bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental investigation of parents and their children's social interaction intentions towards obese children
Authors: Wolfenden Luke , McKeough Alyce , Bowman Jennifer , Paolini Stefania , Francis Lynn , Wye Paula , Puhl Rebecca
Published: July 2013

Aim

The aim of this study was to determine if parent intentions to facilitate social interactions between their child and a peer, or parental perceptions of their child's peer social interaction intentions, differ according to the weight status of a child's peer.

Methods

During a telephone survey, 250 Australian parents of children 5–12 years were randomly assigned to listen to one of two descriptions of a hypothetical child differing by group in the description of child weight status (‘quite overweight’ or ‘healthy weight’). Parents then completed the Social Interaction Intention Scale, which assessed how likely they or their child would engage in a number of behaviours that may facilitate social interaction with the child described in the profile.

Results

Means scores on the overall scale and the child sub‐scale of the Child Social Interaction Intention Scale were significantly higher among participants allocated to the healthy weight child profile, indicating more positive social intentions.

Conclusion

The findings suggest that negative weight‐based stereotypes hinder the development of peer friendships by obese children.
Resource translocation drives 13C fractionation during recovery from disturbance in giant kelp, Macrocystis pyrifera
Authors: Fox Michael D.
Published: July 2013

Resource allocation and translocation are fundamental physiological functions for autotrophs. The mobilization and use of resources drive population dynamics by regulating growth and recovery of individuals, but also influences ecosystem‐level processes such as primary productivity and carbon cycling. This study provides the first observation of translocation‐driven gradients of δ13C in macroalgae, a critically important phenomenon recognized in vascular plants for decades. A ~10‰ δ13C increase in new giant kelp (Macrocystis pyrifera) fronds relative to mature canopy blades was produced after 5 weeks following a biomass removal experiment, more than twice the variation typical for macroalgae. The observed δ13C patterns are consistent with tissue enrichment following resource translocation in vascular plants. The analogous source‐sink relationships and consistent translocation patterns in Macrocystis and vascular plants suggest that translocation of stored resources is critical for structuring productivity and recovery from disturbance in important, habitat‐forming macroalgae such as kelps and fucoids.
Efficacy and Safety of Dapoxetine in Men with Premature Ejaculation and Concomitant Erectile Dysfunction Treated with a Phosphodiesterase Type 5 Inhibitor: Randomized, Placebo-Controlled, Phase III Study
Authors: McMahon Chris G. , Giuliano Francois , Dean John , Hellstrom Wayne J.G. , Bull Scott , Tesfaye Fisseha , Sharma Om , Rivas David A. , Aquilina Joseph W.
Published: July 2013

Introduction

Men with comorbid erectile dysfunction (ED) and premature ejaculation (PE) may be concomitantly prescribed a phosphodiesterase type 5 (PDE5) inhibitor and dapoxetine.

Aim

Evaluate efficacy and safety of dapoxetine 30mg and 60mg on demand (prn) in men with PE and ED who were being treated with PDE5 inhibitors.

Methods

This randomized, double-blind, placebo-controlled, flexible-dose, multicenter study enrolled men ≥18 years who met diagnostic criteria for PE including intravaginal ejaculatory latency time (IELT) of ≤2 minutes in ≥75% of sexual intercourse episodes; were on stable regimen of a PDE5 inhibitor; and had International Index of Erectile Function-erectile function domain score ≥21. Subjects received placebo, dapoxetine 30mg, or dapoxetine 60mg prn (1–3 hours before intercourse) for 12 weeks.

Main Outcome Measure

Stopwatch-measured average IELT, Clinical Global Impression of Change (CGIC) in PE, Premature Ejaculation Profile (PEP), and treatment-emergent adverse events (TEAEs).

Results

Of 495 subjects randomized, 429 completed the study. Arithmetic mean average IELT significantly increased with dapoxetine vs. placebo at end point (5.2 vs. 3.4 minutes) and weeks 4, 8, and 12 (P ≤0.002 for all). Men who described their PE at least “better” using the CGIC were significantly greater with dapoxetine vs. placebo at end point (56.5% vs. 35.4%) and weeks 4, 8, and 12 (P ≤0.001 for all). Significantly better outcomes were also reported with dapoxetine vs. placebo on PEP measures. Incidence of TEAEs was 20.0% and 29.6% in placebo- and dapoxetine-treated subjects, respectively (P =0.0135). TEAEs led to discontinuation in 1.6% of subjects in both groups. Most frequent TEAEs were known adverse drug reactions of dapoxetine treatment including nausea (9.2%), headache (4.4%), diarrhea (3.6%), dizziness (2.4%), and dizziness postural (2.4%).

Conclusions

In men with PE and comorbid ED on a stable regimen of PDE5 inhibitor, dapoxetine provided meaningful treatment benefit and was generally well tolerated.
Aspects of Sexual Self-Schema in Premenopausal Women with Dyspareunia: Associations with Pain, Sexual Function, and Sexual Distress
Authors: Pazmany Els , Bergeron Sophie , Van Oudenhove Lukas , Verhaeghe Johan , Enzlin Paul
Published: July 2013

Introduction

Although it is known that women with dyspareunia suffer from impaired psychological and sexual functioning, the study of the various dimensions of sexual self-schema and their associations with these outcomes has been neglected.

Aim

To examine whether self-image cognitions about vaginal penetration, body image, and feelings and beliefs about one's own genitals contribute to the variance in pain, sexual functioning, and sexual distress.

Methods

Premenopausal women (n=231; M age=24.85, SD=5.55) with self-reported dyspareunia completed an online survey focusing on self-image cognitions about vaginal penetration, body image, female genital self-image, pain during intercourse, sexual functioning, sexual distress, anxiety, and catastrophizing.

