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Functional MR

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https://www.readbyqxmd.com/read/28441477/local-electron-correlation-treatment-in-extended-multireference-calculations-effect-of-acceptor-donor-substituents-on-the-biradical-character-of-the-polycyclic-aromatic-hydrocarbon-heptazethrene
#1
Anita Das, Thomas Müller, Felix Plasser, David B Krisiloff, Emily A Carter, Hans Lischka
The implementation of a local correlation (LC) treatment of multireference (MR) configuration interaction approaches within the COLUMBUS program system is reported. The LC treatment is based on the weak pairs approximation of Sæbø and Pulay (Ann. Rev. Phys. Chem.44 (1993) 213) and a geometrical analysis of Walter et al. (Chem. Phys. Lett. 346 (2001) 177). The weak pairs interactions have been eliminated considering just the reference doubly occupied space leading to a straightforward program implementation and a conceptual simplicity in terms of well-defined localized orbitals...
April 25, 2017: Journal of Chemical Theory and Computation
https://www.readbyqxmd.com/read/28439052/-calcium-and-bone-metabolism-across-women-s-life-stages-pathophysiology-adiagnosis-and-treatment-of-post-pregnancy-osteoporosis
#2
Takumi Kurabayashi
Post-pregnancy osteoporosis is a rare condition with little known pathophysiology. Most cases are diagnosed in the late stage of pregnancy or in the post-partum while breastfeeding, particularly in first pregnancy. Vertebral fractures are most commonly observed and characterized by prolonged severe pain and functional limitations. Measurements of bone mineral density(BMD)of the lumbar spine and proximal femur with dual energy X-ray absorptiometry(DXA)are the clinical methods most commonly used for no fracture women...
2017: Clinical Calcium
https://www.readbyqxmd.com/read/28438779/human-alternative-macrophages-populate-calcified-areas-of-atherosclerotic-lesions-and-display-impaired-rankl-induced-osteoclastic-bone-resorption-activity
#3
Giulia Chinetti-Gbaguidi, Mehdi Daoudi, Mickael Rosa, Manjula Vinod, Loïc Louvet, Corinne Copin, Melanie Fanchon, Jonathan Vanhoutte, Bruno Derudas, Loic Belloy, Stephan Haulon, Christophe Zawadzki, Sophie Susen, Ziad A Massy, Jérôme Eeckhoute, Bart Staels
Rationale: Vascular calcification is a process similar to bone formation leading to an inappropriate deposition of calcium phosphate minerals in advanced atherosclerotic plaques. Monocyte-derived macrophages, located in atherosclerotic lesions and presenting heterogeneous phenotypes, from classical pro-inflammatory M1 to alternative anti-inflammatory M2 macrophages, could potentially display osteoclast-like functions. Objective: To characterize the phenotype of macrophages located in areas surrounding the calcium deposits in human atherosclerotic plaques...
April 24, 2017: Circulation Research
https://www.readbyqxmd.com/read/28438666/how-to-choose-the-right-mr-sequence-for-your-research-question-at-7-t-and-above
#4
José P Marques, David G Norris
The choice of a pulse sequence at ultra-high field can be influenced by a number of considerations and constraints that are not always the same as those at lower fields. Foremost amongst these is of course the information required and the time available, but considerations of static main field- and transmit field- inhomogeneities as well as power deposition can also play an important role. In this review we first briefly examine the characteristics of high field MRI, and then describe the performance and constraints relevant to the major imaging readouts, and their implementation with parallel imaging techniques...
April 21, 2017: NeuroImage
https://www.readbyqxmd.com/read/28438167/dependency-criterion-based-brain-pathological-age-estimation-of-alzheimer-s-disease-patients-with-mr-scans
#5
Yongming Li, Yuchuan Liu, Pin Wang, Jie Wang, Sha Xu, Mingguo Qiu
OBJECTIVES: Traditional brain age estimation methods are based on the idea that uses the real age as the training label. However, these methods ignore that there is a deviation between the real age and the brain age due to the accelerated brain aging. METHODS: This paper considers this deviation and obtains it by maximizing the correlation between the estimated brain age and the class label rather than by minimizing the difference between the estimated brain age and the real age...
