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https://www.readbyqxmd.com/read/28212570/altered-amygdala-and-hippocampus-effective-connectivity-in-mild-cognitive-impairment-patients-with-depression-a-resting-state-functional-mr-imaging-study-with-granger-causality-analysis
#1
Li Juan Zheng, Gui Fen Yang, Xin Yuan Zhang, Yun Fei Wang, Ya Liu, Gang Zheng, Guang Ming Lu, Long Jiang Zhang, Ying Han
Neuroimaging studies have demonstrated that the major depression disorder would increase the risk of dementia in the older with amnestic cognitive impairment. We used granger causality analysis algorithm to explore the amygdala- and hippocampus-based directional connectivity patterns in 12 patients with major depression disorder and amnestic cognitive impairment (mean age: 69.5 ± 10.3 years), 13 amnestic cognitive impairment patients (mean age: 72.7 ± 8.5 years) and 14 healthy controls (mean age: 64.7 ± 7...
February 15, 2017: Oncotarget
https://www.readbyqxmd.com/read/28212059/pediatric-chest-ct-diagnostic-reference-ranges-development-and-application
#2
Keith J Strauss, Marilyn J Goske, Alexander J Towbin, Debapriya Sengupta, Michael J Callahan, Kassa Darge, Daniel J Podberesky, Donald P Frush, Charles Maxfield, Sjirk J Westra, Jeffrey S Prince, Huimin Wu, Mythreyi Bhargavan-Chatfield
Purpose To determine diagnostic reference ranges on the basis of the size of a pediatric patient's chest and to develop a method to estimate computed tomographic (CT) scanner-specific mean size-specific dose estimates (SSDEs) as a function of patient size and the radiation output of each CT scanner at a site. Materials and Methods The institutional review boards of each center approved this retrospective, HIPAA-compliant, multicenter study; informed consent was waived. CT dose indexes (SSDE, volume CT dose index, and dose length product) of 518 pediatric patients (mean age, 9...
February 17, 2017: Radiology
https://www.readbyqxmd.com/read/28212053/transthoracic-echocardiography-pitfalls-and-limitations-as-delineated-at-cardiac-ct-and-mr-imaging
#3
Sachin B Malik, Natalie Chen, Rex A Parker, Joe Y Hsu
Transthoracic echocardiography ( TTE transthoracic echocardiography ) is a critical tool in the field of clinical cardiology. It often serves as one of the first-line imaging modalities in the evaluation of cardiac disease owing to its low cost, portability, widespread availability, lack of ionizing radiation, and ability to evaluate both anatomy and function of the heart. Consequently, a large majority of patients undergoing a cardiac computed tomography (CT) or magnetic resonance (MR) imaging examination will have a TTE transthoracic echocardiography available for review...
February 17, 2017: Radiographics: a Review Publication of the Radiological Society of North America, Inc
https://www.readbyqxmd.com/read/28212051/-99m-tc-mag3-image-wisely
#4
Andrew T Taylor, Russell D Folks, A K M Fazlur Rahman, Aruna Polsani, Eva V Dubovsky, Raghuveer Halkar, Amita Manatunga
Purpose To determine if commonly administered doses of technetium 99m ((99m)Tc) mertiatide (MAG3) in the range of 300-370 MBq (approximately 8-10 mCi) contribute to image interpretation and justify the resulting radiation exposure. Materials and Methods The respective institutional review boards approved this HIPAA-compliant study and waived informed consent. Baseline and furosemide (99m)Tc-MAG3 imaging examinations in 50 patients suspected of having renal obstruction and 48 patients suspected of having renovascular hypertension (RVH) were randomly selected from archived databases and were independently scored by three experienced readers without access to 2-second flow images...
February 17, 2017: Radiology
https://www.readbyqxmd.com/read/28212005/stimuli-responsive-polymersomes-for-biomedical-applications
#5
Xiuli Hu, Yuqi Zhang, Zhigang Xie, Xiabin Jing, Adriano Bellotti, Zhen Gu
Polymersomes, the structural analogues of liposomes, are hollow structures enclosed by a bilayer membrane made from amphiphilic copolymers. Polymersomes have been proposed to mimic the structure and properties of cellular membranes and viral capsids. Excellent robustness and stability, chemical versatility for tunable membrane properties and surface functionalization make polymersomes attractive candidates for drug delivery, diagnostic imaging, nanoreactor vessels, and artificial organelles. In further biomimetic strategies, stimuli-responsive polymersomes that can recognize various external physical or internal biological environmental stimuli and conduct "on demand" release in dose-, spatial-, and temporal-controlled fashions have been widely developed...
