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https://www.readbyqxmd.com/read/28207387/distortion-correction-in-fetal-epi-using-non-rigid-registration-with-a-laplacian-constraint
#1
Maria Kuklisova Murgasova, Georgia Lockwood-Estrin, Rita G Nunes, Shaihan Malik, Mary Rutherford, Daniel Rueckert, Joseph Hajnal
Geometric distortion induced by the main B0 field disrupts the consistency of fetal EPI data, on which diffusion and functional MRI is based. In this paper we present a novel data-driven method for simultaneous motion and distortion correction of fetal EPI. A motion-corrected and reconstructed T2 weighted ssFSE volume is used as a model of undistorted fetal brain anatomy. Our algorithm interleaves two registration steps: estimation of fetal motion parameters by aligning EPI slices to the model; and deformable registration of EPI slices to slices simulated from the undistorted model to estimate the distortion field...
February 9, 2017: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/28196652/simulation-of-fetal-heart-rate-variability-with-a-mathematical-model
#2
Germaine J L M Jongen, M Beatrijs van der Hout-van der Jagt, S Guid Oei, Frans N van de Vosse, Peter H M Bovendeerd
In the clinic, the cardiotocogram (CTG), the combined registration of fetal heart rate (FHR) and uterine contractions, is used to predict fetal well-being. Amongst others, fetal heart rate variability (FHRV) is an important indicator of fetal distress. In this study we add FHRV to our previously developed CTG simulation model, in order to improve its use as a research and educational tool. We implemented three sources of variability by applying either 1/f or white noise to the peripheral vascular resistance, baroreceptor output, or efferent vagal signal...
February 11, 2017: Medical Engineering & Physics
https://www.readbyqxmd.com/read/28191646/non-invasive-evaluation-of-blood-oxygen-saturation-and-hematocrit-from-t1-and-t2-relaxation-times-in-vitro-validation-in-fetal-blood
#3
Sharon Portnoy, Mike Seed, John G Sled, Christopher K Macgowan
PURPOSE: We propose an analytical method for calculating blood hematocrit (Hct) and oxygen saturation (sO2 ) from measurements of its T1 and T2 relaxation times. THEORY: Through algebraic substitution, established two-compartment relationships describing R1=T1-1 and R2=T2-1 as a function of hematocrit and oxygen saturation were rearranged to solve for Hct and sO2 in terms of R1 and R2 . Resulting solutions for Hct and sO2 are the roots of cubic polynomials. METHODS: Feasibility of the method was established by comparison of Hct and sO2 estimates obtained from relaxometry measurements (at 1...
February 12, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28183674/albumin-coatings-by-alternating-current-electrophoretic-deposition-for-improving-corrosion-resistance-and-bioactivity-of-titanium-implants
#4
Sarah Höhn, Annabel Braem, Bram Neirinck, Sannakaisa Virtanen
Although Ti alloys are generally regarded to be highly corrosion resistant, inflammatory conditions following surgery can instigate breakdown of the TiO2 passivation layer leading to an increased metal ion release. Furthermore proteins present in the surrounding tissue will readily adsorb on a titanium surface after implantation. In this paper alternating current electrophoretic deposition (AC-EPD) of bovine serum albumin (BSA) on Ti6Al4V was investigated in order to increase the corrosion resistance and control the protein adsorption capability of the implant surface...
April 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28182551/fetal-qt-interval-estimation-using-sequential-hypothesis-testing
#5
Suhong Yu, Barry VanVeen, William Lutter, Ronald Wakai
OBJECTIVE: Recent studies utilizing fetal magnetocardiography have demonstrated the efficacy of corrected QT interval (QTc) measurement for in utero diagnosis and prognosis of long QT syndrome, a leading cause of sudden death in early life. The objective of the study was to formulate and test a novel statistical estimation method to detect the end of the fetal T-wave and thereby improve the accuracy of fetal QT interval measurement. METHODS: To detect the end of the T-wave we apply a sequential composite hypothesis test to decide when the T-wave has returned to baseline...