Main Outcome Measures

(i) Pain intensity during intercourse, (ii) the Female Sexual Function Index without the Pain subscale, and (iii) the Female Sexual Distress Scale.

Results

Controlling for anxiety and catastrophizing, negative self-image cognitions about vaginal penetration, negative body image, and negative genital self-image together accounted for a portion of the variance in increased pain intensity, sexual dysfunction, and sexual distress. However, only self-image cognitions about vaginal penetration (β=0.25, P =0.005) contributed uniquely to the variance in pain intensity, whereas self-image cognitions about vaginal penetration (β=−0.18, P =0.048) and genital self-image (β=0.21, P =0.008) contributed independently to the variance in sexual functioning. Finally, self-image cognitions about vaginal penetration (β=0.28, P <0.001), body image (β=0.24, P <0.001) and genital self-image (β=−0.14, P =0.006) each contributed independently to the variance in sexual distress.

Conclusions

Findings suggest that self-image cognitions about vaginal penetration and feelings and beliefs about one's own body and genitals are associated with pain and sexuality outcomes in women with dyspareunia.
Relationship of Testis Size and LH Levels with Incidence of Major Adverse Cardiovascular Events in Older Men with Sexual Dysfunction
Authors: Rastrelli Giulia , Corona Giovanni , Lotti Francesco , Boddi Valentina , Mannucci Edoardo , Maggi Mario
Published: July 2013

Introduction

Measurement of testis volume (TV) is a reliable clinical procedure that predicts reproductive fitness. However, the role of TV in overall and cardiovascular (CV) fitness has never been studied.

Aim

The study aims to analyze the clinical correlates of TV in patients with sexual dysfunction (SD) and to verify the value of this parameter and its determinants (i.e., luteinizing hormone [LH] levels) in predicting major adverse CV events (MACE).

Methods

A consecutive series of 2,809 subjects without testiculopathy (age 51.2 ± 13.1) consulting for SD was retrospectively studied. A subset of this sample (n = 1,395) was enrolled in a longitudinal study.

Main Outcome Measures

Several clinical and biochemical parameters were investigated.

Results

After adjusting for confounders, TV was negatively associated with both LH (Adj. r = −0.234; P < 0.0001) and follicle-stimulating hormone (Adj. r = −0.326; P < 0.0001). In addition, overweight/obesity, smoking, and alcohol abuse increased as a function of TV (hazard ratio [HR] = 1.041 [1.021–1.061], P < 0.0001; 1.024 [1.005–1.044], P = 0.012; 1.063 [1.015–1.112], P = 0.009, respectively). Furthermore, mean blood pressure was positively related to increased TV (Adj. r = 0.157; P < 0.0001). The effect of these lifestyle factors on TV were only partially related to changes in gonadotropin levels. In the longitudinal analysis, after adjusting for confounders, TV was associated with a higher incidence of MACE (HR = 1.066 [1.013–1.122]; P = 0.014), and the stepwise introduction in the Cox model of lifestyle factors, mean blood pressure and body mass index progressively smoothed out the association, which was no longer statistically significant in the fully adjusted model. Conversely, the association of higher LH levels with increased incidence of MACE was not attenuated by the progressive introduction of the aforementioned confounders in the model.

Conclusions

Our data show that in SD subjects, TV and LH are associated with an adverse CV risk profile that mediate the higher TV-associated incidence of MACE. High LH levels are an independent marker of CV risk. Further studies are needed for clarifying determinants and mechanisms of testis enlargement that, beyond gonadotropins, could mediate the increased incidence of MACE.
Tomato yellow leaf curl Sardinia virus‐resistant tomato plants expressing the multifunctional N‐terminal domain of the replication‐associated protein show transcriptional changes resembling stress‐related responses
Authors: Lucioli Alessandra , Berardi Alessandra , Gatti Francesca , Tavazza Raffaela , Pizzichini Daniele , Tavazza Mario
Published: July 2013

The N‐terminal domain (amino acids 1–130) of the replication‐associated protein (Rep130) of Tomato yellow leaf curl Sardinia virus (TYLCSV) retains the ability of full‐length Rep to localize to the nucleus and to down‐regulate C1 transcription when ectopically expressed in plants, both functions being required to inhibit homologous viral replication. In this study, we analysed the effect of Rep130 expression on virus resistance and the plant transcriptome in the natural and agronomically important host species of TYLCSV, Solanum lycopersicum. Tomato plants accumulating high levels of Rep130 were generated and proved to be resistant to TYLCSV. Using an in vitro assay, we showed that plant‐expressed Rep130 also retains the catalytic activity of Rep, thus supporting the notion that this protein domain is fully functional. Interestingly, Rep130‐expressing tomatoes were characterized by an altered transcriptional profile resembling stress‐related responses. Notably, the serine‐type protease inhibitor (Ser‐PI) category was over‐represented among the 20 up‐regulated genes. The involvement of Rep130 in the alteration of host mRNA steady‐state levels was confirmed using a distinct set of virus‐resistant transgenic tomato plants expressing the same TYLCSV Rep130, but from a different, synthetic, gene. Eight genes were found to be up‐regulated in both types of transgenic tomato and two encoded Ser‐PIs. Four of these eight genes were also up‐regulated in TYLCSV‐infected wild‐type tomato plants. Implications with regard to the ability of this Rep domain to interfere with viral infections and to alter the host transcriptome are discussed.
Fluorofenidone inhibits nicotinamide adeninedinucleotide phosphate oxidase via PI3K/Akt pathway in the pathogenesis of renal interstitial fibrosis
Authors: Qin Jiao , Xie Yan‐yun , Huang Ling , Yuan Qiong‐jing , Mei Wen‐Juan , Yuan Xiang‐ning , Hu Gao‐yun , Cheng Guang‐jie , Tao Li‐jian , Peng Zhang‐zhe
Published: July 2013

Aim

Oxidative stress plays an important role in the progression of renal interstitial fibrosis. The nicotinamide adeninedinucleotide phosphate (NADPH) oxidase (Nox) family is considered one of the major sources of reactive oxygen species (ROS). In the present study, we investigated the inhibitory effects of a novel anti‐fibrotic agent, Fluorofenidone (AKF‐PD), upon Nox‐mediated oxidative stress and deposition of extracellular matrix (ECM) in the development of renalinterstitial fibrosis.

