bluuebunny/crossref_metadata_2025_split huggingface dataset:
A national survey of the availability of intensity-modulated radiation therapy and stereotactic radiosurgery in Canada
Authors: AlDuhaiby Eman Z , Breen Stephen , Bissonnette Jean-Pierre , Sharpe Michael , Mayhew Linda , Tyldesley Scott , Wilke Derek R , Hodgson David C 
Published: February 2012

Abstract

Background
The timely and appropriate adoption of new radiation therapy (RT) technologies is a challenge both in terms of providing of optimal patient care and managing health care resources. Relatively little is known regarding the rate at which new RT technologies are adopted in different jurisdictions, and the barriers to implementation of these technologies.

Methods
Surveys were sent to all radiation oncology department heads in Canada regarding the availability of RT equipment from 2006 to 2010. Data were collected concerning the availability and use of Intensity Modulated Radiation Therapy (IMRT) and stereotactic radiosurgery (SRS), and the obstacles to implementation of these technologies.

Results
IMRT was available in 37% of responding centers in 2006, increasing to 87% in 2010. In 2010, 72% of centers reported that IMRT was available for all patients who might benefit, and 37% indicated that they used IMRT for "virtually all" head and neck patients. SRS availability increased from 26% in 2006 to 42.5% in 2010. Eighty-two percent of centers reported that patients had access to SRS either directly or by referral. The main barriers for IMRT implementation included the need to train or hire treatment planning staff, whereas barriers to SRS implementation mostly included the need to purchase and/or upgrade existing planning software and equipment.

Conclusions
The survey showed a growing adoption of IMRT and SRS in Canada, although the latter was available in less than half of responding centers. Barriers to implementation differed for IMRT compared to SRS. Enhancing human resources is an important consideration in the implementation of new RT technologies, due to the multidisciplinary nature of the planning and treatment process.
Cardiac tamponade from a giant thymoma: case report
Authors: Fazlıoğulları Osman , Atalan Nazan , Gürer Onur , Akgün Serdar , Arsan Sinan 
Published: February 2012

Abstract
Thymoma, the most common neoplasm of the anterior mediastinum especially in adults, accounts for 20-25% of all mediastinal tumors and 50% of anterior mediastinal masses. These tumors are routinely asymptomatic for prolonged periods of time. Pericardial tamponade is a very rare initial manifestation of a thymoma. This report presents a patient who had hemorrhagic pericardial tamponade that likely resulted from the largest symptomatic mixed type (type AB) thymoma described in the literature.
Enumerating metabolic pathways for the production of heterologous target chemicals in chassis organisms
Authors: Carbonell Pablo , Fichera Davide , Pandit Shashi B , Faulon Jean-Loup 
Published: February 2012

Abstract

Background
We consider the possibility of engineering metabolic pathways in a chassis organism in order to synthesize novel target compounds that are heterologous to the chassis. For this purpose, we model metabolic networks through hypergraphs where reactions are represented by hyperarcs. Each hyperarc represents an enzyme-catalyzed reaction that transforms set of substrates compounds into product compounds. We follow a retrosynthetic approach in order to search in the metabolic space (hypergraphs) for pathways (hyperpaths) linking the target compounds to a source set of compounds.

Results
To select the best pathways to engineer, we have developed an objective function that computes the cost of inserting a heterologous pathway in a given chassis organism. In order to find minimum-cost pathways, we propose in this paper two methods based on steady state analysis and network topology that are to the best of our knowledge, the first to enumerate all possible heterologous pathways linking a target compounds to a source set of compounds. In the context of metabolic engineering, the source set is composed of all naturally produced chassis compounds (endogenuous chassis metabolites) and the target set can be any compound of the chemical space. We also provide an algorithm for identifying precursors which can be supplied to the growth media in order to increase the number of ways to synthesize specific target compounds.

