bluuebunny/crossref_metadata_2025 huggingface dataset:
Long-Term Antibody Memory Induced by Synthetic Peptide Vaccination Is Protective against Streptococcus pyogenes Infection and Is Independent of Memory T Cell Help
Authors: Pandey Manisha , Wykes Michelle N. , Hartas Jon , Good Michael F. , Batzloff Michael R.
Published: February 2013

Streptococcus pyogenes (group A Streptococcus [GAS]) is a leading human pathogen associated with a diverse array of mucosal and systemic infections. Vaccination with J8, a conserved region synthetic peptide derived from the M-protein of GAS and containing only 12 aa from GAS, when conjugated to diphtheria toxoid, has been shown to protect mice against a lethal GAS challenge. Protection has been previously shown to be Ab-mediated. J8 does not contain a dominant GAS-specific T cell epitope. The current study examined long-term Ab memory and dissected the role of B and T cells. Our results demonstrated that vaccination generates specific memory B cells (MBC) and long-lasting Ab responses. The MBC response can be activated following boost with Ag or limiting numbers of whole bacteria. We further show that these memory responses protect against systemic infection with GAS. T cell help is required for activation of MBC but can be provided by naive T cells responding directly to GAS at the time of infection. Thus, individuals whose T cells do not recognize the short synthetic peptide in the vaccine will be able to generate a protective and rapid memory Ab response at the time of infection. These studies significantly strengthen previous findings, which showed that protection by the J8-diphtheria toxoid vaccine is Ab-mediated and suggest that in vaccine design for other organisms the source of T cell help for Ab responses need not be limited to sequences from the organism itself.
Community Mortality from Cholera: Urban and Rural Districts in Zimbabwe
Authors: Morof Diane , Cookson Susan T. , Laver Susan , Chirundu Daniel , Desai Sarika , Mathenge Penninah , Shambare Donald , Charimari Lincoln , Midzi Stanley , Blanton Curtis , Handzel Thomas
Published: February 2013

In 2008–2009, Zimbabwe experienced an unprecedented cholera outbreak with more than 4,000 deaths. More than 60% of deaths occurred at the community level. We conducted descriptive and case–control studies to describe community deaths. Cases were in cholera patients who died outside health facilities. Two surviving cholera patients were matched by age, time of symptom onset, and location to each case-patient. Proxies completed questionnaires regarding mortality risk factors. Cholera awareness and importance of rehydration was high but availability of oral rehydration salts was low. A total of 55 case-patients were matched to 110 controls. The odds of death were higher among males (adjusted odd ratio [AOR] = 5.00, 95% confidence interval [CI] = 1.54–14.30) and persons with larger household sizes (AOR = 1.21, 95% CI = 1.00–1.46). Receiving home-based rehydration (AOR = 0.21, 95% CI = 0.06–0.71) and visiting cholera treatment centers (CTCs) (AOR = 0.07, 95% CI = 0.02–0.23) were protective. Receiving cholera information was associated with home-based rehydration and visiting CTCs. When we compared cases and controls who did not go to CTCs, males were still at increased odds of death (AOR = 5.00, 95% CI = 1.56–16.10) and receiving home-based rehydration (AOR = 0.14, 95% CI = 0.04–0.53) and being married (AOR = 0.26, 95% CI = 0.08–0.83) were protective. Inability to receive home-based rehydration or visit CTCs was associated with mortality. Community education must reinforce the importance of prompt rehydration and CTC referral.
High Levels of Genetic Diversity of Plasmodium falciparum Populations in Papua New Guinea despite Variable Infection Prevalence
Authors: Barry Alyssa E. , Schultz Lee , Senn Nicholas , Nale Joe , Kiniboro Benson , Siba Peter M. , Mueller Ivo , Reeder John C.
Published: February 2013

High levels of genetic diversity in Plasmodium falciparum populations are an obstacle to malaria control. Here, we investigate the relationship between local variation in malaria epidemiology and parasite genetic diversity in Papua New Guinea (PNG). Cross-sectional malaria surveys were performed in 14 villages spanning four distinct malaria-endemic areas on the north coast, including one area that was sampled during the dry season. High-resolution msp2 genotyping of 2,147 blood samples identified 761 P. falciparum infections containing a total of 1,392 clones whose genotypes were used to measure genetic diversity. Considerable variability in infection prevalence and mean multiplicity of infection was observed at all of the study sites, with the area sampled during the dry season showing particularly striking local variability. Genetic diversity was strongly associated with multiplicity of infection but not with infection prevalence. In highly endemic areas, differences in infection prevalence may not translate into a decrease in parasite population diversity.
Elevated Levels of High-Mobility Group Box-1 (HMGB1) in Patients with Severe or Uncomplicated Plasmodium falciparum Malaria
Authors: Angeletti Davide , Kiwuwa Mpungu Steven , Byarugaba Justus , Kironde Fred , Wahlgren Mats
Published: February 2013

Severe malaria is characterized by a massive release of proinflammatory cytokines in the context of sequestration of parasitized and normal red cells (RBCs). High-mobility group box 1 (HMGB1) is a DNA- and heparin-binding protein that also acts as a cytokine when released from cells in the extracellular milieu after a proinflammatory stimulus. In this study, we have measured the circulating levels of HMGB1 in 76 children with severe or uncomplicated malaria. Sera from both severe (P = 0.0022) and uncomplicated (P = 0.0049) patients had significantly higher circulating HMGB1 levels compared with healthy controls. Elevated HMGB1 in patients with ongoing Plasmodium falciparum infections might prolong inflammation and the febrile state of malaria and could offer a potential target for therapeutic intervention.
Validation of Decisional Balance and Self-Efficacy Measures for HPV Vaccination in College Women
Authors: Lipschitz Jessica M. , Fernandez Anne C. , Larson H. Elsa , Blaney Cerissa L. , Meier Kathy S. , Redding Colleen A. , Prochaska James O. , Paiva Andrea L.
Published: February 2013

Purpose.

