Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 12 de 12
Filter
Add more filters










Publication year range
1.
J Magn Reson ; 287: 99-109, 2018 02.
Article in English | MEDLINE | ID: mdl-29328975

ABSTRACT

Improvement in the signal-to-noise ratio of Nuclear Magnetic Resonance (NMR) systems may be achieved either by increasing the signal amplitude or by decreasing the noise. The noise has multiple origins - not all of which are strictly "noise": incoherent thermal noise originating in the probe and pre-amplifiers, probe ring down or acoustic noise and coherent externally broadcast radio frequency transmissions. The last cannot always be shielded in open access experiments. In this paper, we show that pulsed, low radio-frequency data communications are a significant source of broadcast interference. We explore two signal processing methods of de-noising short T2∗ NMR experiments corrupted by these communications: Linear Predictive Coding (LPC) and the Discrete Wavelet Transform (DWT). Results are shown for numerical simulations and experiments conducted under controlled conditions with pseudo radio frequency interference. We show that both the LPC and DWT methods have merit.

2.
Article in English | MEDLINE | ID: mdl-24730972

ABSTRACT

This paper deals with the solution of the spherically symmetric time-dependent Hartree-Fock approximation applied to nuclear giant monopole resonances in the small amplitude regime. The problem is spatially unbounded as the resonance state is in the continuum. The practical requirement to perform the calculation in a finite-sized spatial region yields an artificial boundary, which is not present physically. The question of how to ensure the boundary does not interfere with the internal solution, while keeping the overall calculation time low is studied. Here we propose an absorbing boundary condition scheme to handle the conflict. The derivation, via a Laplace transform method, and implementation is described. An inverse Laplace transform required by the absorbing boundaries is calculated using a method of nonlinear least squares. The accuracy and efficiency of the scheme is tested and results presented to support the case that they are an effective way of handling the artificial boundary.

3.
Acta odontol. venez ; 50(3)2012. ilus
Article in Spanish | LILACS | ID: lil-676698

ABSTRACT

La Estomatitis Sub-Protésica es una afección comúnmente observada en sujetos portadores de prótesis dentales removibles. Son numerosos los reportes publicados en los que se asocia esta patología con la presencia de hongos del Género Candida, y particularmente con Candida albicans. No obstante, algunas cepas identificadas como C. albicans, pudieran no tratarse en realidad de este microorganismo sino de Candida dubliniensis, más aún si se toma en cuenta que ambas especies producen clamidoconidias. Es por ello que resulta necesario comparar distintos métodos fenotípicos que permitan diferenciar en buena medida a ambas especies. En este artículo se describe el caso de una paciente portadora de prótesis removible superior con diagnóstico clínico de Estomatitis Sub-Protésica, a quien se le tomó muestras del paladar afectado y de la prótesis implicada. Se emplearon diferentes métodos fenotípicos de identificación diferencial de ambas especies, entre estos: CHROMagar Candida, Agar tabaco, Agar Pal´s, Agar Tween 80, medio de tomate y zanahoria y de Agar Sabouraud con NaCl al 6,5% (P/V). También se realizaron la pruebas de termotolerancia a 45ºC, aglutinación en latex, así como la identificación a través del sistema ID 32C (bioMerieux). Una vez empleados los métodos antes mencionados, la especie encontrada en el paladar de la paciente fue C. dubliniensis, en tanto que la que se halló en la prótesis fue C. albicans, siendo esta la primera vez que se detecta e identifica en nuestro país a C.dubliniensis en pacientes que presentan esta patología bucal.


Denture stomatitis is a condition commonly observed in subjects with removable dentures. There are numerous reports published in which this disease is associated with the presence of fungi of the genus Candida, particularly Candida albicans. However, some strains identified as C. albicans, may not actually be this organism but Candida dubliniensis, especially if one takes into account that both species produce clamidoconidias. That is why it is necessary to compare different phenotypic methods to differentiate largely to both species. This article describes the case of a patient with upper removable prosthesis with a clinical diagnosis of Denture Stomatitis, whom he took samples of the palate is affected and the prosthesis involved. Different methods were used phenotypic differential identification of both species, among them: CHROMagar Candida Agar snuff, Pal's Agar, Tween 80 Agar, tomato and carrot medium, and Sabouraud Agar with 6.5% NaCl (P / V ). Also thermotolerance tests performed at 45 ° C, latex agglutination, and identification by ID 32C system (bioMerieux) were used. Once employed the above methods, the species found in the mouth of the patient was C. dubliniensis, whereas that was found in the prosthesis was C. albicans, marking the first time it is detected and identified in our country C.dubliniensis in patients with this oral pathology.


