9 resultados para single longitudinal mode
em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo
Resumo:
Noonan syndrome (NS) and Noonan-like syndromes (NLS) are autosomal dominant disorders caused by heterozygous mutations in genes of the RAS/MAPK pathway. The aim of the study was to construct specific growth charts for patients with NS and NLS. Anthropometric measurements (mean of 4.3 measurements per patient) were obtained in a mixed cross-sectional and longitudinal mode from 127 NS and 10 NLS patients with mutations identified in PTPN11 (n?=?90), SOS1 (n?=?14), RAF1 (n?=?10), KRAS (n?=?8), BRAF (n?=?11), and SHOC2 (n?=?4) genes. Height, weight, and body mass index (BMI) references were constructed using the lambda, mu, sigma (LMS) method. Patients had birth weight and length within normal ranges for gestational age although a higher preterm frequency (16%) was observed. Mean final heights were 157.4?cm [-2.4 standard deviation score (SDS)] and 148.4?cm (-2.2?SDS) for adult males and females, respectively. BMI SDS was lower when compared to Brazilian standards (BMI SDS of -0.9 and -0.5 SDS for males and females, respectively). Patients harboring mutations in RAF1 and SHOC2 gene were shorter than other genotypes, whereas patients with SOS1 and BRAF mutations had more preserved postnatal growth. In addition, patients with RAF1 and BRAF had the highest BMI whereas patients with SHOC2 and KRAS mutations had the lowest BMI. The present study established the first height, weight, and BMI reference curves for NS and NLS patients, based only on patients with a proven molecular cause. These charts can be useful for the clinical follow-up of patients with NS and NLS. (c) 2012 Wiley Periodicals, Inc.
Resumo:
Nowadays, the attainment of microsystems that integrate most of the stages involved in an analytical process has raised an enormous interest in several research fields. This approach provides experimental set-ups of increased robustness and reliability, which simplify their application to in-line and continuous biomedical and environmental monitoring. In this work, a novel, compact and autonomous microanalyzer aimed at multiwavelength colorimetric determinations is presented. It integrates the microfluidics (a three-dimensional mixer and a 25 mm length "Z-shape" optical flow-cell), a highly versatile multiwavelength optical detection system and the associated electronics for signal processing and drive, all in the same device. The flexibility provided by its design allows the microanalyzer to be operated either in single fixed mode to provide a dedicated photometer or in multiple wavelength mode to obtain discrete pseudospectra. To increase its reliability, automate its operation and allow it to work under unattended conditions, a multicommutation sub-system was developed and integrated with the experimental set-up. The device was initially evaluated in the absence of chemical reactions using four acidochromic dyes and later applied to determine some key environmental parameters such as phenol index, chromium(VI) and nitrite ions. Results were comparable with those obtained with commercial instrumentation and allowed to demonstrate the versatility of the proposed microanalyzer as an autonomous and portable device able to be applied to other analytical methodologies based on colorimetric determinations.
Resumo:
We present results for longitudinal dynamic hysteresis in single domain particles with uniaxial anisotropy. The combined influence of temperature, field-sweeping frequency, and field amplitude is discussed in detail. A novel and efficient numerical method is proposed, based on the direct solution of the infinite hierarchy of differential recurrence relations obtained from averaging over the stochastic realizations of the magnetic Langevin equation. (C) 2012 American Institute of Physics. [doi:10.1063/1.3676416]
Resumo:
In this work, a ruthenium hexafluorophosphate complex, [Ru(bpy)(3)](PF6)(2) in poly(methylmethacrylate) (PMMA) was employed to build a single layer light electrochemical cell on indium tin oxide polyester flexible substrate. The electroluminescence spectrum features a relatively broad band peaked near 625 run, with CIE (x,y) color coordinates of (0.61,0.39). The driving voltage is only 3 V, and for the maximum electrical current of 10 mA the brightness reaches 1 cd/m(2). Regarding the useful application of the device, its opto-electrical behavior under mechanical strain was studied considering the central curvature. In these situations, both electrical characterization in DC mode and luminance were analyzed. (C) 2007 Elsevier B.V. All rights reserved.
Resumo:
Background: The complex natural history of human papillomavirus (HPV) infections following a single HPV test can be modeled as competing-risks events (i.e., no-, transient- or persistent infection) in a longitudinal setting. The covariates associated with these compet ng events have not been previously assessed using competing-risks regression models. Objectives: To gain further insights in the outcomes of cervical HPV infections, we used univariate- and multivariate competing-risks regression models to assess the covariaies associated with these competing events. Study Design and Methods: Covariates associated with three competing outcomes (no-, transient- or persistent HR-HPV infection) were analysed in a sub-cohort of 1,865 women prospectively followed-up in the NIS (n = 3,187) and LAMS Study (n = 12,114). Results: In multivariate competing-risks models (with two other outcomes as competing events), permanently HR-HPV negative outcome was significantly predicted only by the clearance of ASCUS+Pap during FU, while three independent covariates predicted transient HR-HPV infections: i) number of recent (< 12 months) sexual partners (risk increased), ii) previous Pap screening history (protective), and history of previous CIN (increased risk). The two most powerful predictors of persistent HR-HPV infections were persistent ASCUS+Pap (risk increased), and previous Pap screening history (protective). In pair-wise comparisons, number of recent sexual partners and previous CIN history increase the probability of transient HR-HPV infection against the HR-HPV negative competing event, while previous Pap screening history is protective. Persistent ASCUS+Pap during FU and no previous Pap screening history are significantly associated with the persistent HR-HPV outcome (compared both with i) always negative, and ii) transient events), whereas multiparity is protective. Conclusions: Different covariates are associated with the three main outcomes of cervical HPV infections. The most significant covariates of each competing events are probably distinct enough to enable constructing of a risk-profile for each main outcome.
