bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of three strategies in management of independent movement of the prostate and pelvic lymph nodes
Authors: Xia Ping , Qi Peng , Hwang Andrew , Kinsey Erica , Pouliot Jean , Roach Mack 
Published: August 2010

Purpose:Concurrent irradiation of the prostate and pelvic lymph nodes is technically challenging due to treating one moving target and one immobile target. The purposes of this article are to propose a new management strategy and to compare this strategy to the conventional isocenter shift method and the previously proposed MLC‐shifting method.Methods:To cope with two target volumes (one moving and one immobile), the authors propose a new management strategy referred to as multiple adaptive plans (MAPs). This strategy involves the creation of a pool of plans for a number of potential prostate locations. Without requiring any additional hardware or software, the MAP strategy is to choose a plan from the pool that most closely matches the “prostate position of the day.” This position can be determined by dual image registrations: One aligned to the implant markers in the prostate and the other aligned to the pelvic bones. This strategy was clinically implemented for a special patient with high risk prostate cancer and pathologically confirmed positive pelvic lymph nodes, requiring concurrent IMRT treatment of the prostate and pelvic lymph nodes. Because this patient had an abdominal kidney, small planning margins around the both targets were desired. Using 17 daily acquired megavoltage cone beam CTs (CBCTs), three sets of validation plans were calculated to retrospectively evaluate the MAP strategy as well as the isoshifting and MLC‐shifting strategies.Results:According to the validation plans, MAP, isoshifting, and MLC‐shifting strategies resulted in of the prostate of the daily dose on 65%, 100%, and 100% treatment days, respectively. Similarly, of the pelvic lymph nodal was of the daily dose on 100%, 75%, and 94% of treatment days, respectively.Conclusions:None of the above strategies simultaneously achieved all treatment goals. Among the three strategies, the MLC shifting was most successful. Validation plans based on daily CBCTs are useful to evaluate the effectiveness of the motion management strategies and to provide additional dose guidance if further dose compensation is needed.
In vivo imaging and treatment of solid tumor using integrated photoacoustic imaging and high intensity focused ultrasound system
Authors: Cui Huizhong , Yang Xinmai 
Published: August 2010

Purpose:The purpose of this study is to show the feasibility of combined contrast imaging and treatment of solid tumorin vivo by an integrated photoacoustic imaging and high intensity focused ultrasound (HIFU) system.Methods:During this study, photoacoustic imaging was performed to identify the location of a CT26 tumor, which was subcutaneously inoculated on the hip of a BALB/c mouse. Then the CT26 tumor was ablated by HIFU with the guidance of photoacoustic images. To enhance the contrast and specificity of photoacoustic imaging, gold nanorods were used as the contrast agents during the experiment. After being injected into the blood stream, gold nanorods passively accumulated around the tumor region, and therefore outlined the location and shape of the tumor in the photoacoustic images, which were used to guide the subsequent HIFU therapy.Results:The experiment results showed that the tumor was clearly visible on photoacoustic images after the injection of gold nanorods and HIFU was able to ablate the tumor under the guidance of photoacoustic imaging.Conclusions:The authors demonstrated that their integrated photoacoustic imaging and HIFU system has the potential for contrast imaging with gold nanorods with possible diagnosis and treatment of solid tumors.
4D XCAT phantom for multimodality imaging research
Authors: Segars W. P. , Sturgeon G. , Mendonca S. , Grimes Jason , Tsui B. M. W. 
Published: August 2010