Subject(s)
Humans , Female , Aged , Candida , Candida albicans , Diagnosis/analysis , Stomatitis, Denture/diagnosis , Dental Prosthesis/adverse effects , Chemical Phenomena/methods
4.
Acta odontol. venez ; 47(4): 167-173, dic. 2009.
Article in Spanish | LILACS | ID: lil-630226

ABSTRACT

De los diversos procesos infecciosos que se suscitan en la cavidad bucal humana, las enfermedades periodontales tienen especial importancia ya que cada día que pasa son más las personas que se ven afectadas por estas patologías. Su etiología y desarrollo se ha relacionado desde muchos años con la presencia de microorganismos periodontopatógenos, destacándose entre estos los pertenecientes a la Familia Bacteroidaeceae, representados por los Géneros Porphyromonas y Prevotella. Constantemente surgen nuevas especies del Género Prevotella, las cuales están implicadas en mayor o menor grado en causar daño al periodonto y es por ello que resulta de vital importancia para el Odontólogo el hecho de conocer las especies de este Género que han sido reclasificadas, así como la detección e identificación de nuevas especies a los fines de aplicar el tratamiento antimicrobiano más adecuado y garantizar resultados exitosos luego de la implementación del mismo.


Periodontal diseases are one of the most important oral pathologies occurred in the human oral cavity. There are more people who have been affected by periodontal pathogens. Some of the microorganisms that are related with periodontal diseases belong to the Family Bacteroidaceae, represented by Genus Porphyromonas and Prevotella. In recient years, it can found new species of the Genus Prevotella and the dentist should know about them like resident microflora of the oral cavity and their implications in periodontal diseases, in order to establish the most convenient antimicrobial treatment for these pathologies.

7.
Transplant Proc ; 36(3): 716-7, 2004 Apr.
Article in English | MEDLINE | ID: mdl-15110642

ABSTRACT

We describe a case of polyradiculoneuropathy (PRN) following living donor kidney transplantation, without clinical evidence of preexisting infection. In this study plasma exchange treatment resulted 6 days later in improvement in extremity weakness and paresthesias in the upper and lower extremities. Total neurological recovery was obtained 3 months after the onset of symptoms.


Subject(s)
Kidney Transplantation/adverse effects , Plasma Exchange , Polyradiculoneuropathy/therapy , Humans , Male , Middle Aged , Polyradiculoneuropathy/etiology , Treatment Outcome
8.
Transplant Proc ; 36(10): 3068-70, 2004 Dec.
Article in English | MEDLINE | ID: mdl-15686696

ABSTRACT

BACKGROUND: Originally introduced for cutaneous T-cell lymphomas and autoimmune diseases, extracorporeal photopheresis (ECP) has been proven effective to reverse allograft rejection. The aim of the present work was to show the results of a single-center experience with ECP for the treatment of biopsy-proven rejection in selected liver transplant (LT) recipients. PATIENTS AND METHODS: A retrospective review of five LT patients (M:F=4:1; median age 51 years) undergoing ECP for biopsy-proven allograft rejection between January 1996 and December 2003. In this period 476 LT were performed on 441 patients. RESULTS: The indications for LT were three cases of HCV-related cirrhosis, complicated by hepatocellular carcinoma in two; one HBV-HDV-alcoholic cirrhosis; and one fulminant HBV hepatitis. All patients received calcineurin-inhibitor (CNI)-based immunosuppression with induction using anti-IL2R monoclonal antibodies. Indications for ECP were: ductopenic rejection in one patient with HCV recurrence; steroid-resistant acute rejection in two; acute rejection in a major ABO-mismatched liver graft; and one acute rejection in a patient with a proven allergy to steroids. The median interval from LT to inception of ECP was 43 days. The median number of ECP sessions per patient was 20. During the course of ECP, two patients tested positive for CMV antigenemia, associated in one case with bacterial pneumonia. All patients tolerated ECP and there were no procedure-related complications. At a median follow-up of 7.9 months after start of ECP, neither rejection relapses nor HCV/HBV recurrences have been observed. Three patients are off ECP with complete reversal and low-dose immunosuppression. Two patients are still receiving ECP with full-dose immunosuppression: one has achieved normal liver function but ECP is indicated due to a major ABO-incompatible liver graft, while the other patient's liver functions have not yet returned to baseline values.


