch was associated with reduced ambient concentrations in the wet season (FA < 1.3 nmol mol−1, AA < 2.0 nmol mol−1) relative to the dry season (FA up to 3.3 nmol mol−1, AA up to 6.0 nmol mol−1), and a simultaneous increase in the FA/AA ambient concentration ratios from 0.3–0.8 in the dry season to 1.0–2.1 in the wet season. These observations are consistent with a switch between a biomass burning dominated source in the dry season (FA/AA < 1.0) to a vegetation dominated source in the wet season (FA/AA > 1.0). Our observations provide the first ecosystem-scale evidence of bidirectional FA and AA exchange between a forest canopy and the atmosphere controlled by ambient concentrations and ecosystem scale compensation points (estimated to be 1.3 ± 0.3 nmol mol−1: FA, and 2.1 ± 0.4 nmol mol−1: AA). These results suggest the need for a fundamental change in how future biosphere-atmosphere exchange models should treat FA and AA with a focus on factors that influence net exchange rates (ambient concentrations and ecosystem compensation points) rather than treating emissions and deposition separately.
Seasonal occurrence of anoxygenic photosynthesis in Tillari and Selaulim reservoirs, Western India
Authors: Kurian S. , Roy R. , Repeta D. J. , Gauns M. , Shenoy D. M. , Suresh T. , Sarkar A. , Narvenkar G. , Johnson C. G. , Naqvi S. W. A.
Published: December 2011

Abstract. Phytoplankton and bacterial pigment compositions were determined by high performance liquid chromatography (HPLC) and liquid chromatography- mass spectrometry (LCMS) in two freshwater reservoirs (Tillari Dam and Selaulim Dam), which are located at the foothills of the Western Ghats in India. These reservoirs experience anoxia in the hypolimnion during summer. Water samples were collected from both reservoirs during anoxic periods while one of them (Tillari Reservoir) was also sampled in winter, when convective mixing results in well-oxygenated conditions throughout the water column. During the periods of anoxia (summer), bacteriochlorophyll (BChl) e isomers and isoreneiratene, characteristic of brown sulfur bacteria, were dominant in the anoxic (sulfidic) layer of the Tillari Reservoir under low light intensities. The winter observations showed the dominance of small cells of Chlorophyll-b containing green algae and cyanobacteria, with minor presence of fucoxanthin-containing diatoms and peridinin-containing dinoflagellates. Using total BChl-e concentration observed in June, the standing stock of brown sulfur bacteria carbon in the Tillari Reservoir was computed to be 2.4 gC m−2, which is much higher than the similar estimate for carbon derived from oxygenic photosynthesis (0.82 gC m−2). These results highlight the importance of anoxygenic photosynthetic biomass in tropical freshwater systems. The Selaulim Reservoir also displayed similar characteristics with the presence of BChl-e isomers and isorenieratene in the anoxic hypolimnion during summer. Although sulfidic conditions prevailed in the water column below the thermocline, the occurrence of photoautotrophic bacteria was restricted only to mid-depths (maximal concentration of BChl-e isomers was noted at 0.2 % of the surface incident light). This shows that the vertical distribution of photoautotrophic sulfur bacteria is primarily controlled by light penetration in the water column where the presence of H2S provides a suitable biogeochemical environment for them to flourish.
Fire-derived organic carbon turnover in soils on a centennial scale
Authors: Singh N. , Abiven S. , Torn M. S. , Schmidt M. W. I.
Published: December 2011

Abstract. Pyrogenic Carbon (PyC), the residue of an incomplete combustion of plant biomass, is considered as a carbon (C) sink due to its assumed stability in soil. Our meta-analysis of studies on PyC degradation challenges the assumption that PyC persist in soil for several thousand years. The turnover time for PyC estimated here ranges from decadal to centennial time scales, and is not slower than decomposition of bulk Soil Organic Matter (SOM) and differs with initial biomass, pyrolysis temperature and climate. Thus, using PyC as a strategy for offsetting carbon emissions requires caution and further research.
Private Regional Universities as Alternatives to World Class Universities: Achievable Goals for Developing Nations
Authors: Roberts Keith J.
Published: December 2011