Women younger than 25 years are at greatest risk for human papillomavirus (HPV) infection, including high-risk strains associated with 70% of cervical cancers. Effective model-based measures that can lead to intervention development to increase HPV vaccination rates are necessary. This study validated Transtheoretical Model measures of Decisional Balance and Self-Efficacy for seeking the HPV vaccine in a sample of female college students.

Design.

Cross-sectional measurement development.

Setting.

Online survey of undergraduate college students.

Subjects.

A total of 340 female students ages 18 to 26 years.

Measures.

Stage of Change, Decisional Balance, and Self-Efficacy.

Analysis.

The sample was randomly split into halves for exploratory principal components analyses (PCAs), followed by confirmatory factor analyses (CFAs) to test measurement models. Multivariate analyses examined relationships between constructs.

Results.

For Decisional Balance, PCA indicated two 4-item factors (Pros –α = .90; and Cons –α = .66). CFA supported a two-factor correlated model, χ2(19) = 39.33; p < .01; comparative fit index (CFI) = .97; and average absolute standardized residual statistic (AASR) = .03; with Pros α = .90 and Cons α = .67. For Self-Efficacy, PCA indicated one 6-item factor (α = .84). CFA supported this structure, χ2(9) = 50.87; p < .05; CFI = .94; AASR = .03; and α = .90. Multivariate analyses indicated significant cross-stage differences on Pros, Cons, and Self-Efficacy in expected directions.

Conclusion.

Findings support the internal and external validity of these measures and their use in Transtheoretical Model–tailored interventions. Stage-construct relationships suggest that reducing the Cons of vaccination may be more important for HPV than for behaviors with a true Maintenance stage.
Dosimetry in Targeted Radionuclide Therapy: The Bad Berka Dose Protocol—Practical Experience
Authors: Schuchardt Christiane , Kulkarni Harshad , Zachert Carolin , Baum Richard P
Published: February 2013

Aim

Calculating the absorbed dose is important for the determination of risk and therapeutic benefit of internal radiation therapy. Optimal dose estimations require time-consuming and sophisticated methods, which are difficult due to practical reasons. To make dosimetry available for each of the patients, we developed a specific dosimetry procedure used in daily clinical routine.

Materials and methods

Dosimetry has been performed according to the MIRD scheme and adapted to the special conditions at our department (which we have called as the Bad Berka Dose protocol, BBDP): Conjugated planar whole-body scintigraphies at 0.5, 3, 24, 48 and 72 hours postinjection are analyzed by regions of interest with ‘HERMES WHOLE-BODY DISPLAY’ and the time-dependent organ and tumor activities are determined with Microsoft EXCEL™. The cumulated activity is calculated using the software ORIGIN PRO 8.1G™ and a mono- or biexponential fit of the time-activity curves. Mean absorbed doses are finally estimated using the software OLINDA EXM™.

Results

We found a compromise between the calculation model and practical conditions. It has ensured dose estimation in daily clinical routine with a reasonable effort and within acceptable time. In consequence, the dosimetry method developed for Bad Berka allows each of our patients to undergo dosimetry after therapy using Lu-177-labeled peptides (peptide receptor radionuclide therapy). Additionally, this approach can be used for any internal radiotherapy using a gamma-emitting radionuclide.

Conclusion

The BBDP is a practicable dosimetric approach, which can be used in daily clinical routine. It not only helps in identifying patients who would benefit most from the treatment, but also those with unfavorable dosimetry. Additionally, the analysis of dosimetric data from peptide receptor radionuclide therapy (PRRNT) could help in predicting possible toxicity.

How to cite this article

Schuchardt C, Kulkarni H, Zachert C, Baum RP. Dosimetry in Targeted Radionuclide Therapy: The Bad Berka Dose Protocol—Practical Experience. J Postgrad Med Edu Res 2013;47(1):65-73.
Diurnal variations in middle atmospheric water vapor by ground-based microwave radiometry
Authors: Scheiben D. , Schanz A. , Tschanz B. , Kämpfer N.
Published: February 2013

Abstract. In this paper, we compare the diurnal variations in middle atmospheric water vapor as measured by two ground-based microwave radiometers in the Alpine region near Bern, Switzerland. The observational data set is also compared to data from the chemistry-climate model WACCM. Due to the small diurnal variations of usually less than 1%, averages over extended time periods are required. Therefore, two time periods of five months each, December to April and June to October, were taken for the comparison. The diurnal variations from the observational data agree well with each other in amplitude and phase. The linear correlation coefficients range from 0.8 in the upper stratosphere to 0.5 in the upper mesosphere. The observed diurnal variability is significant at all pressure levels within the sensitivity of the instruments. Comparing our observations with WACCM, we find that the agreement of the phase of the diurnal cycle between observations and model is better from December to April than from June to October. The amplitudes of the diurnal variations for both time periods increase with altitude in WACCM, but remain approximately constant at 0.05 parts per million in the observations. The WACCM data is used to separate the processes that lead to diurnal variations in middle atmospheric water vapor above Bern. The dominating processes were found to be meridional advection below 0.1 hPa, vertical advection between 0.1 and 0.02 hPa and (photo-)chemistry above 0.02 hPa. The contribution of zonal advection is small. The highest diurnal variations in water vapor are found in the mesopause region during the time period from June to October with diurnal amplitudes of 0.2 ppm (approximately 5% in relative units).
Halogen species record Antarctic sea ice extent over glacial-interglacial periods
Authors: Spolaor A. , Vallelonga P. , Plane J. M. C. , Kehrwald N. , Gabrieli J. , Varin C. , Turetta C. , Cozzi G. , Boutron C. , Barbante C.
Published: February 2013

