bluuebunny/crossref_metadata_2025 huggingface dataset:
Rat pancreatitis produced by 13‐week administration of zinc oxide nanoparticles: biopersistence of nanoparticles and possible solutions
Authors: Seok Seung Hyeok , Cho Wan‐Seob , Park Jung Shin , Na Yirang , Jang Ahram , Kim Hojoong , Cho Yujin , Kim Taesung , You Ji‐Ran , Ko Sanghoon , Kang Byeong‐Cheol , Lee Jong Kwon , Jeong Jayoung , Che Jeong‐Hwan
Published: February 2013

Zinc oxide (ZnO) nanoparticles (NPs) are used in diverse applications ranging from paints and cosmetics to biomedicine and food. Although micron‐sized ZnO is a traditional food supplement, ZnO NPs are an unknown public health risk because of their unique physicochemical properties. Herein, we studied the 13‐week subchronic toxicity of ZnO NPs administered via the oral route according to Organization for Economic Cooperation and Development (OECD) test guideline 408. Well‐dispersed ZnO NPs were administered to Sprague–Dawley (SD) rats (11/sex/group) at doses of 67.1, 134.2, 268.4 or 536.8 mg kg–1 per body weight over a 13‐week period. The mean body weight gain in males given 536.8 mg kg–1 ZnO NPs was significantly lower than that of control male rats, whereas no significant differences were observed between the other treatment groups and the controls. Male and female rats dosed at 536.8 mg kg–1 ZnO NPs had significant changes in anemia‐related hematologic parameters. Mild to moderate pancreatitis also developed in both sexes dosed at 536.8 mg kg–1, whereas no histological changes were observed in the other treatment groups. To evaluate the mechanism of toxicity, we performed a bio‐persistence study and evaluated the effects of the ZnO NPs on cell proliferation. The treatment of a human gastric adenocarcinoma cell line with ZnO NPs resulted in a significant inhibition of cellular proliferation. The anti‐proliferative effect of ZnO NPs or Zn2+ was effectively blocked by treatment with chelators. These results indicate that the bio‐persistence of ZnO NPs after ingestion is key to their toxicity; the no‐observed‐adverse effect level (NOAEL) of ZnO NPs was found to be 268.4 mg kg–1 per day for both sexes. Copyright © 2013 John Wiley & Sons, Ltd.
OUTREACH WORKERS’ PERCEPTIONS OF POSITIVE AND NEGATIVE CRITICAL INCIDENTS: CHARACTERISTICS ASSOCIATED WITH SUCCESSFUL AND UNSUCCESSFUL VIOLENCE INTERRUPTION
Authors: Dymnicki Allison B. , Henry David , Quintana Elena , Wisnieski Elise , Kane Candice
Published: February 2013

Evidence suggests positive impacts of AIDS/HIV prevention approaches using outreach workers, but few studies have described the approaches taken by such workers to prevent or de‐escalate serious violence. In this study, we used the Critical Incident Technique to elicit descriptions of positive and negative incidents from 53 outreach workers. Chicago CeaseFire workers were asked to describe the background of the incident, action they took, and outcome of the incident. Incidents the workers described as positive were characterized by a strong sense of control, receptivity of parties involved to worker involvement, higher goal achievement, and desirable outcomes occurring for clients. Conversely, in negative incidents, workers described having little to no control, greater severity of violence, and negative outcomes occurring for the clients. Findings suggest certain strategies were associated with greater receptiveness and responsiveness of the involved parties. Implications for training, supervision, and evaluation of other models using outreach workers are discussed.
THE COSTS OF DELAY: WAITING VERSUS POSTPONING IN INTERTEMPORAL CHOICE
Authors: Paglieri Fabio
Published: February 2013

Intertemporal choices are typically regarded as indicative of delay discounting. In this view, the degree of behavioral propensity to wait for a reward is attributed to an underlying process of reward devaluation as a function of delay. However, this widespread interpretation overlooks the role that the costs of delay might have in determining intertemporal choices. In this paper I review evidence of a marked discrepancy in intertemporal behavior across different tasks, and argue that the differential costs of delay can account for this anomaly better than alternative explanations. In particular, I characterize two types of delay, waiting versus postponing, examine how they impact behavioral choices across delay discounting tasks, what methodological challenges they present for new experimental paradigms, and what theoretical implications they have for our understanding of intertemporal choice.
A Novel Procedure to Synthesize 3‐Chloro‐1‐(4a,10b‐diazaphenanthrene‐2‐yl)‐4‐phenyl Azetidin‐2‐ones and Exploration of Their Anti‐Inflammatory Activity
Authors: Sharma Manisha , Maheshwari Arti , Bindal Nitin
Published: February 2013

Some new derivatives of 3‐chloro‐1‐(4a,10b‐diazaphenanthrene‐2‐yl)‐4‐phenyl azetidin‐2‐one were synthesized through the reaction of N‐{4‐[phenyldiazenyl] phenyl}‐N‐[phenyl methylene] amine with 4‐[phenyldiazenyl] aniline. The resulting 3‐chloro‐4‐phenyl‐1‐{4‐[phenyldiazenyl] phenyl} azetidin‐2‐one intermediate in benzene was irradiated in a Pyrex vessel with 350 nm UV light in a photochemical reactor to give the desired derivatives (4a–j). Structures of the new compounds were verified on the basis of spectral and elemental methods of analyses. Nine of the prepared compounds were tested for their anti‐inflammatory effects; most of these compounds showed potent and significant results compared with indomethacin.
Temperature effects on electrical performance of carbon‐based nano‐interconnects at chip and package level
Authors: Chiariello Andrea G. , Maffucci Antonio , Miano Giovanni
Published: February 2013

