bluuebunny/crossref_metadata_2025 huggingface dataset:
Understanding Photophysical Effects of Cucurbituril Encapsulation: A Model Study with Acridine Orange in the Gas Phase
Authors: Czar Martin F. , Jockusch Rebecca A.
Published: February 2013

Encapsulation of dyes by cucurbituril macrocycles has proven profitable as a strategy to alter fluorescence characteristics in useful ways. Encapsulation generally results in longer fluorescence lifetimes, enhanced brightness, and solvatochromic effects not normally seen in the condensed phase. These effects have been attributed variously to both the removal of interactions with solvent molecules and to the confined environment of extremely low polarizability provided by the cucurbituril interior. It is difficult to disentangle these effects in solution. Here, we present results from gas‐phase experiments designed to separate these effects, using cucurbit[7]uril (CB7), and the cationic dye acridine orange (AOH+) as a probe. Fluorescence properties of gaseous AOH+ are compared with those of the gaseous AOH+‐CB7 complex and with the properties of the dye and complex in aqueous solution. The dependence on the local environment of several spectroscopic properties is discussed, including the fluorescence excitation and emission maxima, the size of the Stokes shift, fluorescence lifetime and relative brightness. An understanding of the modulation of fluorescence properties by the local environment, such as that promoted by this work, will aid in the rational design of improved fluorophores and fluorescent sensors.
Treatment engagement in eating disorders: Who exits before treatment?
Authors: Watson Hunna J. , Fursland Anthea , Byrne Susan
Published: February 2013

Objective

Traditionally, drop‐out has been investigated subsequent to treatment entry; yet some individuals “exit early,” attending assessment but failing to commence the treatment offered. Early exit burdens administrative and clinical resources and means that individuals may not receive the care needed for recovery. This study aimed to describe the prevalence and characteristics associated with early exit at a statewide, outpatient eating disorder service.

Method

From a pool of 972 consecutive referrals of adults and youth (16+ years), two groups were formed; an “early exit” group of individuals who attended assessment but chose to exit the service prior to treatment entry and a “non‐early exit” group that attended assessment and entered treatment. The groups were compared on sociodemographic, clinical, and administrative features.

Results

The prevalence of early exit was 18.7%. The early exit group exhibited less pathology compared with the non‐early exit group; specifically, a lower presence of Axis I comorbidity (p = .04) and self‐induced vomiting (p = .04).

Discussion

The findings, considered in the context of previous research, suggest that there are no measured features to date that are robustly associated with early exit from outpatient eating disorder services. Future research should investigate decision‐making processes at assessment, to inform patient‐centered approaches that optimize transition to treatment. © 2013 by Wiley Periodicals, Inc. (Int J Eat Disord 2013; 46:553–559)
Influence of dam‐induced hydrological regulation on summer water temperature: Sauce Grande River, Argentina
Authors: Casado Ana , Hannah David M. , Peiry Jean‐Luc , Campo Alicia M.
Published: February 2013

This study quantifies for the first time the influence of flow regulation on the river thermal behaviour of an ungauged basin located in central‐eastern Argentina. A 30‐day data set of continuous summer hourly data was assembled for eight water temperature gauging sites deployed along the main channel upstream and downstream from the impoundment. Analysis methods include descriptive statistics of daily temperature data, classification of diurnal regimes by relative differences in the ‘shape’ and the ‘magnitude’ of the thermographs (RSMC), and quantification of the climatic sensitivity of water temperature regimes using a sensitivity index. Results revealed that temporal fluctuations in water temperatures were linked to meteorological drivers; however, spatial variability in the shape and the magnitude of the thermographs revealed the effects of the dam in regulating river thermal behaviour downstream. Water temperatures immediately below the dam were reduced notably; diurnal cycles were reduced in magnitude, delayed in timing, and revealed overall climatic insensitivity and high temporal stability in regime shape. Dam effects persisted along the 15‐km stretch monitored, although declined in the downstream direction. These findings provide new scientific understanding about the river water quality and inform river management about potential shifts in summer water temperature with great implications for the diversity and lifecycles of Neotropical river fauna. The use of the RSMC and sensitivity index approaches in water temperature assessment is novel and has wider applicability for quantifying river thermal regimes and their sensitivity to drivers of change over a range of temporal and spatial scales. Copyright © 2013 John Wiley & Sons, Ltd.
On‐line preconcentration and determination of six sulfonylurea herbicides in cereals by MEKC with large‐volume sample stacking and polarity switching
Authors: Yi Ling‐Xiao , Chen Guan‐Hua , Fang Rou , Zhang Li , Shao Yu‐Xiu , Chen Ping , Tao Xiang‐Xiang
Published: February 2013