February 2, 2017: IEEE Transactions on Bio-medical Engineering
https://www.readbyqxmd.com/read/28153573/development-and-assessment-of-a-novel-task-trainer-and-targeting-tasks-for-ultrasound-guided-invasive-procedures
#6
Joshua F Nitsche, Kristina M Shumard, Brian C Brost
RATIONALE AND OBJECTIVES: The American Institute of Ultrasound in Medicine (AIUM) recommends that all providers performing ultrasound-guided invasive procedures be competent in a core set of guidance skills common to all ultrasound-guided procedures, including in-plane and out-of-plane needle guidance and needle imaging optimization techniques such as probe translation, rotation, and heel-toe standoff. To allow for the practice and assessment of these core skills, we have created a novel task trainer and set of targeting tasks, and sought to obtain validity evidence in the content and response process domains for this training and assessment system according to the Standards for Educational and Psychological Testing...
January 30, 2017: Academic Radiology
https://www.readbyqxmd.com/read/28152274/fe-3-seo42-dual-doped-nano-hydroxyapatite-a-novel-material-for-biomedical-applications
#7
Ammar Z Alshemary, Ahmet Engin Pazarceviren, Aysen Tezcaner, Zafer Evis
Dual ions substituted hydroxyapatite (HA) received attention from scientists and researchers in the biomedical field owing to their excellent biological properties. This paper presents a novel biomaterial, which holds potential for bone tissue applications. Herein, we have successfully incorporated ferric (Fe(3+) )/selenate (SeO42-) ions into the HA structure (Ca10-x-y Fey (PO4 )6-x (SeO4 )x (OH)2-x-y Oy ) (Fe-SeHA) through a microwave refluxing process. The Fe-SeHA materials were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and field emission scanning electron microscopy (FESEM)...
February 2, 2017: Journal of Biomedical Materials Research. Part B, Applied Biomaterials
https://www.readbyqxmd.com/read/28089487/estimation-of-national-regional-and-global-prevalence-of-alcohol-use-during-pregnancy-and-fetal-alcohol-syndrome-a-systematic-review-and-meta-analysis
#8
Svetlana Popova, Shannon Lange, Charlotte Probst, Gerrit Gmel, Jürgen Rehm
BACKGROUND: Alcohol use during pregnancy is the direct cause of fetal alcohol syndrome (FAS). We aimed to estimate the prevalence of alcohol use during pregnancy and FAS in the general population and, by linking these two indicators, estimate the number of pregnant women that consumed alcohol during pregnancy per one case of FAS. METHODS: We began by doing two independent comprehensive systematic literature searches using multiple electronic databases for original quantitative studies that reported the prevalence in the general population of the respective country of alcohol use during pregnancy published from Jan 1, 1984, to June 30, 2014, or the prevalence of FAS published from Nov 1, 1973, to June 30, 2015, in a peer-reviewed journal or scholarly report...
January 13, 2017: Lancet Global Health
https://www.readbyqxmd.com/read/28048319/su-f-p-19-fetal-dose-estimate-for-a-high-dose-fluoroscopy-guided-intervention-using-modern-data-tools
#9
J Moirano
PURPOSE: An accurate dose estimate is necessary for effective patient management after a fetal exposure. In the case of a high-dose exposure, it is critical to use all resources available in order to make the most accurate assessment of the fetal dose. This work will demonstrate a methodology for accurate fetal dose estimation using tools that have recently become available in many clinics, and show examples of best practices for collecting data and performing the fetal dose calculation...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28029359/computational-modeling-of-the-structure-function-relationship-in-human-placental-terminal-villi
#10
R Plitman Mayo, J Olsthoorn, D S Charnock-Jones, G J Burton, M L Oyen
Placental oxygen transport takes place at the final branches of the villous tree and is dictated by the relative arrangement of the maternal and fetal circulations. Modeling techniques have failed to accurately assess the structure-function relationship in the terminal villi due to the geometrical complexity. Three-dimensional blood flow and oxygen transport was modeled in four terminal villi reconstructed from confocal image stacks. The blood flow was analyzed along the center lines of capillary segments and the effect of the variability in capillary diameter, tortuosity and branching was investigated...