This paper investigates the electrical performance of innovative carbon‐based nano‐interconnects made by carbon nanotubes and graphene nanoribbons. The electronic transport in the carbon materials is modeled in the frame of the Transmission Line theory, where the classical per‐unit‐length circuital parameters are corrected by new terms arising from the quantistic nature of the transport. These parameters are related to the number of the conducting channels and the mean free path, which in turn, are expressed as functions of temperature and size. By coupling this model to the heat equation, a simple electro‐thermal model is derived. Case‐studies are carried out with reference to 22‐nm technology node applications. Copyright © 2013 John Wiley & Sons, Ltd.
Are there any relict rock glaciers in the British mountains?
Authors: Jarman David , Wilson Peter , Harrison Stephan
Published: February 2013

The existence of a small population of ‘relict rock glaciers’ scattered across the main British mountain areas has previously been inferred from published cases of individual sites or local clusters. Discrete debris accumulations (DDAs) of widely differing character have been identified as ice‐debris landforms (whether ‘rock glaciers’ or ‘protalus lobes’) partly from morphological, sedimentological and topo‐locational evidence, but principally by analogy with both active and relict examples in present‐day arctic/alpine environments, with consequent palaeoclimate inferences. However, re‐interpretation of several supposed rock glaciers as rock slope failures has cast doubt on both the palaeoclimatic reconstructions and the origin of the remaining features. Issues of polygenesis and mimicry/equifinality have contributed to some previous misidentifications. We re‐evaluate the 28 candidate cases based on new field and image‐analysis evidence and place them on a continuum from no ice presence through passive ice presence and glacial shaping to emplacement onto glacier ice with consequent melt‐out topography. A null hypothesis approach (that there are no relict rock glaciers in the British mountains) is pursued, and the evidence indicates that none of the 28 cases clearly warrants classification as a relict rock glacier; their characteristics can be explained without recourse to any significant forward debris movement controlled or facilitated by incorporated or underlying ice as it deforms and melts out. However, only one‐third of the candidate DDAs are attributed in whole or part to rock slope failure (sensu stricto), with other debris sources including incremental rockfall, bedrock knolls with coarse debris veneer, protalus rampart and moraine. A few cases deserve more detailed investigation of their structure, morphology and sediments within a broader local glaciological/topographical context, with multitemporal/polygenetic evolution in mind. But it is for future researchers to demonstrate that deforming ice played an incontestable part in shaping these often enigmatic DDAs, given that other causes are simpler and commoner. Copyright © 2013 John Wiley & Sons, Ltd.
Bayesian modelling the retreat of the Irish Sea Ice Stream
Authors: Chiverrell Richard C. , Thrasher Ian M. , Thomas Geoffrey S. P. , Lang Andreas , Scourse James D. , van Landeghem Katrien J. J. , Mccarroll Danny , Clark Chris D. , Cofaigh Colm Ó , Evans David J. A. , Ballantyne Colin K.
Published: February 2013

We present an 8000‐year history spanning 650 km of ice margin retreat for the largest marine‐terminating ice stream draining the former British–Irish Ice Sheet. Bayesian modelling of the geochronological data shows the ISIS expanded 34.0–25.3 ka, accelerating into the Celtic Sea to reach maximum limits 25.3–24.5 ka before a collapse with rapid marginal retreat to the northern Irish Sea Basin (ISB). This retreat was rapid and driven by climatic warming, sea‐level rise, mega‐tidal amplitudes and reactivation of meridional circulation in the North Atlantic. The retreat, though rapid, is uneven, with the stepped retreat pattern possibly a function of the passage of the ice stream between normal and adverse ice bed gradients and changing ice stream geometry. Initially, wide calving margins and adverse slopes encouraged rapid retreat (∼550 m a−1) that slowed (∼100 m a−1) at the topographic constriction and bathymetric high between southern Ireland and Wales before rates increased (∼200 m a−1) across adverse bed slopes and wider and deeper basin configuration in the northern ISB. These data point to the importance of the ice bed slope and lateral extent in predicting the longer‐term (>1000 a) patterns and rates of ice‐marginal retreat during phases of rapid collapse, which has implications for the modelling of projected rapid retreat of present‐day ice streams. Copyright © 2013 John Wiley & Sons, Ltd.
The effects of gender, size and life‐cycle stage on the chemical composition of smoothhound shark (Mustelus mustelus) meat
Authors: Bosch Adina C , Sigge Gunnar O , Kerwath Sven E , Cawthorn Donna‐Mareè , Hoffman Louwrens C
Published: February 2013

BACKGROUND

Knowledge on the chemical composition of foods, and on the variation in such components as influenced by endogenous factors, is required for nutritional labelling, dietetic planning and food processing. This study examined the effects of endogenous factors (gender, size and life‐cycle stage) on the chemical components (proximate, amino acid, fatty acid, mineral and mercury contents) of smoothhound shark (Mustelus mustelus) meat.

RESULTS

Levels of moisture, protein, lipids, ash, amino acids and most minerals were not affected (P > 0.05) by the gender, size or life‐cycle stages of the sharks. The fatty acid content was higher in females than in males, as well as in non‐pregnant females compared to pregnant females. Certain fatty acids decreased in quantity in medium‐sized sharks (prior to maturity). Pregnant females had higher aluminium (Al) and copper (Cu) levels than non‐pregnant females and mercury (Hg) levels were highest in large male sharks.