Resumo:
Objective: This study compared the influence of three epoxy resin-based sealers with distinct radiopacities on the observers' ability to detect root canal filling voids during radiographic analysis. Material and methods: The root canals of 48 extracted maxillary canines were prepared and divided into three groups. Each group was laterally condensed with one sealer (AH Plus (TM), Acroseal (R) or a non-radiopaque sealer), and a longitudinal void was simulated in half of the specimens from each group (n = 8). Buccolingual radiographs were obtained and randomly interpreted for voids by a radiologist and an endodontist in a blinded fashion. Teeth were cut and inspected under a microscope to confirm the position of void. Differences in sensitivity and specificity between groups and examiners were compared using the Fisher's Exact and McNemar tests, respectively (alpha = 0.05). Results: Significantly lower sensitivity levels (p<0.05) were observed in the coronal portion of fillings performed with both radiopaque sealers. Specificity values for Acroseal (R) were significantly higher (p<0.05) in the coronal and apical portions of fillings. Conclusion: The type of root canal sealer can affect the observers' ability to detect root canal filling voids during radiographic analysis of upper single-rooted teeth.
Resumo:
The peroxisome proliferator-activated receptor gamma (PPAR gamma) is a target for treatment of type II diabetes and other conditions. PPAR gamma full agonists, such as thiazolidinediones (TZDs), are effective insulin sensitizers and anti-inflammatory agents, but their use is limited by adverse side effects. Luteolin is a flavonoid with anti-inflammatory actions that binds PPAR gamma but, unlike TZDs, does not promote adipocyte differentiation. However, previous reports suggested variously that luteolin is a PPAR gamma agonist or an antagonist. We show that luteolin exhibits weak partial agonist/antagonist activity in transfections, inhibits several PPAR gamma target genes in 3T3-L1 cells (LPL, ORL1, and CEBP alpha) and PPAR gamma-dependent adipogenesis, but activates GLUT4 to a similar degree as rosiglitazone, implying gene-specific partial agonism. The crystal structure of the PPAR gamma ligand-binding domain (LBD) reveals that luteolin occupies a buried ligand-binding pocket (LBP) but binds an inactive PPAR gamma LBD conformer and occupies a space near the beta-sheet region far from the activation helix (H12), consistent with partial agonist/antagonist actions. A single myristic acid molecule simultaneously binds the LBP, suggesting that luteolin may cooperate with other ligands to bind PPAR gamma, and molecular dynamics simulations show that luteolin and myristic acid cooperate to stabilize the Omega-loop among H2', H3, and the beta-sheet region. It is noteworthy that luteolin strongly suppresses hypertonicity-induced release of the pro-inflammatory interleukin-8 from human corneal epithelial cells and reverses reductions in transepithelial electrical resistance. This effect is PPAR gamma-dependent. We propose that activities of luteolin are related to its singular binding mode, that anti-inflammatory activity does not require H12 stabilization, and that our structure can be useful in developing safe selective PPAR gamma modulators.
Resumo:
The Carr-Purcell pulse sequence, with low refocusing flip angle, produces echoes midway between refocusing pulses that decay to a minimum value dependent on T*(2). When the refocusing flip angle was pi/2 (CP90) and tau > T*(2), the signal after the minimum value, increased to reach a steady-state free precession regime (SSFP), composed of a free induction decay signal after each pulse and an echo, before the next pulse. When tau < T*(2), the signal increased from the minimum value to the steady-state regime with a time constant (T*) = 2T(1)T(2)/(T-1 + T-2). identical to the time constant observed in the SSFP sequence, known as the continuous wave free precession (CWFP). The steady-state amplitude obtained with M-cp90 = M0T2/(T-1+T-2) was identical to CWFP. Therefore, this sequence was named CP-CWFP because it is a Carr-Purcell sequence that produces results similar to the CWFP. However, CP-CWFP is a better sequence for measuring the longitudinal and transverse relaxation times in single scan, when the sample exhibits T-1 similar to T-2. Therefore, this sequence can be a useful method in time domain NMR and can be widely used in the agriculture, food and petrochemical industries because those samples tend to have similar relaxation times in low magnetic fields. (C) 2011 Elsevier Inc. All rights reserved.
Resumo:
This work presents an investigation of the ductile tearing properties for a girth weld made of an API 5L X80 pipeline steel using experimentally measured crack growth resistance curves. Use of these materials is motivated by the increasing demand in the number of applications for manufacturing high strength pipes for the oil and gas industry including marine applications and steel catenary risers. Testing of the pipeline girth welds employed side-grooved, clamped SE(T) specimens and shallow crack bend SE(B) specimens with a weld centerline notch to determine the crack growth resistance curves based upon the unloading compliance (UC) method using the single specimen technique. Recently developed compliance functions and η-factors applicable for SE(T) and SE(B) fracture specimens with homogeneous material and overmatched welds are introduced to determine crack growth resistance data from laboratory measurements of load-displacement records.