Abstract. Sea ice is an integral part of the Earth's climate system because it affects planetary albedo, sea surface salinity, and the atmosphere-ocean exchange of reactive gases and aerosols. Bromine and iodine chemistry is active at polar sea ice margins with the occurrence of bromine explosions and the biological production of organo-iodine from sea ice algae. Satellite measurements demonstrate that concentrations of bromine oxide (BrO) and iodine oxide (IO) decrease over sea ice toward the Antarctic interior. Here we present speciation measurements of bromine and iodine in the TALDICE (TALos Dome Ice CorE) ice core (159°11' E, 72°49' S, 2315 m a.s.l.) spanning the last 215 ky. The Talos Dome ice core is located 250 km inland and is sensitive to marine air masses intruding onto the Antarctic Plateau. Talos Dome bromide (Br−) is positively correlated with temperature and negatively correlated with sodium (Na). Based on the Br−/Na seawater ratio, bromide is depleted in the ice during glacial periods and enriched during interglacial periods. Total iodine, consisting of iodide (I−) and iodate (IO3−), peaks during glacials with lower values during interglacial periods. Although IO3− is considered the most stable iodine species in the atmosphere it was only observed in the TALDICE record during glacial maxima. Sea ice dynamics are arguably the primary driver of halogen fluxes over glacial-interglacial timescales, by altering the distance between the sea ice edge and the Antarctic plateau and by altering the surface area of sea ice available to algal colonization. Based on our results we propose the use of both halogens for examining Antarctic variability of past sea ice extent.
Time series inversion of spectra from ground-based radiometers
Authors: Christensen O. M. , Eriksson P.
Published: February 2013

Abstract. Retrieving time series of atmospheric constituents from ground-based spectrometers often requires different temporal averaging depending on the altitude region in focus. This can lead to several datasets existing for one instrument which complicates validation and comparisons between instruments. This paper puts forth a possible solution by incorporating the temporal domain into the maximum a posteriori (MAP) retrieval algorithm. The state vector is increased to include measurements spanning a time period, and the temporal correlations between the true atmospheric states are explicitly specified in the a priori uncertainty matrix. This allows the MAP method to effectively select the best temporal smoothing for each altitude, removing the need for several datasets to cover different altitudes. The method is compared to traditional averaging of spectra using a simulated retrieval of water vapour in the mesosphere. The simulations show that the method offers a significant advantage compared to the traditional method, extending the sensitivity an additional 10 km upwards without reducing the temporal resolution at lower altitudes. The method is also tested on the OSO water vapour microwave radiometer confirming the advantages found in the simulation. Additionally, it is shown how the method can interpolate data in time and provide diagnostic values to evaluate the interpolated data.
MISR Dark Water aerosol retrievals: operational algorithm sensitivity to particle non-sphericity
Authors: Kalashnikova O. V. , Garay M. J. , Martonchik J. V. , Diner D. J.
Published: February 2013

Abstract. The aim of this study is to theoretically investigate the sensitivity of the Multi-angle Imaging SpectroRadiometer (MISR) operational (Version 22) Dark Water retrieval algorithm to aerosol non-sphericity over the global oceans under actual observing conditions, accounting for current algorithm assumptions. Non-spherical (dust) aerosol models, which were introduced in Version 16 of the MISR aerosol product, improved the quality and coverage of retrievals in dusty regions. Due to the sensitivity of the retrieval to the presence of non-spherical aerosols, the MISR aerosol product has been successfully used to track the location and evolution of mineral dust plumes from the Sahara across the Atlantic, for example. However, the MISR global non-spherical aerosol optical depth (AOD) fraction product has been found to have several climatological artifacts superimposed on valid detections of mineral dust, including high non-spherical fraction in the Southern Ocean and seasonally variable bands of high non-sphericity. In this paper we introduce a formal approach to examine the ability of the operational MISR Dark Water algorithm to distinguish among various spherical and non-spherical particles as a function of the variable MISR viewing geometry. We demonstrate that under the criteria currently implemented: (1) Dark Water retrieval sensitivity to particle non-sphericity decreases for AOD below about 0.1 primarily due to an unnecessarily large lower bound imposed on the uncertainty in MISR observations at low light levels, and improves when this lower bound is removed; (2) Dark Water retrievals are able to distinguish between the spherical and non-spherical particles currently used for all MISR viewing geometries when the AOD exceeds 0.1; (3) the sensitivity of the MISR retrievals to aerosol non-sphericity varies in a complex way that depends on the sampling of the scattering phase function and the contribution from multiple scattering; and (4) non-sphericity artifacts occur at those view-illumination geometries where dust aerosols are indistinguishable from certain types of cirrus particles. Based on these results, we suggest that interested parties use caution with the Version 22 MISR Dark Water aerosol non-sphericity product in situations where cirrus may be present.
Greenland ice sheet contribution to sea level rise during the last interglacial period: a modelling study driven and constrained by ice core data
Authors: Quiquet A. , Ritz C. , Punge H. J. , Salas y Mélia D.
Published: February 2013

