Read by QxMD icon Read

CT theory and use

Yingxia Liu, Ziad Saleh, Yulin Song, Maria Chan, Xiang Li, Chengyu Shi, Xin Qian, Xiaoli Tang
Segmentation of prostate Cone Beam CT (CBCT) images is an essential step towards real-time adaptive radiotherapy (ART). It is challenging for Calypso patients, as more artifacts generated by the beacon transponders are present on the images. We herein propose a novel wavelet-based segmentation algorithm for rectum, bladder, and prostate of CBCT images with implanted Calypso transponders. For a given CBCT, a Moving Window-Based Double Haar (MWDH) transformation is applied first to obtain the wavelet coefficients...
August 2017: International Journal of Medical Physics, Clinical Engineering and Radiation Oncology
Federica Maschietto, Marco Campetella, Michael J Frisch, Giovanni Scalmani, Carlo Adamo, Ilaria Ciofini
With the aim of investigating qualitatively and quantitatively the impact of using excited state relaxed or unrelaxed density for the estimation of nature and characteristic of electronic excited states, we analyzed the behavior of 52 exchange correlation functionals for the prediction of density-based indexes such as those recently introduced in literature to evaluate the charge transfer distance (DCT ) (Le Bahers et al. J. Chem. Theory Comput. 2011, 7, 2498) in the case of a prototype family of push-pull dyes...
January 10, 2018: Journal of Computational Chemistry
S P Chang, Y Yang, L Q Shi, Y W Liu, Y Liu, Q Ma
Our aim was to improve the accuracy of measurement of the angulation and the shortening of the height of the ramus in fractures of the mandibular condyle using modified methods. We analysed spiral computed tomography (CT) of 67 unilateral fractures with the OsiriX v 5.0 (©Pixmeo Sarl) and Mimics 19.0 (©2016 Materialise NV, Belgium) and analysed them with SPSS (version 24.0, IBM® SPSS®). Angulation was measured using both the traditional method and our modified method. The results showed significant difference (p = 0...
January 5, 2018: British Journal of Oral & Maxillofacial Surgery
Eduardo Gomez, Mario Gutiérrez, Miquel Moreno, Ichiro Hisaki, Schoichi Nakagawa, Abderrazzak Douhal
In this work, we report on the results of theoretical and experimental studies of a series of dehydrobenzoannulene (DBA) derivatives (Nu-T12 [5,6,11,12,17,18-hexadehydrotribenzo[a,e,i]cyclododecene], T12-COOMe [5,6,11,12,17,18-hexadehydro-2,3,8,9,14,15-hexakis(4-methoxycarbonylphenyl)tribenzo[a,e,i]cyclododecene] and T12-COOH [5,6,11,12,17,18-hexadehydro-2,3,8,9,14,15-hexakis(4-carboxyphenyl)tribenzo[a,e,i]cyclododecene]) in N,N'-dimethylformamide (DMF) solutions. The theoretical and experimental findings show that the S0 → S1 transition of these molecules is forbidden...
January 5, 2018: Physical Chemistry Chemical Physics: PCCP
Said Sönmez, Bayram Şahin, Beldan Polat, Şenol Çomoğlu, Kadir Serkan Orhan
Spontaneous cerebrospinal fluid (CSF) otorrhea frequently occurs without temporal bone trauma, fracture, surgery, or any identifiable causes. It is usually associated with tegmen tympani defects of the temporal bone in adults. The congenital origin theory and the arachnoid granulation theory have been accepted to explain the tegmen tympani defect. Magnetic resonance imaging (MRI) and computed tomography (CT) are used to show the defects, brain tissue, and the meninges. We recently encountered three cases of spontaneous CSF otorrhea with a defect on the tegmental plate of the temporal bone...
December 14, 2017: Journal of International Advanced Otology
Frank Jonker, Cees Jonker, Laura Bronzwaer, Erik Scherder
OBJECTIVE: Amygdalohippocampectomy (AHE) is the resective surgery for medically intractable mesial temporal lobe epilepsy. To date no study has investigated a wide range of neuropsychiatric symptoms in right AHE outpatients. PATIENTS AND METHODS: Three patients with right AHE participated in this study. The control group are patients with cognitive complaints with no history of epilepsy or neurological impairment and no structural abnormalities on the MRI/CT. We expected no difference in verbal memory compared to the controls...
November 21, 2017: Clinical Neurology and Neurosurgery
Emily L Lin, Jonathan M Bock, Carlton J Zdanski, Julia S Kimbell, Guilherme J M Garcia
OBJECTIVES: Subglottic stenosis (SGS) is one of the most common airway disorders in pediatric patients. Currently, treatment decisions rely primarily on the Cotton-Myer scale, which classifies SGS severity based on percentage reduction in airspace cross-sectional area (CSA). However, the precise relationship between upper airway resistance and subglottic CSA is unknown. We hypothesize that airway resistance can be described by the Bernoulli Obstruction Theory, which predicts that airway resistance is inversely proportional to airspace CSA ( R∝A-1) in cases of severe constriction...
November 24, 2017: Laryngoscope
Justin A M J Van Leeuwen, Finnur Snorrason, Stephan M Röhrl
Background and purpose - Although the use of patient-specific positioning guides (PSPGs) in total knee replacement (TKR) in theory is promising, the technique has not yet proven its superior- ity compared with the conventional method. We compared radio- logical alignment and clinical outcome between TKR performed with the use of PSPGs and the conventional operation method. Patients and methods - 3 hospitals participated in a prospec- tive trial. 109 patients were randomized to either the conventional method or to the use of PSPGs...
November 22, 2017: Acta Orthopaedica
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
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"