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https://www.readbyqxmd.com/read/28102943/comparison-of-five-cluster-validity-indices-performance-in-brain-18-f-fet-pet-image-segmentation-using-k-means
#1
Bedor Abualhaj, Guoyang Weng, Melissa Ong, Ali Asgar Attarwala, Flavia Molina, Karen Büsing, Gerhard Glatting
PURPOSE: Dynamic [(18) F]fluoro-ethyl-L-tyrosine positron emission tomography ([(18) F]FET-PET) is used to identify tumor lesions for radiotherapy treatment planning, to differentiate glioma recurrence from radiation necrosis and to classify gliomas grading. To segment different regions in the brain k-means cluster analysis can be used. The main disadvantage of k-means is that the number of clusters must be pre-defined. In this study, we therefore compared different cluster validity indices for automated and reproducible determination of the optimal number of clusters based on the dynamic PET data...
January 2017: Medical Physics
https://www.readbyqxmd.com/read/28102759/antisense-transcription-of-the-myotonic-dystrophy-locus-yields-low-abundant-rnas-with-and-without-cag-n-repeat
#2
Anke E E G Gudde, Simon J van Heeringen, Amanda I de Oude, Ingeborg D G van Kessel, Joseph Estabrook, Eric T Wang, Bé Wieringa, Derick G Wansink
The unstable (CTG·CAG)n trinucleotide repeat in the myotonic dystrophy type 1 (DM1) locus is bidirectionally transcribed from genes with terminal overlap. By transcription in the sense direction, the DMPK gene produces various alternatively spliced mRNAs with a (CUG)n repeat in their 3' UTR. Expression in opposite orientation reportedly yields (CAG)n-repeat containing RNA, but both structure and biological significance of this antisense gene (DM1-AS) are largely unknown. Via a combinatorial approach of computational and experimental analyses of RNA from unaffected individuals and DM1 patients we discovered that DM1-AS spans >6 kb, contains alternative transcription start sites and uses alternative polyadenylation sites up- and downstream of the (CAG)n repeat...
January 19, 2017: RNA Biology
https://www.readbyqxmd.com/read/28102602/postpatterned-electrodes-for-flexible-node-type-lithium-ion-batteries
#3
Minjoon Park, Hyungyeon Cha, Yoonji Lee, Jaehyung Hong, Sung Youb Kim, Jaephil Cho
A flexible node-type lithium-ion battery (LIB) with novel postpatterned electrodes is developed via a simple, one-step process involving an imprinting step of a conventional electrode in the presence of a flattened mesh template. The node-type LIBs containing segmented parts for energy storage and mechanical deformation demonstrate a good cycle stability.
January 19, 2017: Advanced Materials
https://www.readbyqxmd.com/read/28102450/hidden-blood-loss-and-the-influential-factors-after-percutaneous-kyphoplasty-surgery
#4
Yao-Sen Wu, Hui Zhang, Wen-Hao Zheng, Zhen-Hua Feng, Ze-Xin Chen, Yan Lin
PURPOSE: Percutaneous kyphoplasty (PKP) is a minimally invasive procedure for the treatment of osteoporotic vertebral compression fractures (OVCFs). It is generally considered that there is little blood loss during the surgery. However, a significant perioperative hidden blood loss (HBL) is neglected. This study was to examine the amount of HBL and determine the influential factors during PKP. METHODS: From January 2015 to January 2016, 115 patients with OVCFs who were scheduled to have a PKP were enrolled in this study...
January 19, 2017: European Spine Journal
https://www.readbyqxmd.com/read/28102436/-urethral-stricture-rate-after-prostate-cancer-radiotherapy-five-year-data-of-a-certified-prostate-cancer-center
#5
J Kranz, G Maurer, U Maurer, O Deserno, S Schulte, J Steffens
BACKGROUND: A urethral stricture is a scar of the urethral epithelium which can cause obstructive voiding dysfunction with consequential damage of the upper urinary tract. Almost 45% of all strictures are iatrogenic; they develop in 2-9% of patients after radical prostatectomy, but can also occur after prostate cancer radiotherapy. This study provides 5‑year data of a certified prostate cancer center (PKZ) in terms of urethral strictures. MATERIALS AND METHODS: Between 01/2008 and 12/2012 a total of 519 men were irradiated for prostate cancer (LDR and HDR brachytherapy as well as external beam radiation)...