Purpose: The authors develop the 4D extended cardiac‐torso (XCAT) phantom for multimodality imaging research.Methods:Highly detailed whole‐body anatomies for the adult male and female were defined in the XCAT using nonuniform rational B‐spline (NURBS) and subdivision surfaces based on segmentation of the Visible Male and Female anatomical datasets from the National Library of Medicine as well as patient datasets. Using the flexibility of these surfaces, the Visible Human anatomies were transformed to match body measurements and organ volumes for a 50th percentile (height and weight) male and female. The desired body measurements for the models were obtained using thePEOPLESIZE program that contains anthropometric dimensions categorized from 1st to the 99th percentile for US adults. The desired organ volumes were determined from ICRP Publication 89 [ICRP, “Basic anatomical and physiological data for use in radiological protection: reference values,” ICRP Publication 89 (International Commission on Radiological Protection, New York, NY, 2002)]. The male and female anatomies serve as standard templates upon which anatomical variations may be modeled in the XCAT through user‐defined parameters. Parametrized models for the cardiac and respiratory motions were also incorporated into the XCAT based on high‐resolution cardiac‐ and respiratory‐gated multislice CT data. To demonstrate the usefulness of the phantom, the authors show example simulation studies in PET, SPECT, and CT using publicly available simulation packages.Results:As demonstrated in the pilot studies, the 4D XCAT (which includes thousands of anatomical structures) can produce realistic imaging data when combined with accurate models of the imaging process. With the flexibility of the NURBS surface primitives, any number of different anatomies, cardiac or respiratory motions or patterns, and spatial resolutions can be simulated to perform imaging research.Conclusions:With the ability to produce realistic, predictive 3D and 4D imaging data from populations of normal and abnormal patients under various imaging parameters, the authors conclude that the XCAT provides an important tool in imaging research to evaluate and improve imaging devices and techniques. In the field of x‐ray CT, the phantom may also provide the necessary foundation with which to optimize clinical CT applications in terms of image quality versus radiation dose, an area of research that is becoming more significant with the growing use of CT.
Assessment of variation in Elekta® plastic spherical‐calibration phantom and its impact on the Leksell Gamma Knife® calibration
Authors: Novotny Josef , Bhatnagar Jagdish P. , Chung Hyun‐Tai , Johansson Jonas , Bednarz Greg , Ma Lijun , Saiful Huq M. 
Published: August 2010

Purpose:Traditionally, the dose‐rate calibration (output) of the Leksell Gamma Knife® (LGK) unit is performed using a 160 mm diameter plastic spherical phantom provided by the vendor of the LGK, Elekta Instrument AB. The purpose of this study was to evaluate variations in the Elekta spherical phantom and to assess its impact and use for the LGK calibration.Methods:Altogether, 13 phantoms from six different centers were acquired, 10 of these phantoms were manufactured within the past 10 years and the last 3 approximately 15–20 years ago. To assess variation in phantoms, the diameter and mass densities were measured. To assess the impact on LGK calibration, the output of two models of LGK (LGK Perfexion™ and LGK 4C) were measured under identical irradiation conditions using all 13 phantoms for each LGK model.Results:The mean measured deviation in diameter from expected nominal 160 mm for 13 phantoms was 0.51 mm (range of 0.09–1.51 mm). The mean measured phantom mass density for 13 phantoms was (range of ). The percentage deviation of output for individual phantom from mean of 13 phantom outputs ranged from −0.37% to 0.55% for LGK Perfexion™. Similarly, the percentage deviation of output for individual phantom from mean of 13 phantom outputs ranged from −0.72% to 0.47% for LGK 4C.Conclusions:This study demonstrated that small variations in terms of phantom size and mass density of the phantom material do not have a significant impact on dose‐rate measurements of the Leksell Gamma Knife®. Also, date of manufacture of the phantom did not show up to be a significant factor in this study.
Assessment of 2D and 3D fractal dimension measurements of trabecular bone from high‐spatial resolution magnetic resonance images at 3 T
Authors: Alberich‐Bayarri Angel , Marti‐Bonmati Luis , Pérez Maria Angeles , Sanz‐Requena Roberto , Lerma‐Garrido Juan José , García‐Martí Gracián , Moratal David 
Published: August 2010