CONCLUSION

This study has, for the first time, established that endogenous factors have minimal influence on the chemical composition of M. mustelus meat, demonstrating the feasibility of describing an average composition for this species. Additionally, new insights have been obtained on potential safety concerns (mercury) associated with consumption of the meat that require further investigation. © 2013 Society of Chemical Industry
Optimisation of a biotechnological procedure for selective fractionation of bioactive inositols in edible legume extracts
Authors: Ruiz‐Aceituno Laura , Rodríguez‐Sánchez Sonia , Ruiz‐Matute Ana I , Ramos Lourdes , Soria Ana C , Sanz María L
Published: February 2013

BACKGROUND

Currently, disorders such as diabetes mellitus, obesity or atherosclerosis are recognised as major global health problems. The use of inositols for treating these illnesses has attracted considerable attention and their extraction from natural sources presents added value as they are considered bioactive ingredients in the food industry. Legumes are natural and rich sources of inositols; however, the co‐existence of other low molecular weight carbohydrates (LMWCs) in their extracts, which interfere in their bioactivity, might constitute an important drawback, thereby making their removal essential.

RESULTS

LMWCs, including inositols, methyl‐inositols and glycosyl‐inositols of different legume extracts, were determined by GC‐MS; the presence of bornesitol (2.35 mg g−1) and lathyritol (0.27 mg g−1) were reported for the first time in grass peas. The use of Saccharomyces cerevisiae for the selective removal of interfering carbohydrates was optimised. Incubation time (3–40 h) was highly dependent on the composition of the legume considered; inositol contents were generally stable along the treatment.

CONCLUSION

Removal of interfering LMWCs from inositol‐enriched extracts was successfully achieved using a clean and easily scalable fractionation methodology. This biotechnological procedure not only represents high interest for the production of bioactive food ingredients but for applications in other research areas. © 2013 Society of Chemical Industry
Acid‐induced homogenous liquid‐phase microextraction: Application of medium‐chain carboxylic acid as extraction phase
Authors: Ebrahimpour Behnam , Yamini Yadollah , Esrafili Ali
Published: February 2013

In this research, a novel homogeneous liquid‐phase microextraction method was successfully developed based on applying octanoic acid as low‐density extraction solvent. The method was applied for extraction and determination of chlorophenols (CPs) as model compounds. Twelve milliliter of the sample solution was poured into a home‐designed glass vial. Sixty microliter of octanoic acid was solved in water sample by adjusting pH and ionic strength. By rapid addition of 75 μL of concentrated HCl (6 M), a cloudy solution was obtained. Phase separation occurred at 5000 rpm for 5 min. After that, 20 μL of the collected phase (approximately 26 μL) was injected into the HPLC‐UV instrument for analysis. The effect of some parameters such as the volume of concentrated HCl (phase separation reagent), ionic strength, extraction time, centrifugation time, and the volume of extracting phase on the extraction efficiency of the CPs were investigated and optimized. The preconcentration factors in a range of 159–218 were obtained under the optimal conditions. The linear range, detection limits (S/N = 3), and precision (n = 3) were 1– 200, 0.3–0.5 μg/L, and 4.6–5.1%, respectively. Tap water, seawater, and river water samples were successfully analyzed for the existence of CPs using the proposed method and satisfactory results were obtained.
Tungsten‐183 NMR study of cis‐[W(CO)4(PPh3)(4‐RC5H4N)]; effect of varying the σ donor strength of the pyridine
Authors: Carlton Laurence , Mokoena Lebohang V. , Fernandes Manuel A.
Published: February 2013

Tungsten‐183 NMR data are reported for the complexes cis‐[W(CO)4(PPh3)(4‐RC5H4N)] (R = H, Me, Ph, COMe, COPh, OMe, NMe2, Cl, NO2). The 183W chemical shift (obtained by indirect detection using 31P) is found to correlate with the Hammett σ function for the group R, with 183W shielding increasing approximately linearly with the donor strength of the pyridine over a range of 93 ppm. The X‐ray structures of cis‐[W(CO)4(PPh3)(4‐MeOC5H4N)] and cis‐[W(CO)4(PPh3)(4‐PhCOC5H4N)] are also reported. Copyright © 2013 John Wiley & Sons, Ltd.
Synthesis and NMR studies of novel chromone‐2‐carboxamide derivatives
Authors: Gaspar Alexandra , Cagide Fernando , Quezada Elias , Reis Joana , Uriarte Eugenio , Borges Fernanda
Published: February 2013

Chromones are heterocyclic compounds of natural or synthetic origin that possess relevant pharmacological activities. Versatile functionalization of the chromone nucleus allows attaining of a chemical diversity suitable to perform structure–activity relationships in drug discovery and development programs. Accordingly, the synthesis and identification of novel chromone carboxamide derivatives with electron‐donating and electron‐withdrawing substituents in different positions of the exocyclic ring are reported in this work. Their complete structural characterization was performed using one‐dimensional and two‐dimensional resonance techniques. The data acquired are useful for a prompt analysis of related compounds that encompass our integrated medicinal chemistry sketch. Copyright © 2013 John Wiley & Sons, Ltd.
In vivo diffusion‐weighted MRI using perfluorinated gases: ADC comparison between healthy and elastase‐treated rat lungs
Authors: Carrero‐González L. , Kaulisch T. , Stiller D.
Published: February 2013

Purpose

MRI with perfluorinated gases has been shown as an alternative to hyperpolarized gases to image both microstructure and gas diffusivity in the lung. The aim of this study was to measure diffusion restriction of C2F6 in rat lungs and to compare the different levels of restriction between healthy and emphysematous tissue.

Methods

For this purpose, two groups of rats—healthy and mono‐lobar elastase‐induced animals—were measured. While being ventilated with a mixture of C2F6 and oxygen four diffusion weighted 19F‐images where acquired for each animal and corresponding ADC‐maps were calculated.

