bluuebunny/crossref_metadata_2025_split huggingface dataset:
Radiation dose reduction to the breast in thoracic CT: Comparison of bismuth shielding, organ‐based tube current modulation, and use of a globally decreased tube current
Authors: Wang Jia , Duan Xinhui , Christner Jodie A. , Leng Shuai , Yu Lifeng , McCollough Cynthia H. 
Published: October 2011

Purpose:The purpose of this work was to evaluate dose performance and image quality in thoracic CT using three techniques to reduce dose to the breast: bismuth shielding, organ‐based tube current modulation (TCM) and global tube current reduction.Methods:Semi‐anthropomorphic thorax phantoms of four different sizes (15, 30, 35, and 40 cm lateral width) were used for dose measurement and image quality assessment. Four scans were performed on each phantom using 100 or 120 kV with a clinical CT scanner: (1) reference scan; (2) scan with bismuth breast shield of an appropriate thickness; (3) scan with organ‐based TCM; and (4) scan with a global reduction in tube current chosen to match the dose reduction from bismuth shielding. Dose to the breast was measured with an ion chamber on the surface of the phantom. Image quality was evaluated by measuring the mean and standard deviation of CT numbers within the lung and heart regions.Results:Compared to the reference scan, dose to the breast region was decreased by about 21% for the 15‐cm phantom with a pediatric (2‐ply) shield and by about 37% for the 30, 35, and 40‐cm phantoms with adult (4‐ply) shields. Organ‐based TCM decreased the dose by 12% for the 15‐cm phantom, and 34–39% for the 30, 35, and 40‐cm phantoms. Global lowering of the tube current reduced breast dose by 23% for the 15‐cm phantom and 39% for the 30, 35, and 40‐cm phantoms. In phantoms of all four sizes, image noise was increased in both the lung and heart regions with bismuth shielding. No significant increase in noise was observed with organ‐based TCM. Decreasing tube current globally led to similar noise increases as bismuth shielding. Streak and beam hardening artifacts, and a resulting artifactual increase in CT numbers, were observed for scans with bismuth shields, but not for organ‐based TCM or global tube current reduction.Conclusions:Organ‐based TCM produces dose reduction to the breast similar to that achieved with bismuth shielding for both pediatric and adult phantoms. However, organ‐based TCM does not affect image noise or CT number accuracy, both of which are adversely affected by bismuth shielding. Alternatively, globally decreasing the tube current can produce the same dose reduction to the breast as bismuth shielding, with a similar noise increase, yet without the streak artifacts and CT number errors caused by the bismuth shields. Moreover, globally decreasing the tube current reduces the dose to all tissues scanned, not simply to the breast.
Impact of leaf motion constraints on IMAT plan quality, deliver accuracy, and efficiency
Authors: Chen Fan , Rao Min , Ye Jin‐song , Shepard David M. , Cao Daliang 
Published: October 2011

