bluuebunny/crossref_metadata_2025_split huggingface dataset:
Low‐dose dynamic myocardial perfusion CT imaging using a motion adaptive sparsity prior
Authors: Bian Zhaoying , Zeng Dong , Zhang Zhang , Gong Changfei , Tian Xiumei , Yan Gang , Huang Jing , Guo Hong , Chen Bo , Zhang Jing , Feng Qianjin , Chen Wufan , Ma Jianhua 
Published: September 2017

PurposeDynamic myocardial perfusion computed tomography (DM‐PCT) imaging offers benefits over quantitative assessment of myocardial blood flow (MBF) for diagnosis and risk stratification of coronary artery disease. However, one major drawback of DM‐PCT imaging is that a high radiation level is imparted by repeated scanning. To address this issue, in this work, we developed a statistical iterative reconstruction algorithm based on the penalized weighted least‐squares (PWLS) scheme by incorporating a motion adaptive sparsity prior (MASP) model to achieve high‐quality DM‐PCT imaging with low tube current dynamic data acquisition. For simplicity, we refer to the proposed algorithm as “PWLS‐MASP’’.MethodsThe MASP models both the spatial and temporal structured sparsity of DM‐PCT sequence images with the assumption that the differences between adjacent frames after motion correction are sparse in the gradient image domain. To validate and evaluate the effectiveness of the present PWLS‐MASP algorithm thoroughly, a modified XCAT phantom and preclinical porcine DM‐PCT dataset were used in the study.ResultsThe present PWLS‐MASP algorithm can obtain high‐quality DM‐PCT images in both phantom and porcine cases, and outperforms the existing filtered back‐projection algorithm and PWLS‐based algorithms with total variation regularization (PWLS‐TV) and robust principal component analysis regularization (PWLS‐RPCA) in terms of noise reduction, streak artifacts mitigation, and time density curve estimation. Moreover, the PWLS‐MASP algorithm can yield more accurate diagnostic hemodynamic parametric maps than the PWLS‐TV and PWLS‐RPCA algorithms.ConclusionsThe study indicates that there is a substantial advantage in using the present PWLS‐MASP algorithm for low‐dose DM‐PCT, and potentially in other dynamic tomography areas.
Adaptive non‐local means on local principle neighborhood for noise/artifacts reduction in low‐dose CT images
Authors: Zhang Yuanke , Lu Hongbing , Rong Junyan , Meng Jing , Shang Junliang , Ren Pinghong , Zhang Junying 
Published: September 2017

PurposeLow‐dose CT (LDCT) technique can reduce the x‐ray radiation exposure to patients at the cost of degraded images with severe noise and artifacts. Non‐local means (NLM) filtering has shown its potential in improving LDCT image quality. However, currently most NLM‐based approaches employ a weighted average operation directly on all neighbor pixels with a fixed filtering parameter throughout the NLM filtering process, ignoring the non‐stationary noise nature of LDCT images. In this paper, an adaptive NLM filtering scheme on local principle neighborhoods (PC‐NLM) is proposed for structure‐preserving noise/artifacts reduction in LDCT images.MethodsInstead of using neighboring patches directly, in the PC‐NLM scheme, the principle component analysis (PCA) is first applied on local neighboring patches of the target patch to decompose the local patches into uncorrelated principle components (PCs), then a NLM filtering is used to regularize each PC of the target patch and finally the regularized components is transformed to get the target patch in image domain. Especially, in the NLM scheme, the filtering parameter is estimated adaptively from local noise level of the neighborhood as well as the signal‐to‐noise ratio (SNR) of the corresponding PC, which guarantees a “weaker” NLM filtering on PCs with higher SNR and a “stronger” filtering on PCs with lower SNR. The PC‐NLM procedure is iteratively performed several times for better removal of the noise and artifacts, and an adaptive iteration strategy is developed to reduce the computational load by determining whether a patch should be processed or not in next round of the PC‐NLM filtering.ResultsThe effectiveness of the presented PC‐NLM algorithm is validated by experimental phantom studies and clinical studies. The results show that it can achieve promising gain over some state‐of‐the‐art methods in terms of artifact suppression and structure preservation.ConclusionsWith the use of PCA on local neighborhoods to extract principal structural components, as well as adaptive NLM filtering on PCs of the target patch using filtering parameter estimated based on the local noise level and corresponding SNR, the proposed PC‐NLM method shows its efficacy in preserving fine anatomical structures and suppressing noise/artifacts in LDCT images.
Model‐based dose reconstruction for CT dose estimation
Authors: Wu Mingye , Yin Zhye , De Man Bruno 
Published: September 2017