October 12, 2016: Journal of Biomechanics
https://www.readbyqxmd.com/read/28003175/design-of-a-serious-game-for-handling-obstetrical-emergencies
#11
Estelle Jean Dit Gautier, Virginie Bot-Robin, Aurélien Libessart, Guillaume Doucède, Michel Cosson, Chrystèle Rubod
BACKGROUND: The emergence of new technologies in the obstetrical field should lead to the development of learning applications, specifically for obstetrical emergencies. Many childbirth simulations have been recently developed. However, to date none of them have been integrated into a serious game. OBJECTIVE: Our objective was to design a new type of immersive serious game, using virtual glasses to facilitate the learning of pregnancy and childbirth pathologies...
December 21, 2016: JMIR Serious Games
https://www.readbyqxmd.com/read/27943372/imperfect-practice-makes-perfect-error-management-training-improves-transfer-of-learning
#12
Liv Dyre, Ann Tabor, Charlotte Ringsted, Martin G Tolsgaard
CONTEXT: Traditionally, trainees are instructed to practise with as few errors as possible during simulation-based training. However, transfer of learning may improve if trainees are encouraged to commit errors. The aim of this study was to assess the effects of error management instructions compared with error avoidance instructions during simulation-based ultrasound training. METHODS: Medical students (n = 60) with no prior ultrasound experience were randomised to error management training (EMT) (n = 32) or error avoidance training (EAT) (n = 28)...
February 2017: Medical Education
https://www.readbyqxmd.com/read/27924908/development-of-novel-noninvasive-prenatal-testing-protocol-for-whole-autosomal-recessive-disease-using-picodroplet-digital-pcr
#13
Mun Young Chang, Ah Reum Kim, Min Young Kim, Soyoung Kim, Jinsun Yoon, Jae Joon Han, Soyeon Ahn, Changsoo Kang, Byung Yoon Choi
We developed a protocol of noninvasive prenatal testing (NIPT), employing a higher-resolution picodroplet digital PCR, to detect genetic imbalance in maternal plasma DNA (mpDNA) caused by cell-free fetal DNA (cffDNA). In the present study, this approach was applied to four families with autosomal recessive (AR) congenital sensorineural hearing loss. First, a fraction of the fetal DNA in mpDNA was calculated. Then, we made artificial DNA mixtures (positive and negative controls) to simulate mpDNA containing the fraction of cffDNA with or without mutations...
December 7, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27897008/tracing-co-regulatory-network-dynamics-in-noisy-single-cell-transcriptome-trajectories
#14
Pablo Cordero, Joshua M Stuart
The availability of gene expression data at the single cell level makes it possible to probe the molecular underpinnings of complex biological processes such as differentiation and oncogenesis. Promising new methods have emerged for reconstructing a progression 'trajectory' from static single-cell transcriptome measurements. However, it remains unclear how to adequately model the appreciable level of noise in these data to elucidate gene regulatory network rewiring. Here, we present a framework called Single Cell Inference of MorphIng Trajectories and their Associated Regulation (SCIMITAR) that infers progressions from static single-cell transcriptomes by employing a continuous parametrization of Gaussian mixtures in high-dimensional curves...
2016: Pacific Symposium on Biocomputing
https://www.readbyqxmd.com/read/27891739/acardiac-twin-pregnancies-part-iv-acardiac-onset-from-unequal-embryonic-splitting-simulated-by-a-fetoplacental-resistance-model
#15
Martin J C van Gemert, Jeroen P H M van den Wijngaard, K Marieke Paarlberg, Helena M Gardiner, Peter G J Nikkels
BACKGROUND: Benirschke postulated that acardiac twinning occurs when markedly unequal embryonic splitting combines with arterioarterial (AA) and venovenous placental anastomoses. We tested this hypothesis by model simulations and by comparison of outcomes with 18 "pseudo-" (twin fetus with beating heart but otherwise with clear signs of an acardiac) and 3 "normal" acardiac cases. METHODS: The smaller/larger cell volume ratio at embryonic splitting becomes the smaller/larger embryonic/fetal blood volume ratio (a)...