Purpose:Intensity modulated arc therapy (IMAT) is a radiation therapy delivery technique that combines the efficiency of arc based delivery with the dose painting capabilities of intensity modulated radiation therapy (IMRT). A key challenge in developing robust inverse planning solutions for IMAT is the need to account for the connectivity of the beam shapes as the gantry rotates from one beam angle to the next. To overcome this challenge, inverse planning solutions typically impose a leaf motion constraint that defines the maximum distance a multileaf collimator (MLC) leaf can travel between adjacent control points. The leaf motion constraint ensures the deliverability of the optimized plan, but it also impacts the plan quality, the delivery accuracy, and the delivery efficiency. In this work, the authors have studied leaf motion constraints in detail and have developed recommendations for optimizing the balance between plan quality and delivery efficiency.Methods:Two steps were used to generate optimized IMAT treatment plans. The first was the direct machine parameter optimization (DMPO) inverse planning module in the Pinnacle3 planning system. Then, a home‐grown arc sequencer was applied to convert the optimized intensity maps into deliverable IMAT arcs. IMAT leaf motion constraints were imposed using limits of between 1 and 30 mm/deg. Dose distributions were calculated using the convolution/superposition algorithm in the Pinnacle3 planning system. The IMAT plan dose calculation accuracy was examined using a finer sampling calculation and the quality assurance verification. All plans were delivered on an Elekta Synergy with an 80‐leaf MLC and were verified using an IBA MatriXX 2D ion chamber array inserted in a MultiCube solid water phantom.Results:The use of a more restrictive leaf motion constraint (less than 1–2 mm/deg) results in inferior plan quality. A less restrictive leaf motion constraint (greater than 5 mm/deg) results in improved plan quality but can lead to less accurate dose distribution as evidenced by increasing discrepancies between the planned and the delivered doses. For example, the results from our patient‐specific quality assurance measurements demonstrated that the average gamma analysis passing rate decreased from 98% to 80% when the allowable leaf motion increased from 3 to 20 mm/deg. Larger leaf motion constraints also led to longer treatment delivery times (2 to 4 folds) due to the additional MLC leaf motion.Conclusions:Leaf motion constraints significantly impact IMAT plans in terms of plan quality, delivery accuracy, and delivery efficiency with the impact magnified for more complex cases. Our studies indicate that a leaf motion constraint of 2 to 3 mm/deg of gantry rotation can provide an optimal balance between plan quality, delivery accuracy, and efficiency.
Characteristics of fatal abusive head trauma among children in the USA: 2003–2007: an application of the CDC operational case definition to national vital statistics data
Authors: Parks Sharyn E , Kegler Scott R , Annest Joseph L , Mercy James A 
Published: October 2011

ObjectiveIn March of 2008, an expert panel was convened at the Centers for Disease Control and Prevention to develop code-based case definitions for abusive head trauma (AHT) in children under 5 years of age based on theInternational Classification of Diseases, 10th Revision(ICD-10) nature and cause of injury codes. This study presents the operational case definition and applies it to US death data.MethodsNational Center for Health Statistics National Vital Statistics System data on multiple cause-of-death from 2003 to 2007 were examined.ResultsInspection of records with at least oneICD-10injury/disease code and at least oneICD-10cause code from the AHT case definition resulted in the identification of 780 fatal AHT cases, with 699 classified as definite/presumptive AHT and 81 classified as probable AHT. The fatal AHT rate was highest among children age <1 year with a peak in incidence that occurred at 1–2 months of age. Fatal AHT incidence rates were higher for men than women and were higher for non-Hispanic African–Americans compared to other racial/ethnic groups. Fatal AHT incidence was relatively constant across seasons.ConclusionsThis report demonstrates that the definition can help to identify population subgroups at higher risk for AHT defined by year and month of death, age, sex and race/ethnicity. This type of definition may be useful for various epidemiological applications including research and surveillance. These activities can in turn inform further development of prevention activities, including educating parents about the dangers of shaking and strategies for managing infant crying.
An age–period–cohort analysis of cannabis use prevalence and frequency in Germany, 1990–2009
Authors: Piontek Daniela , Kraus Ludwig , Pabst Alexander , Legleye Stéphane 
Published: October 2011

BackgroundIn order to better understand trends in cannabis use, this study estimates independent and non-confounded age, period and cohort effects on 12-month cannabis use prevalence and frequency.MethodsData from seven waves of the German Epidemiological Survey of Substance Abuse (ESA) conducted between 1990 and 2009 were used. The total sample included 29 836 men and 34 877 women aged 18–65 years. Cross-classified random effects models were conducted to estimate fixed effects of age and random effects of periods and birth cohorts. Analyses were stratified by gender.ResultsWith regard to 12-month prevalence, substantial age variations were identified with a peak of cannabis use in young adulthood. The overall effects of periods and birth cohorts were not significant. With regard to frequency of use, there were no significant influences of either variable. The results were largely identical for men and women.ConclusionsThis study identified little variation in trend data of current cannabis use. When confounding influences of period and ageing are controlled, the widely reported increases in cannabis consumption in recent birth cohorts cannot be demonstrated.
ACCURATE RADIOGRAPHIC MEASUREMENT OF THE DISTAL RADIAL TILT
Authors: Rajabi Benjamin , Roed Oyvind , Roed Kristian , Alm-Paulsen Paal Sandoe , Russwurm Harald , Finsen Vilhjalmur 
Published: October 2011