PurposeOur goal is to develop a model‐based approach for CT dose estimation. We previously presented a CT dose estimation method that offered good accuracy in soft tissue regions but lower accuracy in bone regions. In this work, we propose an improved physic‐based approach to achieve high accuracy for any materials and realistic clinical anatomies.MethodsLike Monte Carlo techniques, we start from a model or image of the patient and we model all relevant x‐ray interaction processes. Unlike Monte Carlo techniques, we do not track each individual photon, but we compute the average behavior of the x‐ray interactions, combining pencil‐beam calculations for the first‐order interactions and kernels for the higher order interactions. The new algorithm more accurately models the variation of materials in the human body, especially for higher attenuation materials such as bone, as well as the various x‐ray attenuation processes. We performed validation experiments with analytic phantoms and a polychromatic x‐ray spectrum, comparing to Monte Carlo simulation (GEANT4) as the ground truth.ResultsThe results show that the proposed method has improved accuracy in both soft tissue region and bone region: less than 6% voxel‐wise errors and less than 3.2% ROI‐based errors in an anthropomorphic phantom. The computational cost is on the order of a low‐resolution filtered backprojection reconstruction.ConclusionsWe introduced improved physics‐based models in a fast CT dose reconstruction approach. The improved approach demonstrated quantitatively good correspondence to a Monte Carlo gold standard in both soft tissue and bone regions in a chest phantom with a realistic polychromatic spectrum and could potentially be used for real‐time applications such as patient‐ and organ‐specific scan planning and organ dose reporting.
The Use of Hunting and Herding Spaces: Stable Isotope Analysis of Late Archaic and Early Formative Camelids in the Tulan Transect (Puna de Atacama, Chile)
Authors: López M. P. , Cartajena I. , Loyola R. , Núñez L. , Carrasco C. 
Published: September 2017

AbstractWe present the results of analysing stable carbon and nitrogen isotopes in camelid remains found at the Late Archaic site TU‐52 (ca. 5000–3800 bp), the Tarajne Phase site TU‐94 and the Early Formative sites TU‐54, TU‐85 and TU‐122 (ca. 3100–2400 bp). All of the sites are located in the Puna de Atacama (Northern Chile) along the 14 km Tulan transect, between the head of Tulan ravine (ca. 3000 m.a.s.l.) and the border of the Salar de Atacama (2317 m.a.s.l.). Our aim is to understand how the space was used by hunter‐gatherers and early herders from the beginning of camelid domestication to the consolidation of herding practices. Isotopic analyses were complemented with osteometric data in order to correlate changes in animal size and isotopic values with the initiation of animal husbandry. Isotopic and osteometric results show less variability of δ13C and δ15N values during the Late Archaic and Tarajne Phase, whereas variability is higher during the Early Formative. We postulate that during the latter period, there was more widespread use of hunting and herding spaces along the Tulan ravine, including areas above 3000 m.a.s.l. as result of more consolidated herding practices, while the highlands were used as a complementary space to hold livestock near ritual sites and residential settlements. Copyright © 2017 John Wiley & Sons, Ltd.
Preparation and thermal properties of a novel core‐shell structure flame‐retardant copolymer
Authors: Cui Jianguang , Zhu Changjiang , He Mingshan , Ke Zhenkun , Liu Yu , Tai Qilong , Xiao Xifu , Hu Yuan 
Published: September 2017

