Search results for "value"
showing 10 items of 5321 documents
Physically-Based Approach to the Mechanics of Strong Non-Local Linear Elasticity Theory
2009
In this paper the physically-based approach to non-local elasticity theory is introduced. It is formulated by reverting the continuum to an ensemble of interacting volume elements. Interactions between adjacent elements are classical contact forces while long-range interactions between non-adjacent elements are modelled as distance-decaying central body forces. The latter are proportional to the relative displacements rather than to the strain field as in the Eringen model and subsequent developments. At the limit the displacement field is found to be governed by an integro-differential equation, solved by a simple discretization procedure suggested by the underlying mechanical model itself…
Mechanically-based approach to non-local elasticity: Variational principles
2010
Abstract The mechanically-based approach to non-local elastic continuum, will be captured through variational calculus, based on the assumptions that non-adjacent elements of the solid may exchange central body forces, monotonically decreasing with their interdistance, depending on the relative displacement, and on the volume products. Such a mechanical model is investigated introducing primarily the dual state variables by means of the virtual work principle. The constitutive relations between dual variables are introduced defining a proper, convex, potential energy. It is proved that the solution of the elastic problem corresponds to a global minimum of the potential energy functional. Mo…
Constitutional developments in Latin American abortion law.
2016
Abstract For most of the 20th Century, restrictive abortion laws were in place in continental Latin America. In recent years, reforms have caused a liberalizing shift, supported by constitutional decisions of the countries’ high courts. The present article offers an overview of the turn toward more liberal rules and the resolution of abortion disputes by reference to national constitutions. For such purpose, the main legal changes of abortion laws in the last decade are first surveyed. Landmark decisions of the high courts of Argentina, Bolivia, Colombia, and Mexico are then analyzed. It is shown that courts have accepted the need to balance interests and competing rights to ground less res…
Analogous IgG subclass response to pertussis toxin in vaccinated children, healthy or affected by whooping cough
2003
The study of antigen specific IgG subclass distribution during disease, or during any other natural or artificial immunisation, can provide useful information on the kind of the immune response and the expected levels of protection. This is particularly true for diseases, such as pertussis in which the mechanisms underlying specific defence are still not completely understood. An investigation was therefore performed to evaluate the IgG subclass response to pertussis toxin (PT) in sera from 89 healthy vaccinated children and 131 vaccinated or unvaccinated children convalescent after a confirmed B. pertussis symptomatic infection. Antibody titres were expressed in arbitrary ELISA units/ml, a…
Stress gradient versus strain gradient constitutive models within elasticity
2014
Abstract A stress gradient elasticity theory is developed which is based on the Eringen method to address nonlocal elasticity by means of differential equations. By suitable thermodynamics arguments (involving the free enthalpy instead of the free internal energy), the restrictions on the related constitutive equations are determined, which include the well-known Eringen stress gradient constitutive equations, as well as the associated (so far uncertain) boundary conditions. The proposed theory exhibits complementary characters with respect to the analogous strain gradient elasticity theory. The associated boundary-value problem is shown to admit a unique solution characterized by a Helling…
Flat Panel Computed Tomography Pooled Blood Volume and Infarct Prediction in Endovascular Stroke Treatment
2019
Background and Purpose— Patients with large-vessel stroke frequently need to be transferred to comprehensive stroke centers for endovascular treatment. An update of physiological perfusion parameters and stroke progression on arrival is desirable. We examined the reliability of preinterventional pooled blood volume (PBV)-maps acquired by flat-panel detector computed tomography (CT) in the interventional angiography suite. Methods— The volumes of preinterventional perfusion deficit in flat-panel detector CT-PBV source images were compared with final infarct volume on follow-up multislice-CT after endovascular treatment of 29 consecutive patients with occlusion of the middle cerebral artery …
Expectation of sensory stimulation modulates brain activation during visual motion stimulation.
2005
The differential effects of visual hemifield motion stimulation during fixation of a stationary target were compared under two conditions: fixation straight ahead without any further instructions and fixation straight ahead with attention shifted to the "dark hemifield." Data from nine right-handed volunteers revealed that striate and extrastriate right hemispheric visual areas exhibited larger activations during left hemifield motion stimulation when attention was shifted to the right dark hemifield. Montreal Neurological Institute (MNI) coordinates (26, -98, -4) of the additional clusters activated in the latter condition corresponded best to the kinetic occipital region, which is known t…
A negative rapid urease test is unreliable for exclusion of Helicobacter pylori infection during acute phase of ulcer bleeding
2003
Abstract Background. The reliability of the rapid urease test has not been proven in patients with peptic ulcer bleeding. Some studies show bad diagnostic results with the rapid urease test for gastrointestinal bleeding. Aims. To evaluate the efficacy of the rapid urease test in patients with bleeding gastric or duodenal ulcers. Patients and methods. A total of 96 patients with acute peptic ulcer bleeding without proton pump inhibitor or antibiotic therapy within the last 14 days before bleeding were included into the study. During index endoscopy, specimens for histological and rapid urease test were obtained from the antrum and corpus mucosa of the stomach. Patients were also investigated…
Stool antigen assay (HpSA) is less reliable than urea breath test for post-treatment diagnosis of Helicobacter pylori infection
2002
Summary Background : The diagnostic yield of the stool antigen test (HpSA) in evaluating the results of Helicobacter pylori eradication therapy is controversial, but many studies have used only the 13C-urea breath test (13C-UBT) as a gold standard which has greatly reduced their relevance. Aim : To compare the reliability of HpSA and 13C-UBT in patients post-treatment using biopsy-based methods as reference tests. Methods : A total of 100 consecutive dyspeptic patients (42 male and 58 female; mean age, 56 ± 18 years) were enrolled in our study. All patients were H. pylori positive on the basis of at least two biopsy-based methods, and underwent 1 week of treatment with various triple therap…
Diagnostic Accuracy of <sup>13</sup>C-Urea Breath Test in the Diagnosis of <i>Helicobacter pylori</i> Infection in Patients w…
2001
<i>Aims:</i> We investigated the diagnostic properties of the <sup>13</sup>C-urea breath test (<sup>13</sup>C-UBT) prospectively. These are well validated in nonresected patients before and after treatment of <i>Helicobacter pylori</i> infection but not in patients with partial gastric resection due to peptic ulcer disease. <i>Methods:</i> Hospitalized patients with previous gastric resection and indications for upper gastrointestinal endoscopy were recruited for the study. Biopsy specimens were obtained from the fundus mucosa and the gastric remnant adjacent to the gastroenteric anastomosis for histological examination and rapid u…