Purpose:In vivo two‐dimensional (2D) fractal dimension analysis of the cancellous bone at 1.5 T has been related to bone structural complexity and shown to be a potential imaging‐based biomarker for osteoporosis. The objectives of this study were to assess at 3 T the in vivo feasibility of three‐dimensional (3D) bone fractal dimension analysis, analyze the relationship of and with osteoporosis, and investigate the relationship of with spinal bone mineral density (BMD).Methods:A total of 24 female subjects ( old, ) was included in this study. The cohort consisted of 12 healthy volunteers and 12 patients with osteoporosis. MR image acquisitions were performed in the nondominant metaphysis of the distal radius with a 3 T MR scanner and an isotropic resolution of . After segmentation and structural reconstruction, 2D and 3D box‐counting algorithms were applied to calculate the fractal complexity of the cancellous bone. and values were compared between patients with osteoporosis and healthy subjects, and their relationship with radius BV/TV and spinal BMD was also assessed.Results:Significant differences between healthy subjects and patients with osteoporosis were obtained for , with less differentiation for . The relationship between fractal dimension and BMD was not significant (, and , , for and , respectively).Conclusions:The feasibility of trabecular bone calculations at 3 T and the relationship of both and parameters with osteoporosis were demonstrated, with a better differentiation for the 3D method. Furthermore, the parameter has probably a different nature of information regarding the trabecular bone status not directly explained by BMD alone. Future studies with subjects with osteopenia and larger sample sizes are warranted to further establish the potential of and in the study of osteoporosis.
Compressed sensing based cone‐beam computed tomography reconstruction with a first‐order methoda)
Authors: Choi Kihwan , Wang Jing , Zhu Lei , Suh Tae‐Suk , Boyd Stephen , Xing Lei 
Published: August 2010

Purpose:This article considers the problem of reconstructing cone‐beam computed tomography (CBCT) images from a set of undersampled and potentially noisy projection measurements.Methods:The authors cast the reconstruction as a compressed sensing problem based on norm minimization constrained by statistically weighted least‐squares of CBCT projection data. For accurate modeling, the noise characteristics of the CBCT projection data are used to determine the relative importance of each projection measurement. To solve the compressed sensing problem, the authors employ a method minimizing total‐variation norm, satisfying a prespecified level of measurement consistency using a first‐order method developed by Nesterov.Results:The method converges fast to the optimal solution without excessive memory requirement, thanks to the method of iterative forward and back‐projections. The performance of the proposed algorithm is demonstrated through a series of digital and experimental phantom studies. It is found a that high quality CBCT image can be reconstructed from undersampled and potentially noisy projection data by using the proposed method. Both sparse sampling and decreasing x‐ray tube current (i.e., noisy projection data) lead to the reduction of radiation dose in CBCT imaging.Conclusions:It is demonstrated that compressed sensing outperforms the traditional algorithm when dealing with sparse, and potentially noisy, CBCT projection views.
Environmental Study of Azole-Resistant
Aspergillus fumigatus
and Other Aspergilli in Austria, Denmark, and Spain
Authors: Mortensen Klaus Leth , Mellado Emilia , Lass-Flörl Cornelia , Rodriguez-Tudela Juan Luis , Johansen Helle Krogh , Arendrup Maiken Cavling 
Published: August 2010

ABSTRACT

A single mechanism of azole resistance was shown to predominate in clinical and environmental
Aspergillus fumigatus
isolates from the Netherlands, and a link to the use of azoles in the environment was suggested. To explore the prevalence of azole-resistant
A. fumigatus
and other aspergilli in the environment in other European countries, we collected samples from the surroundings of hospitals in Copenhagen, Innsbruck, and Madrid, flowerbeds in an amusement park in Copenhagen, and compost bags purchased in Austria, Denmark, and Spain and screened for azole resistance using multidish agars with itraconazole, voriconazole, and posaconazole. EUCAST method E.DEF 9.1 was used to confirm azole resistance. The promoter and entire coding sequence of the
cyp51A
gene were sequenced to identify azole-resistant
A. fumigatus
isolates.
A. fumigatus
was recovered in 144 out of 185 samples (77.8%). Four
A. fumigatus
isolates from four Danish soil samples displayed elevated azole MICs (8%), and all harbored the same TR/L98H mutation of
cyp51A
. One
A. lentulus
isolate with voriconazole MIC of 4 mg/liter was detected in Spain. No azole-resistant aspergilli were detected in compost. Finally,
A. terreus
was present in seven samples from Austria. Multi-azole-resistant
A. fumigatus
is present in the environment in Denmark. The resistance mechanism is identical to that of environmental isolates in the Netherlands. No link to commercial compost could be detected. In Spain and Austria, only
Aspergillus
species with intrinsic resistance to either azoles or amphotericin B were found.
Mathematical Modeling To Characterize the Inoculum Effect
Authors: Bhagunde Pratik , Chang Kai-Tai , Singh Renu , Singh Vandana , Garey Kevin W. , Nikolaou Michael , Tam Vincent H. 
Published: August 2010