April 24, 2017: Biomedical Engineering Online
https://www.readbyqxmd.com/read/28437782/detection-of-renal-hypoxia-in-lupus-nephritis-using-blood-oxygen-level-dependent-mr-imaging-a-multiple-correspondence-analysis
#6
Huilan Shi, Tiekun Yan, Dong Li, Junya Jia, Wenya Shang, Li Wei, Zhenfeng Zheng
BACKGROUND/AIMS: Nephrologists have pursued ideal, dynamic and noninvasive methods for assessing renal function and disease progression. Blood oxygen level dependent (BOLD) imaging is a useful technique for assessing renal disease. This current study was performed to explore the correlation between the hypoxia iconographical index and renal pathological features in lupus nephritis. METHODS: Adult patients with lupus nephritis (LN) and healthy volunteers were recruited for this study...
April 5, 2017: Kidney & Blood Pressure Research
https://www.readbyqxmd.com/read/28437634/convolutional-neural-network-regression-for-short-axis-left-ventricle-segmentation-in-cardiac-cine-mr-sequences
#7
Li Kuo Tan, Yih Miin Liew, Einly Lim, Robert A McLaughlin
Automated left ventricular (LV) segmentation is crucial for efficient quantification of cardiac function and morphology to aid subsequent management of cardiac pathologies. In this paper, we parameterize the complete (all short axis slices and phases) LV segmentation task in terms of the radial distances between the LV centerpoint and the endo- and epicardial contours in polar space. We then utilize convolutional neural network regression to infer these parameters. Utilizing parameter regression, as opposed to conventional pixel classification, allows the network to inherently reflect domain-specific physical constraints...
April 12, 2017: Medical Image Analysis
https://www.readbyqxmd.com/read/28436851/synergistic-pet-and-sense-mr-image-reconstruction-using-joint-sparsity-regularization
#8
Abolfazl Mehranian, Martin Belzunce, Claudia Prieto, Alexander Hammers, Andrew Reader
In this work we propose a generalized joint sparsity regularization prior and reconstruction framework for the syner-gistic reconstruction of PET and undersampled sensitivity en-coded (SENSE) MRI data with the aim of improving image quality beyond that obtained through conventional independent recon-structions. The proposed prior improves upon the joint total vari-ation (TV) using a non-convex potential function that assigns a rel-atively lower penalty for the PET and MR gradients whose mag-nitudes are jointly large, thus permitting the preservation and for-mation of common boundaries irrespective of their relative orien-tation...
April 18, 2017: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/28435466/design-of-tumor-acidity-responsive-sheddable-nanoparticles-for-fluorescence-magnetic-resonance-imaging-guided-photodynamic-therapy
#9
Feng Fan, Yue Yu, Fei Zhong, Meng Gao, Tianmeng Sun, Jiaxin Liu, Huimao Zhang, Haisheng Qian, Wei Tao, Xianzhu Yang
Imaging-guided cancer therapy, which integrates diagnostic and therapeutic functionalities into a single system, holds great promise to enhance the accuracy of diagnosis and improve the efficacy of therapy. Specifically, for photodynamic therapy (PDT), it is highly desirable to precisely focus laser light onto the tumor areas to generate reactive oxygen species (ROS) that are cytotoxic tumor cells and avoid light-associated side effects. Herein, a distinct three-layer nanostructured particle with tumor acidity-responsiveness (S-NP) that encapsulates the photosensitizer chlorin e6 (Ce6) and chelates Gd(3+) is successfully developed for fluorescence/magnetic resonance (MR) dual-model imaging-guided precision PDT...
