Recently, we have reported on calculation of π-electron ring currents in several smaller fully benzenoid hydrocarbons having up to eight fused benzene rings and five Clar π-aromatic sextets. In contrast to early HMO ring current calculations and more recent ab initio calculations of π-electron density, our current calculations are based on a graph theoretical model in which contributions to ring currents comes from currents associated with individual conjugated circuits. In this contribution, we consider several larger fully benzenoid hydrocarbons having from 9 to 13 fused rings and from six or seven π-aromatic sextets. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
This paper deals with the FEM simulations of anisotropic flow during bulk forming (forging) of magnesium AZ80 wrought alloy at warm conditions. Anisotropic characteristics are described by the classical formulation of Hill’s (1948) quadratic anisotropic yield law. To define reliable FEM models capable of carrying out numerical simulations of complex bulk forming operations in a reasonable amount of computing time, a simplified approach for determining Hill’s anisotropic coefficients as constants is proposed. On the basis of the determined Hill’s anisotropic coefficients and the mechanical properties, the results of an extensive FEM study of lab-scale and industrial-scale forging are shown. FEM results are also compared to the actual obtained results. It is shown that the approach presented can be successfully used in industrial practice. DOI: http://dx.doi.org/10.5755/j01.mech.18.3.1876
Industrial Control Systems (ICS) are used for operating and monitoring industrial processes. Recent reports state that current ICS infrastructures are not sufficiently protected against cyber threats. Unfortunately, due to the specific nature of these systems, the application of common security counter-measures is often not effective. This paper summarizes experiences over a series of research efforts for building tools and mechanisms to improve the security and awareness in ICS. In particular, we discuss challenges and opportunities identified during an extensive analysis of ICS data resources. We believe that such insights are valuable for further research in the ICS context.
This article discusses the possibilities of diagnosing abdominal imaging in patients with rectal cancer, detecting lesions and assessing the stage of the lesions, in order to select the appropriate therapy. Before the introduction of imaging technologies, the diagnosis of colorectal pathology was based on conventional methods of inspecting intestines with a barium enema, with either a single or double contrast barium enema. Following the development of endoscopic methods and the wide use of colonoscopy, colonoscopy became the method of choice for diagnosing colorectal diseases. The improvement of Computerized Tomography (CT) and Magnetic Resonance Imaging (MRI), gave us new possibilities for diagnosing colorectal cancer. For rectal cancer, trans-rectal US (TRUS) or endo-anal US (EAUS) have a significant role. For staging rectal cancer, the Multi Slice Computed Tomography (MSCT) is not the method of choice, but Magnetic Resonance Imaging (MRI) is preferred when it comes to monitoring the rectum. The role of the MRI in the T staging of rectal cancer is crucial in preoperative assessment of: thickness - the width of the tumor, the extramural invasion, the circumference of resection margin (CRM), and the assessment of the inclusion of mesorectal fascia. For successful execution of surgical techniques, good diagnostic imaging of the cancer is necessary in order to have a low level of recurrence. According to medical studies, the sensitivity of FDG-PET in diagnosing metastatic nodals is low, but for now it is not recommended in routine diagnosis of metastatic colorectal carcinoma.