Both wrists in 189 patients who had been treated for dorsally displaced distal radius fracture were X-rayed with both right angle and 15° tilted lateral views. Two investigators measured the radial tilt. The mean difference in the angles recorded by the two investigators was 2.5° for the tilted and 3.7° for the right angle projections (p = 4.7 × 10-8). The precision of the method was 2.6° for the tilted and 3.5° for right angle projection. The mean angle measured on the tilted views was 3° more dorsal than on the right angle views for wrists with a volar tilt between 10° and 15°, and 0° to 2° for wrists with less volar tilt or dorsal displacement. Lateral projections tilted 15° allow more precise measurements than right angle views. Correction is not necessary when comparing to right angle views, as long as there is displacement in a dorsal direction of the distal fragment.
MACROMASTIA: A RISK FACTOR FOR CARPAL TUNNEL SYNDROME?
Authors: Guerra Ana Silva , Correia Carlos Marques , Videira e Castro José Manuel , Almeida Maria Angélica 
Published: October 2011

Purpose: To evaluate the prevalence of carpal tunnel syndrome (CTS) in a cohort of women with macromastia and to assess the evolution of the CTS signs and symptoms after breast surgery.Population: A series of 123 women was evaluated. CTS was defined by co-existence of symptoms, two physical findings and electrophysiological evaluation. One year after reduction mammaplasty, the 22 patients who had been diagnosed CTS were re-evaluated.Results: CTS group of women had a mean age of 38.8 years, mean body mass index of 28.5 kg/m2and mean breast size of 35.9 cm. Age and nipple-to-sternal notch distance were statistically significantly associated with CTS (p = 0.001 and p = 0.001, respectively). A year after surgery 15 patients were re-assessed: nine patients reported absence or improvement of CTS symptoms while six patients reported symptoms persistence or worsening.Conclusion: Age, breast size, but not body mass index, have a positive correlation with the CTS.
ISOLATED COMPLETE VOLAR DISLOCATION OF THE CAPITATE: A CASE REPORT
Authors: Checcucci Giuseppe , Bigazzi Prospero , Zucchini Maura , Ceruso Massimo 
Published: October 2011

Total dislocation of the capitate is an extremely rare event. We report on one such unusual case. The complete expulsion of the capitate from its physiological position is difficult to diagnose. Standard parameters of the antero-posterior and lateral radiological do not head to a definite diagnosis. In our patient, the only real diagnostic tool was the clinical assessment and the Gilula arches alteration to the standard antero-posterior projection. In the period following trauma, the patient reported a very high level of pain in the wrist. Since this could not be correlated to the lesions that had been diagnosed, we hypothesized the presence of any carpal bones damage. A definite diagnosis was obtained at CT scan, which also revealed the absence of any fractures.
PARAMETERIZED FINITE ELEMENT MODELING OF THE SURFACE SYSTEMS WITH COATINGS WHICH CONSIDERS THE CRACKING OF THE COATINGS AND INFLUENCES OF THE CASE-HARDENING OF THE SUBSTRATE
Authors: FENG J. , QIN Y. , ZENG Q. , ALMANDOZ E. , FUENTE G. , DONG H. , RAGHAVAN R. , MICHLER J. 
Published: October 2011