2017: Theranostics
https://www.readbyqxmd.com/read/28433007/alternative-definition-of-excitation-amplitudes-in-multi-reference-state-specific-coupled-cluster
#10
Yann Garniron, Emmanuel Giner, Jean-Paul Malrieu, Anthony Scemama
A central difficulty of state-specific Multi-Reference Coupled Cluster (MR-CC) in the multi-exponential Jeziorski-Monkhorst formalism concerns the definition of the amplitudes of the single and double excitation operators appearing in the exponential wave operators. If the reference space is a complete active space (CAS), the number of these amplitudes is larger than the number of singly and doubly excited determinants on which one may project the eigenequation, and one must impose additional conditions. The present work first defines a state-specific reference-independent operator T∼^(m) which acting on the CAS component of the wave function |Ψ0(m)⟩ maximizes the overlap between (1+T∼^(m))|Ψ0(m)⟩ and the eigenvector of the CAS-SD (Singles and Doubles) Configuration Interaction (CI) matrix |ΨCAS-SD(m)⟩...
April 21, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28432266/baseline-blood-pressure-effect-on-the-benefit-and-safety-of-intra-arterial-treatment-in-mr-clean-multicenter-randomized-clinical-trial-of-endovascular-treatment-of-acute-ischemic-stroke-in-the-netherlands
#11
Maxim J H L Mulder, Saliha Ergezen, Hester F Lingsma, Olvert A Berkhemer, Puck S S Fransen, Debbie Beumer, Lucie A van den Berg, Geert Lycklama À Nijeholt, Bart J Emmer, H Bart van der Worp, Paul J Nederkoorn, Yvo B W E M Roos, Robert J van Oostenbrugge, Wim H van Zwam, Charles B L M Majoie, Aad van der Lugt, Diederik W J Dippel
BACKGROUND AND PURPOSE: High blood pressure (BP) is associated with poor outcome and the occurrence of symptomatic intracranial hemorrhage in acute ischemic stroke. Whether BP influences the benefit or safety of intra-arterial treatment (IAT) is not known. We aimed to assess the relation of BP with functional outcome, occurrence of symptomatic intracranial hemorrhage and effect of IAT. METHODS: This is a post hoc analysis of the MR CLEAN (Multicenter Randomized Clinical Trial of Endovascular Treatment of Acute Ischemic Stroke in the Netherlands)...
April 21, 2017: Stroke; a Journal of Cerebral Circulation
https://www.readbyqxmd.com/read/28431895/hemolymph-proteins-of-anopheles-gambiae-larvae-infected-by-escherichia-coli
#12
Xuesong He, Xiaolong Cao, Yan He, Krishna Bhattarai, Janet Rogers, Steve Hartson, Haobo Jiang
Anopheles gambiae is a major vector of human malaria and its immune system in part determines the fate of ingested parasites. Proteins, hemocytes and fat body in hemolymph are critical components of this system, mediating both humoral and cellular defenses. Here we assessed differences in the hemolymph proteomes of water- and E. coli-pricked mosquito larvae by a gel-LC-MS approach. Among the 1756 proteins identified, 603 contained a signal peptide but accounted for two-third of the total protein amount on the quantitative basis...
April 18, 2017: Developmental and Comparative Immunology
https://www.readbyqxmd.com/read/28431025/1h-magnetic-resonance-spectroscopy-of-live-human-sperm
#13
S Reynolds, S J Calvert, M N Paley, A A Pacey
STUDY QUESTION: Can 1H Magnetic Resonance Spectroscopy (MRS) be used to obtain information about the molecules and metabolites in live human spermatozoa? SUMMARY ANSWER: Percoll-based density gradient centrifugation (DGC) followed by a further two washing steps, yielded enough sperm with minimal contamination (<0.01%) from seminal fluid to permit effective MRS which detected significant differences (p < 0.05) in the choline/glycerophosphocholine, lipid and lactate regions of the 1H MRS spectrum between sperm in the pellet and those from the 40/80% interface...