A new MEKC method with large‐volume sample stacking and polarity switching was developed for on‐line preconcentration and detection of sulfonylurea herbicide (SUH) residues in cereals, including nicosulfuron (NS), thifensulfuon (methyl) (TFM), tribenuron‐methly (TBM), sulfometuron‐methyl (SMM), pyrazosulfuron‐ethyl (PSE), and chlorimuron‐ethyl (CME). In order to achieve a high resolution and enrichment factor, several parameters were optimized, such as the pH of the running buffer, the concentration of the BGE and the SDS, the separate voltage, the sample size, the pH, and the electrolyte concentration of the sample. The optimal running buffer was composed of 30 mM borate and 80 mM SDS at pH 7.0. The borate concentration in the sample was 30 mM and the pH value of the sample was the same as that of the running buffer. The concentrating voltage and the separating voltage were –15 kV and 15 kV, respectively. The sample size was 1.455 kPa × 780 s (33.11 cm). Under the optimum conditions, for NS, TFM, TBM, SMM, PSE, and CME, the enrichment factors were 613, 642, 835, 570, 709, and 599; the LODs were 0.29–0.50 ng/g, 0.22–0.36 ng/g, 0.60–0.89 ng/g, 0.39–0.72 ng/g, 0.28–0.56 ng/g, and 0.31–0.57 ng/g; the LOQs of six SUHs were all 5 ng/g; the average recoveries of the spiked sample were 86.68–92.99%, 80.73–93.65%, 81.49–94.40%, 82.97–95.1%, 82.96–98.84%, and 80.41–92.94%, respectively.
Metal and selenium concentrations in blood and feathers of petrels of the genus procellaria
Authors: Carvalho Paloma Calábria , Bugoni Leandro , McGill Rona A.R. , Bianchini Adalto
Published: February 2013

Concentrations of copper (Cu), zinc (Zn), cadmium (Cd), lead (Pb), mercury (Hg), and selenium (Se) were determined in blood and feathers of spectacled (Procellaria conspicillata) and white-chinned (Procellaria aequinoctialis) petrels, species that are phylogenetically related, but with distinct ecological niches. In winter, they feed on similar foods, indicated by an overlapping range of whole-blood stable isotopes values (δ15N; δ13C). No relation was found between blood metal concentration and stable isotope values. In spectacled petrels, metal concentrations appeared lower in blood (Cu = 0.79–20.77 µg/g; Zn = 10.95–28.02 µg/g; Cd = 1.73–10.11 µg/g; Pb = 5.02–26.03 µg/g; Hg = 0.84–9.86 µg/g) than in feathers (Cu = 1.05–21.57 µg/g; Zn = 45.30–81.49 µg/g; Cd = 3.76–10.44 µg/g; Pb = 16.53–59.00 µg/g; Hg = 4.24–24.03 µg/g). In white-chinned petrels, metal concentrations also appeared lower in blood (Cu = 0.62–10.4 µg/g; Zn = 10.73–24.69 µg/g; Cd = 2.00–6.31 µg/g; Pb = 5.72–24.03 µg/g) than in feathers (Cu = 2.68–23.92 µg/g; Zn = 48.96–93.54 µg/g; Cd = 5.72–24.03 µg/g; Pb = 18.62–55.51 µg/g), except for Hg (blood = 0.20–15.82 µg/g; feathers = 0.19–8.91 µg/g). Selenium (0.24–14.18 µg/g) and Hg (0.22–1.44 µg/g) concentrations showed a positive correlation in growing feathers of spectacled petrels. Blood and feather Hg levels were higher in spectacled petrels while feathers Cu and Zn concentrations were greater in white-chinned petrels. Juvenile white-chinned petrels exhibited greater blood Hg concentrations than adults. In the south Atlantic Ocean, discards from commercial fishing operations consumed by spectacled petrels year-round and by white-chinned petrels during the wintering period have elevated Hg concentrations. Because Hg toxicity is associated with behavioral and reproductive changes in birds, it could potentially have impacts on breeding of these seabirds, as both species are listed as threatened by extinction. Environ Toxicol Chem 2013;32:1641–1648. © 2013 SETAC
Evaluation of Sulfur Dioxide Poisoning for LSCF Cathodes
Authors: Wang F. , Yamaji K. , Cho D.‐H. , Shimonosono T. , Nishi M. , Kishimoto H. , Brito M. E. , Horita T. , Yokokawa H.
Published: February 2013

Sulfur poisoning behavior of La0.6Sr0.4Co0.2Fe0.8O3–δ (LSCF6428) cathode was investigated at T = 1073 K (800 °C) under 0.1 ppm of SO2‐air mixture gas; the amount of supplied SO2 was controlled by changing the flow rate. Two stages of the performance degradation were found: a rapid degradation at the early stage and a subsequent monotonic degradation. The elemental distributions of SrSO4 showed a strong correlation between the electrochemically active sites and SrSO4 reaction sites in the vicinity of the LSCF6428/10GDC interfaces. Considerations were made to attribute the first and the second stages of performance degradation to the SO2 adsorption and the SrSO4 formation, respectively. The SO2 adsorption mechanism was discussed in terms of the high concentration of oxide ion vacancies in the electrochemically active region under the cathodic polarization condition.
Pricing Forward Skew Dependent Derivatives. Multifactor Versus Single‐Factor Stochastic Volatility Models
Authors: Marabel Romo Jacinto
Published: February 2013

Empirical evidence shows that, in equity options markets, the slope of the skew is largely independent of the volatility level. Single‐factor stochastic volatility models are not flexible enough to account for the stochastic behavior of the skew. On the other hand, multifactor stochastic volatility models are able to account for the existence of stochastic skew. This study studies the effects of introducing stochastic skew in the valuation of forward skew dependent exotic options. In particular, I consider cliquet, as well as reverse cliquet structures. The study also derives a semi‐closed‐form solution for the price of forward‐start options under the multifactor stochastic specification. The empirical results indicate that the consideration of additional volatility factors in the context of stochastic volatility models allows us to generate more flexible smile patterns. This additional flexibility has a relevant impact on the valuation of forward skew dependent derivatives. In this sense, this study shows that similar calibrations of single factor and multifactor stochastic volatility models to the current market prices of plain vanilla options can lead to important discrepancies in the pricing of exotic forward skew dependent derivatives such as regular cliquet structures and reverse cliquet options. © 2013 Wiley Periodicals, Inc. Jrl Fut Mark 34:124–144, 2014
Global propagation of body waves revealed by cross‐correlation analysis of seismic hum
Authors: Nishida K.
Published: February 2013