Accurately predicting the failure of multilayered surface systems, including coatings on tools or products, is of significance for all of the parties concerned within the chain of design, manufacturing and use of a product. Previous modeling work has, however, been focused largely on the effect of individual parameters rather than on the performance of a multilayered system as a whole. Design and manufacture of multilayered surface systems, currently, still relies largely on experiments and failure tests. A parameterized approach which considers geometrical, material, interfacial and loading variables, processing history, thermal effects, surface-failure modeling, etc. has therefore been developed to address the situation in order to be able to improve the efficiency and accuracy of the analysis and design of multilayered coating-systems. Material property values for the hardened case of the substrate are described with a function of the hardened depth and defined with a field method. Initial residual stresses calculated using a newly developed theoretical model are incorporated into the model as initial stress conditions. Thermo-mechanical coupled modeling is incorporated into the model so as to be able to consider temperature effects. These are associated with a cohesive-element modeling approach, which has been used to predict indentation-induced crack initiation and propagation within the coating layer. The comparison of experimental results with those of numerical modeling affords excellent agreement. The parameterized modeling method developed allows for the parameters to be changed easily during a series analysis. Combined with the capability of the prediction of cracking of the coatings, the developed method/model provides an efficient way for investigating the effects of these parameters on the behavior of multilayered systems, which is demonstrated by the analysis of three cases of the coated tool steels (H11): (i) a substrate without being pre-heat-treated; and (ii) two substrates with a shallow and a deep hardened-case, respectively, (both are treated by plasma-nitriding). The results showed that the case-hardening of a substrate has a significant influence on the performance of the surface system with coating, especially on its load-bearing capacity and the cracking of the coating.
Chondrolectin Is a Novel Diagnostic Biomarker and a Therapeutic Target for Lung Cancer
Authors: Masuda Ken , Takano Atsushi , Oshita Hideto , Akiyama Hirohiko , Tsuchiya Eiju , Kohno Nobuoki , Nakamura Yusuke , Daigo Yataro 
Published: October 2011

AbstractPurpose: This study aims to identify molecules that might be useful as diagnostic/prognostic biomarkers and as targets for the development of new molecular therapies for lung cancer.Experimental Design: We screened for genes that were highly transactivated in a large proportion of 120 lung cancers by means of a cDNA microarray representing 27,648 genes and found chondrolectin (CHODL) as a candidate. Tumor tissue microarray was applied to examine the expression of CHODL protein and its clinicopathologic significance in archival non–small cell lung cancer (NSCLC) tissues from 295 patients. A role of CHODL in cancer cell growth and/or survival was examined by siRNA experiments. Cellular invasive effect of CHODL on mammalian cells was examined by Matrigel assays.Results: Immunohistochemical staining revealed that strong positivity of CHODL protein was associated with shorter survival of patients with NSCLC (P = 0.0006), and multivariate analysis confirmed it to be an independent prognostic factor. Treatment of lung cancer cells with siRNAs against CHODL suppressed growth of the cancer cells. Furthermore, induction of exogenous expression of CHODL conferred growth and invasive activity of mammalian cells.Conclusions: CHODL is likely to be a prognostic biomarker in the clinic and targeting CHODL might be a strategy for the development of anticancer drugs. Clin Cancer Res; 17(24); 7712–22. ©2011 AACR.
Accelerated climate aging of building materials and their characterization by Fourier transform infrared radiation analysis
Authors: Jelle Bjørn Petter , Nilsen Tom-Nils , Hovde Per Jostein , Gustavsen Arild 
Published: October 2011

Building materials and their durability and aging are essential to the performance of buildings and their building physical aspects over time. Accelerated climate aging investigations are carried out in order to study the durability of various building materials in a substantial shorter time span than natural weather aging would have allowed. Climate parameters such as temperature that includes freezing/thawing cycles, relative air humidity, water spray amount, solar and/or ultraviolet (UV) radiation and exposure duration are controlled in different climate aging apparatuses. Various aging processes in building materials, aging both by natural and accelerated climate exposure, may be studied in an attenuated total reflectance (ATR) Fourier transform infrared (FTIR) radiation analysis following the decomposition and/or formation of chemical bonds in these building materials and products. ATR-FTIR analysis of different building material samples exhibit various levels of experimental difficulties. In this investigation we have studied the FTIR spectra of climate-weathered wood, wood rot, mold fungus on wood, mold fungus on plasterboard, and plastic degradation by UV radiation. Both qualitative and quantitative results may be obtained by an ATR-FTIR analysis. In order to determine the aging progress and assess the effective lifetime of materials, components, or products, FTIR spectra should be recorded before, during, and after the climate aging. Hence, FTIR may be developed as an important tool to track the condition of various materials, components, and products during the lifetime of a building, and thereby applied as a tool for condition assessment, selection of maintenance intervals, and service life prediction of buildings.
Selecting a single model or combining multiple models for microarray-based classifier development? – A comparative analysis based on large and diverse datasets generated from the MAQC-II project
Authors: Chen Minjun , Shi Leming , Kelly Reagan , Perkins Roger , Fang Hong , Tong Weida 
Published: October 2011

