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https://www.readbyqxmd.com/read/28106429/minkowski-flux-vacua-of-type-ii-supergravities
#1
David Andriot, Johan Blåbäck, Thomas Van Riet
We study flux compactifications of 10D type II supergravities to 4D Minkowski space-time, supported by parallel orientifold O_{p} planes with 3≤p≤8. With some geometric restrictions, the 4D Ricci scalar can be written as a negative sum of squares involving Bogomol'nyi-Prasad-Sommerfield-like conditions. Setting all squares to zero provides automatically a solution to 10D equations of motion. This way we characterize a broad class, if not the complete set, of Minkowski flux vacua with parallel orientifolds...
January 6, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28103549/cardiac-image-reconstruction-via-non-linear-motion-correction-based-on-partial-angle-reconstructed-images
#2
Seungeon Kim, Yongjin Chang, Jong Beom Ra
Even though the X-ray CT scan is considered suitable for fast imaging, motion-artifact-free cardiac imaging is still an important issue because the gantry rotation speed is not fast enough compared with the heart motion. To obtain a heart image with less motion artifacts, a motion estimation (ME) and motion compensation (MC) approach is usually adopted. In this paper, we propose a ME/MC algorithm that can estimate a non-linear heart motion model from a sinogram with a rotation angle of less than 360°. In this algorithm, we first assume the heart motion to be non-rigid but linear, and thereby estimate an initial 4D motion vector field (MVF) during a half rotation by using conjugate partial angle reconstructed images, as in our previous ME/MC algorithm...
January 17, 2017: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/28102956/experimental-verification-of-4d-monte-carlo-simulations-of-dose-delivery-to-a-moving-anatomy
#3
Sara Gholampourkashi, Miro Vujicic, Jason Belec, Joanna E Cygler, Emily Heath
PURPOSE: To evaluate a novel 4D Monte Carlo simulation tool by comparing calculations to physical measurements using a respiratory motion phantom. METHODS: We used a dynamic Quasar phantom in both stationary and breathing states (sinusoidal motion of amplitude of 1.8 cm and period of 3.3 s) for dose measurements on an Elekta Agility linear accelerator. Gafchromic EBT3 film and the RADPOS 4D dosimetry system were placed inside the lung insert of the phantom to measure dose profiles and point-dose values at the center of the spherical tumor inside the insert...
January 2017: Medical Physics
https://www.readbyqxmd.com/read/28102588/three-dimensional-translabial-ultrasound-assessment-of-urethral-supports-and-the-urethral-sphincter-complex-in-stress-urinary-incontinence
#4
Jordi Cassadó Garriga, Antoni Pessarrodona Isern, Monica Rodríguez Carballeira, Mar Pallarols Badia, Manuela Moya Del Corral, Marta Valls Esteve, Eva Huguet Galofré
AIMS: The pathophysiological mechanism of incontinence is multifactorial. We evaluated the role of 3D-4D ultrasound in the assessment of the fascial supports of the urethra and the urethral sphincter complex (USC) for diagnosing stress urinary incontinence. METHODS: Observational case-control study in women with and without stress urinary incontinence attending a urogynecology service and a general gynecology service. All women were interviewed, examined, and classified according to the Pelvic Organ Prolapse Quantification (POP-Q) and underwent a 3D-4D translabial ultrasound...
January 19, 2017: Neurourology and Urodynamics
https://www.readbyqxmd.com/read/28102312/correlations-of-charge-neutrality-level-with-electronic-structure-and-p-d-hybridization
#5
Arkaprava Das, Subodh K Gautam, D K Shukla, Fouran Singh
The formation of charge neutrality level (CNL) in highly conducting Cadmium oxide (CdO) thin films is demonstarted by the observed variation in the band gap upon annealing and doping. It may be explained by the observation that Tin (Sn) doping breaks the perfect periodicity of CdO cubic crystal structure and creates virtual gap states (ViGS). The level of local CNL resides at the branch point of ViGS, making the energy at which native defect's character changes from predominantly donor-like below CNL to predominantly acceptor-like above the CNL and a schematic band diagram is developed to substantiate the same...
