939 resultados para mean curvature flow SE(2) with subriemannian metric existence result


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OBJECTIVE: To establish the allelic and genotypic frequencies related to apolipoprotein E (ApoE) polymorphism and association of the genotypes with risk factors and cardiovascular morbidity in an elderly population with longevity. METHODS: We analyzed 70 elderly patients aged 80 years or more who were part of the Projeto Veranópolis. We used the gene amplification technique through the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and cleavage with the restriction enzyme Hha I to identify the ApoE genotypes. The most frequent genotypes were compared considering biological variables and cardiovascular risks and morbidity. RESULTS: The frequencies of the E2, E3, and E4 alleles were 0.05, 0.84, and 0.11, respectively, and of the genotypes were as follows: E3E3 (0.70), E3E4 (0.22), E2E3 (0.06), and E2E2 (0.02). Individuals with the E3E4 had a mean age greater than those with the E3E3. No association was observed between the genotypes and the variables analyzed, except for obesity, which was associated with the E3E3 genotype. Individuals with the E3E4 genotype had high levels of LDL-cholesterol and fibrinogen as compared with those with the E3E3 genotype. CONCLUSION: The results suggest that the E4E4 genotype may be associated with early mortality. A balance between the protective or neutral factors and the cardiovascular risk factors may occur among the individuals with different genotypes, attenuating the negative effects of the E4 allele.

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OBJECTIVE: To analyze the relationship between myocardial bridges and the anterior interventricular branch (anterior descending) of the left coronary artery. METHODS: The study was carried out with postmortem material, and methods of dissection and observation were used. We assessed the perimeter of the anterior interventricular branch of the left coronary artery using a pachymeter, calculated its proximal and distal diameters in relation to the myocardial bridge, and also its diameter under the myocardial bridge in 30 hearts. We also observed the position of the myocardial bridge in relation to the origin of the anterior interventricular branch. RESULTS: The diameters of the anterior interventricular branch were as follows: the mean proximal diameter was 2.76±0.76 mm; the mean diameter under the myocardial bridge was 2.08±0.54 mm; and the mean distal diameter was 1.98±0.59 mm. In 33.33% (10/30) of the cases, the diameter of the anterior interventricular branch under the myocardial bridge was lower than the diameter of the anterior interventricular branch distal to the myocardial bridge. In 3.33% (1/30) of the cases, an atherosclerotic plaque was found in the segment under the myocardial bridge. The myocardial bridge was located in the middle third of the anterior interventricular branch in 86.66% (26/30) of the cases. CONCLUSION: Myocardial bridges are more frequently found in the middle third of the anterior interventricular branch of the left coronary artery. The diameter of the anterior interventricular branch of the left coronary artery under the myocardial bridge may be smaller than after the bridge. Myocardial bridges may not provide protection against the formation of atherosclerotic plaque inside the anterior interventricular branch of the left coronary artery.

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OBJECTIVE: To detect the prevalence of systemic hypertension in children and to establish the relation between blood pressure levels and sex, age, ethnicity, weight, and height. METHODS: The prevalence of systemic hypertension and its relation to sex, age, ethnicity, weight, and height were studied in 611 students aged 7 to 14 years out of 19.928 students classified according to age, ethnicity, and sex, who underwent anthropometric evaluation and blood pressure measurement. Hypertensive individuals were considered those whose blood pressure level was > the 95th percentile for age and sex, confirmed on 3 examinations. RESULTS: The prevalence of hypertension was 16.6% in the first evaluation, and 4.6% and 2.5% in the subsequent evaluations. The mean blood pressure levels increased with age. Weight was important, not only to determine blood pressure in healthy children, but also to determine systemic hypertension in children, which was not observed with height despite the different studies. The prevalence of systemic hypertension in the different ethnic groups and the mean blood pressure levels according to sex were similar. CONCLUSION: In addition to routine physical examinations, age, weight, and appropriate cuff size should be considered when assessing blood pressure in children to prevent hypertension, morbidity and mortality, and to avoid placing a financial burden on health care providers.