Conclusions
We find the topological approach to be faster by several orders of magnitude than the steady state approach. Yet both methods are generally scalable in time with the number of pathways in the metabolic network. Therefore this work provides a powerful tool for pathway enumeration with direct application to biosynthetic pathway design.
High rates of de novo 15q11q13 inversions in human spermatozoa
Authors: Molina Òscar , Anton Ester , Vidal Francesca , Blanco Joan 
Published: February 2012

Abstract
Low-Copy Repeats predispose the 15q11-q13 region to non-allelic homologous recombination. We have already demonstrated that a significant percentage of Prader-Willi syndrome (PWS) fathers have an increased susceptibility to generate 15q11q13 deletions in spermatozoa, suggesting the participation of intrachromatid exchanges. This work has been focused on assessing the incidence of de novo 15q11q13 inversions in spermatozoa of control donors and PWS fathers in order to determine the basal rates of inversions and to confirm the intrachromatid mechanism as the main cause of 15q11q13 anomalies.
Semen samples from 10 control donors and 16 PWS fathers were processed and analyzed by triple-color FISH. Three differentially labeled BAC-clones were used: one proximal and two distal of the 15q11-q13 region. Signal associations allowed the discrimination between normal and inverted haplotypes, which were confirmed by laser-scanning confocal microscopy.
Two types of inversions were detected which correspond to the segments involved in Class I and II PWS deletions. No significant differences were observed in the mean frequencies of inversions between controls and PWS fathers (3.59% ± 0.46 and 9.51% ± 0.87 vs 3.06% ± 0.33 and 10.07% ± 0.74). Individual comparisons showed significant increases of inversions in four PWS fathers (P < 0.05) previously reported as patients with increases of 15q11q13 deletions.
Results suggest that the incidence of heterozygous inversion carriers in the general population could reach significant values. This situation could have important implications, as they have been described as predisposing haplotypes for genomic disorders. As a whole, results confirm the high instability of the 15q11-q13 region, which is prone to different types of de novo reorganizations by intrachromatid NAHR.
Established and Emerging Markers of Kidney Function
Authors: Ferguson Michael A , Waikar Sushrut S 
Published: February 2012

AbstractBACKGROUNDThe kidney performs a multitude of essential functions to maintain homeostasis. In clinical medicine, glomerular filtration rate (GFR) provides the best index of overall kidney function, and proteinuria adds additional information on renal and nonrenal prognosis. Several novel biomarkers of kidney injury and function are under investigation.CONTENTPlasma creatinine concentration is the most widely used measure for estimation of GFR. Plasma cystatin C and β-trace protein may eventually prove to be superior to creatinine. GFR may be measured directly by use of exogenous filtration markers, although their role is primarily limited to the research setting. Real-time, noninvasive measurement of GFR by using fluorescently labeled markers may be available in the future. Novel biomarkers of tubular injury such as neutrophil gelatinase-associated lipocalin, kidney injury molecule-1, liver-type fatty acid binding protein, N-acetyl-β-(D)-glucosaminidase, and interleukin-18 may enable the early detection of acute kidney injury before or in the absence of a change in GFR.SUMMARYA variety of methods are available to assist clinicians in the assessment of kidney function and injury. Ongoing investigation will help determine the utility of several new markers and clarify their role in the care of patients with and at risk for kidney disease.
Radiolysis of C5-BTBP in cyclohexanone irradiated in the absence and presence of an aqueous phase
Authors: Fermvik Anna , Aneheim Emma , Grüner Bohumir , Hájková Zuzana , Kvicalová Magdaléna , Ekberg Christian 
Published: February 2012

Abstract
Spent nuclear fuel contains many highly radioactive species; hence solvents used in reprocessing will be subjected to radiolysis. In this study, solvents containing one of the BTBP molecules intended for the separation of trivalent actinides and lanthanides, the so called C5-BTBP, have been subjected to radiolysis and hydrolysis. We present here that this compound shows a dramatic decrease in both distribution ratios and separation factor when irradiated with higher doses up to 50 kGy; particularly in the presence of an aqueous phase. Furthermore, fast hydrolytic degradation is observed, which significantly contributes to the overall degree of decomposition. This is supported by speciation studies performed by HPLC and LC-MS methods. Proposed structures of the highest-yield degradation products are presented and they seem to confirm previously drawn structures for these products. From these studies it can be concluded that the presence of nitric acid or nitrate during irradiation leads to higher content of species containing keto groups.
The Effect of Simulated Ostracism on Physical Activity Behavior in Children
Authors: Barkley Jacob E. , Salvy Sarah-Jeanne , Roemmich James N. 
Published: February 2012