Seismic interferometry has now been applied to the exploration of the Earth's interior at scales ranging from local to global. Most studies have used surface‐wave propagation. Recently, some studies have focused on body wave propagation on local and regional scales but not on a global scale. In this study, we succeed in extracting global body wave propagation(of P, PP, PKP, S, SS, ScS, P′P′, etc. waves) using seismic hum with frequency‐wave number filtering in the range of 5 to 40 mHz. Although the observed body wave propagation is similar to that of the corresponding components of Green's functions, there are two differences between them: the lack of reflection phases in the observation and the dominance of shear‐coupled PL waves in the observation. These differences originate from the dominance of shear‐traction sources on the Earth's surface, which causes the breakdown of equipartition among modes with different radial orders. For further studies of body wave exploration by seismic interferometry, these differences should be considered.
Transition of Pi2 ULF wave polarization structure from the ionosphere to the ground
Authors: Ponomarenko P. V. , Waters C. L.
Published: February 2013

Trains of ultra low frequency (ULF) waves in the Pi2 range (40–150 s) are regularly detected in near‐Earth space. While some Pi2 occur just before substorm onset, others do not show any casual relation to substorm activity so that the Pi2 generation and propagation mechanisms are still unclear. The bulk of information on Pi2 morphology is provided by ground‐based magnetometers, subject to distortions due to transition through the highly conducting lower ionosphere. While space‐borne magnetometers provide important in situ information, they cannot match the spatio‐temporal continuity of ground‐based instruments. In this paper, we devise a novel approach using co‐located high‐frequency ionospheric radars and ground magnetometers for the first direct observation of the Pi2 wave polarization transition between the ionosphere and the ground. Furthermore, application of the Hilbert transform enables us to reconstruct the transition dynamics, which resolves an apparent disagreement between the Pi2 spectra measured by the two instruments.
Are vegetation‐related roughness changes the cause of the recent decrease in dust emission from the Sahel?
Authors: Cowie Sophie M. , Knippertz Peter , Marsham John H.
Published: February 2013

Since the 1980s, a dramatic downward trend in North African dustiness and transport to the tropical Atlantic Ocean has been observed by different data sets and methods. The precise causes of this trend have previously been difficult to understand, partly due to the sparse observational record. Here we show that a decrease in surface wind speeds associated with increased roughness due to more vegetation in the Sahel is the most likely cause of the observed drop in dust emission. Associated changes in turbulence and evapotranspiration, and changes in large‐scale circulation, are secondary contributors. Past work has tried to explain negative correlations between North African dust and precipitation through impacts on emission thresholds due to changes in soil moisture and vegetation cover. The use of novel diagnostic tools applied here to long‐term surface observations suggests that this is not the dominating effect. Our results are consistent with a recently observed global decrease in surface wind speed, known as “stilling”, and demonstrate the importance of representing vegetation‐related roughness changes in models. They also offer a new mechanism of how land‐use change and agriculture can impact the Sahelian climate.
Source model of deformation at Lazufre volcanic center, central Andes, constrained by InSAR time series
Authors: Pearse Jill , Lundgren Paul
Published: February 2013

Recent interferometric synthetic aperture radar (InSAR) observations of the Lazufre region, central Andes, show large‐scale uplift at a rate of about 3 cm/yr, beginning between 1998 and 2002. The initiation of this activity during the ERS satellite mission and its proximity to active volcanoes have made Lazufre the focus of several studies aimed at understanding its source geometry, its relation to nearby volcanoes, and whether or not the source area is expanding. There now exists a longer time series from multiple ERS/ENVISAT satellite tracks that allows a more comprehensive examination of the source geometry and its temporal and spatial variation, if any. We processed 15 years of InSAR data from three separate tracks; modeling the different look geometries provided greater resolution of source depth and geometry. We conclude that the source is a shallowly dipping sill at a depth of about 8 km, with no evidence of lateral expansion.
Using Motivational Interviewing Techniques to Address Parallel Process in Supervision
Authors: Giordano Amanda , Clarke Philip , Borders L. DiAnne
Published: February 2013

Supervision offers a distinct opportunity to experience the interconnection of counselor–client and counselor–supervisor interactions. One product of this network of interactions is parallel process, a phenomenon by which counselors unconsciously identify with their clients and subsequently present to their supervisors in a similar fashion (Searles, 1955). Addressing parallel process has the potential to be valuable in the advancement of counselor development, but few strategies exist in the literature for working with the phenomenon. The authors describe the use of motivational interviewing as one method for effectively addressing parallel process in supervision.
A Culturally Responsive Intervention for Addressing Problematic Behaviors in Counseling Students
Authors: Goodrich Kristopher M. , Shin Richard Q.
Published: February 2013

