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Squaring the circle

Anton Khlopas, Morad Chughtai, Randa K Elmallah, David Hip-Flores, Arthur L Malkani, Steven F Harwin, Michael A Mont, Michael D Ries
BACKGROUND: Bone loss in patients undergoing revision THA poses a considerable challenge for orthopaedic surgeons. Often, to achieve better fixation in remaining bone, larger diameter acetabular components and reaming superiorly may be necessary. However, this is likely to raise the hip center of rotation, which may lead to altered biomechanics, specifically, insufficiency of the abductor muscles, altered gait, and increased risk of dislocation from impingement. More recently, a newer acetabular shell has been designed to more closely replicate the native hip center of rotation in these circumstances while maintaining adequate fixation...
February 2018: Clinical Orthopaedics and related Research
Yu Bin Lee, Eun Mi Kim, Hayeon Byun, Hyung-Kwan Chang, Kwanghee Jeong, Zachary M Aman, Yu Suk Choi, Jungyul Park, Heungsoo Shin
Numerous methods have been reported for the fabrication of 3D multi-cellular spheroids and their use in stem cell culture. Current methods typically relying on the self-assembly of trypsinized, suspended stem cells, however, show limitations with respect to cell viability, throughput, and accurate recapitulation of the natural microenvironment. In this study, we developed a new system for engineering cell spheroids by self-assembly of micro-scale monolayer of stem cells. We prepared synthetic hydrogels with the surface of chemically formed micropatterns (squares/circles with width/diameter of 200 μm) on which mesenchymal stem cells isolated from human nasal turbinate tissue (hTMSCs) were selectively attached and formed a monolayer...
March 1, 2018: Biomaterials
Dejan Todorović, Ljubica Jovanović
The Ebbinghaus illusion, in which a central target surrounded by larger context figures looks smaller than when surrounded by smaller context figures, is usually classified as a size contrast illusion. Thus "size contrast" is the dominant account of this effect. However, according to an alternative "contour interaction" account this phenomenon has little to do with size contrast but is rather caused by distance-dependent attractive and repulsive interactions between neural representation of contours...
February 27, 2018: Acta Psychologica
Jing-Min Liu, Xiao-Long Zhang, Yu Zhai, Hui Li
The calculated rovibrational energy levels and infrared spectra for OCS-(pH2 )2 , OCS-(oD2 )2 , OCS-(HD)2 and mixed OCS-pH2 -He trimers are obtained by performing the exact basis-set calculations for the first time based on the newly developed potential energy surfaces (J. Chem. Phys. 2017, 147, 044313). The ``adiabatic-hindered-rotor'' (AHR) method is used for reduced-dimension treatment of the hydrogen rotation. The predicted band origin shifts and the infrared spectra are in good agreement with the available experimental values: for the band origin shifts, and infrared transitions, the root-mean-square(rms) deviations are smaller than 0...
March 1, 2018: Journal of Physical Chemistry. A
Cassandra Philine Köller, Christian H Poth, Arvid Herwig
Object perception across saccadic eye movements is assumed to result from integrating two information sources: incoming peripheral object information and information from a foveal prediction (Herwig and Schneider, J Exp Psychol Gen 143(5):1903-1922, 2014, Herwig, J Vis 15(16), 7, 2015). Predictions are supposed to be based on transsaccadic associations of peripheral and foveal object information. The main function of these predictions may be to conceal discrepancies in resolution and locations across saccades...
January 31, 2018: Psychological Research
Armen Poghosyan, Nickolay Izmailian, Ralph Kenna
The Ising model in two dimensions with special toroidal boundary conditions is analyzed. These boundary conditions, which we call duality-twisted boundary conditions, may be interpreted as inserting a specific defect line ("seam") in the system, along noncontractible circles of the cylinder, before closing it into a torus. We derive exact expressions for the eigenvalues of a transfer matrix for the critical ferromagnetic Ising model on the M×N square lattice wrapped on the torus with a specific defect line...
December 2017: Physical Review. E
Vani Virdyawan, Matthew Oldfield, Ferdinando Rodriguez Y Baena
Puncturing blood vessels during percutaneous intervention in minimally invasive brain surgery can be a life threatening complication. Embedding a forward looking sensor in a rigid needle has been proposed to tackle this problem but, when using a rigid needle, the procedure needs to be interrupted and the needle extracted if a vessel is detected. As an alternative, we propose a novel optical method to detect a vessel in front of a steerable needle. The needle itself is based on a biomimetic, multi-segment design featuring four hollow working channels...