November 28, 2016: Birth Defects Research. Part A, Clinical and Molecular Teratology
https://www.readbyqxmd.com/read/27884665/airway-management-for-cesarean-delivery-performed-under-general-anesthesia
#16
S Rajagopalan, M Suresh, S L Clark, B Serratos, S Chandrasekhar
BACKGROUND: With the increasing popularity of neuraxial anesthesia, there has been a decline in the use of general anesthesia for cesarean delivery. We sought to examine the incidence, outcome and characteristics associated with a failed airway in patients undergoing cesarean delivery under general anesthesia. METHODS: A retrospective review of airway management in women undergoing cesarean delivery under general anesthesia over an eight-year period from 2006-2013 at an academic medical center was conducted...
February 2017: International Journal of Obstetric Anesthesia
https://www.readbyqxmd.com/read/27854395/prediction-of-stillbirth-from-placental-growth-factor-at-19-24-weeks
#17
J E Aupont, R Akolekar, A Illian, S Neonakis, K H Nicolaides
OBJECTIVES: To investigate whether the addition of maternal serum placental growth factor (PlGF) measured at 19-24 weeks' gestation improves the performance of screening for stillbirth that is achieved by a combination of maternal factors, fetal biometry and uterine artery pulsatility index (UtA-PI) and to evaluate the performance of screening with this model for all stillbirths and those due to impaired placentation and unexplained or other causes. METHODS: This was a prospective screening study of 70 003 singleton pregnancies including 268 stillbirths, carried out in two phases...
November 2016: Ultrasound in Obstetrics & Gynecology
https://www.readbyqxmd.com/read/27853245/mechanism-of-consistent-gyrus-formation-an-experimental-and-computational-study
#18
Tuo Zhang, Mir Jalil Razavi, Xiao Li, Hanbo Chen, Tianming Liu, Xianqiao Wang
As a significant type of cerebral cortical convolution pattern, the gyrus is widely preserved across species. Although many hypotheses have been proposed to study the underlying mechanisms of gyrus formation, it is currently still far from clear which factors contribute to the regulation of consistent gyrus formation. In this paper, we employ a joint analysis scheme of experimental data and computational modeling to investigate the fundamental mechanism of gyrus formation. Experimental data on mature human brains and fetal brains show that thicker cortices are consistently found in gyral regions and gyral cortices have higher growth rates...
November 17, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27845652/a-fixed-lag-kalman-smoother-to-filter-power-line-interference-in-electrocardiogram-recordings
#19
Guy J J Warmerdam, Rik Vullings, Lars Schmitt, Judith O E H van Laar, Jan W M Bergmans
OBJECTIVE: Filtering power line interference (PLI) from electrocardiogram (ECG) recordings can lead to significant distortions of the ECG and mask clinically relevant features in ECG waveform morphology. The objective of this study is to filter PLI from ECG recordings with minimal distortion of the ECG waveform. METHODS: In this paper, we propose a fixed-lag Kalman smoother with adaptive noise estimation. The performance of this Kalman smoother in filtering PLI is compared to that of a fixedbandwidth notch filter and several adaptive PLI filters that have been proposed in the literature...
November 8, 2016: IEEE Transactions on Bio-medical Engineering
https://www.readbyqxmd.com/read/27834868/steric-clash-in-the-set-domain-of-histone-methyltransferase-nsd1-as-a-cause-of-sotos-syndrome-and-its-genetic-heterogeneity-in-a-brazilian-cohort
#20
Kyungsoo Ha, Priya Anand, Jennifer A Lee, Julie R Jones, Chong Ae Kim, Debora Romeo Bertola, Jonathan D J Labonne, Lawrence C Layman, Wolfgang Wenzel, Hyung-Goo Kim
Most histone methyltransferases (HMTase) harbor a predicted Su(var)3-9, Enhancer-of-zeste, Trithorax (SET) domain, which transfers a methyl group to a lysine residue in their substrates. Mutations of the SET domains were reported to cause intellectual disability syndromes such as Sotos, Weaver, or Kabuki syndromes. Sotos syndrome is an overgrowth syndrome with intellectual disability caused by haploinsufficiency of the nuclear receptor binding SET domain protein 1 (NSD1) gene, an HMTase at 5q35.2-35.3. Here, we analyzed NSD1 in 34 Brazilian Sotos patients and identified three novel and eight known mutations...
November 9, 2016: Genes
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