Methods

AKF‐PD was used to treat renal fibrosis in unilateral ureteral obstruction (UUO) obstructive nephropathy in rats. The expression of Nox homologues, p‐Akt, collagen I and III were detected by immunoblotting or immunohistochemistry. Levels of 8‐iso prostaglandin F2alpha (8‐Iso PGF2a) was measured by enzyme linked immunosorbent assay. In addition, ROS and the expression of collagen I (1a), Nox subunits and p‐Akt was measured in angiotensin (Ang) II‐stimulated rat proximal tubular epithelial (NRK‐52E) cells in culture.

Results

AKF‐PD treatment significantly attenuated tubulo‐interstitial injury, ECM deposition and oxidative stress in fibrotic rat kidneys. In addition, AKF‐PD inhibited the expression of ROS, Collagen I (1a), Nox2, p‐Akt in Ang II‐stimulated NRK‐52E cells.

Conclusion

AKF‐PD attenuates the progression of renal interstitial fibrosis partly by suppressing NADPH oxidase and ECM deposition via the PI3K/Akt signalling pathway, suggesting AKF‐PD is a potential novel therapeutic agent against renal fibrosis.
The role of adipocytes in the modulation of iron metabolism in obesity
Authors: Coimbra S. , Catarino C. , Santos‐Silva A.
Published: July 2013

A tight relationship between iron deficiency and obesity is known to exist. The chronic low‐grade inflammation that characterizes obesity enhances hepcidin production, the principal regulator of iron availability. Adipose tissue is known to secret interleukin‐6 and leptin that triggers hepcidin production. It was found that adipose tissue also expresses hepcidin and hemojuvelin, a regulator of hepcidin production. These recent findings suggest that adipose tissue may have an important role in erythropoiesis particularly on obesity that is still poorly clarified. This paper discusses these findings and how they can modulate erythropoiesis.
Cloning, characterization and overexpression of a 14‐3‐3 ω protein from oil palm (Elaeis guineensis)
Authors: Nakkaew Alisa , Thitichai Natthaphatra , Nualkaew Sureeporn , Chotigeat Wilaiwan , Phongdara Amornrat
Published: July 2013

Plant 14‐3‐3 proteins are involved in signal transduction pathways of nitrogen and carbohydrate metabolism. An Eg14‐3‐3 ω gene was isolated from the mesocarp of oil palm. The 1055‐bp cDNA had an open reading frame of 774 bp that encoded for 258 amino acids, and the cDNA had 113‐bp and 195‐bp 5′‐ and 3′‐untranslated regions, respectively. The calculated molecular weight was 28.06 kDa, with a pI of 5.04. The palm 14‐3‐3 showed closest identity to 14‐3‐3 proteins of the omega group. The entire sequence of Eg14‐3‐3 ω showed 83% identity with 14‐3‐3 protein isoform 16R from Solanum tuberosum. Phylogenetic analysis showed that the Eg14‐3‐3 isoform was within the omega (ω) subgroup and, thus, was designated Eg14‐3‐3 ω. The Eg14‐3‐3 ω expression patterns were strong in the mesocarp as compared to the root. When Eg14‐3‐3 ω cDNA was overexpressed in transgenic calli, there was higher accumulation of oil in the transgenic calli than in the controls. Therefore, Eg14‐3‐3 ω has potential for applications in the breeding of oil palms in the future.
Neutral pH and copper ions promote eumelanogenesis after the dopachrome stage
Authors: Ito Shosuke , Suzuki Natsumi , Takebayashi Shiori , Commo Stéphane , Wakamatsu Kazumasa
Published: July 2013

The diversity of pigmentation in the skin, hair, and eyes of humans has been largely attributed to the diversity of pH in melanosomes with acidic pH being proposed to suppress melanin production. Tyrosinase has an optimum pH of 7.4 and its activity is suppressed greatly at lower pH values. The first step of eumelanogenesis is the oxidation of tyrosine to dopachrome (DC) via dopaquinone. However, how eumelanogenesis is controlled by pH beyond this stage is not known. In this study, we examined the effects of pH (5.3–7.3) on the conversion of DC to 5,6‐dihydroxyindole (DHI) and 5,6‐dihydroxyindole‐2‐carboxylic acid (DHICA) and the subsequent oxidation of DHI and DHICA to form eumelanin. The effects of Cu2+ ions on those reactions were also compared. The results indicate that an acidic pH greatly suppresses the late stages of eumelanogenesis and that Cu2+ ions accelerate the conversion of DC to DHICA and its subsequent oxidation.
Startle effects on saccadic responses to emotional target stimuli
Authors: Deuter Christian E. , Schilling Thomas M. , Kuehl Linn K. , Blumenthal Terry D. , Schachinger Hartmut
Published: July 2013