Abstract. As pointed out by the forth assessment report of the Intergovernmental Panel on Climate Change, IPCC-AR4 (Meehl et al., 2007), the contribution of the two major ice sheets, Antarctica and Greenland, to global sea level rise, is a subject of key importance for the scientific community. By the end of the next century, a 3–5 °C warming is expected in Greenland. Similar temperatures in this region were reached during the last interglacial (LIG) period, 130–115 ka BP, due to a change in orbital configuration rather than to an anthropogenic forcing. Ice core evidence suggests that the Greenland ice sheet (GIS) survived this warm period, but great uncertainties remain about the total Greenland ice reduction during the LIG. Here we perform long-term simulations of the GIS using an improved ice sheet model. Both the methodologies chosen to reconstruct palaeoclimate and to calibrate the model are strongly based on proxy data. We suggest a relatively low contribution to LIG sea level rise from Greenland melting, ranging from 0.7 to 1.5 m of sea level equivalent, contrasting with previous studies. Our results suggest an important contribution of the Antarctic ice sheet to the LIG highstand.
Large spatial variations in coastal 14C reservoir age – a case study from the Baltic Sea
Authors: Lougheed B. C. , Filipsson H. L. , Snowball I.
Published: February 2013

Abstract. Coastal locations are highly influenced by input from freshwater river runoff, including sources of terrestrial carbon, which can be expected to modify the 14C reservoir age, or R(t), associated with marine water. In this Baltic Sea case study, pre-bomb museum collection mollusc shells of known calendar age, from 30 locations across a strategic salinity transect of the Baltic Sea, were analysed for 14C, δ13C and δ18O. R(t) was calculated for all 30 locations. Seven locations, of which six are within close proximity of the coast, were found to have relatively higher R(t) values, indicative of hard-water effects. δ13Caragonite values were found to be indicative of hard-water influence only for certain locations, suggesting the possibility of different sources of old carbon in different locations. Whenever possible, the Macoma genus of mollusc was selected from the museum collections, in order to exclude species specific reservoir age effects as much as possible. When the Macoma samples are exclusively considered, and samples from hard-water locations excluded, a statistically significant correlation between Macoma R(t) and average salinity is found, indicating a two end-member linear mixing model between 14Cmarine and 14Crunoff. A map of Baltic Sea Macoma aragonite R(t) for the late 19th and early 20th centuries is produced. Such a map can provide an estimate for contemporary Baltic Sea Macoma R(t), although one must exercise caution when applying such estimates back in time or to 14C dates obtained from different sample material. A statistically significant correlation is also found between δ18Oaragonite and Macoma R(t), suggesting that δ18Oaragonite can be used to estimate Macoma palaeo-R(t). The results of this Baltic Sea case study, which show that R(t) is affected by hydrographic conditions and local carbon inputs, have important consequences for other coastal and estuarine locations, where R(t) is also likely to significantly vary on spatial and temporal bases.
Growth in the Constant Growth Model
Authors: Morris James R.
Published: February 2013

This article discusses the conditions that justify the use of the constant growth model. The constant growth model is very sensitive to the assumptions regarding the firm's operating ratios, capital structure, and dividend policy. If the constant growth model is used and these factors are not coordinated and consistent, the valuation estimate using the equity method will not agree with the valuation estimate obtained with the invested capital method. On the other hand, if all the factors are coordinated, or “in sync,” these two methods will generate identical values when the constant growth model is used. Data presented at the end of the article suggests that only a small proportion of companies have growth rates that would make them good candidates to be valued using the constant growth model.
Misuse of Control Premiums in Delaware Appraisals
Authors: Matthews Gilbert E.
Published: February 2013

In statutory appraisal cases, Delaware Courts sometimes apply premiums that are based on questionable reasoning. They commonly adjust guideline company valuations for an “implicit minority discount”, they apply acquisition premiums to subsidiaries, and they often rely upon average premiums in acquisitions as a basis for calculating control premiums. This article discusses the flaws in the reasoning underlying these adjustments.
Democracy, Narcissism, and the World Wide Web
Authors: Condella Craig ,   Philosophy Documentation Center
Published: February 2013

Against a thinker like Martin Heidegger who takes restraints on individual freedom and the promotion of authoritarianism as implicit features in the ongoing development of technology, Andrew Feenberg argues for a “democratic rationalization” of modern technology whereby people effectively choose their own futures, not in spite of their tools, but increasingly because of them. Acknowledging the Web’s democratic potential, I believe that a new threat—far different from authoritarian regimes or structures—has emerged: a rampant and multifarious narcissism that threatens to drown democratic ideals in a wave of self-obsession and self-promotion.
Embodying a Translation Technology
Authors: Besmer Kirk ,   Philosophy Documentation Center
Published: February 2013

In this paper, I seek to contribute to post-phenomenological descriptions of human-technological relations and the intentionalities exhibited in them by focusingon the intentionality exhibited in the use of a cochlear implant. To do so, I will use concepts developed by Don Ihde and further extended by Peter-Paul Verbeek to show that while post-phenomenological categories illuminate the intentional relationship of a cochlear implant wearer to her world, this relationship defies easy categorization. An examination of successful functioning with a cochlear implant will reveal a distinct form of technological embodiment and intentionality that confirms and extends previous post-phenomenological analyses.
Entre ville stérile et ville fertile, l’émergence de l’agriculture urbaine en Suisse
Authors: Salomon Cavin Joëlle
Published: February 2013