OBJECTIVES:To assess the effects of simulated ostracism on children’s physical activity behavior, time allocated to sedentary behavior, and liking of physical activity.METHODS:Nineteen children (11 boys, 8 girls; age 11.7 ± 1.3 years) completed 2 experimental sessions. During each session, children played a virtual ball-toss computer game (Cyberball). In one session, children played Cyberball and experienced ostracism; in the other session, they were exposed to the inclusion/control condition. The order of conditions was randomized. After playing Cyberball, children were taken to a gymnasium where they had free-choice access to physical and sedentary activities for 30 minutes. Children could participate in the activities, in any pattern they chose, for the entire period. Physical activity during the free-choice period was assessed via accelerometery and sedentary time via observation. Finally, children reported their liking for the activity session via a visual analog scale.RESULTS:Children accumulated 22% fewer (P &lt; .01) accelerometer counts and 41% more (P &lt; .04) minutes of sedentary activity in the ostracized condition (8.9e+4 ± 4.5e+4 counts, 11.1 ± 9.3 minutes) relative to the included condition (10.8e+4 ± 4.7e+4 counts, 7.9 ± 7.9 minutes). Liking (8.8 ± 1.5 cm included, 8.1 ± 1.9 cm ostracized) of the activity sessions was not significantly different (P &gt; .10) between conditions.CONCLUSIONS:Simulated ostracism elicits decreased subsequent physical activity participation in children. Ostracism may contribute to children’s lack of physical activity.
Prospective Analysis of Pulmonary Hypertension in Extremely Low Birth Weight Infants
Authors: Bhat Ramachandra , Salas Ariel A. , Foster Chris , Carlo Waldemar A. , Ambalavanan Namasivayam 
Published: February 2012

OBJECTIVES:Pulmonary hypertension is associated with bronchopulmonary dysplasia in extremely low birth weight (ELBW) infants and contributes to morbidity and mortality. The objective was to determine the prevalence of pulmonary hypertension among ELBW infants by screening echocardiography and evaluate subsequent outcomes.METHODS:All ELBW infants admitted to a regional perinatal center were evaluated for pulmonary hypertension with echocardiography at 4 weeks of age and subsequently if clinical signs suggestive of right-sided heart failure or severe lung disease were evident. Management was at discretion of the clinician, and infants were evaluated until discharge from the hospital or pre-discharge death occurred.RESULTS:One hundred forty-five ELBW infants (birth weight: 755 ± 144 g; median gestational age: 26 weeks [interquartile range: 24–27]) were screened from December 2008 to February 2011. Overall, 26 (17.9%) were diagnosed with pulmonary hypertension at any time during hospitalization (birth weight: 665 ± 140 g; median gestational age: 26 weeks [interquartile range: 24–27]): 9 (6.2%) by initial screening (early pulmonary hypertension) and 17 (11.7%) who were identified later (late pulmonary hypertension). Infants with pulmonary hypertension were more likely to receive oxygen treatment on day 28 compared with those without pulmonary hypertension (96% vs 75%, P &lt; .05). Of the 26 infants, 3 died (all in the late group because of cor pulmonale) before being discharged from the hospital.CONCLUSIONS:Pulmonary hypertension is relatively common, affecting at least 1 in 6 ELBW infants, and persists to discharge in most survivors. Routine screening of ELBW infants with echocardiography at 4 weeks of age identifies only one-third of the infants diagnosed with pulmonary hypertension. Further research is required to determine optimal detection and intervention strategies.
Calculation of migration rates of vacancies and divacancies in α-Iron using transition path sampling biased with a Lyapunov indicator
Authors: Picciani Massimiliano , Athènes Manuel , Marinica Mihai-Cosmin 
Published: February 2012