Results

No significant apparent diffusion coefficient (ADC) differences were found between healthy lungs; however, the elastase treated lungs showed a significant increase in ADC.

Conclusion

These results demonstrate that ADC measurements with C2F6 are sensitive to the microstructure of rat lungs showing that the diffusion of this gas is limited to different levels in healthy and in emphysematous tissue. Magn Reson Med 70:1761–1764, 2013. © 2013 Wiley Periodicals, Inc.
Quantitative measurement of cancer metabolism using stimulated echo hyperpolarized carbon‐13 MRS
Authors: Swisher Christine Leon , Larson Peder E. Z. , Kruttwig Klaus , Kerr Adam B. , Hu Simon , Bok Robert A. , Goga Andrei , Pauly John M. , Nelson Sarah J. , Kurhanewicz John , Vigneron Daniel B.
Published: February 2013

Purpose

Magnetic resonance spectroscopy of hyperpolarized substrates allows for the observation of label exchange catalyzed by enzymes providing a powerful tool to investigate tissue metabolism and potentially kinetics in vivo. However, the accuracy of current methods to calculate kinetic parameters has been limited by T1 relaxation effects, extracellular signal contributions, and reduced precision at lower signal‐to‐noise ratio.

Theory and Methods

To address these challenges, we investigated a new modeling technique using metabolic activity decomposition‐stimulated echo acquisition mode. The metabolic activity decomposition‐stimulated echo acquisition mode technique separates exchanging from nonexchanging metabolites providing twice the information as conventional techniques.

Results

This allowed for accurate measurements of rates of conversion and of multiple T1 values simultaneously using a single acquisition.

Conclusion

The additional measurement of T1 values for the reaction metabolites provides further biological information about the cellular environment of the metabolites. The new technique was investigated through simulations and in vivo studies of transgenic mouse models of cancer demonstrating improved assessments of kinetic rate constants and new T1 relaxation value measurements for hyperpolarized 13C‐pyruvate, 13C‐lactate, and 13C‐alanine. Magn Reson Med 71:1–11, 2014. © 2013 Wiley Periodicals, Inc.
Self‐navigated tissue phase mapping using a golden‐angle spiral acquisition—proof of concept in patients with pulmonary hypertension
Authors: Steeden Jennifer A. , Knight Daniel S. , Bali Shreya , Atkinson David , Taylor Andrew M. , Muthurangu Vivek
Published: February 2013

Purpose

To create a high temporal‐ and spatial‐resolution retrospectively cardiac‐gated, tissue phase mapping (TPM) sequence, using an image‐based respiratory navigator calculated from the data itself.

Methods

The sequence was based on a golden‐angle spiral acquisition. Reconstruction of real‐time images allowed creation of an image‐based navigator. The expiratory spiral interleaves were then retrospectively cardiac‐gated using data binning. TPM data were acquired in 20 healthy volunteers and 10 patients with pulmonary hypertension. Longitudinal and radial myocardial velocities were calculated in the left ventricle and right ventricle.

Results

The image‐based navigator was shown to correlate well with simultaneously acquired airflow data in 10 volunteers(r=0.93±0.04). The TPM navigated images had a significantly higher subjective image quality and edge sharpness (P<0.0001) than averaged spiral TPM. No significant differences in myocardial velocities were seen between conventional Cartesian TPM with navigator respiratory‐gating and the proposed self‐navigated TPM technique, in 10 volunteers. Significant differences in the velocities were seen between the volunteers and patients in the left ventricle at systole and end diastole and in the right ventricle at end diastole.

Conclusion

The feasibility of measuring myocardial motion using a golden‐angle spiral TPM sequence was demonstrated, with an image‐based respiratory navigator calculated from the TPM data itself. Magn Reson Med 71:145–155, 2014. © 2013 Wiley Periodicals, Inc.
Fat quantification using multiecho sequences with bipolar gradients: Investigation of accuracy and noise performance
Authors: Peterson Pernilla , Månsson Sven
Published: February 2013

Purpose

To investigate the accuracy and noise performance of fat quantification with multiple gradient‐echo images acquired using bipolar read‐out gradients and compare them with those of the well‐established unipolar technique.

Theory

The bipolar read‐out technique induces phase and amplitude errors caused by gradient delays, eddy currents, and frequency‐dependent coil sensitivity. In this study, these errors were corrected for jointly with the fat/water separation by modeling the impact of these effects on the signal. This approach did not require acquisition of reference data or modification of the pulse sequence.

Methods

Simulations and a phantom experiment were used to investigate the accuracy and noise performance of the technique and compare them with those of a well‐established technique using unipolar read‐out gradients. Also, the in vivo feasibility was demonstrated for abdominal applications.

Results

The phantom experiment demonstrated similar accuracy of the bipolar and unipolar fat quantification techniques. In addition, the noise performance was shown not to be affected by the added estimations of the phase and amplitude errors for most inter‐echo times.

Conclusion

The bipolar technique was found to provide accurate fat quantification with noise performance similar to the unipolar technique given an appropriate choice of inter‐echo time. Magn Reson Med 71:219–229, 2014. © 2013 Wiley Periodicals, Inc.
Rapid measurement of arterial input function in mouse tail from projection phases
Authors: Moroz Jennifer , Wong Clayton L. , Yung Andrew C. , Kozlowski Piotr , Reinsberg Stefan A.
Published: February 2013

Purpose

To measure the arterial input function (AIF) in a mouse tail at high temporal resolution with signal phase of MR projections.