Startle stimuli elicit various physiological and cognitive responses. This study investigated whether acoustic startle stimuli affect saccadic reactions in an emotional pro‐ or antisaccade task. Startle probes were presented either 500 ms before or simultaneous with an imperative stimulus that indicated whether a saccade towards or away from positive, neutral, or negative peripheral target pictures had to be performed. Valence interacted with saccade direction according to an approach‐avoidance pattern of gaze behavior, with delayed prosaccades to negative targets and antisaccades away from positive targets. Acoustic startle stimuli preceding the presentation of peripheral target pictures speeded up the initiation saccades, irrespective of stimulus valence. Results indicate a speeding of cognitive‐motor processing by preceding startle stimuli.
Maternal Social Coaching Quality Interrupts the Development of Relational Aggression During Early Childhood
Authors: Werner Nicole E. , Eaton Ashley D. , Lyle Kelsey , Tseng Heidi , Holst Brooke
Published: July 2013

Previous research has shown that parents of socially competent young children provide them with elaborative, explicit, appropriate, and emotion‐laden advice about peer interactions. The current study analyzed mothers' conversations with preschoolers (N = 175; 52 percent female; M age = 52 months, SD = 7 months) about peer conflicts involving relational aggression. Conversations were coded for maternal elaboration, emotion references, and discussion of norm violations. Information about relational and physical aggression was collected from teachers at two assessments approximately 12 months apart for a subsample of 136 children. Regression analyses, controlling for physical aggression, showed that average and high levels of effective coaching operated as a protective factor against stable high levels of relational aggression. Theoretical and practical implications for our understanding of the early development of relational aggression are discussed.
The Influence of Initiative Signature‐Gathering Campaigns on Political Participation
Authors: Boehmke Frederick J. , Alvarez R. Michael
Published: July 2013

Objective

This article studies the effect of initiative signature‐gathering campaigns on political participation within a state.

Methods

Using data on signatures gathered for eight initiatives and four different elections, we conduct grouped logit regression to test whether counties that are subject to more intense signature‐gathering campaigns, measured by the number of signatures gathered per capita, experience greater levels of turnout and ballot roll‐off in the subsequent election.

Results

Our analysis provides evidence that the intensity of signature‐gathering campaigns has a moderate effect on both of these measures of political participation.

Conclusion

Initiative campaigns influence turnout not just at the state level, but variation in campaigns leads to differences within states as well.
Cellular Uptake and Intracellular Cargo Release From Dextran Based Nanogel Drug Carriers
Authors: Carme Coll Ferrer M. , Sobolewski Peter , Composto Russell J. , Eckmann David M.
Published: July 2013

Nanogels (NG) hold great promise as a drug delivery platform. In this work, we examine the potential of lysozyme-dextran nanogels (LDNG) as drug carriers in vitro using two cell lines: a model target tissue, human umbilical cord vein endothelial cells (HUVEC) and a model of the mononuclear phagocyte system (phorbol 12-myristate 13-acetate (PMA)-stimulated THP-1 cells). The LDNG (∼100 nm) were prepared with rhodamine-label dextran (LRDNG) via Maillard reaction followed by heat-gelation reaction and were loaded with a fluorescent probe, 5-hexadecanoylaminofluorescein (HAF), as a mock drug. Epifluorescence microscopy confirmed rapid uptake of LRDNG by HUVEC. Although LysoTracker Green staining indicated a lysosomal fate for LRDNG, the mock drug cargo (HAF) diffused extensively inside the cell within 15 min. Flow cytometry and confocal microscopy indicated slow uptake of LRDNG in PMA-stimulated THP-1 cells, with only 41% of cells containing LRDNG after 24 h exposure. Finally, 24 h exposure to LRDNG did not affect the viability of either cell type at the dose studied (20 μg/ml). At a higher dose (200 μg/ml), LRDNG resulted in a marked loss of viability of HUVEC and THP-1, measuring 30% and 38%, respectively. Collectively, our results demonstrate the great potential of LRDNG as a drug delivery platform, combining simple production, rapid uptake and cargo release in target cells with “stealth” properties and low cytotoxicity.
Pressure Drop and Void Fraction in Steam-Water Two-Phase Flow at High Pressure
Authors: Liu Wei , Tamai Hidesada , Takase Kazuyuki
Published: July 2013

For a steam generator (SG) in a commercialized sodium-cooled fast breeder reactor (FBR), flow instability in the water side is one of the most important items needing research. As the first step of this research, thermal-hydraulic experiments using water as the test fluid were performed under high pressure conditions at the Japan Atomic Energy Agency (JAEA) by using a circular tube. Void fraction, pressure drop, and heat transfer coefficient data were obtained under 15, 17, and 18 MPa. This paper discusses the steam-water pressure drop and void fraction. Using the obtained data, we evaluated existing correlations for void fraction and two-phase flow multipliers under high pressure. As a result, the drift flux model implemented in the TRAC-BF1 code was confirmed to suitably predict the void fraction well under the present high pressure conditions. For the two-phase flow multiplier, the Chisholm correlation and the homogeneous model were confirmed to be the best under the present high-pressure conditions.
Enhanced Thermographic Detection of Skin Cancer Through Combining Laser Scanning and Biodegradable Nanoparticles
Authors: Jin Chao , He Zhi-Zhu , Zhang Jie , Yang Xue-Yao , Liu Jing
Published: July 2013

