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CT theory and use

Andrew M Vahabzadeh-Hagh, Zhaoyan Zhang, Dinesh K Chhetri
OBJECTIVES/HYPOTHESIS: In 1974, Minoru Hirano proposed his theory of voice production that is now known as the cover-body theory. He described the thyroarytenoid (TA) and cricothyroid (CT) muscles as the major determinants of vocal fold shape and stiffness, and theorized four typical laryngeal configurations resulting from unique TA/CT activations, with implications for the resulting voice quality. In this study, we directly observed the vocal fold medial surface shape under Hirano's unique TA/CT activation conditions to obtain a three-dimensional (3D) understanding of these laryngeal configurations during muscle activation...
November 20, 2017: Laryngoscope
A Goldin, D A Muzykewicz, J Dwek, S J Mubarak
PURPOSE: We aim to retrospectively evaluate patients with non-ossifying fibroma (NOF) of the distal femur by radiographs, CT and MRI, and to provide a theory describing the reasoning for the distal femur NOF's location and aetiology. METHODS: Charts of patients with NOFs between 2003 and 2014 were retrospectively reviewed. Inclusion criteria encompassed a diagnosis of NOF of the distal femur by imaging, and histologically, if available. Radiographs, CT and MRI were used to characterise the relationship of the NOF lesions with the surrounding soft tissues...
October 1, 2017: Journal of Children's Orthopaedics
Juan Andrés, Patricio González-Navarrete, Vicent Sixte Safont, Bernard Silvi
Despite the usefulness of curly arrows in chemistry, their relationship with real electron density flows is still imprecise, and even their direct connection to quantum chemistry is still controversial. The paradigmatic description - from first principles - of the mechanistic aspects of a given chemical process is based mainly on the relative energies and geometrical changes at the stationary points of the potential energy surface along the reaction pathway; however, it is not sufficient to describe chemical systems in terms of bonding aspects...
November 8, 2017: Physical Chemistry Chemical Physics: PCCP
Wei-Feng Xie, Hao-Ran Zhu, Shi-Hao Wei, Da-Yin Hua
The catalytic properties of the magic gold-platinum bimetallic clusters (Au4Pt2 and Au6Pt) for the reduction of SO2 by CO, without or with preadsorbing CO molecules, are firstly investigated using density functional theory calculations. We find that the catalytic activities improve effectively with the preadsorption of CO onto the catalysts and that the catalytic activities of Au6Pt(CO)n are better than those of Au4Pt2(CO)n as more CO molecules are adsorbed onto the catalysts. During the reaction process, the Au4Pt2(CO)n clusters always keep two-dimensional morphologies except for when n = 5 and the Au6Pt(CO)n clusters have three-dimensional geometries except for when n = 0...
November 8, 2017: Physical Chemistry Chemical Physics: PCCP
Antonio Macedo, Marcela Leal da Cruz, João Luiz Gomes Parizi, Gustavo Marconi Caetano Martins, Riberto Liguori, Sérgio Leite Ottoni, Bruno Leslie, Gilmar Garrone
INTRODUCTION AND OBJECTIVE: Urethral duplication is a rare congenital anomaly, with roughly 200 cases reported in the literature (1). It is more frequent in males, with few cases reported in females. The clinical presentation differs according to the anatomical variant present. The duplication most commonly occurs in the sagittal plane with one urethra located ventrally and the other dorsally (2). Usually the ventral urethra is the more functional of both. Duplications occurring in the coronal plane are quite rare and they are usually associated with bladder duplication (3)...
October 24, 2017: International Braz J Urol: Official Journal of the Brazilian Society of Urology
Xuehu Wang, Yongchang Zheng, Lan Gan, Xuan Wang, Xinting Sang, Xiangfeng Kong, Jie Zhao
This study proposes a new liver segmentation method based on a sparse a priori statistical shape model (SP-SSM). First, mark points are selected in the liver a priori model and the original image. Then, the a priori shape and its mark points are used to obtain a dictionary for the liver boundary information. Second, the sparse coefficient is calculated based on the correspondence between mark points in the original image and those in the a priori model, and then the sparse statistical model is established by combining the sparse coefficients and the dictionary...