ABSTRACTPredicting the microstructural evolution of radiation damage in materials requires handling the physics of infrequent-events, in which several time scales are involved. The reactions rates characterizing these events are the main ingredient for simulating the kinetics of materials under irradiation over large time scales and high irradiation doses. We propose here an efficient, finite temperature method to compute reaction rate constants of thermally activated processes. The method consists of two steps. Firstly, rare reactive trajectories in phase-space are sampled using a transition path sampling (TPS) algorithm supplemented with a local Lyapunov bias favoring diverging trajectories. This enables the system to visit transition regions separating stable configurations more often, and thus enhances the probability of observing transitions between stable states during relatively short simulations. Secondly, reaction constants are estimated from the unbiased fraction of reactive trajectories, yielded by an appropriate statistical data analysis tool, the multistate Bennett acceptance ratio (MBAR) package. We apply our method to the calculation of reaction rates for vacancy and di-vacancy migration in α-Iron crystal, using an Embedded Atom Model potential, for temperatures ranging from 300 K to 800 K.
In situ XANES Study of Co2+ Ion Adsorption on Fe3O4 Nanoparticles in Supercritical Aqueous Fluids
Authors: Yan Hao , Mayanovic Robert A. , Demster Joseph , Anderson Alan J. 
Published: February 2012

ABSTRACTIn situ x-ray absorption spectroscopy (XAS) measurements were made on Fe3O4 nanoparticles in supercritical aqueous fluids to 500 °C in order to study their reactivity with Co2+ aqua ions and to investigate the structural properties of the reacted nanoparticles. The analyses of the x-ray absorption near edge structure (XANES) of XAS indicate that reactivity of Fe3O4 nanoparticles with Co2+ ions is minimal to 200 °C but becomes significant in the 250–500 °C temperature range. XANES and angular momentum projected density of states (l-DOS) calculations were carried out using the FEFF8.2 code and analyses were made using multi-peak fitting to determine the origin of the features exhibited in the spectra.
Copper (II) Phthalocyanine Based Field Effect Transistors as Total Dose Sensors for Determining Ionizing Radiation Dose
Authors: Raval Harshil N. , Rao V. Ramgopal 
Published: February 2012

ABSTRACTChanges in the material properties of copper (II) phthalocyanine (CuPc) thin-films were studied upon exposure to increasing dose of ionizing radiation using photoluminescence spectrum. We observe generation of new energy states below the band gap upon exposure to ionizing radiation. Organic electronic devices – CuPc based resistor and an organic field effect transistor (OFET) – are proposed in this work as total dose sensors for ionizing radiation. We observe an increase in the conductivity of CuPc thin-films with increasing dose of ionizing radiation. To overcome the possibility of changes/degradation in the electrical properties of CuPc thin-films upon interaction with various gases and moisture in the environment, a passivation layer of silicon nitride, deposited by hot-wire CVD process is proposed. Effect of ionizing radiation on the electrical properties of thin-films of CuPc has been studied. We observe a 170% increase in the resistance of the thin-film for a total of 50 Gy radiation dose using Cobalt-60 (60Co) radiation source. Moreover, significant changes in the electrical characteristics of an OFET, with CuPc as an organic semiconductor, have been observed with increasing doses of ionizing radiation. Experiments with an OFET (W/L = 19350 μm / 100 μm and tox = 150 nm) as a sensor resulted in a ∼100X change in the OFF current for a total of 50 Gy dose of ionizing radiation exhibiting a sensitivity of ∼1 nA/Gy. Moreover, implementing a reader circuit, shift in the threshold voltage of the OFET at 1e-7 A drain current displayed a sensitivity of 80 mV/Gy for a total of 50 Gy dose of ionizing radiation. CuPc based organic electronic devices have advantages as sensors because of their low-cost fabrication, large area coverage on flexible substrates, etc.
In situTEM Ion Irradiation and Atmospheric Heating of Cladding Materials
Authors: Hattar K. , Rajasekhara S. , Clark B.G. 
Published: February 2012

ABSTRACTOver the course of use, both in-service and during storage, fuel claddings for nuclear reactors undergo complex changes that can drastically change their material properties. Exposures to irradiation, temperature changes, and stresses, as well as contact with coolant, storage pool, and dry storage environments, may induce microstructural changes, such as formation of radiation defects, precipitate dissolution, and chemical segregation, that can ultimately result in failure of the cladding if pushed beyond its limit. In order to predict the performance of cladding in-service and during storage, understanding of the dominant processes related to these changes and their consequences is essential. In situ transmission electron microscopy (TEM) allows dynamic observation, at the nanoscale, of microstructural changes under a range of stimuli, making it an excellent tool for deepening our understanding of microstructural evolution in claddings. This proceeding presents details of the new in situ ion irradiation TEM and in situ gas cell TEM capabilities developed at Sandia National Laboratories. In addition, it will present the initial results from both systems investigating radiation tolerance of potential Generation IV cladding materials and understanding degradation mechanisms in Zr-based claddings of importance for dry storage.
Laser Trace Vaporization of Trace Explosive Materials
Authors: Papantonakis Michael , Furstenberg Robert , Kendziora Christopher A. , Nguyen Viet , Großer Jakob , McGill R. Andrew 
Published: February 2012