A predominant discussion in Asian higher education is the identification and value of world class universities. The pressure to develop world class universities is coming from two sectors. First, the governments themselves see a world class university as a critical prerequisite to moving innovation into the economy and thereby moving the economy ahead and also as a source of status and prestige for the country. Second, parents who are keenly aware of the best universities in the world apply pressure to have equally prestigious universities in their native countries. Although world class universities move the frontiers of knowledge ahead, and clearly help their nation by providing a source of scientists and educated professionals via their graduate schools, many students, especially undergraduates, may be better served by regional universities with emphasis on pedagogy at the undergraduate level. The purpose of this article is to propose that regional private universities provide an alternative, not a replacement, to large research universities as a meaningful investment for both the regional economy and the student.
Opportunities and Obstacles: Technology’s Potential for Expanding Access to Higher Education
Authors: Clothey Rebecca
Published: December 2011

Innovative technologies have forever impacted the field of education by connecting any topic in any discipline to any learner in any place. This new reality provides vastly expanded possibilities for international collaboration, knowledge building, sharing of best practices, and new ways to teach, both within the classroom and without. Nevertheless, even as new modes of providing education proliferate, the digital divide also grows, making technology solutions for expanding access a continuing issue of debate. This article looks at trends and challenges for expanding access to higher education via technology. Specifically it will address how the role of infrastructure, fiscal restraints, and culture relate to differences in accessibility and the application of technology in higher education. Through an overview of current use of technologies in differing educational contexts, the article analyzes some examples that either support or oppose the idea of promoting technology as an effective tool for facilitating equality of access.
Book Review: International Students and Global Mobility in Higher Education: National Trends and New Directions
Authors: Klahr Sabine C.
Published: December 2011

None
Polymer Cross‐Linkling
Authors: Ray Paramita
Published: December 2011

Cross‐linking is a unique tool for polymer modification. Multidirectional chain extension of polymers resulting in the formation of network structure is defined as polymer cross‐linking. It hinders the free movement of polymer chains and restricts them from sliding past each other. Interconnection of the polymer chains generates elasticity in amorphous polymers and makes a polymer more resistant to heat, light, and other physical agencies. It enhances the dimensional stability, mechanical strength, and solvent resistance of a polymer. Cross‐linking may be accomplished either through polymerization of monomers with functionality greater than two (polycondensation) or by covalent bonding between preformed polymer molecules by irradiation, sulfur vulcanization, or miscellaneous chemical reactions. The degree of cross‐linking and regularity of the network are the two vital factors, which control the effects of cross‐linking on the properties of the polymers. Cross‐linking is carried out in elastomers, plastomers, and even on polymer blends to improve properties and to broaden the spectrum of applications. The present review describes different modes and kinetics of polymer cross‐linking as well as its effects on the properties of polymers.
Polymer Solar Cells
Authors: Günes Serap , Mbi Egbe Daniel Ayuk , Sariciftci Niyazi Serdar
Published: December 2011

Polymer solar cells are developing rapidly. The cost effective manufacturing, flexibility and the integration possibilities make them attractive alternatives to conventional Si‐based solar cells. Power conversion efficiencies more than 8% were reported recently by industrial companies. However, even this value has to be improved to be competitive with the other solar cell devices. There is a great amount of interdisiplinary science to be explored within the organic solar cell research, ranging from solid state device physics, photophysics, polymer synthesis, polymer processing and supramolecular chemistry. In this encyclopedia entry, we give an overview of the basic operational principles, limitations and the possible improvements for polymer solar cells.
Mass Spectrometry
Authors: English Robert D. , Haag Anthony M.
Published: December 2011

Mass spectrometry (MS) has experienced tremendous growth throughout numerous scientific disciplines in the last few decades. This chapter will provide a concise summary of informative topics related to the study of therapeutic agents by MS. Our objective is to highlight as many pertinent MS techniques as possible. However, it should be noted that this will not be an all‐inclusive list of approaches due to the large volume of literature. This chapter will be primarily divided into the areas of instrumentation, sample preparation, and applications in proteomics, metabolomics, and emerging fields in drug analysis.
Development of Antimicrobial Peptides as Therapeutic Agents
Authors: Hodges Robert S. , Jiang Ziqing , Whitehurst James , Mant Colin T.
Published: December 2011