Through introducing biodegradable magnesium nanoparticles (Mg-NPs) with excellent property in absorbing laser photon, this paper is dedicated to present a laser scanning based thermogaphic strategy for detecting the skin cancer. It aims at selectively enhancing the thermal responses of the target regions so as to distinguish the tumor from the normal tissues on the infrared images. The carried out three-dimensional simulations and conceptual experiments quantitatively demonstrated the feasibility of the present method in improving the sensitivity and targeting-ability (i.e., specificity) of the thermography. Further parametric studies on the thermal enhanced effects such as by varying the parameters of laser beam (i.e., laser power, action time, and moving frequency) and Mg-NPs (i.e., nanoparticle concentration) disclose more quantitative mechanisms for achieving a better output of the diagnosis. The results indicate the following facts: (1) The parameters could be selected to significantly improve the sensitivity of the thermal detection, such that the maximum temperature difference could even reach 2.31 °C; (2) for safety concern to human body, the default parameter setting (P = 1 W, Δt = 40 ms, f = 1 Hz, n = 0.02 mg/ml) can be a good choice and enhanced results can thus be easily detected; and (3) with the unique biodegradable merits, the Mg-NPs can be considered as an extremely useful agent for enhancing thermogaphy in identifying the early stage tumor.
Calibration of a Quasi-Adiabatic Magneto-Thermal Calorimeter Used to Characterize Magnetic Nanoparticle Heating
Authors: Attaluri Anilchandra , Nusbaum Charlie , Wabler Michele , Ivkov Robert
Published: July 2013

To assess and validate temperature measurement and data analysis techniques for a quasi-adiabatic calorimeter used to measure amplitude-dependent loss power of magnetic nanoparticles exposed to an alternating magnetic field (AMF) at radiofrequencies (160 ± 5 kHz). The data collected and methods developed were used to measure the specific loss power (SLP) for two magnetic iron oxide nanoparticles (IONPs) suspensions, developed for magnetic nanoparticle hyperthermia. Calibration was performed by comparing measured against calculated values of specific absorption rate (SAR) of a copper wire subjected to AMF. Rate of temperature rise from induced eddy currents was measured (n = 4) for a copper wire of radius 0.99 mm and length of 3.38 mm in an AMF at amplitudes (H) of 16, 20, 24, and 28 kA/m. The AMF was generated by applying an alternating current using an 80-kW induction power supply to a capacitance network containing a 13.5-cm vertical solenoid that held the calorimeter. Samples were taped to an optical fiber temperature probe and inserted into a standard (polystyrene, 5 ml) test tube which was suspended in the calorimeter. The sample was subjected to the AMF for 30 s or until the temperature of the sample, increased by 30 °C, recorded at 0.3-s intervals. The SAR of the sample was normalized by H2f1/2, averaged, and compared to theoretical values. Iron (Fe) normalized SLPs of two IONPs (JHU-MION and bionized-nanoferrite (BNF) particles (Micromod Partikeltechnologie, GmbH)) in aqueous suspension were measured in the same setup. We report experimental SAR values for the copper of 2.4 ± 0.1, 4.3 ± 0.2, 6.2 ± 0.1, and 8.5 ± 0.1 W/g compared to theoretical values 3.1 ± 0.1, 4.5 ± 0.2, 6.5 ± 0.1, and 9.2 ± 0.2 W/g at AMF amplitudes of 16 ± 0.1, 20 ± 0.2, 24 ± 0.1, and 28 ± 0.1 kA/m, respectively. Normalized experimental data followed a linear trend approximately parallel to theoretical values with an R2-value of 0.99. The measured SLPs of the JHU particles are higher than BNF particles within the tested AMF amplitude range of 15 kA/m to 45 kA/m. We demonstrated that copper can be used to calibrate magneto-thermal calorimetric systems used for SLP measurements of magnetic nanoparticles for a field range of 15–28 kA/m at 160 ± 5 kHz. We also note that the electrical conductivity, diameter of copper sample and accuracy, and response time of thermometry constrain calibration to lower amplitudes, highlighting the need for development of standard reference materials for such applications.
Detonation Nanodiamonds and Carbon Nanotubes as Reinforcements in Epoxy Composites—A Comparative Study
Authors: Roy Sagar , Mitra Kabir , Desai Chintal , Petrova Roumiana , Mitra Somenath
Published: July 2013

A comparative study between detonation nanodiamonds (DNDs) and carbon nanotubes (CNTs) as low concentration additives to epoxy composites is presented. The dispersibility of the different nanocarbons in resin solutions leading to uniform composite formation is also discussed. Significant increase in glass transition temperature was observed, which were 37 °C and 17 °C for DNDs and CNTs, respectively. Unlike the pure epoxy, the fractured surface of both composites showed resistance to crack propagation. Tensile properties of DNDs and CNTs composites showed enhancement of 6.4% and 2.9%, respectively. The nanocomposites also showed an increase in microhardness by 41% for DNDs and 12% for CNTs, and a decrease in electrical resistivity by 2 orders of magnitude, with the CNTs showing lower resistivity. In general, the DNDs were found to be quite effective and at the reported concentrations between 0.1% and 0.5% and showed superior enhancement compared to the CNTs.
A Novel Approach for the Prediction of Dynamic Features of Air Release and Absorption in Hydraulic Oils
Authors: Zhou Junjie , Vacca Andrea , Manhartsgruber Bernhard
Published: July 2013