In order to improve the flame retardancy of polystyrene (PS), a phosphorus and nitrogen comonomer, named AC2NP2, was synthesized and then incorporated into various amounts of PS by seeded emulsion polymerization. The modified methacrylate (AC2NP2) was used as the core phase, the styrene as the shell phase, then flame‐retardant effect copolymers with core‐shell structure were prepared successfully. The particle size was ranged from 40 to 60 nm, and the structure and properties of the copolymers were characterized in detail. Notably, despite a few amounts of the AC2NP2 units in the copolymers, all the copolymers exhibited significantly enhanced thermal stability and reduced flammability as compared with pure PS. Furthermore, from differential scanning calorimetry test, it was observed that the glass transition temperature was tinily influenced with the incorporation of commoner. The incorporation of P‐N comonomer into PS backbone did not lead to negative effect on the glass transition behavior of PS.
PET/CT versus bone marrow biopsy in the initial evaluation of bone marrow infiltration in various pediatric malignancies
Authors: Zapata Claudia P. , Cuglievan Branko , Zapata Catalina M. , Olavarrieta Raquel , Raskin Scott , Desai Kavita , De Angulo Guillermo 
Published: September 2017

AbstractAccurate staging is essential in the prognosis and management of pediatric malignancies. Current protocols require screening for marrow infiltration with bone marrow biopsy (BMB) as the gold standard. Positron emission tomography–computed tomography (PET–CT) is commonly used to complete the staging process and can also be used to evaluate marrow infiltration.ObjectiveTo compare PET–CT and BMB in the initial evaluation of bone marrow infiltration in pediatric cancers.Design/methodWe retrospectively reviewed new cases of EWS, rhabdomyosarcoma, neuroblastoma, and lymphoma diagnosed between January 2009 and October 2014. Each case had undergone both PET–CT and BMB within 4 weeks without treatment in the interval between screening modalities.ResultsWe reviewed 69 cases. Bone marrow infiltration was demonstrated in 34 cases by PET–CT and in 18 cases by BMB. The sensitivity and negative predictive value of PET–CT were both 100%. Interestingly, the cases in which infiltration was not detected on BMB had an abnormal marrow signal on PET–CT focal or distant to iliac crest.ConclusionPET–CT has a high sensitivity when assessing marrow infiltration in pediatric malignancies. Advances in radiologic modalities may obviate the use of invasive, painful, and costly procedures like BMB. Furthermore, biopsy results are limited by insufficient tissue or the degree of marrow infiltration (diffuse vs. focal disease). PET–CT can improve the precision of biopsy when used as a guiding tool. This study proposes the use of PET–CT as first‐line screening for bone marrow infiltration to improve the accuracy of staging in new diagnoses.
Conjugated Microporous Polymers with Immobilized TiO2 Nanoparticles for Enhanced Visible Light Photocatalysis
Authors: Ayed Cyrine , Huang Wei , Li Run , da Silva Lucas Caire , Wang Di , Suraeva Oksana , Najjar Wahiba , Zhang Kai A. I. 
Published: September 2017

AbstractThe search for heterogeneous, visible light‐active, transition metal‐free, stable, and reusable photocatalysts for organic photoredox reactions remains a challenge for the chemists. Here, this study reports on a series of hybrid photocatalysts consisting of conjugated microporous polymer‐based organic semiconductors with immobilized TiO2 nanoparticles. The organic/inorganic semiconductor‐based hybrid photocatalytic system can enhance the photoinduced charge separation and thereby increasing the photocatalytic efficiency. As model reactions, the photocatalytic oxidative coupling reaction of amines and the selective oxidation of organic sulfides can be catalyzed with almost quantitative conversion and selectivity. The catalytic efficiency of the hybrid photocatalyst is higher than that of the pristine single photocatalytic systems as the conjugated microporous polymer and TiO2. Furthermore, the mechanistic study of the photoredox reactions is also described.
Interactive comparison and remediation of collections of macromolecular structures
Authors: Moriarty Nigel W. , Liebschner Dorothee , Klei Herbert E. , Echols Nathaniel , Afonine Pavel V. , Headd Jeffrey J. , Poon Billy K. , Adams Paul D. 
Published: September 2017