Classical antibiotics work by inhibiting bacterial cell wall synthesis, protein synthesis, DNA (deoxyribonucleic acid) replication, or by modifying metabolism. Bacteria can resist antibiotics as a result of chromosomal changes (mutation or inductive expression of a latent chromosomal gene) or the exchange of genetic material via plasmids and transposons. As this chapter will discuss, antibiotics are rendered inactive by three major mechanisms: (1) antibiotic inactivation by destruction or modification, (2) prevention of access of the antibiotic to the target, and (3) alteration of the target site of the antibiotic. Bacteria have a remarkable ability to overcome each new reagent synthesized as a potential classical antibiotic. Consequently, the current priority is the development of alternative drugs and/or the isolation of native molecules that would allow the consistent and proper control of pathogen‐caused diseases.
Gold Standard Animal Models
Authors: Castaneda Carol , LaPointe Michael S.
Published: December 2011

This chapter highlights how to make smart use of several good animal models. However, these animal experiments must be augmented with human‐based in vitro experiments, good toxicity databases, and computer modeling technology. Differences in animal and human cells do result in differences in the efficacy and toxicology of certain drugs. The old industrial adage does hold true for the development of drugs and other therapeutics–“cheaper, faster, better.” As will be shown here, it is accomplished by the use of computer models, in vitro testing using human cells or cell lines, and gold standard animal models, before human trials begin.
Resistance to Antiplatelet Therapy
Authors: Gurbel Paul A. , Tantry Udaya S.
Published: December 2011

Currently, 25 million people in the United States use aspirin as an antiplatelet agent to prevent cardiovascular events, whereas between 1998 and 2004, use of clopidogrel had increased over 7 times and the use of clopidogrel with aspirin had increased 16 times in the United States. The “nonresponsiveness or resistance” to antiplatelet therapy is becoming a major concern. Therefore, numerous scientific meetings and hundreds of clinical publications have focused on this phenomenon. However, as this chapter will discuss, the mechanism of antiplatelet resistance and the treatment strategies to address these concerns are still unclear.
Non‐Covalent Functionalization of Graphene Using Self‐Assembly of Alkane‐Amines
Authors: Long Brenda , Manning Mary , Burke Micheal , Szafranek Bartholomaeus N. , Visimberga Giuseppe , Thompson Damien , Greer James C. , Povey Ian M. , MacHale John , Lejosne Guaylord , Neumaier Daniel , Quinn Aidan J.
Published: December 2011

A simple, versatile method for non‐covalent functionalization of graphene based on solution‐phase assembly of alkane‐amine layers is presented. Second‐order Møller–Plesset (MP2) perturbation theory on a cluster model (methylamine on pyrene) yields a binding energy of ≈220 meV for the amine–graphene interaction, which is strong enough to enable formation of a stable aminodecane layer at room temperature. Atomistic molecular dynamics simulations on an assembly of 1‐aminodecane molecules indicate that a self‐assembled monolayer can form, with the alkane chains oriented perpendicular to the graphene basal plane. The calculated monolayer height (≈1.7 nm) is in good agreement with atomic force microscopy data acquired for graphene functionalized with 1‐aminodecane, which yield a continuous layer with mean thickness ≈1.7 nm, albeit with some island defects. Raman data also confirm that self‐assembly of alkane‐amines is a non‐covalent process, i.e., it does not perturb the sp2 hybridization of the graphene. Passivation and adsorbate n‐doping of graphene field‐effect devices using 1‐aminodecane, as well as high‐density binding of plasmonic metal nanoparticles and seeded atomic layer deposition of inorganic dielectrics using 1,10‐diaminodecane are also reported.
Preparation and properties of eggshell/β‐polypropylene bio‐composites
Authors: Lin Zhidan , Zhang Zishou , Mai Kancheng
Published: December 2011