Abstract

Background
Genomic biomarkers play an increasing role in both preclinical and clinical application. Development of genomic biomarkers with microarrays is an area of intensive investigation. However, despite sustained and continuing effort, developing microarray-based predictive models (i.e., genomics biomarkers) capable of reliable prediction for an observed or measured outcome (i.e., endpoint) of unknown samples in preclinical and clinical practice remains a considerable challenge. No straightforward guidelines exist for selecting a single model that will perform best when presented with unknown samples. In the second phase of the MicroArray Quality Control (MAQC-II) project, 36 analysis teams produced a large number of models for 13 preclinical and clinical endpoints. Before external validation was performed, each team nominated one model per endpoint (referred to here as 'nominated models') from which MAQC-II experts selected 13 'candidate models' to represent the best model for each endpoint. Both the nominated and candidate models from MAQC-II provide benchmarks to assess other methodologies for developing microarray-based predictive models.

Methods
We developed a simple ensemble method by taking a number of the top performing models from cross-validation and developing an ensemble model for each of the MAQC-II endpoints. We compared the ensemble models with both nominated and candidate models from MAQC-II using blinded external validation.

Results
For 10 of the 13 MAQC-II endpoints originally analyzed by the MAQC-II data analysis team from the National Center for Toxicological Research (NCTR), the ensemble models achieved equal or better predictive performance than the NCTR nominated models. Additionally, the ensemble models had performance comparable to the MAQC-II candidate models. Most ensemble models also had better performance than the nominated models generated by five other MAQC-II data analysis teams that analyzed all 13 endpoints.

Conclusions
Our findings suggest that an ensemble method can often attain a higher average predictive performance in an external validation set than a corresponding “optimized” model method. Using an ensemble method to determine a final model is a potentially important supplement to the good modeling practices recommended by the MAQC-II project for developing microarray-based genomic biomarkers.
Applications of graph theory in protein structure identification
Authors: Yan Yan , Zhang Shenggui , Wu Fang-Xiang 
Published: October 2011

Abstract
There is a growing interest in the identification of proteins on the proteome wide scale. Among different kinds of protein structure identification methods, graph-theoretic methods are very sharp ones. Due to their lower costs, higher effectiveness and many other advantages, they have drawn more and more researchers’ attention nowadays. Specifically, graph-theoretic methods have been widely used in homology identification, side-chain cluster identification, peptide sequencing and so on. This paper reviews several methods in solving protein structure identification problems using graph theory. We mainly introduce classical methods and mathematical models including homology modeling based on clique finding, identification of side-chain clusters in protein structures upon graph spectrum, and de novo peptide sequencing via tandem mass spectrometry using the spectrum graph model. In addition, concluding remarks and future priorities of each method are given.
Bayesian non-negative factor analysis for reconstructing transcription factor mediated regulatory networks
Authors: Meng Jia , Zhang Jianqiu , Chen Yidong , Huang Yufei 
Published: October 2011

Abstract

Background
Transcriptional regulation by transcription factor (TF) controls the time and abundance of mRNA transcription. Due to the limitation of current proteomics technologies, large scale measurements of protein level activities of TFs is usually infeasible, making computational reconstruction of transcriptional regulatory network a difficult task.

Results
We proposed here a novel Bayesian non-negative factor model for TF mediated regulatory networks. Particularly, the non-negative TF activities and sample clustering effect are modeled as the factors from a Dirichlet process mixture of rectified Gaussian distributions, and the sparse regulatory coefficients are modeled as the loadings from a sparse distribution that constrains its sparsity using knowledge from database; meantime, a Gibbs sampling solution was developed to infer the underlying network structure and the unknown TF activities simultaneously. The developed approach has been applied to simulated system and breast cancer gene expression data. Result shows that, the proposed method was able to systematically uncover TF mediated transcriptional regulatory network structure, the regulatory coefficients, the TF protein level activities and the sample clustering effect. The regulation target prediction result is highly coordinated with the prior knowledge, and sample clustering result shows superior performance over previous molecular based clustering method.

Conclusions
The results demonstrated the validity and effectiveness of the proposed approach in reconstructing transcriptional networks mediated by TFs through simulated systems and real data.