ABSTRACT

Killing by beta-lactams is well known to be reduced against a dense bacterial population, commonly known as the inoculum effect. However, the underlying mechanism of this phenomenon is not well understood. We proposed a semimechanistic mathematical model to account for the reduced
in vitro
killing observed. Time-kill studies were performed with 4 baseline inocula (ranging from approximately 1 × 10
5
to 1 × 10
8
CFU/ml) of
Escherichia coli
ATCC 25922 (MIC, 2 mg/liter). Constant but escalating piperacillin concentrations used ranged from 0.25× to 256× MIC. Serial samples were taken over 24 h to quantify viable bacterial burden, and all the killing profiles were mathematically modeled. The inoculum effect was attributed to a reduction of effective drug concentration available for bacterial killing, which was expressed as a function of the baseline inoculum. Biomasses associated with different inocula were examined using a colorimetric method. Despite identical drug-pathogen combinations, the baseline inoculum had a significant impact on bacterial killing. Our proposed mathematical model was unbiased and reasonable in capturing all 28 killing profiles collectively (
r
2
= 0.88). Biomass was found to be significantly more after 24 h with a baseline inoculum of 1 × 10
8
CFU/ml, compared to one where the initial inoculum was 1 × 10
5
CFU/ml (
P
= 0.002). Our results corroborated previous observations that
in vitro
killing by piperacillin was significantly reduced against a dense bacterial inoculum. This phenomenon can be reasonably captured by our proposed mathematical model, and it may improve prediction of bacterial response to various drug exposures in future investigations.
Associations between adolescent seatbelt non-use, normative perceptions and screen media exposure: results from a national US survey
Authors: Dunlop Sally M , Romer Daniel 
Published: August 2010

BackgroundFailure to use seatbelts in motor vehicles is a major source of youth injuries, and previous research has noted the widespread non-use of seatbelts in popular media.ObjectivesTo explore whether increased exposure to entertainment screen media was associated with inflated normative perceptions regarding seatbelt non-use, and to determine any associations between normative perceptions and seatbelt non-use.MethodsA nationally representative telephone survey of school-aged American adolescents (14–17 years, n=915) measuring: screen media exposure; normative perceptions with reference to friends' disapproval of non-use, and prevalence of non-use among friends, school peers and peers; and self-reported seatbelt non-use.ResultsUsing structural equation modelling, analyses indicate that, after demographic and individual characteristics relevant to screen media exposure and seatbelt non-use had been controlled for, frequent exposure to entertainment media was associated with positive normative perceptions about seatbelt non-use for boys, but not for girls. Normative perceptions related to friends' and school peers' seatbelt use were associated with seatbelt non-use for both boys and girls.ConclusionsAttempts to increase adolescent seatbelt use could include public communication campaigns to alter normative perceptions. Broadcasting these campaigns in conjunction with the media that under-represent seatbelt use may be a successful strategy for reducing the influence of such media on male adolescents.
Expanding CS education; improving software development
Authors: Chi Ed H. , Ortega Ruben 
Published: August 2010

http://cacm.acm.org/blogs/blog-cacm/82365

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Communications
Web site, http://cacm.acm.org, features more than a dozen bloggers in the BLOG@CACM community. In each issue of
Communications
, we'll publish selected posts or excerpts.