February 17, 2017: Biomacromolecules
https://www.readbyqxmd.com/read/28211966/formation-of-organometallic-intermediate-states-in-on-surface-ullmann-couplings
#6
Dennis Barton, Hong-Ying Gao, Philipp Alexander Held, Armido Studer, Harald Fuchs, Nikos L Doltsinis, Johannes Neugebauer
Possible origins of the formation of organometallic intermediates in on-surface Ullmann couplings have been investigated by surface tunneling microscopy (STM) and density functional theory (DFT) calculations. We consider the case of iodobenzenes on the coinage metals Au, Ag and Cu. We found experimental evidence for the formation of surface vacancies and the presence of metal adatoms in these coupling reactions, which are taken as a hint for the reactive extraction of surface atoms by adsorbates. In a second step, we demonstrate by ab initio molecular dynamics calculations for aryl-iodides on copper that metal atoms can be pulled out of the surface to form metalorganic species...
February 17, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28211963/a-parametric-model-of-the-brain-vascular-system-for-estimation-of-the-arterial-input-function-aif-at-the-tissue-level
#7
Siamak P Nejad-Davarani, Hassan Bagher-Ebadian, James R Ewing, Douglas C Noll, Tom Mikkelsen, Michael Chopp, Quan Jiang
In this paper, we introduce a novel model of the brain vascular system, which is developed based on laws of fluid dynamics and vascular morphology. This model is used to address dispersion and delay of the arterial input function (AIF) at different levels of the vascular structure and to estimate the local AIF in DCE images. We developed a method based on the simplex algorithm and Akaike information criterion to estimate the likelihood of the contrast agent concentration signal sampled in DCE images belonging to different layers of the vascular tree or being a combination of different signal levels from different nodes of this structure...
February 17, 2017: NMR in Biomedicine
https://www.readbyqxmd.com/read/28211961/an-extended-vascular-model-for-less-biased-estimation-of-permeability-parameters-in-dce-t1-images
#8
Siamak P Nejad-Davarani, Hassan Bagher-Ebadian, James R Ewing, Douglas C Noll, Tom Mikkelsen, Michael Chopp, Quan Jiang
One of the key elements in dynamic contrast enhanced (DCE) image analysis is the arterial input function (AIF). Traditionally, in DCE studies a global AIF sampled from a major artery or vein is used to estimate the vascular permeability parameters; however, not addressing dispersion and delay of the AIF at the tissue level can lead to biased estimates of these parameters. To find less biased estimates of vascular permeability parameters, a vascular model of the cerebral vascular system is proposed that considers effects of dispersion of the AIF in the vessel branches, as well as extravasation of the contrast agent (CA) to the extravascular-extracellular space...
February 17, 2017: NMR in Biomedicine
https://www.readbyqxmd.com/read/28211900/amyloid-%C3%AE-oligomers-interact-with-neurexin-and-diminish-neurexin-mediated-excitatory-presynaptic-organization
#9
Yusuke Naito, Yuko Tanabe, Alfred Kihoon Lee, Edith Hamel, Hideto Takahashi
Alzheimer's disease (AD) is characterized by excessive production and deposition of amyloid-beta (Aβ) proteins as well as synapse dysfunction and loss. While soluble Aβ oligomers (AβOs) have deleterious effects on synapse function and reduce synapse number, the underlying molecular mechanisms are not well understood. Here we screened synaptic organizer proteins for cell-surface interaction with AβOs and identified a novel interaction between neurexins (NRXs) and AβOs. AβOs bind to NRXs via the N-terminal histidine-rich domain (HRD) of β-NRX1/2/3 and alternatively-spliced inserts at splicing site 4 of NRX1/2...
February 13, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28211844/a-tool-named-iris-for-versatile-high-throughput-phenotyping-in-microorganisms
#10
George Kritikos, Manuel Banzhaf, Lucia Herrera-Dominguez, Alexandra Koumoutsi, Morgane Wartel, Matylda Zietek, Athanasios Typas
Advances in our ability to systematically introduce and track controlled genetic variance in microorganisms have, in the past decade, fuelled high-throughput reverse genetics approaches. When coupled to quantitative readouts, such approaches are extremely powerful at elucidating gene function and providing insights into the underlying pathways and the overall cellular network organization. Yet, until now, all efforts to quantify microbial macroscopic phenotypes have been restricted to monitoring growth in a small number of model microorganisms...