Methods

The technique involves the acquisition of one 2D image before injection, followed by a series of projections before, during, and after contrast injection. Differences in the signal phase, relative to the mean preinjection phase, were calculated and converted into a concentration of Gd.

Results

An AIF with a temporal resolution of 100 ms was measured and verified with colorimetry (in a flow phantom) and mass spectrometry analysis (in vivo). The projection‐based AIF is expected to better represent the rapid contrast kinetics in the blood following injection, thus improving the accuracy of quantitative dynamic contrast‐enhanced‐MRI analysis. Colorimetry experiments confirmed that signal phase is preferred over magnitude for a precise determination of an AIF. In‐vivo experiments demonstrate the feasibility of our approach in mice.

Conclusion

AIFs can be measured quickly and precisely using phase from projections. Phase data are sensitive to the flow velocity; but this sensitivity is significantly reduced when flow compensation was used. Magn Reson Med 71:238–245, 2014. © 2013 Wiley Periodicals, Inc.
Collagen Composition and Content‐Dependent Contrast in Porcine Annulus Fibrosus Achieved by Using Double Quantum and Magnetization Transfer Filtered UTE MRI
Authors: Eliav Uzi , Komlosh Michal E. , Basser Peter J. , Navon Gil
Published: February 2013

Purpose

To test the potential of combining double quantum and magnetization transfer filtered ultra‐short echo time (DQF‐MT‐UTE) MRI to obtain information about the macromolecular composition and characteristics of connective tissues.

Methods

A DQF‐MT‐UTE pulse sequence was implemented on a 14.1 T AVANCE III Bruker spectrometer equipped with a Bruker micro2.5‐imaging gradient system to obtain images of porcine annulus fibrosus.

Results

The DQF‐MT‐UTE MRI of the annulus fibrosus of porcine intervertebral disc, where the creation time of the double quantum coherence filtering (DQF) was on a time scale appropriate for excitation of macromolecules, showed stronger signal from the outer layers of the disc than from the inner layers closer to the nucleus pulposus. Similarly, spectroscopic studies showed the same trend in the efficiency of the magnetization transfer (MT) from collagen to water.

Conclusion

DQF‐MT filtered UTE MRI of the annulus fibrosus provides new contrast parameters that depend on the concentration of the collagen and on the rate and efficiency of MT of its protons to water. The latter parameters appear to be different for collagen types I and II in the annulus fibrosus. Magn Reson Med 71:388–393, 2014. © 2013 Wiley Periodicals, Inc.
Thermal Tissue Damage Model Analyzed for Different Whole‐Body SAR and Scan Durations for Standard MR Body Coils
Authors: Murbach Manuel , Neufeld Esra , Capstick Myles , Kainz Wolfgang , Brunner David O. , Samaras Theodoros , Pruessmann Klaas P. , Kuster Niels
Published: February 2013

Purpose

This article investigates the safety of radiofrequency induced local thermal hotspots within a 1.5T body coil by assessing the transient local peak temperatures as a function of exposure level and local thermoregulation in four anatomical human models in different Z‐positions.

Methods

To quantize the effective thermal stress of the tissues, the thermal dose model cumulative equivalent minutes at 43°C was employed, allowing the prediction of thermal tissue damage risk and the identification of potentially hazardous MR scan‐scenarios. The numerical results were validated by B1+− and skin temperature measurements.

Results

At continuous 4 W/kg whole‐body exposure, peak tissue temperatures of up to 42.8°C were computed for the thermoregulated model (60°C in nonregulated case). When applying cumulative equivalent minutes at 43°C damage thresholds of 15 min (muscle, skin, fat, and bone) and 2 min (other), possible tissue damage cannot be excluded after 25 min for the thermoregulated model (4 min in nonregulated).

Conclusion

The results are found to be consistent with the history of safe use in MR scanning, but not with current safety guidelines. For future safety concepts, we suggest to use thermal dose models instead of temperatures or SAR. Special safety concerns for patients with impaired thermoregulation (e.g., the elderly, diabetics) should be addressed. Magn Reson Med 71:421–431, 2014. © 2013 Wiley Periodicals, Inc.
From solid to granular gases: the steady state for granular materials
Authors: Vescovi D. , di Prisco C. , Berzi D.
Published: February 2013

This paper aims at extending the well‐known critical state concept, associated with quasi‐static conditions, by accounting for the role played by the strain rate when focusing on the steady, simple shear flow of a dry assembly of identical, inelastic, soft spheres. An additional state variable for the system, the granular temperature, is accounted for. The granular temperature is related to the particle velocity fluctuations and measures the agitation of the system. This state variable, as is in the context of kinetic theories of granular gases, is assumed to govern the response of the material at large strain rates and low concentrations. The stresses of the system are associated with enduring, frictional contacts among particles involved in force chains and nearly instantaneous collisions. When the first mechanism prevails, the material behaves like a solid, and constitutive models of soil mechanics hold, whereas when inelastic collisions dominate, the material flows like a granular gas, and kinetic theories apply. Considering a pressure‐imposed flow, at large values of the normal stress and small values of the shear rate, the theory predicts a nonmonotonic shear rate dependence of the stress ratio at the steady state, which is likely to govern the evolution of landslides. Copyright © 2013 John Wiley & Sons, Ltd.
Second‐order work analysis for granular materials using a multiscale approach
Authors: Nicot François , Hadda Nejib , Darve Félix
Published: February 2013