In this article, a novel eggshell/β‐PP bio‐composite was prepared and evaluated. First the waste chicken eggshell (ES) was modified by a stingy amount of pimelic acid (PA) through solution method, and then compounded with PP through melt blending method. The crystalline form, mechanical properties, and morphology of the ES/β‐PP composites were studied. The results showed that ES modified by PA was a β nucleating agent with high efficiency and selectivity, resulting in the maximum Kβ value of 0.99 in PP composites. PA modification promoted the dispersion and interfacial bonding of ES in PP. Although the addition of PA‐modified ES slightly decreased tensile properties and flexural properties of PP, it increased the impact strength of PP by 228% than that of pure PP. Taking all factors into consideration, the optimal mass ratio of PP/ES/PA composites for reaching optimum mechanical properties should be 100/5/0.000471. Thus, the application of modified ES to prepare ES/β‐PP bio‐composites represents a promising way to mitigate environmental pollution and to reduce the cost of polyolefin products. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Influence of vibrations on interface delamination in metal–polymer composites
Authors: Zumelzu E. , Pereira R. , Arenas J. P. , Rull F. , Silva R.
Published: December 2011

The main objective of this work was the study of vibration effects on the viscoelastic coating protecting the steel layer in a metal–polymer composite, with simulated conditions of the transportation of food containers. Mechanical resonance tests in metal–polymer [electrolytic chromium‐coated steel–poly(ethylene terephthalate) (PET)] sheets were performed to generate vibration conditions to induce structural modifications in the viscoelastic layer covering the surface of the plates. Consequently, schematic representations of the areas affected by these modifications were made. The modified structures were later analyzed by electron microscopy to detect and evaluate alterations in the morphology of the material. In addition, vibrational Raman spectroscopy analyses were performed to assess the chemical and structural changes on the protective PET at the metal–polymer interface level. The results of this study are expected to provide basic information on the mechanisms and nature of the delamination processes taking place in metal–polymer laminates employed in food‐container applications. These damages have previously been detected in some food containers made of PET materials. The study of these damages can lead to the improvement of current composites or the development of higher quality materials. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Polymerization of styrene using pyrazolylimine nickel (II)/methylaluminoxane catalytic systems
Authors: Wang Yuan‐yuan , Li Ben‐xia , Zhu Fang‐ming , Gao Hai‐yang , Wu Qing
Published: December 2011

The polymerization of styrene with two pyrazolylimine nickel (II) complexes of (2‐(C3HN2Me2‐3, 5)(C(Ph) = N(4‐R2C6H2(R1)2‐2, 6)NiBr2 (Complex 1, R1 = iPr, R2 = H; Complex 2, R1 = H, R2 = NO2)) activated by methylaluminoxane was studied. The influences of polymerization parameters such as polymerization temperature, Al/Ni molar ratio, and reaction time on catalytic activity and molecular weight of the polystyrene (PS) were investigated in detail. The electron‐withdrawing of nitro group in Complex 2 could not enhance the catalytic activity for styrene polymerization; however, the molecular weights of polymers were increased. Both of the two catalytic systems exhibited high activity [up to 8.45 × 105 gPS/(mol Ni h)] for styrene polymerization and provide PS with moderate to low‐molecular weights (Mw = 2.21 × 104∼ 5.71 × 103 g/mol) and narrower molecular weight distributions about 2.0. The obtained PS were characterized by means of IR, 1H NMR, and 13C NMR techniques. The results indicated that the PS was atactic polymer. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Induced Circular‐Dichroism Chirality Probes for Selective Amino Acid Detection through Screening of a Dynamic Combinatorial Library of Lanthanide Complexes
Authors: Shinoda Satoshi , Terada Keiko , Tsukube Hiroshi
Published: December 2011