An accurate evaluation of fluid density and bulk modulus is essential for predicting the operation of hydraulic systems and components. Among the models reported in literature to describe fluid properties, of particular success in the fluid power field are the continuous methods that assume the gas and liquid phases to be the same fluid. However, these models are typically based on steady-state equilibrium relations and, consequently, they fail in correctly predicting the dynamic features of both air release and air absorption processes. These phenomena are particularly important for machines based on open-system hydraulic circuits, in which a significant part of the system can operate with a fluid below the saturation pressure. This paper addresses this topic by proposing a novel approach suitable to describe the dynamic features of both vaporization and air release processes. The approach is based on simplified transport equations to evaluate the phase change rate and the air release/dissolve rate. These transport equation are obtained from the well-known theoretical “full cavitation model” previously developed for computational fluid dynamics (CFD). Specific tests were performed to validate particularly as concerns the air release/absorption features using a standard ISO32 mineral oil. Comparisons between model predictions and measurement data are presented for compression/decompression cycles as concerns transient fluid density and bulk modulus, and a good agreement between the two trends is found, showing the potentials of the new approach to describe typical cavitation phenomena in hydraulic systems.
SU‐C‐105‐03: Progress Toward the Development of a Deformable Anthropomorphic 3D Dosimetric Phantom
Authors: Juang T , Das S , Adamovics J , Oldham M
Published: July 2013

Purpose: Previous work has demonstrated that Presage‐Def, a deformable, polyurethane‐based radiochromic 3D dosimeter, has strong potential for validating deformable image registration algorithms by tracking optically measured radiation patterns from the deformed shape to the non‐deformed shape. Here we present recent investigations into the efficacy of variant Presage‐Def formulations with a range of elastic properties in terms of increased dose sensitivity and post‐irradiation stability. Methods: Eleven formulations of Presage‐Def were created from combinations of 3 elastic polyurethane matrices (Shore Hardness 10–20A and 30A) and 7 leuco dyes. Dose sensitivity for each formulation was determined by irradiating cuvettes from 0–8Gy and measuring change in optical density at 633nm. Sensitivity readings were tracked over time to determine stability. Complementary to the small volume studies, a 15.7cm diameter cylindrical Presage‐Def deformable dosimeter was created incorporating two air cavities (4.0cm diameter) and a rigid high‐Z spine‐mimic insert (2.8cm diameter). The dosimeter was subjected to bilateral compression to demonstrate complex, non‐uniform deformation, and also irradiated with an 8.6cm×7.4cm field and imaged with optical‐CT to investigate feasibility of optical‐CT dose readout in a heterogeneous phantom. Results: Dose sensitivities ranged from 0.0004‐0.0071ΔOD/(Gy*cm) versus 0.0032ΔOD/(Gy*cm) in the original formulation. Highest sensitivity and stability were both seen in formulation PD1 (#2 polyurethane, leuco dye 1‐napthal‐N,N‐diethylamine LMG), which retained 98.6% initial sensitivity over 4 hours whereas the original dropped to 90.6% after 1 hour. X‐ray CT images of the prototype phantom with and without compression demonstrated non‐uniform deformation of Presage‐Def and air cavity geometry while the rigid region remained constant. The irradiated field was clearly visible in 3D dose distributions obtained by optical‐CT. Conclusion: A Presage‐Def formulation was identified from 10 variants with improved dosimetric characteristics. Optical‐CT dose readout was achieved in the prototype phantom, demonstrating feasibility of 3D dosimetry in a large deformable dosimeter containing air and rigid bone‐mimic inserts. NIH R01CA100835
SU‐C‐137‐02: A Failure Mode and Effects Analysis for Tandem and Ring Brachytherapy
Authors: Stern R , Mayadev J , Harse R , Lentz S , Mathai M , Boddu S , Kern M , Courquin J , Dieterich S
Published: July 2013

Purpose: To improve the quality and safety of our tandem and ring brachytherapy practice and procedure, we performed a treatment process analysis following the failure modes and effects analysis (FMEA) method. Methods: The FMEA analysis was performed by a multi‐disciplinary team. The treatment process was divided into six sub‐processes and a flowchart was created for each. For each action point within a sub‐process, failure modes (FM) were collected. A scoring guideline was developed based on published FMEA studies and adapted for brachytherapy at UC Davis. Scores were assigned through team consensus. FM were ranked according to overall score as well as severity score alone. FM ranking above 5% of the highest risk priority number (RPN) score, representing half the FM, were selected for in‐depth analysis. The efficiency of each existing QA process to detect FM and the number of QA tests in place for each FM were analyzed. Results: 96 FM were scored for severity, occurrence and detectability. RPN scores ranged from 1 to 192. Of the 12 highest ranking FM with RPN scores > 80, half had severity scores of 8 or 9, with no mode having severity of 10. Of the top 48 FM, the originating process steps were insertion (10%), simulation (33%), planning (29%) and delivery (25%). Checklist efficiency and comprehensiveness including physician, nurse and physics checks, ranged from 25% to 79% in preventing the top 48 FM ranked by RPN. Physics machine QA was inefficient in detecting the top ranked FM (<5%), but was very efficient to catch FM with severity >7 (15%). Conclusion: This is the first reported FMEA process in gynecologic brachytherapy. We were able to identify failure modes that could potentially and severely impact the patient's treatment. We continue to adjust our QA program based on the results of our FMEA analysis.
SU‐C‐137‐03: Inter‐Machine Comparison of Volumetric Intensity Modulated Arc Therapy (VIMAT) Delivery Based On Trajectory Log Analysis
Authors: Chan Kenny SK , Lau Taskie SK , Lee Louis KY , Kam Michael KM , Yu Brian KH , Chan Anthony TC
Published: July 2013