Counseling faculty serve as gatekeepers to protect the public from trainees who demonstrate significant deficiencies in professional functioning. Two issues that have not been thoroughly examined are how different cultural values may intersect with the assessment of appropriate professional competencies and whether the multicultural environment of programs is considered when assessing potentially problematic students. The authors suggest a group systems intervention and provide implications and recommendations for counselor educators.
Grief and Loss Education: Recommendations for Curricular Inclusion
Authors: Doughty Horn Elizabeth A. , Crews Judith A. , Harrawood Laura K.
Published: February 2013

Currently, the Council for Accreditation of Counseling and Related Educational Programs (2009) does not require course work on grief and loss, and it is possible for counselors to practice without any formal training in the area. The purpose of this article is to highlight the need for additional grief and loss education in the curriculum, provide a brief overview of the current literature surrounding grief and loss, and suggest pedagogical strategies for counselor preparation.
A New and Simple Electrocatalyst for Formaldehyde Oxidation; Nickel/poly(o‐Anisidine)/Film Modified Ionic Liquid Carbon Paste Electrode
Authors: Ojani Reza , Raoof Jahan‐Bakhsh , Zamani Saeed
Published: February 2013

In present work, the ionic liquid, 1‐butyl‐3‐methylimidazolium bis (trifluoromethylsulfonyl) imide was incorporated in the carbon paste electrode as the binder (IL‐CPE). O‐anisidine (OA) monomer is electropolymerized in the presence of an aqueous acidic solution onto IL‐CPE (POA/IL‐CPE). The as‐prepared substrate is used as a porous matrix for dispersion of Ni(II) ions by immersing the modified electrode in a nickel(II) nitrite solution. The modified electrodes are characterized by scanning electron microscopy (SEM) and electrochemical methods. The POA/IL‐CPE was applied successfully to highly efficient (current density of 18.2 mA cm−2) electrocatalytic oxidation of formaldehyde in alkaline medium. Finally, the rate constant for chemical reaction between formaldehyde and redox sites of the electrode was calculated.
SUSTAINING INNOVATIONS IN COMMUNITY PREVENTION SYSTEMS: A DATA‐INFORMED SUSTAINABILITY STRATEGY
Authors: Johnson Knowlton , Collins David , Wandersman Abraham
Published: February 2013

This article presents a sustainability strategy, its implementation protocols, and a pilot study of implementation and sustainability readiness. The strategy is guided by a conceptual framework that integrates (a) a strategy for sustaining prevention infrastructure and interventions and (b) a planning and evaluation process known as Getting To Outcomes. Data‐informed decision making is key to this strategy, which includes initial assessment of sustainability capacity and sustainable innovation characteristics, and progresses through planning, implementation, evaluation, and continuous quality improvement to sustain targeted innovations. A support system for implementing the strategy, including a toolkit, primer, electronic tools, and training and technical assistance, is described. Lessons learned from a pilot study for future testing and implementation of the strategy are also discussed. In sum, the article presents a conceptual‐based strategy to sustainability, an innovative support system, and lessons learned that have important implications for improving the evaluation and practice of sustainability.
PREFERENCE REVERSAL BETWEEN IMPULSIVE AND SELF‐CONTROL CHOICE
Authors: Beeby Emma , White K. Geoffrey
Published: February 2013

In a concurrent‐chains procedure, pigeons chose between reinforcers varying in delay and amount. Reinforcer amount was determined by duration of access to grain, and delay was determined by fixed‐interval schedules in the terminal links. Preference was measured by the ratio of responses in initial links. Dependent scheduling of variable‐interval schedules in initial links ensured that delay and amount were not confounded with frequency of outcomes, which remained equal for the two choices. In Experiment 1, in components signaled by red keys in the initial links, small and large reinforcers were delivered after delays of 1 s and 10 s respectively. In components signaled by green, additional time was added to both delays. Smaller–sooner reinforcers were preferred in red components. In green components, smaller–sooner reinforcers were preferred at short delays, and choices for the larger–later reinforcer generally increased with increasing duration of the added delay. At longer delays, up to 15 s, the larger–later reinforcer was preferred. That is, the pigeons showed within‐session preference reversal, with impulsive choice at short delays in red components and self‐control choice at long delays in green components. In Experiment 2, added delay to both reinforcement and reinforcer amount were varied. Sensitivity of initial‐link response ratios to ratios of amount increased with increasing duration of the added delay. This interaction between delay and amount was predicted if the temporal discounting functions assumed the magnitude effect in which discounting rate was inversely proportional to amount. It was also predicted by the contextual choice model of performance in concurrent‐chains procedures.
A trial of a real‐time Alert for clinical deterioration in Patients hospitalized on general medical wards
Authors: Bailey Thomas C. , Chen Yixin , Mao Yi , Lu Chenyang , Hackmann Gregory , Micek Scott T. , Heard Kevin M. , Faulkner Kelly M. , Kollef Marin H.
Published: February 2013

BACKGROUND

With limited numbers of intensive care unit (ICU) beds available, increasing patient acuity is expected to contribute to episodes of inpatient deterioration on general wards.

OBJECTIVE

To prospectively validate a predictive algorithm for clinical deterioration in general–medical ward patients, and to conduct a trial of real‐time alerts based on this algorithm.

DESIGN

Randomized, controlled crossover study.

SETTING/PATIENTS

Academic center with patients hospitalized on 8 general wards between July 2007 and December 2011.

INTERVENTIONS

Real‐time alerts were generated by an algorithm designed to predict the need for ICU transfer using electronically available data. The alerts were sent by text page to the nurse manager on intervention wards.