January 11, 2018: Bioinspiration & Biomimetics
Adeola N Harewood Smith, Jnana Aditya Challa, Michael A Silver
Acetylcholine and dopamine are neurotransmitters that play multiple important roles in perception and cognition. Pharmacological cholinergic enhancement reduces excitatory receptive field size of neurons in marmoset primary visual cortex and sharpens the spatial tuning of visual perception and visual cortical fMRI responses in humans. Moreover, previous studies show that manipulation of cholinergic or dopaminergic signaling alters the spatial tuning of macaque prefrontal cortical neurons during the delay period of a spatial working memory (SWM) task and can improve SWM performance in macaque monkeys and human subjects...
2017: Frontiers in Neural Circuits
Sakari Kallio, Mika Koivisto, Johanna K Kaakinen
Are synaesthetic experiences congenital and so hard-wired, or can a functional analogue be created? We induced an equivalent of form-colour synaesthesia using hypnotic suggestions in which symbols in an array (circles, crosses, squares) were suggested always to have a certain colour. In a Stroop type-naming task, three of the four highly hypnotizable participants showed a strong synaesthesia-type association between symbol and colour. This was verified both by their subjective reports and objective eye-movement behaviour...
December 11, 2017: Scientific Reports
Alar Ainla, Mohit S Verma, Dian Yang, George M Whitesides
This article describes a soft pneumatic actuator that generates cyclical motion. The actuator consists of several (three, four, or five) chambers (arranged around the circumference of a circle surrounding a central rod) that can be actuated independently using negative pressure (or partial vacuum). Sequential actuation of the four-chamber device using reduced pressure moves the central rod cyclically in an approximately square path. We characterize the trajectory of the actuator and the force exerted by it, as we vary the material used for fabrication, the number of chambers, and the size of the actuator...
September 2017: Soft Robotics
P Godoy, M Alsedà, M Falguera, T Puig, P Bach, M Monrabà, A Manonelles
The transmission of tuberculosis (TB) in bars is difficult to study. The objective was to describe a large TB outbreak in a company's bar and other leisure settings. A descriptive study of a TB outbreak was carried out. Contacts were studied in the index case's workplace bar (five circles of contacts) and other recreational areas (social network of three bars in the index case's neighbourhood). Chest X-rays were recommended to contacts with positive tuberculin skin tests (TST) (⩾5 mm). The risk of latent tuberculosis infection (LTBI) was determined using an adjusted odds ratio...
December 2017: Epidemiology and Infection
David M Williams, Toby Nicholson, Catherine Grainger
Memory for (and perception of) information about the self is superior to memory for (and perception of) other kinds of information. This self-reference effect (SRE) in memory appears diminished in ASD and related to the number of ASD traits manifested by neurotypical individuals (fewer traits = larger SRE). Here, we report the first experiments exploring the relation between ASD and the SRE in perception. Using a "Shapes" Task (Sui et al., Journal of Experimental Psychology: Human Perception and Performance, 38, 1105, 2012), participants learned to associate three different shapes (triangle, circle, square) with three different labels representing self, a familiar other, or an unfamiliar other (e...
November 21, 2017: Autism Research: Official Journal of the International Society for Autism Research
Carlos Francisco Sampaio Bonafe, Jose Ailton Conceição Bispo, Marcelo Bispo de Jesus
Metabolism involves numerous reactions and organic compounds that the student must master to understand adequately the processes involved. Part of biochemical learning should include some knowledge of the structure of biomolecules, although the acquisition of such knowledge can be time-consuming and may require significant effort from the student. In this report, we describe the "polygonal model" as a new means of graphically representing biomolecules. This model is based on the use of geometric figures such as open triangles, squares, and circles to represent hydroxyl, carbonyl, and carboxyl groups, respectively...