January 19, 2017: Der Urologe. Ausg. A
https://www.readbyqxmd.com/read/28102102/impact-of-thoracic-endovascular-aortic-repair-on-pulsatile-circumferential-and-longitudinal-strain-in-patients-with-aneurysm
#6
Foeke J H Nauta, Guido H W van Bogerijen, Chiara Trentin, Michele Conti, Ferdinando Auricchio, Frans L Moll, Joost A van Herwaarden, Santi Trimarchi
PURPOSE: To quantify both pulsatile longitudinal and circumferential aortic strains before and after thoracic endovascular aortic repair (TEVAR), potentially clarifying TEVAR-related complications. METHODS: This retrospective study assessed the impact of TEVAR on pulsatile aortic strains through custom developed software and cardiac-gated computed tomography imaging of 8 thoracic aneurysm patients (mean age 71.0±8.2 years; 6 men) performed before TEVAR and during follow-up (median 0...
January 1, 2017: Journal of Endovascular Therapy
https://www.readbyqxmd.com/read/28101866/titin-and-nebulin-in-thick-and-thin-filament-length-regulation
#7
Larissa Tskhovrebova, John Trinick
In this review we discuss the history and the current state of ideas related to the mechanism of size regulation of the thick (myosin) and thin (actin) filaments in vertebrate striated muscles. Various hypotheses have been considered during of more than half century of research, recently mostly involving titin and nebulin acting as templates or 'molecular rulers', terminating exact assembly. These two giant, single-polypeptide, filamentous proteins are bound in situ along the thick and thin filaments, respectively, with an almost perfect match in the respective lengths and structural periodicities...
2017: Sub-cellular Biochemistry
https://www.readbyqxmd.com/read/28101864/filamentous-structure-of-hard-%C3%AE-keratins-in-the-epidermal-appendages-of-birds-and-reptiles
#8
R D Bruce Fraser, David A D Parry
The structures of avian and reptilian epidermal appendages, such as feathers, claws and scales, have been modelled using X-ray diffraction and electron microscopy data, combined with sequence analyses. In most cases, a family of closely related molecules makes up the bulk of the appendage, and each of these molecules contains a central β-rich 34-residue segment, which has been identified as the principal component of the framework of the 3.4 nm diameter filaments. The N- and C-terminal segments form the matrix component of the filament/matrix complex...
2017: Sub-cellular Biochemistry
https://www.readbyqxmd.com/read/28101862/crystallographic-studies-of-intermediate-filament-proteins
#9
Dmytro Guzenko, Anastasia A Chernyatina, Sergei V Strelkov
Intermediate filaments (IFs), together with microtubules and actin microfilaments, are the three main cytoskeletal components in metazoan cells. IFs are formed by a distinct protein family, which is made up of 70 members in humans. Most IF proteins are tissue- or organelle-specific, which includes lamins, the IF proteins of the nucleus. The building block of IFs is an elongated dimer, which consists of a central α-helical 'rod' domain flanked by flexible N- and C-terminal domains. The conserved rod domain is the 'signature feature' of the IF family...
2017: Sub-cellular Biochemistry
https://www.readbyqxmd.com/read/28101860/the-structure-and-topology-of-%C3%AE-helical-coiled-coils
#10
Andrei N Lupas, Jens Bassler, Stanislaw Dunin-Horkawicz
α-Helical coiled coils constitute one of the most diverse folds yet described. They range in length over two orders of magnitude; they form rods, segmented ropes, barrels, funnels, sheets, spirals, and rings, which encompass anywhere from two to more than 20 helices in parallel or antiparallel orientation; they assume different helix crossing angles, degrees of supercoiling, and packing geometries. This structural diversity supports a wide range of biological functions, allowing them to form mechanically rigid structures, provide levers for molecular motors, project domains across large distances, mediate oligomerization, transduce conformational changes and facilitate the transport of other molecules...