February 17, 2017: Nature Microbiology
https://www.readbyqxmd.com/read/28211792/one-pot-synthesis-of-in-situ-carbon-coated-fe3o4-as-long-life-lithium-ion-battery-anode
#11
Min Liu, Hongyun Jin, Evan Uchaker, Zhiqiang Xie, Ying Wang, Guozhong Cao, Shuen Hou, Jiangyu Li
Fe3O4 has been regarded as a promising anode material for lithium-ion batteries (LIBs) due to its high theoretical capacity, low cost, and environmental friendliness. In this work, we present a one-pot reducing-composite-hydroxide-mediated (R-CHM) method to synthesize in-situ carbon-coated Fe3O4 (Fe3O4@C) at 280 oC, using Fe(NO3)3·9H2O and PEG800 as raw materials and NaOH/KOH as the medium. The as-prepared Fe3O4 octahedron has an average size of 100 nm in diameter, covered by carbon layer with the thickness of 3 nm , as revealed by FESEM and HRTEM images...
February 17, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28211367/high-quality-four-dimensional-cone-beam-ct-reconstruction-using-motion-compensated-total-variation-regularization
#12
Hua Zhang, Jianhua Ma, Zhaoying Bian, Dong Zeng, Qianjin Feng, Wufan Chen
Four dimensional cone-beam computed tomography (4D-CBCT) has great potential clinical value because its ability to describe tumor and organ motion. But the challenge in 4D-CBCT reconstruction is the limited number of projections at each phase, which resulting in the reconstruction full of noise and streak artifacts with the conventional analytical algorithms. To address this problem, in this paper, we propose a motion compensated total variation regularization approach which tries to maximum explore the temporal coherence of the spatial structures among 4D-CBCT phases...
February 17, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28211218/the-integration-of-mri-in-radiation-therapy-collaboration-of-radiographers-and-radiation-therapists
#13
Robba Rai, Shivani Kumar, Vikneswary Batumalai, Doaa Elwadia, Lucy Ohanessian, Ewa Juresic, Lynette Cassapi, Shalini K Vinod, Lois Holloway, Paul J Keall, Gary P Liney
The increased utilisation of magnetic resonance imaging (MRI) in radiation therapy (RT) has led to the implementation of MRI simulators for RT treatment planning and influenced the development of MRI-guided treatment systems. There is extensive literature on the advantages of MRI for tumour volume and organ-at-risk delineation compared to computed tomography. MRI provides both anatomical and functional information for RT treatment planning (RTP) as well as quantitative information to assess tumour response for adaptive treatment...
February 16, 2017: Journal of Medical Radiation Sciences
https://www.readbyqxmd.com/read/28211187/deletion-of-junctional-adhesion-molecule-a-from-platelets-increases-early-stage-neointima-formation-after-wire-injury-in-hyperlipidemic-mice
#14
Zhen Zhao, Tanja Vajen, Ela Karshovska, Annemiek Dickhout, Martin M Schmitt, Remco T A Megens, Philipp von Hundelshausen, Thomas A Koeppel, Tilman M Hackeng, Christian Weber, Rory R Koenen
Platelets play an important role in the pathogenesis of vascular remodelling after injury. Junctional adhesion molecule A (JAM-A) was recently described to regulate platelet activation. Specific deletion of JAM-A from platelets resulted in increased reactivity and in accelerated progression of atherosclerosis. The aim of this study was to investigate the specific contribution of platelet-derived JAM-A to neointima formation after vascular injury. Mice with or without platelet-specific (tr)JAM-A-deficiency in an apolipoprotein e (apoe(-/-) ) background underwent wire-induced injury of the common carotid artery...
February 17, 2017: Journal of Cellular and Molecular Medicine
https://www.readbyqxmd.com/read/28211036/unconscious-phantasy-as-a-structural-principle-and-organizer-of-mental-life-the-evolution-of-a-concept-from-freud-to-klein-and-some-of-her-successors
#15
Heinz Weiss
Starting with Freud's discovery of unconscious phantasy as a means of accessing his patients' internal world, the author discusses the evolution of the concept in the work of Melanie Klein and some of her successors. Whereas Freud sees phantasy as a wish fulfilling imagination, dominated by primary process functioning and kept apart from reality testing, Klein understands phantasies as a structural function and organizer of mental life. From their very beginnings they involve object relations and gradually evolve from primitive body-near experiences to images and symbolic representations...