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Background: Cardiac tumors are rare, mostly benign with high embolic potential. Objectives: To correlate the histological type of cardiac masses with their embolic potential, implantation site and long term follow up in patients undergoing surgery. Methods: Between January 1986 and December 2011, we retrospectively analyzed 185 consecutive patients who underwent excision of intracardiac mass (119 females, mean age 48±20 years). In 145 patients, the left atrium was the origin site. 72% were asymptomatic and prior embolization was often observed (19.8%). The diagnosis was established by echocardiography, magnetic resonance and histological examination. Results: Most tumors were located in the left side of the heart. Myxoma was the most common (72.6%), followed by fibromas (6.9%), thrombi (6.4%) and sarcomas (6.4%). Ranging from 0.6cm to 15cm (mean 4.6 ± 2.5cm) 37 (19.8%) patients had prior embolization, stroke 10.2%, coronary 4.8%, peripheral 4.3% 5.4% of hospital death, with a predominance of malignant tumors (40% p < 0.0001). The histological type was a predictor of mortality (rhabdomyomas and sarcomas p = 0.002) and embolic event (sarcoma, lipoma and fibroelastoma p = 0.006), but not recurrence. Tumor size, atrial fibrillation, cavity and valve impairment were not associated with the embolic event. During follow-up (mean 80±63 months), there were 2 deaths (1.1%) and two recurrences 1 and 11 years after the operation, to the same cavity. Conclusion: Most tumors were located in the left side of the heart. The histological type was predictor of death and preoperative embolic event, while the implantation site carries no relation with mortality or to embolic event.

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Metamysidopsis elongata atlantica (Bacescu, 1968) was reared in the laboratory for 45 days at 20±1°C and salinity of 30ppt. Growth curves (von Bertalanffy model) were calculated for both sexes and for each sex. The daily rate of carapace growth was significantly different between females and males (F test, p <0.05). Before the sexual maturity (14 days), the growth rate of females was higher than that of males (females, 0.0457 mm day-1; males, 0.0448 mm day-1). After the maturity (15 to 45 days), these rates decreased similarly for both sexes (females, 0.0203 mm day-1; males, 0.0174mm day-1). The average growth rate was 0.0207mm day-1 over the 45 days. Twelve molts were observed in a period of 60 days. The first five molts occurred up to 14 days old (age of the sexual differentiation), with a mean intermolt period of 2.9 days. From the 6th molt it increased to 5.6 days. The results suggest that the use of the carapace length is a good measure to calculate the growth and longevity of the organisms.

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I analyze an economy with uncertainty in which a set of indivisible objects and a certain amount of money is to be distributed among agents. The set of intertemporally fair social choice functions based on envy-freeness and Pareto efficiency is characterized. I give a necessary and sufficient condition for its non-emptiness and propose a mechanism that implements the set of intertemporally fair allocations in Bayes-Nash equilibrium. Implementation at the ex ante stage is considered, too. I also generalize the existence result obtained with envy-freeness using a broader fairness concept, introducing the aspiration function.

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Molecular monitoring of BCR/ABL transcripts by real time quantitative reverse transcription PCR (qRT-PCR) is an essential technique for clinical management of patients with BCR/ABL-positive CML and ALL. Though quantitative BCR/ABL assays are performed in hundreds of laboratories worldwide, results among these laboratories cannot be reliably compared due to heterogeneity in test methods, data analysis, reporting, and lack of quantitative standards. Recent efforts towards standardization have been limited in scope. Aliquots of RNA were sent to clinical test centers worldwide in order to evaluate methods and reporting for e1a2, b2a2, and b3a2 transcript levels using their own qRT-PCR assays. Total RNA was isolated from tissue culture cells that expressed each of the different BCR/ABL transcripts. Serial log dilutions were prepared, ranging from 100 to 10-5, in RNA isolated from HL60 cells. Laboratories performed 5 independent qRT-PCR reactions for each sample type at each dilution. In addition, 15 qRT-PCR reactions of the 10-3 b3a2 RNA dilution were run to assess reproducibility within and between laboratories. Participants were asked to run the samples following their standard protocols and to report cycle threshold (Ct), quantitative values for BCR/ABL and housekeeping genes, and ratios of BCR/ABL to housekeeping genes for each sample RNA. Thirty-seven (n=37) participants have submitted qRT-PCR results for analysis (36, 37, and 34 labs generated data for b2a2, b3a2, and e1a2, respectively). The limit of detection for this study was defined as the lowest dilution that a Ct value could be detected for all 5 replicates. For b2a2, 15, 16, 4, and 1 lab(s) showed a limit of detection at the 10-5, 10-4, 10-3, and 10-2 dilutions, respectively. For b3a2, 20, 13, and 4 labs showed a limit of detection at the 10-5, 10-4, and 10-3 dilutions, respectively. For e1a2, 10, 21, 2, and 1 lab(s) showed a limit of detection at the 10-5, 10-4, 10-3, and 10-2 dilutions, respectively. Log %BCR/ABL ratio values provided a method for comparing results between the different laboratories for each BCR/ABL dilution series. Linear regression analysis revealed concordance among the majority of participant data over the 10-1 to 10-4 dilutions. The overall slope values showed comparable results among the majority of b2a2 (mean=0.939; median=0.9627; range (0.399 - 1.1872)), b3a2 (mean=0.925; median=0.922; range (0.625 - 1.140)), and e1a2 (mean=0.897; median=0.909; range (0.5174 - 1.138)) laboratory results (Fig. 1-3)). Thirty-four (n=34) out of the 37 laboratories reported Ct values for all 15 replicates and only those with a complete data set were included in the inter-lab calculations. Eleven laboratories either did not report their copy number data or used other reporting units such as nanograms or cell numbers; therefore, only 26 laboratories were included in the overall analysis of copy numbers. The median copy number was 348.4, with a range from 15.6 to 547,000 copies (approximately a 4.5 log difference); the median intra-lab %CV was 19.2% with a range from 4.2% to 82.6%. While our international performance evaluation using serially diluted RNA samples has reinforced the fact that heterogeneity exists among clinical laboratories, it has also demonstrated that performance within a laboratory is overall very consistent. Accordingly, the availability of defined BCR/ABL RNAs may facilitate the validation of all phases of quantitative BCR/ABL analysis and may be extremely useful as a tool for monitoring assay performance. Ongoing analyses of these materials, along with the development of additional control materials, may solidify consensus around their application in routine laboratory testing and possible integration in worldwide efforts to standardize quantitative BCR/ABL testing.