L’agriculture urbaine interroge la relation entre ville et agriculture, deux catégories traditionnellement distinctes et opposées dans la sphère des représentations sociales. Dans l’imaginaire antiurbain helvétique, la référence à l’agriculture est toujours mobilisée pour dévaloriser la ville ; d’abord via l’idée d’une ville parasite incapable d’assurer sa propre subsistance et qui éloigne l’homme des occupations saines de la campagne; ensuite, via l’idée de l’urbanisation dévoreuse du sol agricole. Par contraste, les expériences actuelles d’agriculture urbaine s’accompagnent de discours qui mettent en avant le mariage heureux entre ville et agriculture et participent à la construction d’une représentation positive de la ville. Cependant, comme l’illustre un cas emblématique dans la région genevoise, l’opposition entre ville et agriculture associée à des représentations négatives de la ville demeure encore très prégnante. Ce constat permet d’esquisser deux grandes figures types du rapport actuel de la ville à l’agriculture en Suisse : la ville stérile et la ville fertile.
Optimized look‐ahead tree policies: a bridge between look‐ahead tree policies and direct policy search
Authors: Jung Tobias , Wehenkel Louis , Ernst Damien , Maes Francis
Published: February 2013

Direct policy search (DPS) and look‐ahead tree (LT) policies are two popular techniques for solving difficult sequential decision‐making problems. They both are simple to implement, widely applicable without making strong assumptions on the structure of the problem, and capable of producing high‐performance control policies. However, computationally, both of them are, each in their own way, very expensive. DPS can require huge offline resources (effort required to obtain the policy) to first select an appropriate space of parameterized policies that works well for the targeted problem and then to determine the best values of the parameters via global optimization. LT policies do not require any offline resources; however, they typically require huge online resources (effort required to calculate the best decision at each step) in order to grow trees of sufficient depth. In this paper, we propose optimized LTs (OLTs), a model‐based policy learning scheme that lies at the intersection of DPS and LT. In OLT, the control policy is represented indirectly through an algorithm that at each decision step develops, as in LT by using a model of the dynamics, a small LT until a prespecified online budget is exhausted. Unlike LT, the development of the tree is not driven by a generic heuristic; rather, the heuristic is optimized for the target problem and implemented as a parameterized node scoring function learned offline via DPS. We experimentally compare OLT with pure DPS and pure LT variants on optimal control benchmark domains. The results show that the LT‐based representation is a versatile way of compactly representing policies in a DPS scheme (which results in OLT being easier to tune and having lower offline complexity than pure DPS) and at the same time DPS helps to significantly reduce the size of the LTs that are required to take high‐quality decisions (which results in OLT having lower online complexity than pure LT). Moreover, OLT produces overall better performing policies than pure DPS and pure LT, and also results in policies that are robust with respect to perturbations of the initial conditions. Copyright © 2013 John Wiley & Sons, Ltd.
Intrinsic and Extrinsic Fluorescence in Carbon Nanodots: Ultrafast Time‐Resolved Fluorescence and Carrier Dynamics
Authors: Wen Xiaoming , Yu Pyng , Toh Yon‐Rui , Hao Xiaotao , Tang Jau
Published: February 2013

Using a femtosecond resolved up‐conversion technique, the ultrafast carrier dynamics in fluorescent carbon nanodots are investigated in order to shed light on the mysterious origins of their fluorescence. These experiments reveal that the fluorescence of carbon nanodots consists of two spectral overlapped bands that can be ascribed to the intrinsic and extrinsic fluorescence. The intrinsic band exhibits a small bandwidth of 175 meV at 459 nm, and it is attributed to the sp2 nano domains. The extrinsic band originates from the surface states with a much broader bandwidth of 450 meV. The relaxation with time constants of a few picoseconds, tens of picoseconds, and a few nanoseconds are attributed to optical phonon scattering, acoustic phonon scattering, and carrier (e–h pair) recombination, respectively. A fast trapping is observed from the nano domains into the surface states with a time constant of 400 fs. The excitation wavelength‐dependent fluorescence can arise from the abundant carboxyl functional groups on the surface.
Nanocomposite Development with Organically Modified Clay through In Situ Polymerization of Poly(ethylene terephthalate)
Authors: Kim Sung‐Gi , Lofgren Elizabeth A. , Jabarin Saleh A.
Published: February 2013

In situ polymerization of poly(ethylene terephthalate) (PET) organo‐montmorillonite clay nanocomposites was investigated in terms of the natures of organic clay modifiers and their affinities with PET, esterification versus polycondensation mode of clay addition, time and temperature of polymerization, ethylene glycol/terephthalic acid (E/T) ratio, and other process modifications such as foam and diethylene glycol suppression, reactor pressure, and variations in catalyst, antioxidant, and metal stabilizer. The nanocomposites were found to degrade during polymerization. This degradation increased diethylene glycol concentrations and reduced melting temperatures. It also increased carboxyl and decreased hydroxyl end group concentrations from normal PET values, which caused reduced rates of nanocomposite solid‐state polymerization. Cloisite 30B had the best affinity with PET as a result of the hydroxyl groups present in both PET and the organic clay modifier. Polycondensation of Cloisite 30B nanocomposites at 270°C from bis(2‐hydroxyethyl)terephthalate, with an E/T ratio of 1.2:1, yielded the most fully exfoliated nanostructures as verified by X‐ray diffraction and transmission electron microscopy evaluations. © 2013 Wiley Periodicals, Inc. Adv Polym Technol 2013, 32, 21342; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.21342
Influence of formic acid on electrochemical properties of high‐porosity Pt/TiN nanoparticle aggregates
Authors: Ogi Takashi , Balgis Ratna , Okuyama Kikuo , Tajima Naoko , Setyawan Heru
Published: February 2013