November 13, 2017: Biochemistry and Molecular Biology Education
Takashi Sakai, Noriyuki Matsutani, Eiichi Kanai, Yoshikane Yamauchi, Hirofumi Uehara, Hisae Iinuma, Masafumi Kawamura
OBJECTIVE: Polyglycolic acid and oxidized regenerated cellulose have been widely used as a sealant for repairing pulmonary air leakage during respiratory surgery. However, fundamental research of these materials has not been sufficiently conducted. Therefore, we conducted studies to assess the pressure resistance ability of these materials using a canine visceral pleural defect model at the early phase. METHOD: The 6-mm circular defect and the 12-mm square defect were created on the visceral pleura of anesthetized beagles...
November 3, 2017: General Thoracic and Cardiovascular Surgery
Samuel Rosset, Christine de Saint-Aubin, Alexandre Poulin, Herbert R Shea
We present an automated system to measure the degradation of compliant electrodes used in dielectric elastomer actuators (DEAs) over millions of cycles. Electrodes for DEAs generally experience biaxial linear strains of more than 10%. The decrease in electrode conductivity induced by this repeated fast mechanical deformation impacts the bandwidth of the actuator and its strain homogeneity. Changes in the electrode mechanical properties lead to reduced actuation strain. Rather than using an external actuator to periodically deform the electrodes, our measurement method consists of measuring the properties of an electrode in an expanding circle DEA...
October 2017: Review of Scientific Instruments
Jiangang Feng, Qian Song, Bo Zhang, Yuchen Wu, Tie Wang, Lei Jiang
Deterministic assembly of nanoparticles with programmable patterns is a core opportunity for property-by-design fabrication and large-scale integration of functional materials and devices. The wet-chemical-synthesized colloidal nanocrystals are compatible with solution assembly techniques, thus possessing advantages of high efficiency, low cost, and large scale. However, conventional solution process suffers from tradeoffs between spatial precision and long-range order of nanocrystal assembly arising from the uncontrollable dewetting dynamics and fluid flow...
December 2017: Advanced Materials
Andreas Mädebach, Marie-Luise Kieseler, Jörg D Jescheniak
In this study we explored the locus of semantic interference in a novel picture-sound interference task in which participants name pictures while ignoring environmental distractor sounds. In a previous study using this task (Mädebach, Wöhner, Kieseler, & Jescheniak, in Journal of Experimental Psychology: Human Perception and Performance, 43, 1629-1646, 2017), we showed that semantically related distractor sounds (e.g., BARKINGdog) interfere with a picture-naming response (e.g., "horse") more strongly than unrelated distractor sounds do (e...
October 13, 2017: Psychonomic Bulletin & Review
Lu Zhang, Yue Zhang, Yanlin Liu, Kai Wang, Mingwei Zhao
PURPOSE: To evaluate a novel fitting algorithm for estimation of alignment curve (AC) radius during orthokeratology lens trial. METHODS: Fifty myopic children were recruited in this study. AC radii were estimated by both traditional method using flat K readings and eccentricity values and by a novel fitting algorithm, which was composed of 256 circle fittings using corneal elevation data from the corresponding AC region and a succedent toric fitting based on these calculated AC curvatures...
October 4, 2017: Contact Lens & Anterior Eye: the Journal of the British Contact Lens Association
Quyen D Chu, Meijiao Zhou, Kaelen L Medeiros, Prakash Peddi, Xiao Cheng Wu
BACKGROUND: The Cancer and Leukemia Group B (CALGB) 9343 trial demonstrated that adjuvant radiation therapy (RT) can be omitted in women 70 years or older, with small (≤2 cm), negative lymph nodes, estrogen receptor (ER)-positive breast cancer. We examined whether RT usage following the CALGB publication had decreased over time and evaluated sociodemographic and clinical factors associated with RT omission. MATERIALS AND METHODS: From the National Cancer Data Base, we analyzed a cohort of 120,308 women aged 70 years or older with stage I, ER-positive breast cancer who underwent lumpectomy...
October 2017: Anticancer Research
Blaire Dube, Stephen M Emrich, Naseem Al-Aidroos
Across 2 experiments we revisited the filter account of how feature-based attention regulates visual working memory (VWM). Originally drawing from discrete-capacity ("slot") models, the filter account proposes that attention operates like the "bouncer in the brain," preventing distracting information from being encoded so that VWM resources are reserved for relevant information. Given recent challenges to the assumptions of discrete-capacity models, we investigated whether feature-based attention plays a broader role in regulating memory...
October 2017: Journal of Experimental Psychology. Human Perception and Performance
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