Purpose: To compare the machine performance including the MU delivery, Gantry Angle trajectory and Multi‐Leaf Collimator (MLC) leaf motion of RapidArc delivery based on trajectory log analysis. Method: Five RapidArc cases were selected for the study. Each case was delivered at Varian Unique, iX23 and TrueBeam Linear Accelerator (LINAC) system. The system log files were obtained after their corresponding field measurements. During measurements, an independent inclinometer was mounted on the machine to verify the gantry rotation dynamically. In‐house software was developed to extract and reconstruct the data into trajectory plots for comparison. Another in‐house software was used to compare the Integrated Transient Fluence Map (ITFM) to check the accuracy of MLC leaf position and dose index. Result: For all selected cases delivered in the Unique, iX23 and TrueBeam system, the typical deviations of gantry angle and MU were found to be (0.6+/−0.1°, 0.0+/−0.2 MU), (0.4+/−0.1°, 0.0+/−0.1 MU) and (0.0+/−0.1°, 0.0+/−0.0 MU) respectively. Their angular trajectories of the independent inclinometer agreed well with the digital readout of gantry angle. The trajectory plots of dose index against gantry angle were in a good agreement with their plans. The reconstructed ITFM showed no observable difference when compared with the planned one, and their typical correlation coefficients were very close to unity. This indicated accurate MU delivery and MLC leaf position during the delivery. The higher accuracy of RapidArc delivery was achieved by the digital control system (TrueBeam). Conclusion: The analysis of trajectory log is presented in the form of trajectory plot and ITFM, which are the powerful tools to check the machine performance of RapidArc delivery. For the inter‐machine comparison, the integrated and digital control LINAC (TrueBeam) delivers the RapidArc treatment more precisely compared to its counterparts (iX23 and Unique).
SU‐C‐137‐07: A Comprehensive Investigation of Dosimetric Uncertainties in Junction Region of Breast Superclavicular and Tangential Fields
Authors: Han T , Tailor R , Melancon A , Howell R , Mourtada F , Salehpour M
Published: July 2013

Purpose: The dosimetric uncertainties in junction regions are one of the major concerns in treatments involving field‐junctions, especially tangential breast and supraclavicular fossa radiotherapy fields. The uncertainties are linked to dose calculation algorithms, set‐up, jaw/couch position uncertainties, and choice of mono‐versus multiple‐isocentric techniques. The purpose of this study was to comprehensively investigate the effects of these common variants to understand dose non‐uniformity in junction regions. Methods: To understand the effects from dose algorithms and setup uncertainties, a typical tangential/superclav field combination was planned to an anthropomorphic Rando phantom using the Pinnacle‐9.0 treatment‐planning system and delivered 6 times on different days. 3 films (EBT2) were placed in coronal plane across the field‐junction. Pinnacle CCC‐9.0, Eclipse AAA‐10.0 and AcurosXB‐11.0 were used for calculation. To understand the effects from the linac's mechanical uncertainties, junctions were generated with two open fields using both mono‐isocentric and two‐isocentric techniques. Junction‐fields were delivered on 6 different linacs to EBT2 in a solid water phantom. Impacts of couch position accuracy/reproducibility, and jaw‐position accuracy/reproducibility were analyzed. Results: In general, the major contributor to the dose uncertainties in junction region is the jaw position accuracy. Among the 6 linacs investigated in this study, the uncertainty of jaw position can be up to ±3mm, subsequently leading to about 25% hot/cold of dose distributions in junction region. The impact of mono versus two‐isocentric technique is relatively small (within 5%), because the patient‐couch positioning was found to have good accuracy and reproducibility. All dose algorithms are found to be in close mutual agreement (within 5%) for most regions of the junction. Jaw positioning has good short‐term reproducibility, but might change over months. Conclusion: Dose inhomogeneities at field‐junctions are more strongly dependent on jaw‐positioning accuracy compared to setup, dose‐calculation, and other source of errors.Impact:Guidance to improve dose uniformity in field‐junction. This work was funded by National Institutes of Health grants 2R44CA105806‐02, CA010953
SU‐C‐500‐04: Three‐Dimensional Energy Fluence Estimates for Future Treatment Planning Systems
Authors: Titt U , Mirkovic D , Mohan R
Published: July 2013

Purpose: Innovative proton treatment planning necessitates taking variations in the relative biological effectiveness (RBE) of the particles into account. To calculate variable RBE, knowledge of the dose averaged linear energy transfer (LET‐d) is of essence. Furthermore, LET‐d is dependent on the energy fluence spectrum at the location of interest. This study was designed to provide three dimensional energy fluence spectra for the scanned proton beams at the Proton Therapy Center used by the M. D. Anderson Cancer Center. Methods: A water phantom containing 21,000 cells, arranged concentric around the beam axis, was designed and implemented in the Monte Carlo code MCNPX. Each cell scores the fluence spectrum of protons as a function of radius from central axis and as a function of depth. The energy spectrum is scored in 1 MeV resolution from 0 to 230 MeV, the spatial resolution in the phantom is 1 mm in radius and 1 mm in depth. Each simulation provides a total number of 4.83e6 values for the analysis. Results: All clinically used scanned proton beams have been simulated and the 3‐dimensional energy fluence in water has been scored. From this data the determination of 3‐d doses, as well as 3‐d LET‐d spectra is straight forward by application of stopping power values, which are provided by the Monte Carlo simulation code. Current efforts focus on the development of a method to scale energy fluence in water to energy fluence in arbitrary materials by use of stopping power ratios. Conclusion: A complete library of 3‐dimensional energy fluence values for protons in water has been computed. Further efforts are made to estimate the energy fluence in arbitrary media in patients. NCI grant P01CA021239
SU‐C‐WAB‐01: Computerized Production of Statistical Clinical Target Volume Models in Prostate Cancer Radiation Treatment Planning
Authors: matsushita N , Arimura H , Nakamura K , Kagami Y , Shioyama Y , Nakamura Y , Honda H , Hirata H
Published: July 2013