2017: PloS One
Jeffrey R Vittengl, Lee Anna Clark, Michael E Thase, Robin B Jarrett
Consistent with theories of depression, several personality (e.g., high neuroticism, low extraversion) and psychosocial (e.g., interpersonal problems, cognitive content) variables predict depressive symptoms substantively. In this extended replication, we clarified whether 13 theoretically relevant personality and psychosocial variables were unique versus overlapping predictors of symptoms among 351 adult outpatients with recurrent major depressive disorder who received acute-phase cognitive therapy (CT). Using factor analysis and regression methods, we partitioned the measures' variance into general components common across the two types of measures (psychosocial and personality), within-type components shared only with other measures of the same type, and scale-specific components...
September 13, 2017: Journal of Personality Disorders
Quanjiang Li, Maodu Chen
Surface-enhanced Raman scattering (SERS) and absorption spectra of the pyridine molecule adsorbed on AumAgn (m+n=6) bimetallic cluster are theoretically investigated by time-dependent density functional theory (TD-DFT). The contributions of static chemical enhancement to the ground-state system are analyzed, and the static Raman intensity of Py-AumAgn complexes are enhanced on the order of 10. A method of visualization on charge transfer is used to distinguish the contributions of charge-transfer (CT) enhancement and electromagnetic enhancement (EM)...
September 8, 2017: Nanotechnology
Kuntang Shen, Xiaodong Gao
With the increasing incidence of early gastric cancer, endoscopic treatment has been widely used. It has also played an important role in the diagnosis and treatment of gastric cancer. Therefore, it is very important to carry out standardized treatment with endoscopy. In theory, endoscopic resection can be performed in early gastric cancers which have no lymph node metastasis and also can be resected completely. Endoscopic therapy is absolutely indicated in macroscopically intramucosal differentiated carcinomas (pT1a) without ulcer or ulcer scar and with diameter ≤2 cm...
August 25, 2017: Zhonghua Wei Chang Wai Ke za Zhi, Chinese Journal of Gastrointestinal Surgery
James C Williams, Michael S Borofsky, Sharon B Bledsoe, Andrew P Evan, Fredric L Coe, Elaine M Worcester, James E Lingeman
PURPOSE: Mechanisms of early stone retention in the kidney are under studied and poorly understood. To date attachment via Randall plaque is the only widely accepted theory in this regard, which is best described in idiopathic calcium oxalate stone formers. Brushite stone formers are known to have distinct papillary morphology relative to calcium oxalate stone formers. As such we sought to determine whether stone attachment mechanisms in such patients may be similarly unique. MATERIALS AND METHODS: Patients undergoing percutaneous and or ureteroscopic procedures for stone removal consented to endoscopic renal papillary examination and individual stone collection...
August 16, 2017: Journal of Urology
Punam K Saha, Dakai Jin, Yinxiao Liu, Gary E Christensen, Cheng Chen
Skeletonization offers a compact representation of an object while preserving important topological and geometrical features. Literature on skeletonization of binary objects is quite mature. However, challenges involved with skeletonization of fuzzy objects are mostly unanswered. This paper presents a new theory and algorithm of skeletonization for fuzzy objects, evaluates its performance, and demonstrates its applications. A formulation of fuzzy grassfire propagation is introduced; its relationships with fuzzy distance functions, level sets, and geodesics are discussed; and new results are presented...
August 10, 2017: IEEE Transactions on Visualization and Computer Graphics
Marco Campetella, Federica Maschietto, Mike J Frisch, Giovanni Scalmani, Ilaria Ciofini, Carlo Adamo
This work presents a new index, MAC , enabling the on-the-fly detection of ghost charge transfer (CT) states, a major problem in time-dependent density-functional theory calculations. This computationally inexpensive index, derived as a modification of the Mulliken estimation of transition energy for CT excitations, relies on two basic ingredients: an effective CT distance, computed using our density-based index (DCT ), and an orbital weighted estimation of the Ionization Potential and Electron Affinity. Some model systems, representative of both intermolecular and intramolecular CT excitations, were chosen as test cases...
August 1, 2017: Journal of Computational Chemistry
Neda Jafari, Lyle Gesner, Joseph M Koziol, Giorgio Rotoli, Otakar R Hubschmann
BACKGROUND: The origin of chronic subdural hematomas (CSDH) and the pathophysiology of its enlargement remain unknown. The chemical fluid composition of CSDH, the contribution of cerebrospinal fluid (CSF) to its enlargement, and the relationship to its appearance on computed tomography (CT) also are not entirely clear. METHODS: In this prospective study, 58 samples in 41 patients treated surgically for CSDH were analyzed. CSDHs were evaluated for the presence of CSF via β-2 transferrin and substances related to cell breakdown and hemolysis...