A dynamic combinatorial library of lanthanide complexes was prepared to develop induced‐circular‐dichroism (CD) chirality probes. It totaled 168 combinations of coordinative N‐aromatic chromophores, trivalent lanthanide centers, and guest amino acids. Eu3+ and Tb3+ complexes prepared with quinolinecarboxylic acid were particularly effective as induced‐CD chirality probes for selective alanine detection, whereas a Yb3+ complex with terpyridine exhibited glutamine selectivity. The former two complexes highly preferred alanine to the corresponding amine, ester, amino alcohol, and carboxylic acid derivatives. As such, the present combinatorial screening of a dynamic lanthanide complex library has led to a new series of induced‐CD chirality probes for specific amino acids.
Fuzzy Identification of Nonlinear Systems via Orthogonal Transform
Authors: Wang Hongwei , Wang Jia , Gu Hong
Published: December 2011

This paper is concerned with the application of orthogonal transforms and fuzzy competitive learning to extract fuzzy rules from data. The least square algorithm with orthogonal transforms is proposed to supervise the progress of fuzzy competitive learning. First of all, competitive learning takes place in the product space of system inputs and outputs and each cluster corresponds to a fuzzy IF–THEN rule. The fuzzy relation matrix, confirmed by fuzzy competitive learning, is studied by the orthogonal least square algorithm. The validity of fuzzy rules is obtained by analyzing the effect of orthogonal vectors in the fuzzy model, and subsequently removing less important ones. The structure identification and parameter identification of the fuzzy model are simultaneously confirmed in the proposed algorithm. Using simulation results as an example, the fuzzy model of non‐linear systems can be built by using the proposed algorithm.

Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Mammalian cells as biopharmaceutical production hosts in the age of omics
Authors: Dietmair Stefanie , Nielsen Lars K. , Timmins Nicholas E.
Published: December 2011

Mammalian cells are important hosts for the production of a wide range of biopharmaceuticals due to their ability to produce correctly folded and glycosylated proteins. Compared to microbes and yeast, however, the productivity of mammalian cells is low because of their comparatively slow growth rate, tendency to undergo apoptosis, and low production capacities. While much effort has been invested in the engineering of mammalian cells with superior production characteristics, the success of these approaches has been limited to date. One factor responsible for this lack of success is our limited understanding of the cellular basis for high productivity, and of how discrete mechanisms within a cell contribute to the overall phenotype. Aiming to measure and characterize all cellular components at different functional levels, omics technologies have the potential to improve our understanding of mammalian cell physiology, elucidating new targets for the generation of a superior host cell line. This review provides a comprehensive analysis of recent examples of omics studies in the context of mammalian cells as production hosts, highlighting both the challenges and successes in the application of these powerful technologies.
Oromandibular reconstruction
Authors: Cannon Trinitia Y. , Strub Graham M. , Yawn Robert J. , Day Terry A.
Published: December 2011

Mandibular reconstruction is often necessary due to congenital, traumatic, infectious, and following treatment for neoplasms of the region. Mandibular defects following ablative surgery for malignant tumors of the head and neck region impact both form and function and require a multidisciplinary approach to optimize functional and cosmetic outcomes. A variety of options exist for mandibular reconstruction and ranging from primary closure, allografts, and autografts, to locoregional and free tissue transfers. This article will focus upon the reconstructive and rehabilitative options for mandibular defects following treatment for head and neck tumors. Clin. Anat. 25:108–119, 2012. © 2011 Wiley Periodicals, Inc
Silylboranes as New Sources of Silyl Radicals for Chain‐Transfer Reactions
Authors: Rouquet Guy , Robert Frédéric , Méreau Raphaël , Castet Frédéric , Renaud Philippe , Landais Yannick
Published: December 2011

Various silylboranes, which were outfitted with a catecholborane moiety at one end and a (Me3Si)3Si moiety at the other end of a carbon chain, were prepared through the hydroboration of the corresponding unsaturated silanes. The C‐centered radical species generated from these silylboranes efficiently cyclized to provide, through a 5‐exo intramolecular homolytic substitution at the silicon center, the corresponding silacycle and a Me3Si radical that was subsequently trapped by sulfonyl acceptors. These cyclizations proceeded at unprecedented rates, due, in part, to a strong gem‐dialkyl effect that was attributable to the presence of bulky substituents on a quaternary center located on the chain. In parallel, we designed arylsilylboranes that produced silyl radicals through a 1,5‐hydrogen transfer. Such silyl radicals may be valuable radical chain carriers, for instance, in oximation reactions of alkyl halides. Finally, computational studies allowed calculation of activation barriers of the homolytic substitution step and additionally illustrated that the overall reaction mechanism involved a transition state in which the attacking carbon center, the central silicon atom, and the Me3Si leaving group were collinear.
Active surveillance for prostate cancer compared with immediate treatment
Authors: Keegan Kirk A. , Dall'Era Marc A. , Durbin‐Johnson Blythe , Evans Christopher P.
Published: December 2011