Purpose: Inter‐and intra‐observer variability of clinical target volume (CTV) contours for prostate cancer is a critical issue in radiation treatment planning. Automated contouring based on statistical CTV models could be one of possible approaches for reducing the variability. Therefore, the purpose of our study is to develop a computerized method for producing the statistical CTV models to be used as CTV templates for automated contouring in prostate cancer radiation treatment planning. Methods: Eighteen, seventeen and sixteen radiation oncologists belonging to different facilities delineated CTV contours for low‐, intermediate‐and high‐risk prostate cancers, respectively. The low‐risk, intermediate‐risk, and high‐risk CTVs include only a prostate, a prostate plus a 1‐cm seminal vesicle base, and a prostate plus 2‐cm seminal vesicle, respectively. The statistical CTV models for the three risk types were derived based on a principal component analysis (PCA), which statistically took into account the inter‐observer variability. CTV regions were triangulated by using a marching cubes method. For matching the number of points on the surfaces of all CTV regions, the number of vertices on each CTV region was reduced to 1,000 with a quadric error metrics. All CTV regions were registered with a reference CTV by using an iterative closest point algorithm for calculation of a covariance matrix to be employed for the PCA‐based CTV modeling. Results: CTV models of three risk types were produced, which consisted of a mean CTV and PCA coefficients multiplied by eigenvectors, i.e., eigen‐CTV image. Average Euclidean distances between corresponding points of a mean CTV and the other CTVs for three risk types were 2.05 mm, 3.64 mm, 2.55 mm, respectively. Conclusion: The proposed method could provide probabilistic CTV models to be used as CTV templates in delineating CTV contours.
SU‐C‐WAB‐02: Voxel‐By‐Voxel Validation of Deformable Image Registration Between External Beam and Intracavitary Brachytherapy Images Using Artificial CT Images Created From Patient Populations
Authors: Yu Z , Yang J , Dong L , Zhang Y , Court L , Mourtada F , Tucker S , Klopp A , Eifel P , Kudchadker R
Published: July 2013

Purpose: This study aims to develop a novel method for volumetric validation of deformable image registration. The developed method was used to determine the accuracy in bladder and rectum registration between external beam radiation therapy (EBRT) and intracavitary brachytherapy (ICBT) CT images. Methods: Twenty patients treated for intact cervical cancer were used for this study. All patients had EBRT CT (CT1) and ICBT CT (CT2). A single patient from the population was chosen as the reference patient. CT1 from the remaining 19 patients were then deformed to the reference CT1 (CT1_ref). The mean deformation and principle components of deformation fields were determined and used to simulate a known interpatient deformation. For each patient, CT1 was also deformed to CT2 to quantify deformation within each patient. The mean deformation and principal components of those fields were used to create a known intrapatient deformation field. The inter‐patient deformation field was applied to the CT1_ref and inter‐and intra‐patient deformation field was applied to CT2_ref to create artificial CT1 and CT2, respectively. Our DIR algorithm was tested by deforming artificial CT1 to CT2. Errors in DIR were determined by taking the difference between calculated and the known fields. Results: We have successfully created artificial CT images that were realistic, represented our patient population, and had realistic deformations between EBRT and ICBT. The mean errors in registration for the bladder were 0.98 mm, 1.09 mm, −0.17 mm, and 3.47 mm in the RL, AP, SI directions, and total magnitude, respectively. For the rectum, the mean errors in registration were 0.02 mm, −0.86 mm, −0.37 mm, and 2.74 mm in the RL, AP, SI directions, and total magnitude, respectively. Conclusion: We have developed a method to validate any DIR algorithm for any particular patient population and organs of interest.
SU‐C‐WAB‐05: Automatic Bladder Segmentation On CBCT for Plan Selection During Cervical ART
Authors: van de Schoot A , Schooneveldt G , Wognum S , Hoogeman M , Chai X , Stalpers L , Rasch C , Bel A
Published: July 2013

Purpose: Adaptive radiotherapy (ART) with a plan‐of‐the‐day (PotD) approach is suitable for cervical cancer patients, due to the highly mobile cervix‐uterus. PotD selection is not obvious given the poor soft‐tissue contrast of CBCT and bladder volume can be used as indirect measure of cervix‐uterus position. The aim of this study is to automatically segment the bladder on CBCT, in order to automate plan selection. Methods: Four cervical cancer patients, treated in prone position on a bellyboard, with planning‐CT and in total 25 CBCT (Elekta) images were included. A patient‐specific statistical training set was developed to guide automatic bladder segmentation. This training set was built from full and empty bladder contour interpolations and principal component analysis was applied to model deformation patterns. Bladder segmentation on CBCT was obtained by consistently deforming the planning contour using the training set while maximizing the cross‐correlation between directional gradient fields on both images. The segmentations could be improved by manually adding correction points. The training set could be expanded with the segmentation. The segmentations, acquired with expanded (ETs) or non‐expanded training set (NETs), were validated with manual delineations by volume comparison and contour‐to‐contour distance. The volume range between empty and full bladder was divided into three equally‐sized subranges, representing PotDs. The segmented and manually obtained volumes were classified into subranges, representing selected PotD. Results: Average volume correlations between segmentation and manual delineation were 0.84 (NETs) and 0.89 (ETs) and the mean absolute contour‐to‐contour distance was 0.59cm (NETs) and 1.21cm (ETs) using on average 2.48[0–4] (NETs) and 2.80[0–6] (ETs) correction points per segmentation. PotD selection using manual and segmented volumes (NETs and ETs) was equal in 92%. Conclusion: Bladder volumes of cervical cancer patients can be detected automatically on CBCT using a patient‐specific training set. The accuracy is sufficient for plan selection during cervical ART.