January 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28101251/antifungal-and-anthelmintic-activity-of-novel-benzofuran-derivatives-containing-thiazolo-benzimidazole-nucleus-an-in-vitro-evaluation
#6
R Kenchappa, Yadav D Bodke, Sandeep Telkar, M Aruna Sindhe
A novel series of thiazolo[3,2-a]benzimidazole derivatives containing benzofuran nucleus (5a-l) have been synthesized. The key intermediate, substituted benzimidazol-sulfanyl benzofuran ethanone (3a-d) was prepared by refluxing the mixture of substituted 2-acetyl benzofuran and substituted 2-mercaptobenzimidazole in acetic acid. The cyclisation of compounds (3a-d) using polyphosphoric acid furnished the corresponding 6-substituted benzofuran thiazolo[3,2-a]benzimidazoles (4a-d). Further, the cyclized compounds (4a-d) were subjected for Mannich reaction to give corresponding Mannich bases (5a-l)...
January 2017: Journal of Chemical Biology
https://www.readbyqxmd.com/read/28097212/feasibility-of-reduced-dose-three-dimensional-four-dimensional-digital-subtraction-angiogram-using-a-weighted-edge-preserving-filter
#7
Erick L Oberstar, Michael A Speidel, Brian J Davis, Charles M Strother, Charles A Mistretta
A conventional three-dimensional/four-dimensional (3D/4D) digital subtraction angiogram (DSA) requires two rotational acquisitions (mask and fill) to compute the log-subtracted projections that are used to reconstruct a 3D/4D volume. Since all of the vascular information is contained in the fill acquisition, it is hypothesized that it is possible to reduce the x-ray dose of the mask acquisition substantially and still obtain subtracted projections adequate to reconstruct a 3D/4D volume with noise level comparable to a full-dose acquisition...
January 2017: Journal of Medical Imaging
https://www.readbyqxmd.com/read/28092111/design-and-synthesis-of-5-substituted-benzo-d-1-3-dioxole-derivatives-as-potent-anticonvulsant-agents
#8
Shiyang Dong, Tiantian Wang, Chundi Hu, Xiaodong Chen, Yi Jin, Zengtao Wang
A series of 5-substituted benzo[d][1,3]dioxole derivatives was designed, synthesized, and tested for anticonvulsant activity using the maximal electroshock (MES) and subcutaneous pentylenetetrazole (scPTZ) screens. Neurotoxicity was determined by rotarod test. In the preliminary screening, six compounds, 3a, 3c, 3d, and 4d-f, showed promising anticonvulsant activities in the MES model, and compounds 4c and 4d exhibited full protection against seizures at doses of 300 mg/kg in the scPTZ model. Among the synthesized compounds, 3c as the most active compound showed high protection against the MES-induced seizures with an ED50 value of 9...
January 16, 2017: Archiv der Pharmazie
https://www.readbyqxmd.com/read/28088127/cerebral-laterality-for-language-is-related-to-adult-salivary-testosterone-levels-but-not-digit-ratio-2d-4d-in-men-a-functional-transcranial-doppler-ultrasound-study
#9
Marietta Papadatou-Pastou, Maryanne Martin
The adequacy of three competing theories of hormonal effects on cerebral laterality are compared using functional transcranial Doppler sonography (fTCD). Thirty-three adult males participated in the study (21 left-handers). Cerebral lateralization was measured by fTCD using an extensively validated word generation task. Adult salivary testosterone (T) and cortisol (C) concentrations were measured by luminescence immunoassay and prenatal T exposure was indirectly estimated by the somatic marker of 2nd to 4th digit length ratio (2D:4D)...
January 11, 2017: Brain and Language
https://www.readbyqxmd.com/read/28079906/4d-and-5d-bimetal-doped-tubular-silicon-clusters-si12m2-with-m-nb-ta-mo-and-w-a-bimetallic-configuration-model
#10
Hung Tan Pham, Devashis Majumdar, Jerzy Leszczynski, Minh Tho Nguyen
Geometries and electronic properties related to the ground state stabilities of several Si12M2 clusters (M: second-row (Nb and Mo) and third-row (Ta and W) transition metals, and their mixed bimetallic clusters M2: NbMo and TaW) were explored using density functional theory (DFT) computations. The computed results show that two different structural motifs emerge as the global energy minima of such clusters. They are basically singlet tubular structures in either a C2v prism ((1)A1) or a C6v antiprism ((1)A1) form...