November 2017: World Neurosurgery
Junichi Hashimoto, Shinji Abe, Yoshiyuki Ishimori, Masahiko Monma, Akio Tsumuraya, Kaneyoshi Miyauchi
The low-contrast detectability of computed tomography (CT) images is commonly evaluated by the contrast-to-noise ratio (CNR) because of its convenience to measure. However, the correlation between CNR and visual detectability is poor because the CNR is a simple index determined by both the contrast of the object and the standard deviation of the image noise. On the other hand, the signal-to-noise ratio (SNR), especially SNR based on the statistical decision theory model (SNRS, D) and SNR based on the matched-filter model (SNRM) are considered superior to CNR...
2017: Nihon Hoshasen Gijutsu Gakkai Zasshi
Basant A Ali, Nageh K Allam
We report density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations on the widely used N3 dye (cis-[Ru(2,2'-bipyridine-4,4'-dicarboxylic acid)2(NCS)2] and its trans isomer with different π-spacers. The study compared the sensitization properties of the two isomers in terms of their electronic properties such as light harvesting efficiency (LHE), absorbed wavelength (λMax) and molecular orbital distribution. Also, charge transfer descriptors, such as the charge transfer distance (D(CT)), dipole moment (μ(CT)), and the amount of charge transferred (q(CT)) were investigated...
January 5, 2018: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Zhizhong Zheng, Ailong Cai, Lei Li, Bin Yan, Fulong Le, Linyuan Wang, Guoen Hu
Sparse-view imaging is a promising scanning approach which has fast scanning rate and low-radiation dose in X-ray computed tomography (CT). Conventional L1-norm based total variation (TV) has been widely used in image reconstruction since the advent of compressive sensing theory. However, with only the first order information of the image used, the TV often generates dissatisfactory image for some applications. As is widely known, image curvature is among the most important second order features of images and can potentially be applied in image reconstruction for quality improvement...
July 7, 2017: Journal of X-ray Science and Technology
Bradley Franks, Adrian Bangerter, Martin W Bauer, Matthew Hall, Mark C Noort
Conspiracy theories (CTs) are widespread ways by which people make sense of unsettling or disturbing cultural events. Belief in CTs is often connected to problematic consequences, such as decreased engagement with conventional political action or even political extremism, so understanding the psychological and social qualities of CT belief is important. CTs have often been understood to be "monological," displaying the tendency for belief in one conspiracy theory to be correlated with belief in (many) others...
2017: Frontiers in Psychology
A F Brookes, Caw Macano, T Stone, M Cheetham, L Meecham
INTRODUCTION Anecdotally, surgeons claim splenic flexure mobilisation is more difficult in male patients. There have been no scientific studies to confirm or disprove this hypothesis. The implications in colorectal surgery could be profound. The aim of this study was to assess quantitatively whether there is an anatomical difference in the position of the splenic flexure between men and women using computed tomography (CT). METHODS Portal venous phase CT performed for preoperative assessment of colorectal malignancy was analysed using the hospital picture archiving and communication system...
July 2017: Annals of the Royal College of Surgeons of England
Zhen Deng, Kuan Wang, Huihao Wang, Tianying Lan, Hongsheng Zhan, Wenxin Niu
PURPOSE: Traditional Chinese cervical manipulation (TCCM) has been claimed as an effective treatment for diseases of the cervical spine, but its biomechanical effects on the vertebral body and intervertebral discs remain unclear. The aim of this study was to develop and validate a detailed finite element model of cervical spine, which was then used to investigate the biomechanical response of the cervical spine to TCCM. METHODS: The model of a C2-T1 cervical spine was constructed based on CT images of a healthy male volunteer and validated against published in vitro studies under different loading conditions...
June 28, 2017: European Spine Journal
Chenkai Dai, Mohamed Lehar, Daniel Q Sun, Lani Swarthout Rvt, John P Carey, Tim MacLachlan, Doug Brough, Hinrich Staecker, Alexandra M Della Santina, Timothy E Hullar, Charles C Della Santina
Sensorineural losses of hearing and vestibular sensation due to hair cell dysfunction are among the most common disabilities. Recent preclinical research demonstrates that treatment of the inner ear with a variety of compounds, including gene therapy agents, may elicit regeneration and/or repair of hair cells in animals exposed to ototoxic medications or other insults to the inner ear. Delivery of gene therapy may also offer a means for treatment of hereditary hearing loss. However, injection of a fluid volume sufficient to deliver an adequate dose of a pharmacologic agent could, in theory, cause inner ear trauma that compromises functional outcome...
August 2017: Journal of the Association for Research in Otolaryngology: JARO
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