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Receptors for interleukin 2 (IL-2) esit in at least three forms which differ in their subunit compositio, their affinity for ligand and their ability to mediate a cellular reponse. Type I receptors occur following cellular acitivation and consist of the 55,000 m. w. glycoprotein Tac. These receptors bind IL-2 with a low affinity, do not internalize ligand and have not been definitively associated with any response. Type II receptors, on the other hand, conssit of one or more glycoproteins of 70,000 m. w. which have been termed "beta ([beta]) chains." They bind IL-2 with an intermediate affinity and rapidly internalize the ligand. [Beta] proteins mediate many cellular IL-2-dependent reponses, including the short-term activation of natural killer cells and the induction of Tac protein expression. Type III receptors consist of a ternary complex of the Tac protein, the [beta] chain(s) and IL-2. They are characterized by a paricularly high affinity for ligand association. Type III receptors also internalize ligand and mediate IL-2-dependent responses at low factor concentrations. The identification of two independent IL-2-binding molecules, Tac and [beta], thus provides the elusive molecular explanation for the differences in IL-2 receptor affinity and suggests the potential for selective therapeutic manipulation of IL-2 reponses.

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OBJECTIVE: To compare the acute and sustained renal hemodynamic effects on hypertensive patients of 100 mg irbesartan and 20 mg enalapril each once daily. PATIENTS: Twenty patients (aged 35-70 years) with uncomplicated, mild-to-moderate essential hypertension and normal serum creatinine levels completed this study. STUDY DESIGN: After random allocation to treatment (n=10 per group), administration schedule (morning or evening) was determined by further random allocation, with crossover of schedules after 6 weeks' therapy. Treatment and administration assignments were double-blind. Twenty-four-hour ambulatory blood pressure was monitored before and after 6 and 12 weeks of therapy. Renal hemodynamics were determined on the first day of drug administration and 12 and 24 h after the last dose during chronic treatment. RESULTS: Administration of each antihypertensive agent induced a renal vasodilatation with no significant change in glomerular filtration rate. However, the time course appeared to differ: irbesartan had no significant acute effect 4 h after the first dose, but during chronic administration a renal vasodilatory response was found 12 and 24 h after the dose; enalapril was effective acutely and 12 h after administration, but no residual effect was found 24 h after the dose. Both antihypertensive agents lowered mean ambulatory blood pressure effectively, with no significant difference between treatments or between administration schedules (morning versus evening). CONCLUSIONS: Irbesartan and enalapril have comparable effects on blood pressure and renal hemodynamics in hypertensive patients with normal renal functioning. However, the time profiles of the renal effects appear to differ, which might be important for long-term renoprotective effects.