It has been established that the second‐order work criterion is a general necessary condition for all instabilities by divergence in rate‐independent granular materials. The relation between the values of discrete second‐order work at the intergranular contact point level and its global macroscopic value is recalled at the beginning of this paper. Then, the basic purpose of the paper is tackled by an analysis of the main features of second‐order work criterion in relation with the granular microstructure. For that, it is considered a novel micromechanical model (the so‐called ‘H‐microdirectional model’), which has the property to involve three scales: grain scale, mesoscale with a specific granular configuration and continuum mechanics macroscale. Eventually, these exhibited features (a bifurcation stress domain and some instability cones) are qualitatively compared with the ones provided by direct numerical simulations issued from a discrete element model. The ultimate goal is to analyse what happens at the granular scale, when the macrosecond‐order work is vanishing at the macrolevel. Copyright © 2013 John Wiley & Sons, Ltd.
Nonintrusive reduced‐order modeling of parametrized time‐dependent partial differential equations
Authors: Audouze Christophe , De Vuyst Florian , Nair Prasanth B.
Published: February 2013

We propose a nonintrusive reduced‐order modeling method based on the notion of space‐time‐parameter proper orthogonal decomposition (POD) for approximating the solution of nonlinear parametrized time‐dependent partial differential equations. A two‐level POD method is introduced for constructing spatial and temporal basis functions with special properties such that the reduced‐order model satisfies the boundary and initial conditions by construction. A radial basis function approximation method is used to estimate the undetermined coefficients in the reduced‐order model without resorting to Galerkin projection. This nonintrusive approach enables the application of our approach to general problems with complicated nonlinearity terms. Numerical studies are presented for the parametrized Burgers' equation and a parametrized convection‐reaction‐diffusion problem. We demonstrate that our approach leads to reduced‐order models that accurately capture the behavior of the field variables as a function of the spatial coordinates, the parameter vector and time. © 2013 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2013
To pay or not to pay — the role of monetary incentives in an optimal blood donation service bundle
Authors: Mews Marius
Published: February 2013

This study derives four attributes that make up the typical blood donation service bundle. It focuses on the role of monetary incentives in such bundles, but also discusses three other attributes, namely the offering organization, the distance to donation location, and the donation time. Each attribute is discussed in the context of a blood donation marketing mix. In an empirical conjoint study, 529 potential blood donors evaluate different designs of blood donation service bundles. Monetary incentives are found to be the most important factor when donors compare different blood donation service bundles. It is found that the distance to the donation location is almost as important as monetary incentives. Blood donation organizations aiming to collect all blood donations from unremunerated blood donors should therefore shape their service bundles to be attractive for potential blood donors. It is concluded that nonpaying blood donation organizations have to offer superior convenience to their donors to be able to compensate for not offering monetary incentives. Operating with mobile donation teams is one of the concrete suggestions for blood donation marketing that are given in this study.

Copyright © 2013 John Wiley & Sons, Ltd.
Cats differ from other species in their cytokine and antioxidant enzyme response when developing obesity
Authors: Hoenig Margarethe , Pach Nicole , Thomaseth Karl , Le Anh , Schaeffer David , Ferguson Duncan C.
Published: February 2013

Objectives: Obese cats show many similarities to obese people, including insulin resistance and an increased diabetes risk. However, atherosclerosis and cardiovascular disease are not seen in cats. In people, they are associated with the development of an inflammatory response, which, we hypothesized, does not occur in cats.

Design and Methods: Twenty neutered cats of equal gender distribution were allowed to gain weight by offering food ad libitum and were examined before and at 10, 30, 60, and 100% weight gain. All cats reached 60% of weight gain, 12 cats gained 100 % in 12 months.

Results: Fat was equally distributed between subcutaneous and visceral depots. Insulin‐independent glucose uptake increased and insulin sensitivity decreased with increasing adiposity. However, baseline glucose concentrations were unchanged suggesting a decrease in EGP. Inflammatory cytokines (Il‐1, IL‐6, TNFa) and catalase, superoxide dismutase, glutathione peroxidase did not change. Insulin, proinsulin, and leptin were positively and adiponectin negatively correlated with adiposity. Heat production increased with obesity, but became less when body weight gain was > 60 %.

Conclusions: This indicates that metabolism adapts more appropriately to the higher intake of calories in the initial phase of obesity but slows at higher body fat content. This likely contributes to the difficulty to lose weight.
Differential associations of abdominal visceral, subcutaneous adipose tissue with cardiometabolic risk factors between African and European Americans
Authors: Liu Jiankang , Coady Sean , Carr J. Jeffery , Hoffmann Udo , Taylor Herman A. , Fox Caroline S.
Published: February 2013

Objective

To examine the relative association of abdominal visceral adipose tissue (VAT) with cardiometabolic risk factors between African and European Americans.

Methods

A cross‐sectional study of 2,035 African Americans from the Jackson Heart Study (JHS) and 3,170 European Americans from the Framingham Heart Study (FHS) who underwent computed tomography assessment of VAT and subcutaneous adipose tissue (SAT) was conducted. The FHS participants were weighted to match the age distribution of the JHS participants, and the metabolic risk factors were examined by study groups in relation to VAT.

Results

JHS participants had higher rates of obesity, hypertension, diabetes, and metabolic syndrome than FHS participants (all P = 0.001). The associations were weaker in JHS women for VAT with blood pressure, triglycerides, HDL‐C, and total cholesterol (Pinteraction = 0.03‐0.001) than FHS women. In contrast, JHS men had stronger associations for VAT with high triglycerides, low HDL, and metabolic syndrome (all Pinteraction = 0.001) compared to FHS men. Similar associations and gender patterns existed for SAT with most metabolic risk factors.