April 18, 2017: Molecular Human Reproduction
https://www.readbyqxmd.com/read/28430882/inhibition-of-the-cardiac-myocyte-mineralocorticoid-receptor-ameliorates-doxorubicin-induced-cardiotoxicity
#14
Achim Lother, Stella Bergemann, Jessica Kowalski, Michael Huck, Ralf Gilsbach, Christoph Bode, Lutz Hein
Aim: HASH(0x4befd48) Anthracyclines such as doxorubicin are widely used in cancer therapy but their use is limited by cardiotoxicity. Up to date there is no established strategy for the prevention of anthracyclin-induced heart failure. In this study, we evaluated the role of the cardiac myocyte mineralocorticoid receptor (MR) during doxorubicin-induced cardiotoxicity. Methods and results: HASH(0x4bf37a8) A single high-dose or repetitive low-dose doxorubicin administration lead to markedly reduced left ventricular function in mice...
April 18, 2017: Cardiovascular Research
https://www.readbyqxmd.com/read/28427220/multiparametric-imaging-using-18f-fdg-pet-ct-heterogeneity-parameters-and-functional-mri-techniques-prognostic-significance-in-patients-with-primary-advanced-oropharyngeal-or-hypopharyngeal-squamous-cell-carcinoma-treated-with-chemoradiotherapy
#15
Sheng-Chieh Chan, Nai-Ming Cheng, Chia-Hsun Hsieh, Shu-Hang Ng, Chien-Yu Lin, Tzu-Chen Yen, Cheng-Lung Hsu, Hung-Ming Wan, Chun-Ta Liao, Kai-Ping Chang, Jiun-Jie Wang
BACKGROUND: In this study, PET heterogeneity was combined with functional MRI techniques to refine the prediction of prognosis in patients with oropharyngeal or hypopharyngeal squamous cell carcinoma (OHSCC). METHODS: A total of 124 patients with primary advanced OHSCC who underwent pretreatment 18F-FDG PET/CT, dynamic contrast-enhanced MR imaging (DCE-MRI), and diffusion-weighted MR imaging (DWI) were enrolled. Conventional and heterogeneity parameters from 18F-FDG PET as well as perfusion parameters from DCE-MRI and diffusion parameter from DWI of primary tumors were analyzed in relation to recurrence-free survival (RFS) and overall survival (OS)...
March 4, 2017: Oncotarget
https://www.readbyqxmd.com/read/28425537/using-fluorescently-labeled-magnetic-nanocomposites-as-a-dual-contrast-agent-for-optical-and-magnetic-resonance-imaging
#16
Taofeng Zhu, Xiuqin Ma, Ruhua Chen, Zhijun Ge, Jun Xu, Xiaoke Shen, Lei Jia, Tao Zhou, Yifeng Luo, Tieliang Ma
Dual-modality imaging probes synergistically combine magnetic resonance (MR) and fluorescence into a single nanocomposite. This promising technique affords a new level of flexibility for molecular imaging uses in biomedical research. In this study, we report a new strategy for the synthesis of a novel attapulgite nanorod-based atta@Fe3O4@[Ru(bpy)2(fmp)]Cl2 nanocomposite (atta@Fe3O4@Ru NC). Our synthesized NC has both photoluminescent and magnetic properties, bright fluorescence, as well as significant magnetic resonance...
April 20, 2017: Biomaterials Science
https://www.readbyqxmd.com/read/28418820/case-241-hemiparkinsonism-hemiatrophy-spect-with-99m-tc-trodat-1-and-muscle-mr-imaging-abnormalities
#17
Thiago Cardoso Vale, Flávia Cristina de Lima Pinto, José Luiz Pedroso, Marília Alves Dos Reis, Ilza Rosa Batista, Rodrigo Affonseca Bressan, René Leandro Magalhães Rivero, Renato Adam Mendonça, Orlando G Barsottini
History A 43-year-old right-handed man presented with a history of progressive mild left-sided weakness and slowness of movements. Symptoms began 4 years earlier, and the patient noticed a progressive decline in his daily routine due to gait difficulties in the past year. There was no history of head trauma, surgery, drug therapy, smoking, or alcohol abuse, nor was there any relevant family history. Examination revealed normal cognition (29 of 30 points on the Mini-Mental State Examination and 27 of 30 points on the Montreal Cognitive Assessment) and normal cerebellar, sensory, cranial nerve, and autonomic function...