January 12, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28079267/estimating-4d-cbct-from-prior-information-and-extremely-limited-angle-projections-using-structural-pca-and-weighted-free-form-deformation-for-lung-radiotherapy
#11
Wendy Harris, You Zhang, Fang-Fang Yin, Lei Ren
PURPOSE: To investigate the feasibility of using structural-based principal component analysis (PCA) motion-modeling and weighted free-form deformation to estimate on-board 4D-CBCT using prior information and extremely limited angle projections for potential 4D target verification of lung radiotherapy. METHODS: A technique for lung 4D-CBCT reconstruction has been previously developed using a deformation field map (DFM)-based strategy. In the previous method, each phase of the 4D-CBCT was generated by deforming a prior CT volume...
January 12, 2017: Medical Physics
https://www.readbyqxmd.com/read/28078670/levator-ani-muscle-avulsion-is-a-risk-factor-for-vaginal-pessary-expulsion-within-1-year-for-pelvic-organ-prolapse
#12
Rachel Yau Kar Cheung, Jacqueline Ho Sze Lee, Lai Loi Lee, Tony Kwok Hung Chung, Symphorosa Shing Chee Chan
OBJECTIVE: The aim of this study was to investigate whether presence of levator ani muscle (LAM) avulsion was associated with expulsion of vaginal pessary for women with pelvic organ prolapse (POP). METHODS: This prospective observational study recruited consecutive women with symptomatic POP. Vaginal pessary was offered and offline analysis of the 3D/4D transperineal ultrasound volume data of women was performed. Volume acquisition had been performed before pessary insertion...
January 12, 2017: Ultrasound in Obstetrics & Gynecology
https://www.readbyqxmd.com/read/28077634/characterization-of-hcv-envelope-diversification-from-acute-to-chronic-infection-using-smrt-sequencing-within-a-sexually-transmitted-hepatitis-c-virus-cluster
#13
Cynthia K Y Ho, Jayna Raghwani, Sylvie Koekkoek, Richard H Liang, Jan T M Van der Meer, Marc Van Der Valk, Menno De Jong, Oliver G Pybus, Janke Schinkel, Richard Molenkamp
: In contrast to other available next generation sequencing platforms, Pacbio Single Molecule, Real-Time (SMRT) sequencing has the advantage of generating long reads, albeit with a relatively higher error rate in unprocessed data. Using this platform we longitudinally sampled and sequenced the hepatitis C virus (HCV) envelope genome region (1680 nt) from individuals belonging to a cluster of sexually-transmitted cases. All five subjects were HIV-1 coinfected and infected with a closely related strain of HCV genotype 4d...
January 11, 2017: Journal of Virology
https://www.readbyqxmd.com/read/28076795/hangover-links-nuclear-rna-signaling-to-camp-regulation-via-the-phosphodiesterase-4d-ortholog-dunce
#14
Manuela Ruppert, Mirjam Franz, Anastasios Saratsis, Laura Velo Escarcena, Oliver Hendrich, Li Ming Gooi, Isabell Schwenkert, Ansgar Klebes, Henrike Scholz
The hangover gene defines a cellular stress pathway that is required for rapid ethanol tolerance in Drosophila melanogaster. To understand how cellular stress changes neuronal function, we analyzed Hangover function on a cellular and neuronal level. We provide evidence that Hangover acts as a nuclear RNA binding protein and we identified the phosphodiesterase 4d ortholog dunce as a target RNA. We generated a transcript-specific dunce mutant that is impaired not only in ethanol tolerance but also in the cellular stress response...
January 10, 2017: Cell Reports
https://www.readbyqxmd.com/read/28075570/contrasting-behavior-of-the-z-bonds-in-x-z%C3%A2-%C3%A2-%C3%A2-y-weak-interactions-z-main-group-elements-versus-the-transition-metals
#15
Jyothish Joy, Eluvathingal D Jemmis
In contrast to the increasing family of weak intermolecular interactions in main-group compounds (X-Z···Y, Z = main-group elements), an analysis of the Cambridge Structural Database indicates that electron-saturated (18-electron) transition-metal complexes show reluctance toward weak M bond formation (X-M···Y, M = transition metal). In particular, weak M bonds involving electron-saturated (18-electron) complexes of transition metals with partially filled d-orbitals are not found. We propose that the nature of valence electron density distribution in transition-metal complexes is the primary reason for this reluctance...
