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Shape modelling

Morteza Bashash, Maelle Marchand, Howard Hu, Christine Till, E Angeles Martinez-Mier, Brisa N Sanchez, Niladri Basu, Karen E Peterson, Rivka Green, Lourdes Schnaas, Adriana Mercado-García, Mauricio Hernández-Avila, Martha María Téllez-Rojo
BACKGROUND: Epidemiologic and animal-based studies have raised concern over the potential impact of fluoride exposure on neurobehavioral development as manifested by lower IQ and deficits in attention. To date, no prospective epidemiologic studies have examined the effects of prenatal fluoride exposure on behavioral outcomes using fluoride biomarkers and sensitive measures of attention. OBJECTIVE: We aimed to examine the association between prenatal fluoride exposure and symptoms associated with attention-deficit/hyperactivity disorder (ADHD)...
October 10, 2018: Environment International
Mengsuo Cui, Yuenan Li, Shu Wang, Yuanyuan Chai, Jintong Lou, Fen Chen, Qijun Li, Weisan Pan, Pingtian Ding
Levetiracetam therapy is often associated with high levels of individual variation in the recommended dose required to achieve preferential treatment. Thus, a reliable and dynamic regulation system to accurately tailor dose is necessary. The main objective of this work was to explore and prepare a dose-flexible control system suitable for rapid release tablets equipped with high drug loading and a cylindrical model design. Semisolid extrusion 3D printing was utilized to fabricate a series of tablets of increased volume...
October 10, 2018: Journal of Pharmaceutical Sciences
Sunil Kumar Yadav, Ella Maria Kadas, Seyedamirhosein Motamedi, Konrad Polthier, Frank Haußer, Kay Gawlik, Friedemann Paul, Alexander Brandt
We present a method for optic nerve head (ONH) 3-D shape analysis from retinal optical coherence tomography (OCT). The possibility to noninvasively acquire in vivo high-resolution 3-D volumes of the ONH using spectral domain OCT drives the need to develop tools that quantify the shape of this structure and extract information for clinical applications. The presented method automatically generates a 3-D ONH model and then allows the computation of several 3-D parameters describing the ONH. The method starts with a high-resolution OCT volume scan as input...
October 2018: Journal of Biomedical Optics
Kenneth A Fetterly
PURPOSE: Electronic noise associated with passive pixel (PP) x-ray angiography flat panel detectors is known to compromise fluoroscopic image quality. An active pixel (AP) crystalline silicon x-ray detector with potential for reduced influence of electronic noise is commercially available. The purpose of this work was to compare the performance of the AP vs PP x-ray angiography detectors over a detector target dose (DTD) range relevant for invasive cardiology procedures. METHODS: A total of 16 passive pixel detector systems representing two models and two active pixel detector systems of a single model were tested...
October 12, 2018: Medical Physics
L L Xiao, W W Yan, Y Liu, S Chen, B M Fu
The blood flow behaviors in the microvessels determine the transport modes and further affect the metastasis of circulating tumor cells (CTCs). Much biochemical and biological efforts have been made on CTC metastasis; however, precise experimental measurement and accurate theoretical prediction on its mechanical mechanism are limited. To complement these, numerical modeling of a CTC extravasation from the blood circulation, including the steps of adhesion and transmigration, is discussed in this chapter. The results demonstrate that CTCs prefer to adhere at the positive curvature of curved microvessels, which is attributed to the positive wall shear stress/gradient...
2018: Advances in Experimental Medicine and Biology
Yunjiao Zhang, Rui Sha, Lan Zhang, Wenbin Zhang, Peipei Jin, Weiguo Xu, Jianxun Ding, Jun Lin, Jing Qian, Guangyu Yao, Rui Zhang, Fanchen Luo, Jie Zeng, Jie Cao, Long-Ping Wen
Chemo-PTT, which combines chemotherapy with photothermal therapy, offers a viable approach for the complete tumor eradication but would likely fail in drug-resistant situations if conventional chemotherapeutic agents are used. Here we show that a type of copper (Cu)-palladium (Pd) alloy tetrapod nanoparticles (TNP-1) presents an ideal solution to the chemo-PTT challenges. TNP-1 exhibit superior near-infrared photothermal conversion efficiency, thanks to their special sharp-tip structure, and induce pro-survival autophagy in a shape- and composition-dependent manner...
