2,775 research outputs found
Development of a microfluidic paper-based analytical device for the determination of iodide
info:eu-repo/semantics/publishedVersio
Newly designed microfluidic paper-based device for iodide determination in both food and biological samples
info:eu-repo/semantics/publishedVersio
Development of a sequential injection method for bromate determination in soil leachates
info:eu-repo/semantics/publishedVersio
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Plasmablastic lymphoma: an atypical cutaneous presentation of a rare entity
Plasmablastic lymphoma is a very rare B-cell lymphoma typically associated with immunosuppression: It occurs primarily in the oral cavity, although some cases were reported in other organs and tissues.To date, only 10 cases of primary cutaneous plasmablastic lymphoma have been described. Clinically, primary cutaneous plasmablastic lymphoma presents as non-specific cutaneous lesions (purple nodules, erythematous infiltrated plaques). In previously described cases, as in this case, histology and immunohistochemistry are required to make the diagnosis. Owing to the rarity of this entity, there is no established therapy, which makes its management an individualized, patient-based decision.info:eu-repo/semantics/publishedVersio
Modified Beer-Lambert law for blood flow
FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPWe develop and validate a Modified Beer-Lambert law for blood flow based on diffuse correlation spectroscopy (DCS) measurements. The new formulation enables blood flow monitoring from temporal intensity autocorrelation function data taken at single or multiple delay-times. Consequentially, the speed of the optical blood flow measurement can be substantially increased. The scheme facilitates blood flow monitoring of highly scattering tissues in geometries wherein light propagation is diffusive or non-diffusive, and it is particularly well-suited for utilization with pressure measurement paradigms that employ differential flow signals to reduce contributions of superficial tissues.51140534075FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP2012/02500-82013/07559-3We gratefully acknowledge help from Marion Knaus and Victoria Pallett per preparing the pig, and we thank longtime collaborators Daniel Licht, John Detre, Emile Mohler, Thomas Floyd, Turgut Durduran, and Theresa Busch for valuable discussions. We acknowledge support from the National Institutes of Health (R01-NS060653, NHLBI-HL007915, 8P41-EB015893), the American Heart Association (ABP, 14POST20460161), the Thrasher Pediatric Research Foundation Early Career Award (DRB), and the Sao Paulo Research Foundation (RCM, 2012/02500-8, 2013/07559-3)
Modified Beer-Lambert law for blood flow
FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOThe modified Beer-Lambert law is among the most widely used approaches for analysis of near-infrared spectroscopy (NIRS) reflectance signals for measurements of tissue blood volume and oxygenation. Briefly, the modified Beer-Lambert paradigm is a scheme to derive changes in tissue optical properties based on continuous-wave (CW) diffuse optical intensity measurements. In its simplest form, the scheme relates differential changes in light transmission (in any geometry) to differential changes in tissue absorption. Here we extend this paradigm to the measurement of tissue blood flow by diffuse correlation spectroscopy (DCS). In the new approach, differential changes of the intensity temporal auto-correlation function at a single delay-time are related to differential changes in blood flow. The key theoretical results for measurement of blood flow changes in any tissue geometry are derived, and we demonstrate the new method to monitor cerebral blood flow in a pig under conditions wherein the semi-infinite geometry approximation is fairly good. Specifically, the drug dinitrophenol was injected in the pig to induce a gradual 200% increase in cerebral blood flow, as measured with MRI velocity flow mapping and by DCS. The modified Beer-Lambert law for flow accurately recovered these flow changes using only a single delay-time in the intensity auto-correlation function curve. The scheme offers increased DCS measurement speed of blood flow. Further, the same techniques using the modified Beer-Lambert law to filter out superficial tissue effects in NIRS measurements of deep tissues can be applied to the DCS modified Beer-Lambert law for blood flow monitoring of deep tissues.The modified Beer-Lambert law is among the most widely used approaches for analysis of near-infrared spectroscopy (NIRS) reflectance signals for measurements of tissue blood volume and oxygenation. Briefly, the modified Beer-Lambert paradigm is a scheme to derive changes in tissue optical properties based on continuous-wave (CW) diffuse optical intensity measurements. In its simplest form, the scheme relates differential changes in light transmission (in any geometry) to differential changes in tissue absorption. Here we extend this paradigm to the measurement of tissue blood flow by diffuse correlation spectroscopy (DCS). In the new approach, differential changes of the intensity temporal auto-correlation function at a single delay-time are related to differential changes in blood flow. The key theoretical results for measurement of blood flow changes in any tissue geometry are derived, and we demonstrate the new method to monitor cerebral blood flow in a pig under conditions wherein the semi-infinite geometry approximation is fairly good. Specifically, the drug dinitrophenol was injected in the pig to induce a gradual 200% increase in cerebral blood flow, as measured with MRI velocity flow mapping and by DCS. The modified Beer-Lambert law for flow accurately recovered these flow changes using only a single delay-time in the intensity auto-correlation function curve. The scheme offers increased DCS measurement speed of blood flow. Further, the same techniques using the modified Beer-Lambert law to filter out superficial tissue effects in NIRS measurements of deep tissues can be applied to the DCS modified Beer-Lambert law for blood flow monitoring of deep tissues.9319123FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO2012/02500-8; 2013/07559-311. Conference on Optical Tomography and Spectroscopy of Tissue9 a 11 de Fevereiro de 2015San Francisco, CASPIE - International Society for Optical EngineeringAgências de fomento estrangeiras apoiaram essa pesquisa, mais informações acesse artig