MEASUREMENTS

Intensive care unit transfer, hospital mortality, and hospital length of stay.

RESULTS

Patients meeting the alert threshold were at nearly 5.3‐fold greater risk of ICU transfer (95% confidence interval [CI]: 4.6‐6.0) than those not satisfying the alert threshold (358 of 2353 [15.2%] vs 512 of 17678 [2.9%]). Patients with alerts were at 8.9‐fold greater risk of death (95% CI: 7.4‐10.7) than those without alerts (244 of 2353 [10.4%] vs 206 of 17678 [1.2%]). Among patients identified by the early warning system, there were no differences in the proportion of patients who were transferred to the ICU or who died in the intervention group as compared with the control group.

CONCLUSIONS

Real‐time alerts were highly specific for clinical deterioration resulting in ICU transfer and death, and were associated with longer hospital length of stay. However, an intervention notifying a nurse of the risk did not result in improvement in these outcomes. Journal of Hospital Medicine 2013;8:236–242. © 2013 Society of Hospital Medicine
Neuropathological correlate of the “concentric target sign” in MRI of HIV‐associated cerebral toxoplasmosis
Authors: Mahadevan Anita , Ramalingaiah Arvinda Hanumantapura , Parthasarathy Satishchandra , Nath Avindra , Ranga Udaykumar , Krishna Shankar Susarla
Published: February 2013

Cerebral toxoplasmosis is a frequent cause of focal brain lesions in the setting of immunodeficiency states, particularly acquired immune deficiency syndrome (AIDS), and magnetic resonance imaging (MRI) is an important diagnostic modality to differentiate toxoplasmosis from tuberculoma, and primary central nervous system lymphoma with diverse therapeutic implications. Several imaging patterns have been described in cerebral toxoplasmosis. The “concentric target sign” is a recently described MRI sign on T2‐weighted imaging of cerebral toxoplasmosis that has concentric alternating zones of hypo‐ and hyperintensities. It is believed to be more specific than the well‐known “eccentric target sign” in the diagnosis of cerebral toxoplasmosis and hence more useful in differentiation from other focal brain lesions in the context of AIDS. The concentric target sign, seen in deep parenchymal lesions, is distinct from the surface‐based cortical “eccentric” target sign. The histopathological correlate of the latter has been recently described, but that of the concentric target sign is not known. In this study we describe the neuropathological correlate of this concentric target sign from the postmortem of a 40‐year‐old man with AIDS‐associated cerebral toxoplasmosis. The concentric alternating zones of hypo/hyper/iso/intensities corresponded to zones of hemorrhage/fibrin‐rich necrosis with edema/coagulative compact necrosis/inflammation with foamy histiocytes admixed with hemorrhage forming the outermost zone, respectively. The exclusive specificity of this sign in cerebral toxoplasmosis remains to be further elucidated. J. Magn. Reson. Imaging 2013;38:488–495. © 2013 Wiley Periodicals, Inc.
MRI: From science to society
Authors: Lee Vivian S.
Published: February 2013

In this 2012 ISMRM Lauterbur Lecture, my goal is to challenge the members of the ISMRM to think critically about how we approach our research. From the perspective of a leader of an academic health sciences center, which is also a health care delivery system, I address three specific questions:

Are we developing great technologies?

Are we advancing scientific knowledge?

Are we advancing human health?

Specifically, with respect to increasing pressure in health care to improve patient outcomes and lower costs, I ask members to consider how we select the areas of research we focus on and whether we have sufficiently prioritized research that assesses the impact of our MR methods on patient outcomes. For imaging research to meet higher standards of evidence‐based medicine, multicenter consortia should be developed, potentially under the auspices of the ISMRM, and priority should be given to developing investigators with expertise in health services research. J. Magn. Reson. Imaging 2013;37:753–760. © 2013 Wiley Periodicals, Inc.
Imaging early stage osteogenic differentiation of mesenchymal stem cells
Authors: Corn David J. , Kim Yunhui , Krebs Melissa D. , Mounts Troy , Molter Joseph , Gerson Stanton , Alsberg Eben , Dennis James E. , Lee Zhenghong
Published: February 2013

Stem cells, such as mesenchymal stem cells (MSCs), contribute to bone fracture repair if they are delivered to the injury site. However, it is difficult to assess the retention and differentiation of these cells after implantation. Current options for non‐invasively tracking the transplanted stem cells are limited. Cell‐based therapies using MSCs would benefit greatly through the use of an imaging methodology that allows cells to be tracked in vivo and in a timely fashion. In this study, we implemented an in vivo imaging methodology to specifically track early events such as differentiation of implanted human MSCs (hMSCs). This system uses the collagen type 1 (Col1α1) promoter to drive expression of firefly luciferase (luc) in addition to a constitutively active promoter to drive the expression of green fluorescent protein (GFP). The resulting dual‐promoter reporter gene system provides the opportunity for osteogenic differentiation‐specific luc expression for in vivo imaging and constitutive expression of GFP for cell sorting. The function of this dual‐promoter reporter gene was validated both in vitro and in vivo. In addition, the ability of this dual‐promoter reporter system to image an early event of osteogenic differentiation of hMSCs was demonstrated in a murine segmental bone defect model in which reporter‐labeled hMSCs were seeded into an alginate hydrogel scaffold and implanted directly into the defect. Bioluminescence imaging (BLI) was performed to visualize the turn‐on of Col1α1 upon osteogenic differentiation and followed by X‐ray imaging to assess the healing process for correlation with histological analyses. © 2013 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res XX:XXX–XXX, 2013 © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 871–879, 2013
Robust analysis of multiplexed SERS microscopy of Ag nanocubes using an alternating minimization algorithm
Authors: Chen Yaqi , Moran Christine H. , Tan Zhao , Lake Wooten A. , O'Sullivan Joseph A.
Published: February 2013