2017: Sub-cellular Biochemistry
https://www.readbyqxmd.com/read/28101760/a-cad-of-fully-automated-colonic-polyp-detection-for-contrasted-and-non-contrasted-ct-scans
#11
Gökalp Tulum, Bülent Bolat, Onur Osman
PURPOSE: Computer-aided detection (CAD) systems are developed to help radiologists detect colonic polyps over CT scans. It is possible to reduce the detection time and increase the detection accuracy rates by using CAD systems. In this paper, we aimed to develop a fully integrated CAD system for automated detection of polyps that yields a high polyp detection rate with a reasonable number of false positives. METHODS: The proposed CAD system is a multistage implementation whose main components are: automatic colon segmentation, candidate detection, feature extraction and classification...
January 18, 2017: International Journal of Computer Assisted Radiology and Surgery
https://www.readbyqxmd.com/read/28101700/predicting-brain-metastases-for-non-small-cell-lung-cancer-based-on-magnetic-resonance-imaging
#12
Gang Yin, Churong Li, Heng Chen, Yangkun Luo, Lucia Clara Orlandini, Pei Wang, Jinyi Lang
In this study the relationship between brain structure and brain metastases (BM) occurrence was analyzed. A model for predicting the time of BM onset in patients with non-small cell lung cancer (NSCLC) was proposed. Twenty patients were used to develop the model, whereas the remaining 69 were used for independent validation and verification of the model. Magnetic resonance images were segmented into cerebrospinal fluid, gray matter (GM), and white matter using voxel-based morphometry. Automatic anatomic labeling template was used to extract 116 brain regions from the GM volume...
January 18, 2017: Clinical & Experimental Metastasis
https://www.readbyqxmd.com/read/28101674/posterior-tail-development-in-the-salamander-eurycea-cirrigera-exploring-cellular-dynamics-across-life-stages
#13
Janet L Vaglia, Chet Fornari, Paula K Evans
During embryogenesis, the body axis elongates and specializes. In vertebrate groups such as salamanders and lizards, elongation of the posterior body axis (tail) continues throughout life. This phenomenon of post-embryonic tail elongation via addition of vertebrae has remained largely unexplored, and little is known about the underlying developmental mechanisms that promote vertebral addition. Our research investigated tail elongation across life stages in a non-model salamander species, Eurycea cirrigera (Plethodontidae)...
January 18, 2017: Development Genes and Evolution
https://www.readbyqxmd.com/read/28101648/the-limits-of-boundaries-unpacking-localization-and-cognitive-mapping-relative-to-a-boundary
#14
Ruojing Zhou, Weimin Mou
Previous research (Zhou, Mou, Journal of Experimental Psychology: Learning, Memory and Cognition 42(8):1316-1323, 2016) showed that learning individual locations relative to a single landmark, compared to learning relative to a boundary, led to more accurate inferences of inter-object spatial relations (cognitive mapping of multiple locations). Following our past findings, the current study investigated whether the larger number of reference points provided by a homogeneous circular boundary, as well as less accessible knowledge of direct spatial relations among the multiple reference points, would lead to less effective cognitive mapping relative to the boundary...
January 19, 2017: Psychological Research
https://www.readbyqxmd.com/read/28101418/multi-surface-segmentation-of-oct-images-with-amd-using-sparse-high-order-potentials
#15
Jorge Oliveira, Sérgio Pereira, Luís Gonçalves, Manuel Ferreira, Carlos A Silva
In age-related macular degeneration (AMD), the quantification of drusen is important because it is correlated with the evolution of the disease to an advanced stage. Therefore, we propose an algorithm based on a multi-surface framework for the segmentation of the limiting boundaries of drusen: the inner boundary of the retinal pigment epithelium + drusen complex (IRPEDC) and the Bruch's membrane (BM). Several segmentation methods have been considerably successful in segmenting retinal layers of healthy retinas in optical coherence tomography (OCT) images...
January 1, 2017: Biomedical Optics Express
https://www.readbyqxmd.com/read/28101412/visualization-of-micro-capillaries-using-optical-coherence-tomography-angiography-with-and-without-adaptive-optics
#16
Matthias Salas, Marco Augustin, Laurin Ginner, Abhishek Kumar, Bernhard Baumann, Rainer Leitgeb, Wolfgang Drexler, Sonja Prager, Julia Hafner, Ursula Schmidt-Erfurth, Michael Pircher
The purpose of this work is to investigate the benefits of adaptive optics (AO) technology for optical coherence tomography angiography (OCTA). OCTA has shown great potential in non-invasively enhancing the contrast of vessels and small capillaries. Especially the capability of the technique to visualize capillaries with a lateral extension that is below the transverse resolution of the system opens unique opportunities in diagnosing retinal vascular diseases. However, there are some limitations of this technology such as shadowing and projection artifacts caused by overlying vasculature or the inability to determine the true extension of a vessel...