Repeatability and temporal consistency of lower limb biomechanical variables expressing interlimb coordination during the double-support phase in people with and without stroke sequelae
Reliable biomechanical methods to assess interlimb coordination during the double-support phase in post-stroke subjects are needed for assessing movement dysfunction and related variability. The data obtained could provide a significant contribution for designing rehabilitation programs and for their monitorisation. The present study aimed to determine the minimum number of gait cycles needed to obtain adequate values of repeatability and temporal consistency of lower limb kinematic, kinetic, and electromyographic parameters during the double support of walking in people with and without stroke sequelae. Eleven post-stroke and thirteen healthy participants performed 20 gait trials at self-selected speed in two separate moments with an interval between 72 h and 7 days. The joint position, the external mechanical work on the centre of mass, and the surface electromyographic activity of the tibialis anterior, soleus, gastrocnemius medialis, rectus femoris, vastus medialis, biceps femoris, and gluteus maximus muscles were extracted for analysis. Both the contralesional and ipsilesional and dominant and non-dominant limbs of participants with and without stroke sequelae, respectively, were evaluated either in trailing or leading positions. The intraclass correlation coefficient was used for assessing intra-session and inter-session consistency analysis. For most of the kinematic and the kinetic variables studied in each session, two to three trials were required for both groups, limbs, and positions. The electromyographic variables presented higher variability, requiring, therefore, a number of trials ranging from 2 to >10. Globally, the number of trials required inter-session ranged from 1 to >10 for kinematic, from 1 to 9 for kinetic, and 1 to >10 for electromyographic variables. Thus, for the double support analysis, three gait trials were required in order to assess the kinematic and kinetic variables in cross-sectional studies, while for longitudinal studies, a higher number of trials (>10) were required for kinematic, kinetic, and electromyographic variables.info:eu-repo/semantics/publishedVersio
Stokes' Drift of linear Defects
A linear defect, viz. an elastic string, diffusing on a planar substrate
traversed by a travelling wave experiences a drag known as Stokes' drift. In
the limit of an infinitely long string, such a mechanism is shown to be
characterized by a sharp threshold that depends on the wave parameters, the
string damping constant and the substrate temperature. Moreover, the onset of
the Stokes' drift is signaled by an excess diffusion of the string center of
mass, while the dispersion of the drifting string around its center of mass may
grow anomalous.Comment: 14 pages, no figures, to be published in Phys.Rev.
Depression and anxiety in systemic lupus erythematosus: The crosstalk between immunological, clinical, and psychosocial factors
Depression and anxiety cause severe loss of quality of life for patients with systemic lupus erythematosus. The causes and factors that contribute to these psychological manifestations in lupus are difficult to disentangle. This study compared clinical, psychological, and demographic factors between lupus patients, depressed patients, and rheumatoid arthritis patients to discover lupus-specific contributors to depression. Lupus-specific manifestations of depression were also investigated. Physiological, clinical, and psychosocial data were collected from 77 patients. ELISA was used to measure cytokine levels. Univariate and Multivariate analyses were used to compare the patient populations and identify correlations between key physical and psychological indicators. The prevalence of depression in the SLE cohort was 6 times greater than the healthy control subjects. Pain, IL-6, and Pittsburgh Sleep Quality index values were all significantly higher in SLE patients compared with the healthy control group (P < .001, P = .038, and P = .005, respectively). Anxiety levels were significantly higher in SLE patients compared to healthy and RA control patients (P = .020 and .011, respectively). Serum IL-10 concentrations, relationship assessment scale, and fatigue severity scale values were found to be correlated with depression among the SLE patients (P = .036, P = .007, and P = .001, respectively). Relationship assessment and fatigue severity scale scores were found to be the best indicators of depression for the SLE patients (P = .042 and .028, respectively). Fatigue Severity, relationship satisfaction, and IL-10 concentrations are indicators of depression in lupus patients. Despite also suffering from the pain and disability that accompanies chronic autoimmune disease, the rheumatoid arthritis patients had less anxiety and better relationship scores.The authors thank the Portugal Fulbright Commission for funding Dr. Pool
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