ABSTRACTThe low vapor pressure of many energetic materials presents a challenge for detection by non-contact methods. We address this limitation by illuminating energetic materials including TNT and RDX with infrared lasers tuned to strong molecular absorption bands to efficiently heat trace amounts present on substrates. This substantially increases their vapor signatures for direct detection, obviating the need to swab surfaces for solid particles or to collect headspace vapors for extended time periods. The instantaneously generated vapor produced by Laser Trace Vaporization (LTV) can be detected by any number of techniques which can accommodate vapor sampling or spectroscopic analysis. Currently the testbed for LTV incorporates a tunable quantum cascade laser (QCL) to illuminate the sample and an ion mobility spectrometer (IMS) to validate the signal enhancement. The LTV technique works well with all tested substrates, though the thermal and spectroscopic properties of the substrate can influence the efficiency of the vaporization. Computational results from laser heating along with experimental thermal kinetic measurements were used to optimize LTV laser irradiation parameters. In addition to a range of LTV results for different explosives and substrates, we explore the effects of wavelength-dependent heating on the sample and substrate.
Workplace Safety in Polymer Nanocomposite Research
Authors: Cattin Cyrill , Debia Maximilien , Dufresne André , Hubert Pascal 
Published: February 2012

ABSTRACTThe topic of this study is focused on exposure control measures and working practices to minimize/eliminate potential health, safety, and environmental risks associated with the handling of dry nanoparticles. First, it is shown that a glove box with attached vacuum chamber for material transport and air cleaning is highly effective in minimizing occupational exposure to airborne nanoparticles. Second, the propensity for Baytubes C 150 P multi-walled carbon nanotubes to form airborne particles is found to be very low. The combined results provide useful guidelines for both the selection and the use of an engineering control to minimize/eliminate exposure to airborne carbon nanotubes, and nanoparticles in general.
Coarse-Grained Molecular Dynamics Simulation of Epoxy-Based Chemically-Amplified Resist for MEMS Application
Authors: Yagyu Hiromasa , Hirai Yoshikazu , Uesugi Akio , Makino Yoshihide , Sugano Koji , Tsuchiya Toshiyuki , Tabata Osamu 
Published: February 2012

ABSTRACTA unique simulation method of epoxy-based chemically-amplified resist by coarse-grained molecular dynamics was proposed. The mechanical properties of an epoxy-based chemically-amplified resists with various cross-linking ratios were simulated using a newly developed coarse-grained molecular dynamics simulation that employs a bead-spring model. Models with the different cross-linking ratios were created in the molecular dynamics calculation step and uniaxial elongation simulations were performed. The results reveal that the simulated elastic modulus of the resist modeled by the bead-spring model with an extended angle bending potential depends on the cross-linking ratio; its dependency exhibits good agreement with that determined by nanoindentation tests.
A Systematic Study of Metal-assisted Chemical Etching Parameters for Well-Ordered Silicon Nanowire Array Fabrication
Authors: Alagoz Arif S. , Karabacak Tansel 
Published: February 2012

ABSTRACTMetal-assisted chemical etching is a simple and low-cost silicon nanowire fabrication method which allows control of nanowire diameter, length, shape and orientation. In this work, we fabricated well-ordered silicon nanowire array by patterning gold thin film by nanosphere lithography and etching single crystalline silicon wafer by metal-assisted chemical etching technique. We investigated relation between etched solution concentration and nanowire morphology, wafer crystal orientation, etching rate. This well-ordered silicon nanowires arrays have the potential applications in many fields but especially next generation energy related applications from solar cells to lithium-ion batteries.