BackgroundDysphagia or swallowing disorder negatively impacts a child’s health and development. The gold standard of dysphagia detection is videofluoroscopy which exposes the child to ionizing radiation, and requires specialized clinical expertise and expensive institutionally-based equipment, precluding day-to-day and repeated assessment of fluctuating swallowing function. Swallowing accelerometry is the non-invasive measurement of cervical vibrations during swallowing and may provide a portable and cost-effective bedside alternative. In particular, dual-axis swallowing accelerometry has demonstrated screening potential in older persons with neurogenic dysphagia, but the technique has not been evaluated in the pediatric population.MethodsIn this study, dual-axis accelerometric signals were collected simultaneous to videofluoroscopic records from 29 pediatric participants (age 6.8 ± 4.8 years; 20 males) previously diagnosed with neurogenic dysphagia. Participants swallowed 3-5 sips of barium-coated boluses of different consistencies (normally, from thick puree to thin liquid) by spoon or bottle. Videofluoroscopic records were reviewed retrospectively by a clinical expert to extract swallow timings and ratings. The dual-axis acceleration signals corresponding to each identified swallow were pre-processed, segmented and trimmed prior to feature extraction from time, frequency, time-frequency and information theoretic domains. Feature space dimensionality was reduced via principal components.ResultsUsing 8-fold cross-validation, 16-17 dimensions and a support vector machine classifier with an RBF kernel, an adjusted accuracy of 89.6% ± 0.9 was achieved for the discrimination between swallows with and with out airway entry.ConclusionsOur results suggest that dual-axis accelerometry has merit in the non-invasive detection of unsafe swallows in children and deserves further consideration as a pediatric medical device.
Dysphagia or swallowing disorder negatively impacts a child’s health and development. The gold standard of dysphagia detection is videofluoroscopy which exposes the child to ionizing radiation, and requires specialized clinical expertise and expensive institutionally-based equipment, precluding day-to-day and repeated assessment of fluctuating swallowing function. Swallowing accelerometry is the non-invasive measurement of cervical vibrations during swallowing and may provide a portable and cost-effective bedside alternative. In particular, dual-axis swallowing accelerometry has demonstrated screening potential in older persons with neurogenic dysphagia, but the technique has not been evaluated in the pediatric population. In this study, dual-axis accelerometric signals were collected simultaneous to videofluoroscopic records from 29 pediatric participants (age 6.8 ± 4.8 years; 20 males) previously diagnosed with neurogenic dysphagia. Participants swallowed 3-5 sips of barium-coated boluses of different consistencies (normally, from thick puree to thin liquid) by spoon or bottle. Videofluoroscopic records were reviewed retrospectively by a clinical expert to extract swallow timings and ratings. The dual-axis acceleration signals corresponding to each identified swallow were pre-processed, segmented and trimmed prior to feature extraction from time, frequency, time-frequency and information theoretic domains. Feature space dimensionality was reduced via principal components. Using 8-fold cross-validation, 16-17 dimensions and a support vector machine classifier with an RBF kernel, an adjusted accuracy of 89.6% ± 0.9 was achieved for the discrimination between swallows with and with out airway entry. Our results suggest that dual-axis accelerometry has merit in the non-invasive detection of unsafe swallows in children and deserves further consideration as a pediatric medical device.
External application of seabuckthorn oil (Hippophae rhamnoides L.) is difficult due to its liquid state in spite of its benefits for damaged skin. In order to overcome this inadequacy the semisolid emulsion with seabuckthorn oil was prepared. Previous research showed that this emulsion possessing an enhanced structure with liquid crystals showed a higher wound healing potential than seabuckthorn oil. The aim of this investigation was to characterize suitability of this emulsion for topical use. The emulsion was prepared by combining emulsifiers that form liquid crystals. Two different quantities of seabuckthorn oil were incorporated. Samples were prepared with 10% and 40% of seabuckthorn oil. Organoleptic characteristics were estimated visually and by smearing samples on a thin glass plate. Type of emulsion was determined by a conductometric method, while a pH value of the emulsion was measured by a pH meter. Samples of seabuckthorn emulsion were orange, semisolid, shiny, easily spreadable on skin, and the smear on the glass plate was homogeneous. There was an absence of smell and the emulsion could be rinsed by water after the application on skin, which is a desired characteristic of oil/water emulsions. Results of an electrical conductivity confirmed that an outer phase is water. Samples possesed an acceptable pH value for an external topical use. This research confirmed that constituents and a method used were suitable for preparing semisolid emulsion with seabuckthorn oil. Organoleptic properties, a pH value and a type of obtained emuslion appear to be adequate for topical use.
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