AbstractOften similar structures need to be compared to reveal local differences throughout the entire model or between related copies within the model. Therefore, a program to compare multiple structures and enable correction any differences not supported by the density map was written within the Phenix framework (Adams et al., Acta Cryst 2010; D66:213–221). This program, called Structure Comparison, can also be used for structures with multiple copies of the same protein chain in the asymmetric unit, that is, as a result of non‐crystallographic symmetry (NCS). Structure Comparison was designed to interface with Coot(Emsley et al., Acta Cryst 2010; D66:486–501) and PyMOL(DeLano, PyMOL 0.99; 2002) to facilitate comparison of large numbers of related structures. Structure Comparison analyzes collections of protein structures using several metrics, such as the rotamer conformation of equivalent residues, displays the results in tabular form and allows superimposed protein chains and density maps to be quickly inspected and edited (via the tools in Coot) for consistency, completeness and correctness.
Molecular dynamics simulation of the interaction between methyl benzotriazole and Cu2O crystal
Authors: Zeng Jianping , Ma Xiaotian , Zhu Zhidong , Hou Yingying , Shi Wenyan , Bai Yunshan 
Published: September 2017

In circulating water system, methyl benzotriazole (TTA) is one of the common corrosion inhibitors for copper. But the inhibition mechanisms have not been clearly understood so far. In different number of water molecules, the interaction between TTA and Cu2O (copper surface) was investigated with molecular dynamics (MD) method. The results showed that the MD simulation result with water was more consistent with the experiment results. In different number of water molecules, the sequence of the interaction energies between TTA and Cu2O (001) was ∆E1 (150H2O) > ∆E1(200H2O) > ∆E1(100H2O) > ∆E1(50H2O) > ∆E1(0H2O). The number of water molecules had an important influence on the interaction between corrosion inhibitors and Cu2O crystal. From non‐bond energy and pair correlation functions, the interaction energies of the model system were mainly contributed by the non‐bond interaction. Strong adsorption could be raised by the Coulomb interaction between the negatively charged functional groups in TTA and the positive copper ions in the Cu2O (001) face, and further interaction between aggressive media and copper could be restricted. So, copper corrosion could be avoided. Chemical bonds and non‐bond interactions were formed between TTA and Cu2O (001) in different number of water molecules. Water molecules could not be ignored during the MD simulation, too. The results obtained here may provide theoretical supports for developing new corrosion inhibitors.
Synthesis of Gold Nanoparticle‐Embedded Silver Cubic Mesh Nanostructures Using AgCl Nanocubes for Plasmonic Photocatalysis
Authors: Joo Jang Ho , Kim Byung‐Ho , Lee Jae‐Seung 
Published: September 2017

AbstractA novel room‐temperature aqueous synthesis for gold nanoparticle‐embedded silver cubic mesh nanostructures using AgCl templates via a template‐assisted coreduction method is developed. The cubic AgCl templates are coreduced in the presence of AuCl4− and Ag+, resulting in the reduction of AuCl4− into gold nanoparticles on the outer region of AgCl templates, followed by the reduction of AgCl and Ag+ into silver cubic mesh nanostructures. Removal of the template clearly demonstrates the delicately designed silver mesh nanostructures embedded with gold nanoparticles. The synthetic mechanism, structural properties, and surface functionalization are spectroscopically investigated. The plasmonic photocatalysis of the cubic mesh nanostructures for the degradation of organic pollutants and removal of highly toxic metal ions is investigated; the photocatalytic activity of the cubic mesh nanostructures is superior to those of conventional TiO2 catalysts and they are catalytically functional even in natural water, owing to their high surface area and excellent chemical stability. The synthetic development presented in this study can be exploited for the highly elaborate, yet, facile design of nanomaterials with outstanding properties.
A Proteoliposome Method for Assessing Nanotoxicity on Synaptic Fusion and Membrane Integrity
Authors: Crowe Michael , Lai Ying , Wang Yongyao , Lu Jiuwei , Zhao Minglei , Tian Zhiqi , Long Jiangang , Zhang Peng , Diao Jiajie 
Published: September 2017