Platinum‐deposited titanium nitride (Pt/TiN) nanoparticle aggregates with high porosities were successfully prepared via a self‐assembly‐assisted spray pyrolysis method. The addition of formic acid (HCOOH) had a significant influence on the process, promoting the simultaneous formation of metallic Pt and reduction on the surface of the TiN support material. Complete reduction of the Pt/TiN nanoparticle aggregates improved the catalytic activity. The electrochemical surface area (ECSA) of Pt/TiN with HCOOH (Pt/TiNw/HCOOH) was 87.15 m2/g‐Pt, which was higher than that of Pt/TiN without HCOOH (Pt/TiNw/o‐HCOOH). The catalytic durability of Pt/TiNw/HCOOH was twice that of Pt/TiNw/o‐HCOOH. An effective strategy for obtaining carbon‐free catalysts with high activities and durabilities was identified. © 2013 American Institute of Chemical Engineers AIChE J, 59: 2753–2760, 2013
FRET interaction between pyrene‐tagged β‐hydroxy acid and perylen‐3‐ylmethylmethacrylate co‐N‐dodecylmethacrylamide in film and solution
Authors: Calderon Isen Andrew C. , Lao Kendricks S. , Chua Elvis T. , Romano Edwin , Anore Kristine Haizell S. , Cabatuando Anna Charina R. , Ibabao Marlon Jose P. , Guerrero Raphael A. , So Regina C.
Published: February 2013

Synthesis, characterization, and FRET interaction of pyrene‐tagged β‐hydroxy acid and perylen‐3‐ylmethylmethacrylate co‐N‐dodecylmethacrylamide polymer are described. The fluorescent donor, β‐hydroxy acid‐pyrene boronic ester was synthesized from commercially available alkyl ketene dimer via subsequent hydrolysis, reduction and esterification providing the donor. Conversely, the fluorescent acceptor was synthesized by co‐polymerization of N‐dodecylmethacryamide and perylen‐3‐ylmethylmethacrylate, where the latter was prepared from commercially available perylene in three steps. FRET interaction between the donor and acceptor was carried out by titration and monitored using fluorescence spectroscopy. Fluorescence quenching and enhancement in both film and solution formats were observed; furthermore, a more prominent lipophilic‐induced interaction was observed in solution. Fluorescence enhancement (at 460 nm) is higher for the acceptor and quenching efficiency (at 420 nm) is higher for donor‐acceptor pair, pyrene‐tagged β‐hydroxy acid and perylen‐3‐ylmethylmethacrylate co‐N‐dodecylmethacryl‐amide polymer, compared to control, pyrene boronic ester. The quenching is due to dynamic quenching between the donor and acceptor. Furthermore, aggregation was not observed from the pyrene‐tagged β‐hydroxy acid ester donor as the concentration of the solution is increased up to 3000 ppm. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Polymer stain resistance: Prediction versus experiment
Authors: Narses Sebastien , Sadaka Faten , Brachais Claire‐Hélène , Couvercelle Jean‐Pierre
Published: February 2013

The coloration of different polymer films (from commodity and packaging films to performance films) by contact with various food coloring substances was evaluated. For this purpose, both solubility parameters as a prediction tool, and immersion experiments for time range between 24 and 1000 h were established. The two predicting tools are the Hoy and Hoftyzer‐Van Krevelen (HVK) methods. For PE and PP, HVK's method is preferred for predicting coloration. Neither of the HVK's and Hoy's methods was able to establish a coloration prediction for PET while both methods could predict the staining of PEEK. The coloration of partially and fully fluorinated polymers is well predicted by the Hoy's method. The behavior of PP/PA and PP/PA/PP multilayer films was also studied. Crystallinity degree of polymers, temperature and concentration of coloring molecules are also important parameters, which are not taken into account in solubility theories. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
MOLECULAR CHARACTERIZATION OF TWO CARBOXYLESTERASE GENES OF THE CITRUS RED MITE, Panonychus citri (ACARI: TETRANYCHIDAE)
Authors: Zhang Kun , Niu Jin‐Zhi , Ding Tian‐Bo , Dou Wei , Wang Jin‐Jun
Published: February 2013

The citrus red mite, Panonychus citri, is known for its ability to rapidly evolve resistance to insecticides/acaricides and to adapt to hosts that produce toxins. To get better insight into the detoxification mechanism of P. citri, two carboxylesterase (CarE) genes, PCE1 and PCE2, were isolated and characterized. PCE1 and PCE2 contained open reading frames of 1,653 and 1,392 nucleotides, encoding proteins of 550 and 463 amino acid residues, respectively. Phylogenetic analyses showed that PCE1 and PCE2 were most closely related to the CarE genes from other phytophagous mites. The transcriptional profiles of two CarE genes among developmental stages (egg, larva, nymph, adult female, and adult male), after exposing to four acaricides (avermectin, azocyclotin, pyridaben, and spirodiclofen) and acid rain were investigated using real‐time quantitative PCR (qPCR). The results showed that during development, PCE1 was highly expressed at the egg stage, whereas PCE2 was abundantly expressed at the adult stage of males. The expression levels of PCE1 were highly induced upon exposure to acaricides and acid rain. On the other hand, the expression levels of PCE2 were increased after treatment with avermectin and pyridaben. These results suggest that PCE1 and PCE2 may have distinct roles in different developmental stages and participate in the detoxification of acaricides.
Synthesis of Antitumor‐Active Betulinic Acid‐Derived Hydroxypropargylamines by Copper‐Catalyzend Mannich Reactions
Authors: Csuk René , Nitsche Christoph , Sczepek Ronny , Schwarz Stefan , Siewert Bianka
Published: February 2013