Subject(s)
Graft Rejection/therapy , Liver Transplantation , Photopheresis , Adult , Extracorporeal Circulation , Female , Hepatitis C/surgery , Humans , Liver Cirrhosis/surgery , Liver Cirrhosis/virology , Male , Middle Aged , Retrospective Studies , Transplantation, Homologous
10.
Minerva Pediatr ; 53(2): 107-19, 2001 Apr.
Article in Italian | MEDLINE | ID: mdl-11404732

ABSTRACT

The assessment of global pain in infants and children involves the analysis of subjective, behavioural and physiological components, beyond the psychological, familiar and environmental factors that influence and modulate the manifestation of painful symptom. Therefore, researchers and clinicians need valid and reliable instruments to obtain a correct measure of pain. Although subjective indices carry out a fundamental role in the assessment of pain (instruments adjusted to the age of the child), behavioural and physiological indices should be used when intelligence deficit or serious physical handicaps exclude such possibility. Behavioural aspects, associated and correlated to physiological changes, allow to obtain a reliable enough measure of pain. In this paper, the main instruments for measuring pain in infants and children will be described, and their advantages and disadvantages underlined.


Subject(s)
Pain Measurement , Pain/psychology , Adolescent , Age Factors , Child , Child, Preschool , Humans , Infant , Infant, Newborn , Pain Measurement/methods , Pain Measurement/standards , Pain, Postoperative/diagnosis
11.
Immunol Lett ; 63(2): 97-105, 1998 Sep.
Article in English | MEDLINE | ID: mdl-9761371

ABSTRACT

T. cruzi-infected macrophages are potential candidates for the presentation of parasite antigens to T. cruzi-specific T lymphocytes. To assess this question, we examine the ability of peritoneal exudate macrophages to process exogenous live or dead parasites and to activate defined populations of T. cruzi-specific immune T-cells. Macrophages infected with live amastigotes activated both lymph node CD4+ and spleen CD8 + T-primed cells that proliferated and secreted cytokines. Lymph node CD4+ T-cells produced IFN-gamma and IL-10 while CD8 + T-cells produced IFN-gamma. In contrast, macrophages pulsed with dead parasites activated only lymph node CD4+ T-cells, which proliferated and secreted IFN-gamma. Interestingly, the immunization with heat-killed parasites primed mice for CD8+ T-cells which were expanded in vitro by recognition of infected macrophages. Taken together, these results demonstrated that amastigote infected macrophages present parasite peptides associated with MHC I and II molecules, activating both CD4 + and CD8+ T-cells. Furthermore, the development of T. cruzi-specific CD8+ T-cells in vivo using the immunization protocol with non-living parasites as described in this report could be explored for further studies on the role of CTL in the outcome of infection.


Subject(s)
Antigens, Protozoan/immunology , CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , Cell Communication/physiology , Lymphocyte Activation/immunology , Macrophages, Peritoneal/immunology , Macrophages, Peritoneal/parasitology , Trypanosoma cruzi/immunology , Animals , Antibodies, Monoclonal/pharmacology , Antigen Presentation/immunology , Antigen-Presenting Cells/immunology , Antigen-Presenting Cells/parasitology , CD4 Antigens/immunology , CD4-Positive T-Lymphocytes/metabolism , CD8 Antigens/immunology , CD8-Positive T-Lymphocytes/metabolism , Interferon-gamma/biosynthesis , Interleukins/biosynthesis , Lymph Nodes/cytology , Lymph Nodes/immunology , Lymph Nodes/metabolism , Male , Mice , Mice, Inbred BALB C , Phenotype , Sensitivity and Specificity , Spleen/cytology , Spleen/immunology , Spleen/metabolism
SELECTION OF CITATIONS
SEARCH DETAIL
...