January 1, 2017: Biomedical Optics Express
https://www.readbyqxmd.com/read/28101399/stimulus-evoked-outer-segment-changes-occur-before-the-hyperpolarization-of-retinal-photoreceptors
#17
Yiming Lu, Benquan Wang, David R Pepperberg, Xincheng Yao
Transient retinal phototropism (TRP) has been predominantly observed in rod photoreceptors activated by oblique visible light stimulation. Dynamic confocal microscopy and optical coherence tomography (OCT) have revealed rod outer segment (ROS) movement as the physical source of TRP. However, the physiological source of ROS movement is still not well understood. In this study, concurrent near-infrared imaging of TRP and electroretinogram (ERG) measurement of retinal electrophysiology revealed that ROS movement occurs before the onset of the ERG a-wave, which is known to reflect the hyperpolarization of retinal photoreceptors...
January 1, 2017: Biomedical Optics Express
https://www.readbyqxmd.com/read/28101349/clear-cell-carcinoma-of-the-lower-uterine-segment-a-case-report
#18
Yusuke Matoba, Iori Kisu, Keiko Saotome, Motoko Katayama, Makiko Taniguchi, Yumiko Miura, Taeko Goto, Nobumaru Hirao
Uterine carcinoma of the lower uterine segment (LUS) is a rare tumor that accounts for 3-3.5% of cases of uterine malignant cancer. The tumor arises from the lower region of the uterine body through the upper region of the cervix. The present study reported a case of clear cell carcinoma that originated from the LUS. A 50-year-old woman visited a local hospital due to irregular vaginal bleeding. She was suspected to have a uterine tumor and was referred to Tachikawa Hospital (Tokyo, Japan). Transvaginal ultrasound and magnetic resonance imaging revealed a uterine tumor from the lower region of the uterine body through the upper region of the cervix...
December 2016: Molecular and Clinical Oncology
https://www.readbyqxmd.com/read/28100880/significant-association-of-serum-adiponectin-and-creatine-kinase-mb-levels-in-st-segment-elevation-myocardial-infarction
#19
Tomoaki Natsukawa, Norikazu Maeda, Shiro Fukuda, Masaya Yamaoka, Yuya Fujishima, Hirofumi Nagao, Fumi Sato, Hitoshi Nishizawa, Hirotaka Sawano, Yasuyuki Hayashi, Tohru Funahashi, Tatsuro Kai, Iichiro Shimomura
AIMS: Adiponectin, an adipocyte-specific secretory protein, abundantly exists in the blood stream while its concentration paradoxically decreases in obesity. Hypoadiponectinemia is one of risks of cardiovascular diseases. However, impact of serum adiponectin concentration on acute ischemic myocardial damages has not been fully clarified. The present study investigated the association of serum adiponectin and creatine kinase (CK)-MB levels in subjects with ST-segment elevation myocardial infarction (STEMI)...
January 17, 2017: Journal of Atherosclerosis and Thrombosis
https://www.readbyqxmd.com/read/28100805/differences-in-mobility-at-the-range-edge-of-an-expanding-invasive-population-of-xenopus-laevis-in-the-west-of-france
#20
Vivien Louppe, Julien Courant, Anthony Herrel
Theoretical models predict that spatial sorting at the range edge of expanding populations should favor individuals with increased mobility relative to individuals at the center of the range. Despite the fact that empirical evidence for the evolution of locomotor performance at the range edge is rare, data on cane toads support this model. However, whether this can be generalized to other species remains largely unknown. Here, we provide data on locomotor stamina and limb morphology in individuals from two sites: one from the center and one from the periphery of an expanding population of the clawed frog Xenopus laevis in France where it was introduced about 30 years ago...
January 15, 2017: Journal of Experimental Biology
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