Several novel betulin derivates were prepared using Mannich reactions as a key step. Starting from 3‐ethynyl‐3‐hydroxy‐lup‐20(29)‐ene derivatives, copper‐catalyzed Mannich reactions yielded hydroxypropargyl ammonium hydrochlorides or their corresponding methiodides. All compounds were screened in a sulforhodamine B assay for their antitumor activity using a panel of 9 human cancer cell lines. Some of these compounds showed significant cytotoxicity; they act by triggering apoptotic cell death as shown by additional acridine orange/propidium iodide assays, Trypan blue tests, DNA laddering experiments, and investigations of the cell cycle.
Nepem‐211 ion exchange conductive membrane immobilized tris(2,2´‐bipyridyl) ruthenium(II) electrogenerated chemiluminescence flow sensor for high‐performance liquid chromatography and its application
Authors: Li Yongbo , Zhang Zhujun
Published: February 2013

We developed a sensitive and robust electrogenerated chemiluminescence (ECL) flow sensor based on Ru(bpy)32+ immobilized with a Nepem‐211 perfluorinated ion exchange conductance membrane, which has robustness and stability under a wide range of chemical and physical conditions, good electrical conductivity, isotropy and a high exchange capacity for immobilization of Ru(bpy)32+. The flow sensor has been used as a post‐column detector in high‐performance liquid chromatography for determination of erythromycin and clarithromycin in honey and pork, and tricyclic antidepressant drugs in human urine. Under optimal conditions, the linear ranges were 0.03–26 ng/μL and 0.01–1 ng/μL for macrolides and tricyclic antidepressant drugs, respectively. The detection limits were 0.02, 0.01, 0.01, 0.06 and 0.003 ng/μL for erythromycin, clarithromycin, doxepin, amitriptyline and clomipramine, respectively. There is no post‐column reagent addition. In addition to the conservation expensive reagents, the experimental setup was simplified. The flow sensor was used for 2 years with high sensitivity and stability. Copyright © 2013 John Wiley & Sons, Ltd.
Renewable bio ionic liquids‐water mixtures‐mediated selective removal of lignin from rice straw: Visualization of changes in composition and cell wall structure
Authors: Hou Xue‐Dan , Li Ning , Zong Min‐Hua
Published: February 2013

Pretreatment of rice straw by using renewable cholinium amino acids ionic liquids ([Ch][AA] ILs)‐water mixtures and the subsequent enzymatic hydrolysis of the residues were conducted in the present work. Of the eight mixtures composed of ILs and water, most were found to be effective for rice straw pretreatment. After pretreatment with 50% ILs‐water mixtures, the enzymatic digestion of the lignocellulosic biomass was enhanced significantly, thus leading to satisfactory sugar yields of >80% for glucose and approximately 50% for xylose. To better understand the ILs pretreatment mechanism, confocal laser scanning microscopy combined with immunolabeling and transmission electron microscopy were used to visualize changes in the contents and distribution of two major components—lignin and xylan. The results coupled with changes in chemical structures (infrared spectra) of the substrates indicated occurrence of extensive delignification, especially in cell corner and compound middle lumen of cell walls, which made polysaccharides more accessible to enzymes. This pretreatment process is promising for large‐scale application because of the high sugar yields, easy handling, being environmentally benign and highly tolerant to moisture, and significantly reduced cost and energy consumption. Biotechnol. Bioeng. 2013; 110: 1895–1902. © 2013 Wiley Periodicals, Inc.
Periplasmic expression of carbonic anhydrase in Escherichia coli: A new biocatalyst for CO2 hydration
Authors: Patel Tushar N. , Park Ah‐Hyung Alissa , Banta Scott
Published: February 2013

Carbonic anhydrase is a valuable and efficient catalyst for CO2 hydration. Most often the free enzyme is employed which complicates catalyst recycling, and can increase cost due to the need for protein purification. Immobilization of the enzyme may address these shortcomings. Here we report the development of whole‐cell biocatalysts for CO2 hydration via periplasmic expression of two forms of carbonic anhydrase in Escherichia coli using two different targeting sequences. The enzymatic turnover numbers (kcat) and catalytic efficiencies (kcat/KM) were decreased by an order of magnitude as compared to the free soluble enzyme, indicating the introduction of transport limitations. However, the thermal stabilities were improved for most configurations (>88% activity retention up to 95°C for three of four whole‐cell biocatalysts), operational stabilities were more than satisfactory (100% retention after 24 h of use for all four whole‐cell biocatalysts), and CO2 hydration was significantly enhanced relative to the uncatalyzed reaction (∼50–70% increase in CaCO3 precipitate formed). A significant advantage of the whole‐cell approach is that protein purification is no longer necessary, and the cells can be easily separated and recycled in future applications including biofuel production, biosensors, and carbon capture and storage. Biotechnol. Bioeng. 2013; 110: 1865–1873. © 2013 Wiley Periodicals, Inc.
Prevention of inflammation‐mediated neurotoxicity by butylidenephthalide and its role in microglial activation
Authors: Nam Kyong Nyon , Kim Kyoo‐Pil , Cho Ki‐Ho , Jung Woo‐Sang , Park Jung‐Mi , Cho Seung‐Yeon , Park Su‐Kyung , Park Tae‐Hoon , Kim Young‐Suk , Lee Eunjoo H.
Published: February 2013