January 11, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28074541/comparison-of-respiratory-motion-suppression-techniques-for-4d-flow-mri
#16
Petter Dyverfeldt, Tino Ebbers
PURPOSE: The purpose of this work was to assess the impact of respiratory motion and to compare methods for suppression of respiratory motion artifacts in 4D Flow MRI. METHODS: A numerical 3D aorta phantom was designed based on an aorta velocity field obtained by computational fluid mechanics. Motion-distorted 4D Flow MRI measurements were simulated and several different motion-suppression techniques were evaluated: Gating with fixed acceptance window size, gating with different window sizes in inner and outer k-space, and k-space reordering...
January 11, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28074019/point-organ-radiation-dose-in-abdominal-ct-effect-of-patient-off-centering-in-an-experimental-human-cadaver-study
#17
Ranish Deedar Ali Khawaja, Sarabjeet Singh, Atul Padole, Alexi Otrakji, Diego Lira, Da Zhang, Bob Liu, Andrew Primak, George Xu, Mannudeep K Kalra
To determine the effect of patient off-centering on point organ radiation dose measurements in a human cadaver scanned with routine abdominal CT protocol. A human cadaver (88 years, body-mass-index 20 kg/m(2)) was scanned with routine abdominal CT protocol on 128-slice dual source MDCT (Definition Flash, Siemens). A total of 18 scans were performed using two scan protocols (a) 120 kV-200 mAs fixed-mA (CTDIvol 14 mGy) (b) 120 kV-125 ref mAs (7 mGy) with automatic exposure control (AEC, CareDose 4D) at three different positions (a) gantry isocenter, (b) upward off-centering and (c) downward off-centering...
January 10, 2017: Radiation Protection Dosimetry
https://www.readbyqxmd.com/read/28073579/robustness-of-4d-optimized-scanned-carbon-ion-beam-therapy-against-interfractional-changes-in-lung-cancer
#18
Christian Graeff
BACKGROUND AND PURPOSE: Moving targets could be conformally treated with actively scanned carbon ion beams using 4D-optimization. As this heavily exploits 4D-CTs, an important question is whether the conformity also upholds in the context of interfractional changes, i.e. variable positioning, anatomy and breathing patterns. MATERIALS AND METHODS: In 4 lung cancer patients, 6 weekly 4D-CTs were available. 4D-CTs and their phases were non-rigidly registered to propagate contours and 4D-doses...
January 7, 2017: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
https://www.readbyqxmd.com/read/28073377/magnitude-and-influencing-factors-of-respiration-induced-liver-motion-during-abdominal-compression-in-patients-with-intrahepatic-tumors
#19
Yong Hu, Yong-Kang Zhou, Yi-Xing Chen, Zhao-Chong Zeng
PURPOSE: The purpose of this study was to use 4-dimensional-computed tomography (4D-CT) to evaluate respiration-induced liver motion magnitude and influencing factors in patients with intrahepatic tumors undergoing abdominal compression. METHODS: From January 2012 to April 2016, 99 patients with intrahepatic tumors were included in this study. They all underwent 4D-CT to assess respiratory liver motion. This was performed during abdominal compression in 53 patients and during free-breathing (no abdominal compression) in 46 patients...
January 10, 2017: Radiation Oncology
https://www.readbyqxmd.com/read/28070244/assessment-of-fetus-during-second-trimester-ultrasonography-using-hdlive-software-what-is-its-real-application-in-the-obstetrics-clinical-practice
#20
Gabriele Tonni, Gianpaolo Grisolia, Eduardo Félix Santana, Edward Araujo Júnior
AIM: To show imaging results from application of four-dimensional (4D) ultrasound lightening technique (HDlive™) in clinical obstetrics practice. METHODS: Normal and abnormal fetuses at second and third trimester of pregnancy undergoing routine scan with 4D HDlive™ (5DUS) in the rendering mode are described. Realistic features of fetal structures were provided by 5DUS in the rendering mode. Normal anatomy as well as pathology like cleft lip, hypoplastic face, micrognathia, low-set ears, corpus callosum, arthrogryposis, aortic arch, left congenital diaphragmatic hernia are highlighted in this study...
December 28, 2016: World Journal of Radiology
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