Conclusions

The relative association between VAT and cardiometabolic risk factors is weaker in JHS women compared to FHS women, whereas stronger associations with triglycerides and HDL were observed in JHS men.
A randomized, phase 3 trial of naltrexone SR/bupropion SR on weight and obesity‐related risk factors (COR‐II)
Authors: Apovian Caroline M. , Aronne Louis , Rubino Domenica , Still Christopher , Wyatt Holly , Burns Colleen , Kim Dennis , Dunayevich Eduardo ,   for the COR‐II Study Group
Published: February 2013

Objective:

To examine the effects of naltrexone/bupropion (NB) combination therapy on weight and weight‐related risk factors in overweight and obese participants.

Design and Methods:

CONTRAVE Obesity Research‐II (COR‐II) was a double‐blind, placebo‐controlled study of 1,496 obese (BMI 30‐45 kg/m2) or overweight (27‐45 kg/m2 with dyslipidemia and/or hypertension) participants randomized 2:1 to combined naltrexone sustained‐release (SR) (32 mg/day) plus bupropion SR (360 mg/day) (NB32) or placebo for up to 56 weeks. The co‐primary endpoints were percent weight change and proportion achieving ≥5% weight loss at week 28.

Results:

Significantly (P < 0.001) greater weight loss was observed with NB32 versus placebo at week 28 (−6.5% vs. −1.9%) and week 56 (−6.4% vs. −1.2%). More NB32‐treated participants (P < 0.001) experienced ≥5% weight loss versus placebo at week 28 (55.6% vs. 17.5%) and week 56 (50.5% vs. 17.1%). NB32 produced greater improvements in various cardiometabolic risk markers, participant‐reported weight‐related quality of life, and control of eating. The most common adverse event with NB was nausea, which was generally mild to moderate and transient. NB was not associated with increased events of depression or suicidality versus placebo.

Conclusion:

NB represents a novel pharmacological approach to the treatment of obesity, and may become a valuable new therapeutic option.
Caesarean section and body mass index among danish men
Authors: Svensson Elisabeth , Hyde Matthew , Modi Neena , Ehrenstein Vera
Published: February 2013

Objective:

We conducted a prevalence study to examine the association between Caesarean section and body mass index (BMI) in 21,051 adult Danish men born in 1977‐1983 who presented for mandatory conscription evaluation around age 18 years.

Design and methods:

Data on BMI from conscription records were linked to the men's birth records to identify mode of delivery and other perinatal data.

Results:

Two thousand one hundred thirty‐eight men (10%) had been delivered by a Caesarean section. Prevalence of obesity at conscription was 6% for those born vaginally and 9% for those born by a Caesarean section. The adjusted prevalence ratio (PR) for obesity (BMI ≥ 30 kg/m2) was 1.35 (95% CI 1.14‐1.60); the adjusted PR for overweight (25 ≤ BMI < 30 kg/m2) was 1.05 (95% CI 0.94‐1.17). The adjusted mean difference in BMI was 0.38 kg/m2 (95% CI 0.16‐0.60) comparing men born by Caesarean versus vaginal delivery. The estimates were similar for planned and nonplanned Caesarean deliveries.

Conclusion:

Birth by a Caesarean section was associated with an increased risk of obesity among men.
An automated algorithm to identify and quantify brown adipose tissue in human 18F‐FDG‐PET/CT scans
Authors: Ruth Megan R. , Wellman Tyler , Mercier Gustavo , Szabo Thomas , Apovian Caroline M.
Published: February 2013

Objective

To develop an algorithm to identify and quantify BAT from PET/CT scans without radiologist interpretation.

Design and Methods

Cases (n = 17) were randomly selected from PET/CT scans with documented “brown fat” by the reviewing radiologist. Controls (n = 18) had no documented “brown fat” and were matched with cases for age (49.7 [31.0‐63.0] vs. 52.4 [24.0‐70.0] yrs), outdoor temperature at scan date (51.8 [38.9‐77.0] vs. 54.9 [35.2‐74.6] °F), sex (F/M: 15/2 cases; 16/2 controls) and BMI (28.2 [20.0‐45.7] vs. 26.8 [21.4‐37.1] kg/m2]). PET/CT scans and algorithm‐generated images were read by the same radiologist blinded to scan identity. Regions examined included neck, mediastinum, supraclavicular fossae, axilla and paraspinal soft tissues. BAT was scored 0 for no BAT; 1 for faint uptake possibly compatible with BAT or unknown; and 2 for BAT positive.

Results

Agreement between the algorithm and PET/CT scan readings was 85.7% across all regions. The algorithm had a low false negative (1.6%) and higher false positive rate (12.7%). The false positive rate was greater in mediastinum, axilla and neck regions.

Conclusion

The algorithm's low false negative rate combined with further refinement will yield a useful tool for efficient BAT identification in a rapidly growing field particularly as it applies to obesity.
A randomized trial of energy‐restricted high‐protein versus high‐carbohydrate, low‐fat diet in morbid obesity
Authors: Dalle Grave Riccardo , Calugi Simona , Gavasso Ilaria , El Ghoch Marwan , Marchesini Giulio
Published: February 2013

Objective

Conflicting evidence exists as to weight loss produced by diets with different carbohydrate/protein ratio. The aim was to compare the long‐term effects of high‐protein vs. high‐carbohydrate diet (HPD, HCD), combined with cognitive behavior therapy (CBT).

Design and Methods

In a randomized trial, 88 obese participants (mean age, 46.7; mean BMI, 45.6 kg m−2) were enrolled in a 3‐week inpatient and 48‐week outpatient treatment, with continuous CBT during the study period. All subjects consumed a restricted diet (1,200 kcal day−1 for women, 1,500 for men; 20% energy from fat, <10% saturated fat). HPD derived 34% energy from proteins, 46% from carbohydrates; HCD 17% from proteins, 64% from carbohydrates. The primary outcome was 1‐year percent weight loss. Secondary outcomes were attrition rates and changes in cardiovascular risk factors and psychological profile.