To drive the application of surface‐enhanced Raman spectroscopy (SERS) mapping inex vivodiagnostic imaging and non‐biological material characterization, we have designed a robust and accurate multiplex spectral fitting method using an alternating minimization algorithm to extract individual constituent Raman spectra with very small overall fitting error (as low as 2%). For each mixed Raman signal, constituent spectra and mixture coefficients were estimated jointly based on reference spectra that were measured in the lab. Our method is based on a Poisson model to reflect the photon counting nature of Raman signals and includes the nonlinear noise in the measured data, making our method robust against data containing relatively large random noise. In our method, we minimized a cost function consisting of two terms: (1) the overall fitting error between the measured and modeled spectra and (2) the sum of the individual error between each reference spectrum and its corresponding constituent. This method inherently guarantees that the estimates will approach the global minimum with monotonic convergence. The accuracy of our method was validated by applying it to a SERS spectral fitting problem and comparing our results to those from existing methods. Copyright © 2013 John Wiley & Sons, Ltd.
Study of Raman scattering and luminescence properties of orchil dye for its nondestructive identification on artworks
Authors: Rosi F. , Clementi C. , Paolantoni M. , Romani A. , Pellegrino R. , Brunetti B. G. , Nowik W. , Miliani C.
Published: February 2013

Ultraviolet and visible (UV‐vis) fluorescence and subtracted shifted Raman spectroscopy have exploited to identify orchil in a fragment from the ninth century Bible de Théodulphe and a parchment fragment sampled from a 16th century map of Auvergne.

Orchil is a purple lichen dye widely used since ancient times in place of the more expensive Tyrian purple and therefore known as the ‘poor person's purple’. Unlike the latter, orchil has a low lightfastness, and in ancient works, it is often faded. Orchil is a complex mixture of different coloured compounds, and they all share a common structure resulting from phenoxazone with a number of different substituents. In this work, UV‐vis fluorescence combined with resonance Raman spectroscopy allowed for the identification of orchil in a fragment from the ninth century Bible de Théodulphe. Raman spectroscopy has been applied also for studying a parchment fragment sampled from a 16th century map of Auvergne. In both cases, subtracted shifted Raman spectroscopy (SSRS) has been exploited for removing the strong fluorescence background. Overall results have been confirmed by liquid chromatography with quadrupole time‐of‐flight mass spectrometry (LC/ QTOF‐MS).

Both the electronic and vibrational spectral features of ancient orchil showed some interesting differences with respect to those of the standard sample. Taking into account the poor lightfastness of the purple dye, the same investigation has been carried out on photochemically aged orchil reproducing the spectral modification observed on the ancient fragments. Copyright © 2013 John Wiley & Sons, Ltd.
Promoting Relationship Marketing of Tour Leaders’ Blog: The Role of Charisma
Authors: Tsaur Sheng‐Hshiung , Wu Der‐Huang , Yen Chang‐Hua , Wu Ming‐Hsiu
Published: February 2013

Whether blogs possess relationship marketing outcomes is a subject that has not been analyzed empirically. The purpose of this study is to examine the relationship between blog function characteristics and relationship marketing outcomes as well as to clarify the role of tour leaders’ charisma. Online survey data from 415 customers indicate that blog function characteristics have a positive effect on relationship marketing outcomes. Tour leaders’ charisma also has a significant moderating effect on the relationship between blog function characteristics and relationship marketing outcomes. Implications of these findings as well as future research are subsequently discussed. Copyright © 2013 John Wiley & Sons, Ltd.
Gas in scattering media absorption spectroscopy – from basic studies to biomedical applications
Authors: Svanberg Sune
Published: February 2013

The recently introduced Gas in Scattering Media Absorption Spectroscopy (GASMAS) technique provides novel possibilities for analysis in biophotonics. Free gas in pores or cavities is monitored with narrow‐band laser radiation, which can discern the gas absorptive imprints which are typically several orders of magnitude more narrow than the features of the surrounding tissue through which the diffusely scattered light emerges to the detector. Important gases monitored are oxygen and water vapour. Applications include diagnosis of human sinus cavities and surveillance of neonatal children, but also characterization of food‐stuffs, food packages and pharmaceutical preparations. Non‐biological applications include the study of construction materials such as wood, polystyrene foams and ceramics. For nano‐porous materials, information on the pore sizes can be obtained from observed line broadening. Apart from concentration measurements, the GASMAS technique also allows the study of gas transport and diffusion, and pressure and temperature information can also be obtained.
Dielectric‐loaded plasmonic waveguide components: Going practical
Authors: Kumar Ashwani , Gosciniak Jacek , Volkov Valentyn S. , Papaioannou Sotirios , Kalavrouziotis Dimitrios , Vyrsokinos Konstantinos , Weeber Jean‐Claude , Hassan Karim , Markey Laurent , Dereux Alain , Tekin Tolga , Waldow Michael , Apostolopoulos Dimitrios , Avramopoulos Hercules , Pleros Nikos , Bozhevolnyi Sergey I.
Published: February 2013