BACKGROUND:

The costs associated with a contemporary active surveillance strategy compared with immediate treatment for prostate cancer are not well characterized. The purpose of this study is to elucidate the health care costs of an active surveillance paradigm for prostate cancer.

METHODS:

A theoretical cohort of 120,000 men selecting active surveillance for prostate cancer was created. The number of men remaining on active surveillance and those exiting to each of 5 treatments over 5 years were simulated in a Markov model. Estimated total costs after 5 years of active surveillance with subsequent delayed treatment were compared with immediate treatment. Sensitivity analyses were performed to test the effect of various surveillance strategies and attrition rates. Additional analyses to include 10 years of follow‐up were performed.

RESULTS:

The average simulated cost of treatment for 120,000 men initiating active surveillance with 5 years of follow‐up and subsequent delayed treatment resulted in per patient cost savings of $16,042 (95% confidence interval [CI], $16,039‐$16,046) relative to initial curative treatment. This represents a $1.9 billion dollar savings to the cohort. The strict costs of active surveillance exceeded those of brachytherapy in the ninth year of follow‐up. A yearly biopsy within the active surveillance cohort increased costs by 22%, compared with every other year biopsy. At 10 years of follow‐up, active surveillance still resulted in a cost benefit; however, the savings were reduced by 38% to $9944 (95% CI, $9941‐$9948) per patient relative to initial treatment.

CONCLUSIONS:

These data demonstrate that active surveillance represents a considerable cost savings over immediate treatment for prostate cancer in a theoretical cohort after 5 and 10 years of follow‐up. Cancer 2012;3512–3518. © 2011 American Cancer Society.
A study of circulating interleukin 10 in prognostication of unresectable hepatocellular carcinoma
Authors: Chan Stephen L. , Mo Frankie K. F. , Wong Cesar S. C. , Chan Charles M. L. , Leung Linda K. S. , Hui Edwin P. , Ma Brigette B. , Chan Anthony T. C. , Mok Tony S. K. , Yeo Winnie
Published: December 2011

BACKGROUND:

The level of circulating interleukin 10 (IL‐10) is elevated in a proportion of patients with hepatocellular carcinoma (HCC). The objective of the current study was to evaluate the prognostic significance of serum the IL‐10 level in patients with unresectable HCC.

METHODS:

Patients with unresectable HCC who provided serum at the time of diagnosis were enrolled prospectively in the study. The level of circulating IL‐10 in serum samples was determined by enzyme‐linked immunosorbent assay. The association of the IL‐10 level with overall survival was evaluated in relation to sociodemographics, liver function, hepatitis B viral load, and tumor staging.

RESULTS:

In total, 222 patients were recruited; of these, 82.4% were positive for hepatitis B virus surface antigen, and 65.8% had Barcelona Clinic Liver Cancer stage C disease. The mean log IL‐10 level was 1.1 pg/mL, and 146 patients had an IL‐10 level >1 pg/mL (high IL‐10 group). The high IL‐10 group had worse overall survival than the low IL‐10 group (5.0 months vs 14.9 months; hazard ratio, 2.192; P < .0001). The IL‐10 level was associated with worse hepatic function and with a high alanine transaminase (ALT) level. The IL‐10 level remained an independent prognostic factor (hazard ratio, 1.824; P = .0005) after adjustment for sociodemographics, tumor staging, treatment, Child‐Pugh stage, and ALT level. The IL‐10 level also subdivided patients into 2 populations with distinct survival (10.2 months vs 3.5 months; P = .0027).