May 2017: Radiology
https://www.readbyqxmd.com/read/28418811/hypertrabeculated-left-ventricular-myocardium-in-relationship-to-myocardial-function-and-fibrosis-the-multi-ethnic-study-of-atherosclerosis
#18
Nadine Kawel-Boehm, Robyn L McClelland, Filip Zemrak, Gabriella Captur, W Gregory Hundley, Chia-Ying Liu, James C Moon, Steffen E Petersen, Bharath Ambale-Venkatesh, João A C Lima, David A Bluemke
Purpose To determine if excess greater left ventricle (LV) trabeculation is associated with decreased average regional myocardial function, diffuse fibrosis, or both. Materials and Methods This was a HIPAA-compliant institutional board approved multicenter study, and all participants provided written informed consent. Participants in the Multi-Ethnic Study of Atherosclerosis (MESA) underwent a comprehensive cardiac magnetic resonance (MR) examination. LV trabeculation was measured with the maximal apical fractal dimension (FD), which is a marker of endocardial complexity...
April 17, 2017: Radiology
https://www.readbyqxmd.com/read/28418400/short-telomere-length-is-associated-with-impaired-cognitive-performance-in-european-ancestry-cohorts
#19
S Hägg, Y Zhan, R Karlsson, L Gerritsen, A Ploner, S J van der Lee, L Broer, J Deelen, R E Marioni, A Wong, A Lundquist, G Zhu, N K Hansell, E Sillanpää, I O Fedko, N A Amin, M Beekman, A J M de Craen, S Degerman, S E Harris, K-J Kan, C M Martin-Ruiz, G W Montgomery, A N Adolfsson, C A Reynolds, N J Samani, H E D Suchiman, A Viljanen, T von Zglinicki, M J Wright, J-J Hottenga, D I Boomsma, T Rantanen, J A Kaprio, D R Nyholt, N G Martin, L Nyberg, R Adolfsson, D Kuh, J M Starr, I J Deary, P E Slagboom, C M van Duijn, V Codd, N L Pedersen
The association between telomere length (TL) dynamics on cognitive performance over the life-course is not well understood. This study meta-analyses observational and causal associations between TL and six cognitive traits, with stratifications on APOE genotype, in a Mendelian Randomization (MR) framework. Twelve European cohorts (N=17 052; mean age=59.2±8.8 years) provided results for associations between qPCR-measured TL (T/S-ratio scale) and general cognitive function, mini-mental state exam (MMSE), processing speed by digit symbol substitution test (DSST), visuospatial functioning, memory and executive functioning (STROOP)...
April 18, 2017: Translational Psychiatry
https://www.readbyqxmd.com/read/28415104/p697new-indices-for-a-best-quantification-of-left-ventricular-function-in-heart-valve-diseases
#20
A Hubert, E Galli, G Bouzille, E Samset, E Donal
Aims. The Assessment of left ventricular (LV) function remains a clinical challenge especially in patients with preserved LV ejection fraction (EF) and valvular heart diseases (VHD). Mechanical dispersion is supposed to be a strong predictor of events and, to be related to the extent of fibrosis. Regional cardiac work is a new validated and very promising approach to quantify LV-function. We investigated the differences in mechanical dispersions and global LV work (totW) and wasted work fraction (WWF) in normal subjects and in patients with severe primary mitral regurgitation (MR) and severe aortic stenosis (AS)...
December 1, 2016: European Heart Journal Cardiovascular Imaging
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