Surface plasmon propagating modes supported by metal/dielectric interfaces in various configurations can be used for radiation guiding similarly to conventional dielectric waveguides. Plasmonic waveguides offer two attractive features: subdiffraction mode confinement and the presence of conducting elements at the mode‐field maximum. The first feature can be exploited to realize ultrahigh density of nanophotonics components, whereas the second feature enables the development of dynamic components controlling the plasmon propagation with ultralow signals, minimizing heat dissipation in switching elements. While the first feature is yet to be brought close to the domain of practical applications because of high propagation losses, the second one is already being investigated for bringing down power requirements in optical communication systems. In this review, the latest application‐oriented research on radiation modulation and routing using thermo‐optic dielectric‐loaded plasmonic waveguide components integrated with silicon‐based photonic waveguides is overviewed. Their employment under conditions of real telecommunications is addressed, highlighting challenges and perspectives.
Study of the effect of antimicrobial peptide mimic, CSA‐13, on an established biofilm formed by Pseudomonas aeruginosa
Authors: Nagant Carole , Pitts Betsey , Stewart Philip S. , Feng Yanshu , Savage Paul B. , Dehaye Jean‐Paul
Published: February 2013

The formation of a Pseudomonas aeruginosa biofilm, a complex structure enclosing bacterial cells in an extracellular polymeric matrix, is responsible for persistent infections in cystic fibrosis patients leading to a high rate of morbidity and mortality. The protective environment created by the tridimensional structure reduces the susceptibility of the bacteria to conventional antibiotherapy. Cationic steroid antibiotics (CSA)‐13, a nonpeptide mimic of antimicrobial peptides with antibacterial activity on planktonic cultures, was evaluated for its ability to interact with sessile cells. Using confocal laser scanning microscopy, we demonstrated that the drug damaged bacteria within an established biofilm showing that penetration did not limit the activity of this antimicrobial agent against a biofilm. When biofilms were grown during exposure to shear forces and to a continuous medium flow allowing the development of robust structures with a complex architecture, CSA‐13 reached the bacteria entrapped in the biofilm within 30 min. The permeabilizing effect of CSA‐13 could be associated with the death of the bacteria. In static conditions, the compound did not perturb the architecture of the biofilm. This study confirms the potential of CSA‐13 as a new strategy to combat persistent infections involving biofilms formed by P. aeruginosa.
The treatment of composite defect of bone and soft tissues with a combined latissimus dorsi and serratus anterior and RIB free flap
Authors: Trignano Emilio , Fallico Nefer , Nitto Agnese , Chen Hung‐Chi
Published: February 2013

Background:

Composite defects of bone and soft tissues represent a reconstructive challenge. Several techniques have been described in the medical literature; however, extensive composite defects should be reconstructed with microvascular free tissue transfer. The purpose of this report is to present the use of a composite latissimus dorsi and serratus anterior and rib free flap (LD‐SA/rib) as an alternative procedure in patients who cannot undergo more commonly used vascularized bone‐containing free flap reconstruction.

Methods:

Since January 2009, 12 patients have undergone bone and soft tissues reconstruction with a composite LD‐SA/rib flap. In this case series, indications for LD‐SA/rib reconstruction were large mandibular defects after oral cancer ablation, scalp defects, and lower extremity defects.

Results:

All flaps survived entirely. With reference to postoperative complications, haematoma occurred in four patients, scar contractures in three cases, lower lip incontinence in one patient, and local infection in one patient. Skin graft revision was performed in two cases and secondary debulking procedure in three patients. Flap viability was consistent during the 2‐year follow‐up.

Conclusions:

LD‐SA/rib free flap should be regarded as an effective procedure for reconstruction of composite tissue defects in patients who are not candidates for more commonly used vascularized bone‐containing free flaps. © 2013 Wiley Periodicals, Inc. Microsurgery, 2013.
Evaluation of a non‐invasive monitoring method for free flap breast reconstruction using laser doppler flowmetrie and tissue spectrophotometry
Authors: Rothenberger Jens , Amr Amro , Schaller Hans‐Eberhard , Rahmanian‐Schwarz Afshin
Published: February 2013

Background

Despite advances in the monitoring of free flaps, there is still a demand for new technology to detect ischemic complications at an early stage. The aim of the present study was to evaluate the reliability of the O2C‐device in terms of detecting flap failure in commonly used perforator flaps for breast reconstruction.

Methods

A total of 34 patients undergoing breast reconstruction were involved in this study. The perfusion dynamics of 23 deep inferior epigastric perforator flaps and 11 superior gluteal arterial perforator flaps were assessed using the O2C‐device, which combines a laser light, to determine blood flow (flow), velocity, and white light to determine hemoglobin oxygenation (SO2) and relative amount of hemoglobin (rHB). Measurements were carried out intra‐operatively after clamping and declamping the perforator vessels. In the post‐operative period measurements were carried out every hour for the first 48 hours and from 3rd to 7th for every 2 hours. These dates were compared to findings of clinical assessment.

Results

Several intra‐operative measurements, during the clamping and declamping the different perforator vessels, revealed a high correlation for all parameters: Flow (r = 0.89, P < 0. 05), Velo (r = 0.92, P < 0. 05), SO2 (r =0.84, P <0. 05), and rHB (r =0.83 P < 0.05). Vessel occlusion was detected in five cases, of which three were due to arterial thrombosis and two further cases were due to venous occlusion. Of the five cases, one flap loss caused by venous occlusion was noted.