CONCLUSIONS:

The serum IL‐10 level was identified as an independent prognostic factor for unresectable HCC. The current findings suggested that an elevated IL‐10 level may be related to hepatic injury caused by cirrhotic processes rather than tumor load. The authors concluded that the IL‐10 level offers additional prognostic value to the existing tumor staging systems. Cancer 2012. © 2011 American Cancer Society.
Thiolato‐Bridged Arene–Ruthenium Complexes: Synthesis, Molecular Structure, Reactivity, and Anticancer Activity of the Dinuclear Complexes [(arene)2Ru2(SR)2Cl2]
Authors: Ibao Anne‐Flore , Gras Michaël , Therrien Bruno , Süss‐Fink Georg , Zava Olivier , Dyson Paul J.
Published: December 2011

Treatment of an arene–ruthenium dichloride dimer with thiols RSH to lead to cationic trithiolato complexes of the type [(arene)2Ru2(SR)3]+ was shown to proceed through the neutral thiolato complexes [(arene)2Ru2(SR)2Cl2], which have been isolated and characterized for arene = p‐MeC6H4iPr and R = CH2Ph (1), CH2CH2Ph (2), CH2C6H4‐p‐tBu (3), and C6H11 (4). The single‐crystal X‐ray structure analysis of the p‐tert‐butylbenzyl derivative 3 reveals that the two ruthenium atoms are bridged by the two thiolato ligands without a metal–metal bond. The neutral dithiolato complexes[(arene)2Ru2(SR)2Cl2] (1–3) are intermediates in the formation of the cationic trithiolato complexes [(arene)2Ru2(SR)3]+ (5–7). Of the new [(arene)2Ru2(SR)2Cl2] complexes, derivative 2 is highly cytotoxic against human ovarian cancer cells, with IC50 values of 0.20 μM for the A2780 cell line and 0.31 for the cisplatin‐resistant cell line A2780cisR.
Synthesis, Structural Characterization, and Catalytic Performance of a Vanadium‐Based Metal–Organic Framework (COMOC‐3)
Authors: Liu Ying‐Ya , Leus Karen , Grzywa Maciej , Weinberger David , Strubbe Katrien , Vrielinck Henk , Van Deun Rik , Volkmer Dirk , Van Speybroeck Veronique , Van Der Voort Pascal
Published: December 2011

A vanadium 2,6‐naphthalenedicarboxylate, VIII(OH)(O2C–C10H6–CO2)·H2O, denoted as COMOC‐3as (COMOC = Center for Ordered Materials, Organometallics and Catalysis, Ghent University), has been synthesized under hydrothermal conditions by means of both a solvothermal and a microwave synthesis procedure. The structure shows the topology of an aluminium 2,6‐naphthalenedicarboxylate, the so‐called MIL‐69 (MIL = Materials of the Institute Lavoisier). After calcination at 250 °C in air, the VIII center was oxidized to VIV with the structure of VIVO(O2C–C10H6–CO2) (COMOC‐3). The oxidation process was verified by cyclic voltammetry and EPR spectroscopy. The crystallinity was investigated by variable‐temperature XRD. The title compound is stable against air and moisture. The catalytic performance of COMOC‐3 was examined in the liquid‐phase oxidation of cyclohexene. COMOC‐3 exhibited similar catalytic performance to MIL‐47 [VO(O2C–C6H4–CO2)]. The compound is reusable and maintains its catalytic activity through several runs.
Highly sensitive capillary electrophoresis analysis of N‐linked oligosaccharides in glycoproteins following fluorescence derivatization with rhodamine 110 and laser‐induced fluorescence detection
Authors: Ijiri Soichiro , Todoroki Kenichiro , Yoshida Hideyuki , Yoshitake Takashi , Nohta Hitoshi , Yamaguchi Masatoshi
Published: December 2011