February 17, 2017: International Journal of Psycho-analysis
https://www.readbyqxmd.com/read/28210996/quantitative-evaluation-of-oxygen-metabolism-in-the-intratumoral-hypoxia-18-f-fluoromisonidazole-and-15-o-labelled-gases-inhalation-pet
#16
Tadashi Watabe, Yasukazu Kanai, Hayato Ikeda, Genki Horitsugi, Keiko Matsunaga, Hiroki Kato, Kayako Isohashi, Kohji Abe, Eku Shimosegawa, Jun Hatazawa
BACKGROUND: Intratumoral hypoxia is one of the resistant factors in radiotherapy and chemotherapy for cancer. Although it is detected by (18)F-fluoromisonidazole (FMISO) PET, the relationship between intratumoral hypoxia and oxygen metabolism has not been studied. The purpose of this study was to evaluate the intratumoral perfusion and oxygen metabolism in hypoxic regions using the rat xenograft model. Ten male Fischer rats with C6 glioma (body weight = 220 ± 15 g) were investigated with (18)F-FMISO PET and steady-state inhalation method of (15)O-labelled gases PET...
December 2017: EJNMMI Research
https://www.readbyqxmd.com/read/28210983/multi-view-ensemble-classification-of-brain-connectivity-images-for-neurodegeneration-type-discrimination
#17
Michele Fratello, Giuseppina Caiazzo, Francesca Trojsi, Antonio Russo, Gioacchino Tedeschi, Roberto Tagliaferri, Fabrizio Esposito
Brain connectivity analyses using voxels as features are not robust enough for single-patient classification because of the inter-subject anatomical and functional variability. To construct more robust features, voxels can be aggregated into clusters that are maximally coherent across subjects. Moreover, combining multi-modal neuroimaging and multi-view data integration techniques allows generating multiple independent connectivity features for the same patient. Structural and functional connectivity features were extracted from multi-modal MRI images with a clustering technique, and used for the multi-view classification of different phenotypes of neurodegeneration by an ensemble learning method (random forest)...
February 16, 2017: Neuroinformatics
https://www.readbyqxmd.com/read/28210978/future-directions-in-imaging-neurodegeneration
#18
REVIEW
Joseph C Masdeu
Neuroimaging comprises a powerful set of instruments to diagnose various neurodegenerative disorders, clarifies their neurobiology, and monitors their treatment. Magnetic resonance imaging depicts volume changes, as well as abnormalities in functional and structural connectivity. Positron emission tomography (PET) allows for the quantification of regional cerebral metabolism, characteristically altered in Alzheimer's disease, amyotrophic lateral sclerosis, diffuse Lewy-body disease, and the frontotemporal dementias...
January 2017: Current Neurology and Neuroscience Reports
https://www.readbyqxmd.com/read/28210930/emotion-specific-nocebo-effects-an-fmri-study
#19
Anne Schienle, Carina Höfler, Sonja Übel, Albert Wabnegger
The neurobiological mechanisms of nocebos are still poorly understood. Thirty-eight women participated in a 'smell study' using functional magnetic resonance imaging. They were presented with an odorless stimulus (distilled water) together with the verbal suggestion that this fluid has an aversive odor which enhances disgust feelings. The nocebo was presented while the participants viewed disgusting, fear-inducing, and neutral images. Participants' affective and neuronal responses during nocebo administration were compared with those in a control condition without nocebo...
February 16, 2017: Brain Imaging and Behavior
https://www.readbyqxmd.com/read/28210922/resting-cerebral-blood-flow-alteration-in-severe-obstructive-sleep-apnoea-an-arterial-spin-labelling-perfusion-fmri-study
#20
Si Nie, De-Chang Peng, Hong-Han Gong, Hai-Jun Li, Li-Ting Chen, Cheng-Long Ye
STUDY OBJECTIVES: The aim of this study is to investigate changes in regional cerebral blood flow (rCBF) in awake people with untreated severe obstructive sleep apnoea (OSAs) compared with good sleepers (GSs). DESIGN: Arterial spin labelling perfusion imaging was used to quantify cerebral perfusion based on resting-state functional magnetic resonance imaging (MRI). SETTING: Lying supine in a 3.0-T magnetic resonance imaging scanner in the night was done...
February 16, 2017: Sleep & Breathing, Schlaf & Atmung
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