AbstractNanoparticles have received significant research interest for potential biomedical applications. Before nanomaterials are administered to patients, their biocompatibility should be thoroughly evaluated through in vitro experiments and other preclinical procedures. Many studies have sought to assess the toxicity of nanomaterials on synaptic transmission for neuroscience applications. However, it may be hard to perform such experiments because of the difficulty associated with delivering synthesized nanomaterials across cell membranes. Here, an in vitro method is demonstrated that mimics neuronal exocytosis, which features protein‐reconstituted liposomes for nanotoxicity testing; the effects of graphene oxide and pristine graphene on fusogenic activity and membrane integrity are examined. These results demonstrate the potential of this system as a novel in vitro platform for assessing the biocompatibility of nanomaterials, drug molecules, and other substances.
How Do You Increase Students’ Global Learning in the Classroom?
Authors: Fezzey Hilary N. , Fujieda Eri , Goerdt Lynn Amerman , Kahler Heather , Nikoi Ephraim 
Published: September 2017

AbstractThis chapter will discuss global awareness in five distinctive disciplines (Communications, Literature, Mathematics, Social Work, and Sociology). Comparisons between the pedagogies in the disciplines focus on academic settings other than study abroad.
High Patient Satisfaction with Daylight-Activated Methyl Aminolevulinate Cream in the Treatment of Multiple Actinic Keratoses: Results of an Observational Study in Australia
Authors: See Jo-Ann , Gebauer Kurt , Wu Jason K. , Manoharan Shobhan , Kerrouche Nabil , Sullivan John 
Published: September 2017

Abstract
Introduction
Actinic keratoses (AK) are treated to reduce the risk of progression to squamous cell carcinoma and for symptomatic and cosmetic benefits. The objective of this observational study was to generate real-life data on the use of daylight photodynamic therapy with methyl aminolevulinate cream (MAL DL-PDT) in treating mild to moderate facial/scalp AK.

Methods
A multicenter, prospective, observational study was conducted in Australia in patients receiving a single treatment of MAL DL-PDT for mild to moderate AK. Efficacy was assessed 3 months after treatment by investigator-assessed improvement and patient- and physician-completed satisfaction questionnaires. Adverse events were recorded throughout the study.

Results
Overall, 81 patients were enrolled of mean age 62.7 years, mostly men (76.5%) with skin phototype I (64.2%) or II (35.8%) and a long history of AK (mean duration 16.8 years). Most had multiple lesions (82.7% had >10 lesions) of predominantly grade I (75.3%). At 3 months after treatment, almost half the patients (46.8%) required no further treatment. The proportions of patients and physicians satisfied to very satisfied with the MAL DL-PDT treatment were 79.7% and 83.3%, respectively. After receiving the treatment, 74.1% of patients indicated via the questionnaire that they were not bothered at all by the pain. Related AEs were reported in 48.1% of patients, mainly mild erythema (44.4%).

Conclusions
In clinical practice in Australia, the use of MAL DL-PDT in treating multiple mild to moderate non-hyperkeratotic AK of the face and/or scalp results in high levels of patient and physician satisfaction reflecting the good efficacy and tolerability of this almost painless, convenient procedure.

Trial Registration
ClinicalTrials.gov identifier, NCT02674048.

Funding
Galderma R&D.
Association of midlife lipids with 20‐year cognitive change: A cohort study
Authors: Power Melinda C. , Rawlings Andreea , Sharrett A. Richey , Bandeen‐Roche Karen , Coresh Josef , Ballantyne Christie M. , Pokharel Yashashwi , Michos Erin D. , Penman Alan , Alonso Alvaro , Knopman David , Mosley Thomas H. , Gottesman Rebecca F. 
Published: September 2017

AbstractIntroductionExisting studies predominantly consider the association of late‐life lipid levels and subsequent cognitive change. However, midlife rather than late‐life risk factors are often most relevant to cognitive health.MethodsWe quantified the association between measured serum lipids in midlife and subsequent 20‐year change in performance on three cognitive tests in 13,997 participants of the Atherosclerosis Risk in Communities study.ResultsElevated total cholesterol, low‐density lipoprotein cholesterol, and triglycerides were associated with greater 20‐year decline on a test of executive function, sustained attention, and processing speed. Higher total cholesterol and triglycerides were also associated with greater 20‐year decline in memory scores and a measure summarizing performance on all three tests. High‐density lipoprotein cholesterol was not associated with cognitive change. Results were materially unchanged in sensitivity analyses addressing informative missingness.DiscussionElevated total cholesterol, low‐density lipoprotein cholesterol, and triglycerides in midlife were associated with greater 20‐year cognitive decline.