We describe a highly sensitive CE with laser‐induced fluorescence (LIF) detection for the analysis of N‐linked oligosaccharides in glycoproteins using rhodamine 110 as a fluorescence derivatization reagent. One CE separation is performed using a fused‐silica capillary and neutral pH buffer conditions and allows for the separation of sialo‐oligosaccharides according to the number of sialic acids. An alternate separation is performed using the same capillary and acidic pH buffer conditions, enabling the separation of asialo‐oligosaccharides according to their sizes. The derivatization and separation conditions for the analysis of sialo‐ and asialo‐oligosaccharides were optimized. Furthermore, we applied the proposed method for the analyses of N‐linked sialo‐ and asialo‐oligosaccharides in glycoproteins (ribonuclease B, fetuin, and recombinant human erythropoietin).
High‐throughput lectin magnetic bead array‐coupled tandem mass spectrometry for glycoprotein biomarker discovery
Authors: Choi Eunju , Loo Dorothy , Dennis James W. , O'Leary Caroline A. , Hill Michelle M.
Published: December 2011

Alterations in protein glycosylation occur during development and progression of many diseases, hence glycomics and glycoproteomics have emerged as important tools in glycobiomarker discovery. High‐throughput glycan profiling can now be achieved with the recent developments in MS‐based techniques. To enable identification and rapid monitoring of glycosylation changes in serum proteins, we developed a semi‐automated high‐throughput glycoprotein biomarker discovery platform termed lectin magnetic bead array‐coupled tandem mass spectrometry (LeMBA‐MS) which includes (i) effective single‐step serum glycoprotein isolation using a panel of 20 individual lectin‐coated magnetic beads in microplate format, (ii) on‐bead trypsin digestion, and (iii) nanoLC‐MS/MS with lectin exclusion list. With use of appropriate sequence databases, LeMBA‐MS can detect glycosylation changes regardless of the species. By spiking known amounts of titrated ovalbumin to a serum sample, we report nanomolar sensitivity, and linearity of response of LeMBA‐MS using concanavalin A‐coupled beads. Neuraminidase treatment led to reduction of binding to sialic acid‐binding lectins. Interestingly, we found that desialylation caused increased binding of haptoglobin and hemopexin to mannose‐specific lectins, pointing to the importance of identifying a signature of lectin‐binding. High‐throughput LeMBA‐MS to generate glycosylation signatures will facilitate glycobiomarker discovery. LeMBA can be coupled to down‐stream detection platforms for validation, making it a truly versatile platform.
Memantine for late‐life depression and apathy after a disabling medical event: a 12‐week, double‐blind placebo‐controlled pilot study
Authors: Lenze Eric J. , Skidmore Elizabeth R. , Begley Amy E. , Newcomer John W. , Butters Meryl A. , Whyte Ellen M.
Published: December 2011

Objective

Preclinical data suggests that memantine, a noncompetitive glutamate N‐methyl‐ D‐aspartate‐receptor blocker used for the treatment of moderate to severe Alzheimer's disease, could reduce depressive and amotivated behavior occurring in the context of psychosocial stress. Therefore, we examined whether memantine could reduce depressive symptoms and amotivation manifesting in older adults after a disabling medical event, thereby improving their functional recovery.

Method

We recruited subjects aged 60 years and older who had recently suffered a disabling medical event and were admitted to a skilled nursing facility for rehabilitation. Participants with significant depressive symptoms, defined as a Hamilton Rating Scale for Depression score of 10 or greater, and/or significant apathy symptoms, defined as an Apathy Evaluation Scale score of 40 or greater, were randomized to memantine (10 mg/d for 1 week, then 10 mg twice daily) or placebo, for 12 weeks. We also recruited participants without depressive or apathy symptoms for naturalistic follow‐up as a non‐depressed comparison group. Depressive and apathy symptoms were main outcomes; functional recovery, and self‐report rating of helplessness, and onset of new depressive disorders were secondary outcomes.

Results

Thirty‐five older adults with significant depressive and/or apathy symptoms were randomized, of whom 27 (77.1%) completed the 12 week randomized controlled trial. Both groups showed reduction in depressive symptoms (but no significant reduction in apathy symptoms) and improved function. However, there were no group differences between the memantine‐randomized and placebo randomized participants on any outcome.

Conclusion

Memantine was not associated with superior affective or functional outcome compared with placebo in medically rehabilitating older adults with depressive and apathy symptoms. Copyright © 2011 John Wiley & Sons, Ltd.