Conclusion

The O2C‐device seems to be a reliable, objective, and non‐invasive device for the monitoring of free flaps. Thus, it may improve flap survival rates by detecting vascular compromise at an early stage. © 2013 Wiley Periodicals, Inc. Microsurgery 33:350–357, 2013.
Initial clinical evaluation of a non‐contrast‐enhanced MR angiography method in the distal lower extremities
Authors: Priest Andrew Nicholas , Joubert Ilse , Winterbottom Andrew Philip , See Teik Choon , Graves Martin John , Lomas David John
Published: February 2013

Purpose

To report the initial experience and diagnostic performance applying a novel flow‐dependent non‐contrast‐enhanced MR angiography (NCE‐MRA) method, in patients with suspected peripheral vascular disease, in comparison with established contrast‐enhanced MRA (CE‐MRA).

Methods

The lower legs of 34 patients were imaged at 1.5 T with both NCE‐MRA and CE‐MRA. The NCE‐MRA method consisted of a cardiac‐gated balanced‐SSFP sequence with controllable flow‐suppression preparation. Flow‐suppressed and unsuppressed datasets were subtracted to obtain angiograms. Two experienced radiologists assessed both NCE‐MRA and CE‐MRA images, first independently and then in consensus to resolve significant disagreements. Signal loss, vessel conspicuity, vascular disease, venous contamination, artifacts, and diagnostic confidence were assessed.

Results

Using the CE‐MRA as the “gold standard,” the per‐segment sensitivity and specificity for detection of significant disease were 81.7% and 90.9%, respectively. Mean diagnostic confidence (scale 0–4) was 3.4 for NCE‐MRA and 3.9 for CE‐MRA. Most vessel segments were well visualized but the popliteal arteries often suffered some technique‐related signal loss.

Conclusions

The NCE‐MRA method was able to visualize most vessel segments with good or excellent confidence, few artifacts, and excellent background suppression, giving moderate agreement with CE‐MRA. However, some segments were poorly visualized, probably due to flow profile distortion in these patients. Magn Reson Med 70:1644–1652, 2013. © 2013 Wiley Periodicals, Inc.
Analysis of image heterogeneity using 2D Minkowski functionals detects tumor responses to treatment
Authors: Larkin Timothy J. , Canuto Holly C. , Kettunen Mikko I. , Booth Thomas C. , Hu De‐En , Krishnan Anant S. , Bohndiek Sarah E. , Neves André A. , McLachlan Charles , Hobson Michael P. , Brindle Kevin M.
Published: February 2013

Purpose

The acquisition of ever increasing volumes of high resolution magnetic resonance imaging (MRI) data has created an urgent need to develop automated and objective image analysis algorithms that can assist in determining tumor margins, diagnosing tumor stage, and detecting treatment response.

Methods

We have shown previously that Minkowski functionals, which are precise morphological and structural descriptors of image heterogeneity, can be used to enhance the detection, in T1‐weighted images, of a targeted Gd3+‐chelate‐based contrast agent for detecting tumor cell death. We have used Minkowski functionals here to characterize heterogeneity in T2‐weighted images acquired before and after drug treatment, and obtained without contrast agent administration.

Results

We show that Minkowski functionals can be used to characterize the changes in image heterogeneity that accompany treatment of tumors with a vascular disrupting agent, combretastatin A4‐phosphate, and with a cytotoxic drug, etoposide.

Conclusions

Parameterizing changes in the heterogeneity of T2‐weighted images can be used to detect early responses of tumors to drug treatment, even when there is no change in tumor size. The approach provides a quantitative and therefore objective assessment of treatment response that could be used with other types of MR image and also with other imaging modalities. Magn Reson Med 71:402–410, 2014. © 2013 Wiley Periodicals, Inc.
Reproduction of motion artifacts for performance analysis of prospective motion correction in MRI
Authors: Herbst Michael , Maclaren Julian , Lovell‐Smith Cris , Sostheim Rebecca , Egger Karl , Harloff Andreas , Korvink Jan , Hennig Juergen , Zaitsev Maxim
Published: February 2013

Purpose

Despite numerous publications describing the ability of prospective motion correction to improve image quality in magnetic resonance imaging of the brain, a reliable approach to assess this improvement is still missing. A method that accurately reproduces motion artifacts correctable with prospective motion correction is developed, and enables the quantification of the improvements achieved.

Methods

A software interface was developed to simulate rigid body motion by changing the scanning coordinate system relative to the object. Thus, tracking data recorded during a patient scan can be used to reproduce the prevented motion artifacts on a volunteer or a phantom. The influence of physiological motion on image quality was investigated by filtering these data. Finally, the method was used to reproduce and quantify the motion artifacts prevented in a patient scan.

Results

The accuracy of the method was tested in phantom experiments and in vivo. The calculated quality factor, as well as a visual inspection of the reproduced artifacts shows a good correspondence to the original.

Conclusion

Precise reproduction of motion artifacts assists qualification of prospective motion correction strategies. The presented method provides an important tool to investigate the effects of rigid body motion on a wide range of sequences, and to quantify the improvement in image quality through prospective motion correction. Magn Reson Med 71:182–190, 2014. © 2013 Wiley Periodicals, Inc.