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Questions: A multiple plot design was developed for permanent vegetation plots. How reliable are the different methods used in this design and which changes can we measure? Location: Alpine meadows (2430 m a.s.l.) in the Swiss Alps. Methods: Four inventories were obtained from 40 m(2) plots: four subplots (0.4 m(2)) with a list of species, two 10m transects with the point method (50 points on each), one subplot (4 m2) with a list of species and visual cover estimates as a percentage and the complete plot (40 m(2)) with a list of species and visual estimates in classes. This design was tested by five to seven experienced botanists in three plots. Results: Whatever the sampling size, only 45-63% of the species were seen by all the observers. However, the majority of the overlooked species had cover < 0.1%. Pairs of observers overlooked 10-20% less species than single observers. The point method was the best method for cover estimate, but it took much longer than visual cover estimates, and 100 points allowed for the monitoring of only a very limited number of species. The visual estimate as a percentage was more precise than classes. Working in pairs did not improve the estimates, but one botanist repeating the survey is more reliable than a succession of different observers. Conclusion: Lists of species are insufficient for monitoring. It is necessary to add cover estimates to allow for subsequent interpretations in spite of the overlooked species. The choice of the method depends on the available resources: the point method is time consuming but gives precise data for a limited number of species, while visual estimates are quick but allow for recording only large changes in cover. Constant pairs of observers improve the reliability of the records.

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Tetrasomy, pentasomy, and hexasomy 8 (polysomy 8) are relatively rare compared to trisomy 8. Here we report on a series of 12 patients with acute myeloid leukemia (AML), myelodysplastic syndrome (MDS), or myeloproliferative disorder (MPD) associated with polysomy 8 as detected by conventional cytogenetics and fluorescence in situ hybridization (FISH). In an attempt to better characterize the clinical and hematological profile of this cytogenetic entity, our data were combined with those of 105 published patients. Tetrasomy 8 was the most common presentation of polysomy 8. In 60.7% of patients, polysomy 8 occurred as part of complex changes (16.2% with 11q23 rearrangements). No cryptic MLL rearrangements were found in cases in which polysomy 8 was the only karyotypic change. Our study demonstrates the existence of a polysomy 8 syndrome, which represents a subtype of AML, MDS, and MPD characterized by a high incidence of secondary diseases, myelomonocytic or monocytic involvement in AML and poor overall survival (6 months). Age significantly reduced median survival, but associated cytogenetic abnormalities did not modify it. Cytogenetic results further demonstrate an in vitro preferential growth of the cells with a high level of aneuploidy suggesting a selective advantage for polysomy 8 cells.

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Purpose: First, to report ECU subsheath's normal MRI appearance and the findings in athletic injuries. Second, to determine the best MRI sequence for diagnosis. Methods and materials: Sixteen patients (13 males, 3 females, mean age 30.3 years) with ECU subsheath's athletic injuries sustained between January 2003 and June 2009 were retrospectively reviewed. Wrist MRI studies were performed on 1.5-T units and consisted of at least transverse T1 and STIR sequences in pronation, and FS Gd T1 in pronation and supination. Two radiologists assessed the following items, in consensus: injury type (A to C according to Inoue), ECU tendon stability, and associated lesions (ulnar head oedema, extensor retinaculum injury, ECU tendinosis and tenosynovitis). Then, each reader independently rated the sequences' diagnostic value: 0 = questionable, 1 = suggestive, 2 = certain. Follow-up studies were present in 8 patients. ECU subsheath's normal visibility (medial, central and lateral parts) was retrospectively evaluated in 30 consecutive control MRI studies. Results: FS Gd T1 sequences in supination (1.63) and pronation (1.59) were the most valuable for diagnosis, compared to STIR (1.22) and T1 (1). The study group included 9 type A, 1 type B and 6 type C injuries. There were trends towards diminution in pouches' size, signal intensity and enhancement in follow-up studies, along with tendon stabilization within the ulnar groove. In control studies, ECU subsheath's visibility in medial, central and lateral parts were noted in 66.7-80%, 63.3-80% and 30-50% respectively. Conclusion: ECU subsheath's athletic injuries are visible on 1.5-T MRI studies. FS Gd T1 sequences in supination and pronation are the most valuable.