Microglial cells are the prime effectors in immune and inflammatory responses of the central nervous system (CNS). During pathological conditions, the activation of these cells helps restore CNS homeostasis. However, chronic microglial activation endangers neuronal survival through the release of various proinflammatory molecules and neurotoxins. Thus, negative regulators of microglial activation have been considered as potential therapeutic candidates to target neurodegeneration, such as that in Alzheimer's and Parkinson's diseases. The rhizome of Ligusticum chuanxiong Hort. (Ligusticum wallichii Franch) has been widely used for the treatment of vascular diseases in traditional oriental medicine. Butylidenephthalide (BP), a major bioactive component from L. chuanxiong, has been reported to have a variety of pharmacological activities, including vasorelaxant, anti‐anginal, anti‐platelet and anti‐cancer effects. The aim of this study was to examine whether BP represses microglial activation. In rat brain microglia, BP significantly inhibited the lipopolysaccharide (LPS)‐induced production of nitric oxide (NO), tumour necrosis factor‐α and interleukin‐1β. In organotypic hippocampal slice cultures, BP clearly blocked the effect of LPS on hippocampal cell death and inhibited LPS‐induced NO production in culture medium. These results newly suggest that BP provide neuroprotection by reducing the release of various proinflammatory molecules from activated microglia. Copyright © 2013 John Wiley & Sons, Ltd.
Phosphite‐Thiazoline versus Phosphite‐Oxazoline for Pd‐Catalyzed Allylic Substitution Reactions: A Case for Comparison
Authors: Mazuela Javier , Pàmies Oscar , Diéguez Montserrat
Published: February 2013

We have expanded the ligand design of one of the most successful phosphite‐oxazoline ligands, derived from hydroxyl amino acid derivatives, in Pd‐catalyzed allylic alkylation by replacing the oxazoline group with a thiazoline moiety. These phosphite‐thiazoline ligands have been evaluated in the Pd‐catalyzed allylic substitution of a wide range of mono‐, di‐, and trisubstituted substrates with several carbon nucleophiles, such as the less studied α‐substituted malonates and β‐diketones. For comparison we have also expanded our previous work on phosphite‐oxazoline to carbon nucleophiles other than dimethyl malonate and to the alkylation of trisubstituted substrates. For hindered substrates such as disubstituted rac‐1,3‐diphenyl‐3‐acetoxyprop‐1‐ene and trisubstituted rac‐1,1,‐diphenyl‐1‐hepten‐3‐yl acetate and rac‐1,3,3‐triphenylprop‐2‐enyl acetate, enantioselectivities (ee values up to >99 %) are best obtained with phosphite‐oxazoline ligands, whereas for unhindered cyclic substrates such as rac‐3‐acetoxycyclohexene, rac‐3‐acetoxycyclopentene, and rac‐3‐acetoxycycloheptene, enantioselectivities (ee values up to 94 %) improved considerably with phosphite‐thiazoline ligands. In the case of monosubstituted substrates, the regio‐ and enantioselectivities obtained with both ligand types were comparable and excellent (regioselectivities up to 90 % and ee values up to 95 %). Therefore, by correctly combining substrate and ligand type (phosphite‐oxazoline or phosphite‐thiazoline), we have identified one of the few catalytic systems that provide high regio‐ and enantioselectivities in both enantiomers of the alkylation product for a wide range of hindered and unhindered mono‐, di‐, and trisubstituted substrates with several carbon nucleophiles. We have also discussed the synthesis and characterization of Pd‐π‐allyl intermediates to provide greater insight into the origin of enantioselectivity in these catalytic systems.
A Note on the Incremental Validity of Integrity Tests beyond Standard Personality Inventories for the Criterion of Counterproductive Behaviour
Authors: Marcus Bernd , Ashton Michael C. , Lee Kibeom
Published: February 2013

Although the validity of integrity tests for predicting the focal criterion of counterproductive work behaviour (CWB) is well‐established, little research has yet addressed the incremental CWB‐related validity of integrity tests beyond basic personality traits. The present research addresses this issue by re‐analyzing data adopted from Marcus, Lee, and Ashton (2007), in which four different overt and personality‐based integrity tests and the HEXACO‐Personality Inventory (Lee & Ashton, 2004) were related to CWB. Integrity accounted for practically significant proportions of incremental variance beyond personality across all integrity tests, yet effect sizes of incremental validity dropped considerably if Honesty‐Humility was added to traditional Big Five dimensions. In addition, findings suggest that CWB is best predicted by a combination of integrity and personality tests. Copyright © 2013 ASAC. Published by John Wiley & Sons, Ltd.
Generalized estimating equations for mixtures with varying concentrations
Authors: Maiboroda Rostyslav , Sugakova Olena , Doronin Alexey
Published: February 2013

A finite mixture model is considered in which the mixing probabilities vary from observation to observation. A parametric model is assumed for one mixture component distribution, while the others are nonparametric nuisance parameters. Generalized estimating equations (GEE) are proposed for the semi‐parametric estimation. Asymptotic normality of the GEE estimates is demonstrated and the lower bound for their dispersion (asymptotic covariance) matrix is derived. An adaptive technique is developed to derive estimates with nearly optimal small dispersion. An application to the sociological analysis of voting results is discussed. The Canadian Journal of Statistics 41: 217–236; 2013 © 2013 Statistical Society of Canada