October 12, 2018: Nature Communications
A Sarno, G Mettivier, F Di Lillo, R M Tucciariello, K Bliznakova, P Russo
PURPOSE: To provide mean glandular dose (MGD) estimates via Monte Carlo (MC) simulations as a function of the breast models and scan parameters in mammography, digital breast tomosynthesis (DBT) and dedicated breast CT (BCT). METHODS: The MC code was based on GEANT4 toolkit. The simulated compressed breast was either a cylinder with a semi-circular section or ad hoc shaped for oblique view (MLO). In DBT we studied the influence of breast models and exam parameters on the T-factors (i...
October 9, 2018: Physica Medica: PM
Thierry Baasch, Peter Reichert, Stefan Lakämper, Nadia Vertti-Quintero, Gamuret Hack, Xavier Casadevall I Solvas, Andrew deMello, Rudiyanto Gunawan, Jürg Dual
The acoustic compressibility of Caenorhabditis elegans is a necessary parameter for further understanding the underlying physics of acoustic manipulation techniques of this widely used model organism in biological sciences. In this work, numerical simulations were combined with experimental trajectory velocimetry of L1 C. elegans larvae to estimate the acoustic compressibility of C. elegans. A method based on bulk acoustic wave acoustophoresis was used for trajectory velocimetry experiments in a microfluidic channel...
September 22, 2018: Biophysical Journal
Louis-Marie Bobay, Howard Ochman
BACKGROUND: Knowledge of population-level processes is essential to understanding the efficacy of selection operating within a species. However, attempts at estimating effective population sizes (Ne) are particularly challenging in bacteria due to their extremely large census populations sizes, varying rates of recombination and arbitrary species boundaries. RESULTS: In this study, we estimated Ne for 153 species (152 bacteria and one archaeon) defined under a common framework and found that ecological lifestyle and growth rate were major predictors of Ne; and that contrary to theoretical expectations, Ne was unaffected by recombination rate...
October 12, 2018: BMC Evolutionary Biology
Taoran Wang, Yangchao Luo
In this study, the innovative and multifunctional nanoparticles⁻hydrogel nanocomposites made with chitosan hydrogel beads and solid lipid⁻polymer hybrid nanoparticles (SLPN) were prepared through conjugation between SLPN and chitosan beads. The SLPNs were first fabricated via coating the bovine serum albumin (BSA)-emulsified solid lipid nanoparticles with oxidized dextran. The aldehyde groups of the oxidized dextran on the surface of the SLPN enabled an in situ conjugation with the chitosan beads through the Schiff base linkage...
October 11, 2018: International Journal of Molecular Sciences
Duncan M Stevens, Jacqueline Bishop, Mike D Picker
The low vagility of the southern African Notonemouridae (stoneflies, Plecoptera), and their restriction to temperate montane refugia, make them a useful model for examining the evolution and biogeography of the rich palaeogenic fauna of the region. Here we use maximum parsimony tree reconstruction based on morphological characters and a partial COI mtDNA sequence to explore the evolutionary history and biogeography of the family in southern Africa. Morphological and molecular parsimony cladograms were largely in agreement, and supported monophyly of all six genera in the region...
September 24, 2018: Zootaxa
Zijian Li
Exploring better models for evaluating the distribution of pesticide residues in soil and sediment is necessary to assess and avoid population health risk. Frequentist philosophy and probability are widely used in many studies to apply a log-normal distribution associated with the maximum likelihood estimation, which assumes fixed parameters and relies on a large sample size for long-run frequency. However, frequentist probability might not be suitable for analyzing pesticide residue distribution, whose parameters are affected by many complex factors and should be treated as unfixed...
October 9, 2018: Environment International
Lionel Cervera Gontard, Adrián Barroso-Bogeat, Rafal E Dunin-Borkowski, José Juan Calvino
A simple computational method that can be used to simulate TEM image contrast of an electron beam diffracted by a crystal under two-beam dynamical scattering conditions is presented. The approach based on slicing the shape factor is valid for a general crystal morphology, with and without crystalline defects, avoids the column approximation, and provides the complex exit wave at the focal and the image planes also under weak-beam conditions. The approach is particularly efficient for large crystals and the 3D model required for the calculations can be measured experimentally using electron tomography...
September 13, 2018: Ultramicroscopy
Qingchuan Li, Xiaojun Han
Nature has evolved elaborate, dynamic organelle morphologies for optimal organelle functions. Among them, cisternae stacks are the universal structure for most organelles. However, compared with the well-studied spherical cell/organelle membrane mimic, the fabrication of the ubiquitously present cisternal organelle-like membrane structures for organelle mimic remains a challenging task. Herein, rough endoplasmic reticulum (RER)-like helicoidal cisternae stacks were assembled to mimic the enzyme crowded environment in spatially confined RER cisternae...