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OBJECTIVE:: To examine the accuracy of brain multimodal monitoring-consisting of intracranial pressure, brain tissue PO2, and cerebral microdialysis-in detecting cerebral hypoperfusion in patients with severe traumatic brain injury. DESIGN:: Prospective single-center study. PATIENTS:: Patients with severe traumatic brain injury. SETTING:: Medico-surgical ICU, university hospital. INTERVENTION:: Intracranial pressure, brain tissue PO2, and cerebral microdialysis monitoring (right frontal lobe, apparently normal tissue) combined with cerebral blood flow measurements using perfusion CT. MEASUREMENTS AND MAIN RESULTS:: Cerebral blood flow was measured using perfusion CT in tissue area around intracranial monitoring (regional cerebral blood flow) and in bilateral supra-ventricular brain areas (global cerebral blood flow) and was matched to cerebral physiologic variables. The accuracy of intracranial monitoring to predict cerebral hypoperfusion (defined as an oligemic regional cerebral blood flow < 35 mL/100 g/min) was examined using area under the receiver-operating characteristic curves. Thirty perfusion CT scans (median, 27 hr [interquartile range, 20-45] after traumatic brain injury) were performed on 27 patients (age, 39 yr [24-54 yr]; Glasgow Coma Scale, 7 [6-8]; 24/27 [89%] with diffuse injury). Regional cerebral blood flow correlated significantly with global cerebral blood flow (Pearson r = 0.70, p < 0.01). Compared with normal regional cerebral blood flow (n = 16), low regional cerebral blood flow (n = 14) measurements had a higher proportion of samples with intracranial pressure more than 20 mm Hg (13% vs 30%), brain tissue PO2 less than 20 mm Hg (9% vs 20%), cerebral microdialysis glucose less than 1 mmol/L (22% vs 57%), and lactate/pyruvate ratio more than 40 (4% vs 14%; all p < 0.05). Compared with intracranial pressure monitoring alone (area under the receiver-operating characteristic curve, 0.74 [95% CI, 0.61-0.87]), monitoring intracranial pressure + brain tissue PO2 (area under the receiver-operating characteristic curve, 0.84 [0.74-0.93]) or intracranial pressure + brain tissue PO2+ cerebral microdialysis (area under the receiver-operating characteristic curve, 0.88 [0.79-0.96]) was significantly more accurate in predicting low regional cerebral blood flow (both p < 0.05). CONCLUSION:: Brain multimodal monitoring-including intracranial pressure, brain tissue PO2, and cerebral microdialysis-is more accurate than intracranial pressure monitoring alone in detecting cerebral hypoperfusion at the bedside in patients with severe traumatic brain injury and predominantly diffuse injury.

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Research into the biomechanical manifestation of fatigue during exhaustive runs is increasingly popular but additional understanding of the adaptation of the spring-mass behaviour during the course of strenuous, self-paced exercises continues to be a challenge in order to develop optimized training and injury prevention programs. This study investigated continuous changes in running mechanics and spring-mass behaviour during a 5-km run. 12 competitive triathletes performed a 5-km running time trial (mean performance: 17 min 30 s) on a 200 m indoor track. Vertical and anterior-posterior ground reaction forces were measured every 200 m by a 5-m long force platform system, and used to determine spring-mass model characteristics. After a fast start, running velocity progressively decreased (- 11.6%; P<0.001) in the middle part of the race before an end spurt in the final 400-600 m. Stride length (- 7.4%; P<0.001) and frequency (- 4.1%; P=0.001) decreased over the 25 laps, while contact time (+ 8.9%; P<0.001) and total stride duration (+ 4.1%; P<0.001) progressively lengthened. Peak vertical forces (- 2.0%; P<0.01) and leg compression (- 4.3%; P<0.05), but not centre of mass vertical displacement (+ 3.2%; P>0.05), decreased with time. As a result, vertical stiffness decreased (- 6.0%; P<0.001) during the run, whereas leg stiffness changes were not significant (+ 1.3%; P>0.05). Spring-mass behaviour progressively changes during a 5-km time trial towards deteriorated vertical stiffness, which alters impact and force production characteristics.

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PURPOSE: To introduce a new k-space traversal strategy for segmented three-dimensional echo planar imaging (3D EPI) that encodes two partitions per radiofrequency excitation, effectively reducing the number excitations used to acquire a 3D EPI dataset by half. METHODS: The strategy was evaluated in the context of functional MRI applications for: image quality compared with segmented 3D EPI, temporal signal-to-noise ratio (tSNR) (the ability to detect resting state networks compared with multislice two-dimensional (2D) EPI and segmented 3D EPI, and temporal resolution (the ability to separate cardiac- and respiration-related fluctuations from the desired blood oxygen level-dependent signal of interest). RESULTS: Whole brain images with a nominal voxel size of 2 mm isotropic could be acquired with a temporal resolution under half a second using traditional parallel imaging acceleration up to 4× in the partition-encode direction and using novel data acquisition speed-up of 2× with a 32-channel coil. With 8× data acquisition speed-up in the partition-encode direction, 3D reduced excitations (RE)-EPI produced acceptable image quality without introduction of noticeable additional artifacts. Due to increased tSNR and better characterization of physiological fluctuations, the new strategy allowed detection of more resting state networks compared with multislice 2D-EPI and segmented 3D EPI. CONCLUSION: 3D RE-EPI resulted in significant increases in temporal resolution for whole brain acquisitions and in improved physiological noise characterization compared with 2D-EPI and segmented 3D EPI. Magn Reson Med 72:786-792, 2014. © 2013 Wiley Periodicals, Inc.