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Ed H. Chi writes about the social Web's impact on CS education. Ruben Ortega discusses software and test-driven development.
Enabling self-adaptivity in component-based streaming applications
Authors: Derin Onur , Ferrante Alberto 
Published: August 2010

Self-adaptivity is the capability of a system to adapt itself dynamically to achieve its goals. By means of this mechanism the system is able to autonomously modify its behavior or the way in which applications are run and implemented to achieve the goals set.
In this paper we propose a framework that uses a componentbased approach to implement self-adaptivity at application level. By using this mechanism, the framework provides the ability to perform both adaptation on the structure of the application (i.e., how the components are connected together) and on internal parameters of each component. At application level, there is a mechanism to monitor different parameters and to check whether the system is meeting the assigned goals or not. A controller drives adaptations when goals are not met.
Haemostatic safety of a unique recombinant plasmin molecule lacking kringles 2–5
Authors: Manyak Steve , Gruber Theresa , Goyal Abha , Moreno Guillermo , Hunt Jennifer , Bromirski John , Scuderi Philip , Petteway Stephen , Novokhatny Valery , Marder Victor 
Published: August 2010

SummaryWe previously demonstrated a significant margin of haemostatic safety for full-length plasmin in comparison with tissue plasminogen activator (t-PA). We now report studies that compare haemostatic safety of full-length plasmin with a novel recombinant plasmin derivative, (Δ K2–5) plasmin, consisting of kringle 1 linked to the serine protease domain of plasmin. Agent was administered intravenously in a randomised, blinded manner in a rabbit model of fibrinolytic haemorrhage. A dose-related decrease in α2-antiplasmin, factor VIII, and fibrinogen followed administration of 1.8, 2.7, 3.7 and 4.6 mg/kg of (Δ K2–5) plasmin, with nadir fibrinogen concentrations of 65%, 40%, 30%, and 0% of initial levels, respectively. Mean primary bleeding time was undisturbed at 1.8 mg/kg (2.2 ± 0.7 minutes), minimally prolonged at 2.7 or 3.7 mg/kg (5 ± 2.9 and 4.4 ± 2.2 minutes), and prolonged at the purposefully toxic 4.6 mg/kg dose (12.8 ± 18.8 minutes). Equimolar amounts of (Δ K2–5) plasmin and full-length plasmin had equal in vitro clot lysis efficacy, but in the bleeding model, (Δ K2–5) plasmin showed better haemostatic competency than full-length plasmin. This safety advantage may be explained by higher residual amounts of plasma fibrinogen in animals given (Δ K2–5) plasmin rather than full-length plasmin. We demonstrate that a unique recombinant plasmin mutant, (Δ K2–5) plasmin, possesses an advantage in hemostatic safety over an equimolar amount of full-length plasmin.
Cost-effectiveness of rivaroxaban versus enoxaparin for the prevention of postsurgical venous thromboembolism in Canada
Authors: Diamantopoulos Alexander , Lees Michael , Wells Philip , Forster Fiona , Ananthapavan Jaithri , McDonald Heather 
Published: August 2010

SummaryThis study aimed to evaluate the cost-effectiveness of prophylaxis with rivaroxaban vs. enoxaparin in the prevention of venous thromboembolism (VTE) after total hip replacement (THR) and total knee replacement (TKR) from the perspective of the Canadian healthcare system. A model was developed that included both acute VTE (represented as a decision tree) and long-term complications (represented as a Markov process with one-year cycles). Transition probabilities were derived from phase III clinical trials comparing rivaroxaban with enoxaparin and published literature. Costs were derived from the Ontario Case Costing Initiative and publicly available sources. Utilities were derived from published literature. The model reported VTE event rates, quality-adjusted life expectancy and direct medical costs over a five-year horizon. Costs are reported in 2007 Canadian Dollars (C$). When rivaroxaban and enoxaparin are compared in patients undergoing THR, rivaroxaban dominates enoxaparin. That is, rivaroxaban is associated with improved health outcomes as measured by increased quality-adjusted life years (QALYs; 0.0006) and fewer symptomatic VTE events (0.0061), and also with lower cost (savings of C$300) per patient. Similarly, rivaroxaban dominates enoxaparin in patients undergoing TKR, achieving a gain of 0.0018 QALYs, a reduction of 0.0192 symptomatic venous thromboembolic events and savings of C$129 per patient. Rivaroxaban is a cost-effective alternative to enoxaparin for VTE prophylaxis in patients undergoing THR and TKR. Over a five-year horizon, rivaroxaban dominated enoxaparin in the prevention of VTE events in patients undergoing THR and TKR, providing more quality-of-life benefit at a lower cost.