September 27, 2018: iScience
Irene Appolloni, Francesco Alessandrini, Davide Ceresa, Daniela Marubbi, Eleonora Gambini, Daniele Reverberi, Fabrizio Loiacono, Paolo Malatesta
The mutual reshape of tumor and immune system cells during tumor progression is a widely accepted notion in different cancers including gliomas. The importance of this phenomenon in shaping glioma progression and the mechanisms governing it, however, are not fully elucidated. Taking advantage of a well-characterized in vivo glioma model we performed an analysis of glioma cells transcriptomes at different stages of progression and unveiled the reorganization of glioma-immune system interactions. Specifically, we show that the inability of low-grade glioma cells to orthotopically graft in syngeneic immunocompetent mice, positively correlates with the abundance of infiltrating lymphocytes in donor tumors and with a highly immunostimulatory transcriptional profile...
October 9, 2018: Cancer Letters
Piyawan Paisrisarn, Surapun Tepaamorndech, Mattaka Khongkow, Pongtanawat Khemthong, Panita Kasamechonchung, Wantana Klysubun, Tuksadon Wutikhun, Liping Huang, Kanittha Chantarasakha, Suwimon Boonrungsiman
The present study investigated the effect of lead (Pb) on bone ultrastructure and chemistry using an in vitro bone model. MC3T3-E1 preosteoblasts were differentiated and treated with lead acetate at 0.2, 0.4, 2, 10, and 50 µM. No abnormalities in either cell growth or bone nodule formation were observed with the treated dose of lead acetate. However, Pb treatments could significantly increase Pb accumulation in differentiated osteoblast cultures and upregulate expression of Divalent metal transporter 1 (Dmt1) in a dose dependent manner...
October 9, 2018: Toxicology Letters
M Cecilia Latham, Dean P Anderson, Grant Norbury, Catherine J Price, Peter B Banks, A David M Latham
Foraging mammalian predators face a myriad of odors from potential prey. To be efficient they must focus on rewarding odor while ignoring consistently unrewarding ones. This may be exploited as a non-lethal conservation tool if predators can be deceived into ignoring odors of vulnerable secondary prey. To explore critical design components and assess the potential gains to prey survival of this technique, we created an individual-based model that simulated the hunting behavior of three introduced mammalian predators on one of their secondary prey (a migratory shorebird) in the South Island of New Zealand...
October 12, 2018: Ecological Applications: a Publication of the Ecological Society of America
Nathan J Wispinski, Jason P Gallivan, Craig S Chapman
Decision making is a fundamental cognitive function, which not only determines our day-to-day choices but also shapes the trajectories of our movements, our lives, and our societies. While immense progress has been made in recent years on our understanding of the mechanisms underlying decision making, research on this topic is still largely split into two halves. Good-based models largely state that decisions are made between representations of abstract value associated with available options; while action-based models largely state that decisions are made at the level of action representations...
October 12, 2018: Annals of the New York Academy of Sciences
Farhood Saremi, Cameron Hassani, Leah M Lin, Christopher Lee, Alison G Wilcox, Fernando Fleischman, Mark J Cunningham
Treatment of thoracic aortic dissection remains highly challenging and is rapidly evolving. Common classifications of thoracic aortic dissection include the Stanford classification (types A and B) and the DeBakey classification (types I to III), as well as a new supplementary classification geared toward endovascular decision making. By using various imaging techniques, the extent of the dissection, the location of the primary intimal tear, the shape of the aortic arch, and the zonal involvement of the aortic arch-factors that affect the treatment strategy-can easily be identified...
October 12, 2018: Radiographics: a Review Publication of the Radiological Society of North America, Inc
Zhaoru Sun, Lixin Zheng, Mohan Chen, Michael L Klein, Francesco Paesani, Xifan Wu
Electron-hole excitation theory is used to unveil the role of nuclear quantum effects on the x-ray absorption spectral signatures of water, whose structure is computed via path-integral molecular dynamics with the MB-pol intermolecular potential model. Compared to spectra generated from the classically modeled water, quantum nuclei introduce important effects on the spectra in terms of both the energies and line shapes. Fluctuations due to delocalized protons influence the short-range ordering of the hydrogen bond network via changes in the intramolecular covalence, which broaden the preedge spectra...
September 28, 2018: Physical Review Letters
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