Results

Attrition rates were similar between groups (25.6%). In the intention‐to‐treat analysis, weight loss averaged 15.0% in HPD and 13.3% in HCD at 1 year, without any difference throughout the study period. Both diets produced a similar improvement in secondary outcomes.

Conclusions

The relative carbohydrate and protein content of the diet, when combined with intensive CBT, does not significantly affect attrition rate, weight loss and psychosocial outcome in patients with severe obesity.
Associations of leukocyte telomere length with body anthropometric indices and weight change in chinese women
Authors: Cui Yong , Gao Yu‐Tang , Cai Qiuyin , Qu Shimian , Cai Hui , Li Hong‐Lan , Wu Jie , Ji Bu‐Tian , Yang Gong , Chow Wong‐Ho , Shu Xiao‐Ou , Zheng Wei
Published: February 2013

Objective: This study evaluated associations of telomere length with various anthropometric indices of general and abdominal obesity, as well as weight change.

Design and Methods: The study included 2,912 Chinese women aged 40‐70 years. Monochrome multiplex quantitative polymerase chain reaction was applied to measure relative telomere length.

Results: Telomere length was inversely associated with body mass index (BMI), waist circumference, waist‐to‐height ratio, weight, and hip circumference (Ptrend = 0.005, 0.004, 0.004, 0.010, and 0.026, respectively), but not waist‐to‐hip ratio (Ptrend = 0.116) or height (Ptrend = 0.675). Weight change since age 50 was further evaluated among women over age 55. Women who maintained their weight within ±5% since age 50, particularly within a normal range (BMI = 18.5‐24.9 kg/m2), or reduced their weight from overweight (BMI = 25‐29.9 kg/m2) or obesity (BMI ≥30 kg/m2) to normal range, had a longer mean of current telomere length than women who gained weight since age 50 (Ptrend = 0.025), particularly those who stayed in obesity or gained weight from normal range or overweight to obesity (P = 0.023).

Conclusion: Our findings show that telomere shortening is associated with obesity and that maintaining body weight within a normal range helps maintain telomere length.
Metabolic disregulation in obese adolescents with sleep‐disordered breathing before and after weight loss
Authors: Van Hoorenbeeck K. , Franckx H. , Debode P. , Aerts P. , Ramet J. , Gaal L. F. Van , Desager K. N. , Backer W. A. De , Verhulst S. L.
Published: February 2013

Objective

Sleep‐disordered breathing (SDB) is prevalent in obesity. Weight loss is one of the most effective treatment options. The aim was to assess the association of SDB and metabolic disruption before and after weight loss.

Design and Methods

Obese adolescents were included when entering an in‐patient weight loss program. Fasting blood analysis was performed at baseline and after 4‐6 months. Sleep screening was done at baseline and at follow‐up in case of baseline SDB.

Results

224 obese adolescents were included. Median age was 15.5 years (10.1‐18.0) and mean BMI z‐score was 2.74 ± 0.42. About 30% had SDB at baseline (N = 68). High‐density lipoprotein (HDL)‐cholesterol was associated with mean nocturnal oxygen saturation () (partial r = 0.21; P = 0.002). Aspartate aminotransferase (ASAT) and alanine aminotransferase were related with oxygen desaturation index (partial r = −0.15; P = 0.03 and partial r = −0.15; P = 0.02), but this became insignificant after correction for sex. After weight loss, 24% had residual SDB. Linear regression showed an association between ASAT and  (partial r = −0.34; P = 0.002). There were no significant correlations between improvements in laboratory measurements and sleep parameters. HDL‐cholesterol improved in relation with the decrease in BMI z‐score.

Conclusion

SDB at baseline was associated with higher levels of liver enzymes and lower HDL‐cholesterol concentration. Improvements in sleep parameters were not associated with improvements in laboratory measurements. © 2013 American Institute of Chemical Engineers AIChE J, 2013
Abdominal fat is associated with a greater brain reward response to high‐calorie food cues in hispanic women
Authors: Luo Shan , Romero Ana , Adam Tanja C. , Hu Houchun H. , Monterosso John , Page Kathleen A.
Published: February 2013

Objective

Exposure to high‐calorie foods may promote overeating by stimulating brain reward pathways and appetite. Abdominal fat has particularly adverse metabolic consequences and may alter brain pathways that regulate feeding behavior. Functional magnetic resonance imaging (fMRI) was used to test the hypothesis that high‐calorie food cues activate brain reward regions and increase appetite, and to examine the relationship between abdominal fat and brain reward responsiveness in Hispanic women.

Design and Methods

fMRI was performed while 13 volunteers viewed 12 blocks of pictures of food and non‐food items. Participants rated hunger and food desire after each block of pictures. Brain activation to high‐calorie foods was determined by calculating a contrast of high‐calorie food minus non‐food images. Pearson's correlations were used to test the relationship between brain reward activation and waist circumference.

Results

High‐calorie food images activated brain reward regions (Z > 2.3, P < 0.05 corrected for multiple comparisons) and increased hunger (P = 0.001), desire for sweet (P = 0.012) and savory (P = 0.009) foods. The striatal response to high‐calorie foods positively correlated with waist circumference, independent of BMI (r = 0.621, P = 0.031).

Conclusions

Exposure to high‐calorie food images activates brain reward pathways and increases appetitive drive in Hispanic females. Abdominal fat, independent of BMI, parallels striatal responsiveness to high‐calorie food images.