999 resultados para Rijke type pulse combustor
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The potential of type-2 fuzzy sets for managing high levels of uncertainty in the subjective knowledge of experts or of numerical information has focused on control and pattern classification systems in recent years. One of the main challenges in designing a type-2 fuzzy logic system is how to estimate the parameters of type-2 fuzzy membership function (T2MF) and the Footprint of Uncertainty (FOU) from imperfect and noisy datasets. This paper presents an automatic approach for learning and tuning Gaussian interval type-2 membership functions (IT2MFs) with application to multi-dimensional pattern classification problems. T2MFs and their FOUs are tuned according to the uncertainties in the training dataset by a combination of genetic algorithm (GA) and crossvalidation techniques. In our GA-based approach, the structure of the chromosome has fewer genes than other GA methods and chromosome initialization is more precise. The proposed approach addresses the application of the interval type-2 fuzzy logic system (IT2FLS) for the problem of nodule classification in a lung Computer Aided Detection (CAD) system. The designed IT2FLS is compared with its type-1 fuzzy logic system (T1FLS) counterpart. The results demonstrate that the IT2FLS outperforms the T1FLS by more than 30% in terms of classification accuracy.
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PURPOSE: To analyze components of the deposits in the corneal flap interface of granular corneal dystrophy type II (GCD II) patients after laser in situ keratomileusis (LASIK). METHODS: Four corneal GCD II specimens displaying disease exacerbation after LASIK were analyzed. Three of these specimens included the recipient corneal button after penetrating keratoplasty or deep lamellar keratoplasty for advanced GCD II after LASIK. The fourth specimen, a similar case of GCD II after LASIK, included the amputated corneal flap. Specimens were processed for histopathologic and immunohistochemical analyses. RESULTS: Corneal stromal deposits in the LASIK flaps of all specimens were stained with 3 anti-transforming growth factor-beta-induced protein (TGFBIp) antibodies. The deposits displayed bright red color staining with Masson trichrome; however, negative staining was seen with Congo red, suggesting that hyaline is the main component localizing to the TGFBIp deposits rather than amyloid. CONCLUSIONS: Amorphous granular material deposited along the interface of the LASIK flap in GCD II corneas is composed mainly of hyaline deposits.
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PURPOSE: Diabetic retinopathy (DR) is a leading cause of blindness, yet pertinent animal models are uncommon. The sand rat (Psammomys obesus), exhibiting diet-induced metabolic syndrome, might constitute a relevant model. METHODS: Adult P. obesus (n = 39) were maintained in captivity for 4 to 7 months and fed either vegetation-based diets (n = 13) or standard rat chow (n = 26). Although plant-fed animals exhibited uniform body weight and blood glucose levels over time, nearly 60% of rat chow-raised animals developed diabetes-like symptoms (test group). Animals were killed, and their eyes and vitreous were processed for immunochemistry. RESULTS: Compared with plant-fed animals, diabetic animals showed many abnormal vascular features, including vasodilation, tortuosity, and pericyte loss within the blood vessels, hyperproteinemia and elevated ratios of proangiogenic and antiangiogenic growth factors in the vitreous, and blood-retinal barrier breakdown. Furthermore, there were statistically significant decreases in retinal cell layer thicknesses and densities, accompanied by profound alterations in glia (downregulation of glutamine synthetase, glutamate-aspartate transporter, upregulation of glial fibrillar acidic protein) and many neurons (reduced expression of protein kinase Cα and Cξ in bipolar cells, axonal degeneration in ganglion cells). Cone photoreceptors were particularly affected, with reduced expression of short- and mid-/long-wavelength opsins. Hypercaloric diet nondiabetic animals showed intermediate values. CONCLUSIONS: Simple dietary modulation of P. obesus induces a rapid and severe phenotype closely resembling human type 2 DR. This species presents a valuable novel experimental model for probing the neural (especially cone photoreceptor) pathogenic modifications that are difficult to study in humans and for screening therapeutic strategies.
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We introduce simple nonparametric density estimators that generalize theclassical histogram and frequency polygon. The new estimators are expressed as linear combination of density functions that are piecewisepolynomials, where the coefficients are optimally chosen in order to minimize the integrated square error of the estimator. We establish the asymptotic behaviour of the proposed estimators, and study theirperformance in a simulation study.
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The type material of three species of Polietina Schnabl & Dziedzicki, 1911 was examined. Polietina flavidicincta (Stein, 1904) is redescribed and a lectotype is designated; P. stellata (Couri, 1982) is considered junior synonym of P. flavithorax (Stein, 1904), and for the latter a lectotype is designated. The neotype previously designated is considered invalid.
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We present strategies for chemical shift assignments of large proteins by magic-angle spinning solid-state NMR, using the 21-kDa disulfide-bond-forming enzyme DsbA as prototype. Previous studies have demonstrated that complete de novo assignments are possible for proteins up to approximately 17 kDa, and partial assignments have been performed for several larger proteins. Here we show that combinations of isotopic labeling strategies, high field correlation spectroscopy, and three-dimensional (3D) and four-dimensional (4D) backbone correlation experiments yield highly confident assignments for more than 90% of backbone resonances in DsbA. Samples were prepared as nanocrystalline precipitates by a dialysis procedure, resulting in heterogeneous linewidths below 0.2 ppm. Thus, high magnetic fields, selective decoupling pulse sequences, and sparse isotopic labeling all improved spectral resolution. Assignments by amino acid type were facilitated by particular combinations of pulse sequences and isotopic labeling; for example, transferred echo double resonance experiments enhanced sensitivity for Pro and Gly residues; [2-(13)C]glycerol labeling clarified Val, Ile, and Leu assignments; in-phase anti-phase correlation spectra enabled interpretation of otherwise crowded Glx/Asx side-chain regions; and 3D NCACX experiments on [2-(13)C]glycerol samples provided unique sets of aromatic (Phe, Tyr, and Trp) correlations. Together with high-sensitivity CANCOCA 4D experiments and CANCOCX 3D experiments, unambiguous backbone walks could be performed throughout the majority of the sequence. At 189 residues, DsbA represents the largest monomeric unit for which essentially complete solid-state NMR assignments have so far been achieved. These results will facilitate studies of nanocrystalline DsbA structure and dynamics and will enable analysis of its 41-kDa covalent complex with the membrane protein DsbB, for which we demonstrate a high-resolution two-dimensional (13)C-(13)C spectrum.
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Treatment of status epilepticus (SE) consists in the sequential administration of three lines of drugs. The first is represented by benzodiazepines, and enjoys quite robust scientific evidence. The second one includes (phos-) phenytoin, valproate, phenobarbital, and increasingly levetiracetam, but its rationale is relatively scarce. The third line is pharmacological coma induction with barbiturates, propofol, or midazolam, which lacks the support of prospective, controlled studies and is reserved for refractory SE. Several other drugs are used after failure of this scheme, including newer antiepileptic compounds, other medications, and non-pharmacological approaches; no comparative assessment of their respective role has been conducted. It is important to tailor this relatively simple protocol to each particular situation; the supposed advantages of coma induction should be balanced with the morbidity related to prolonged mechanical ventilation. Awide consensus exists to treat generalized-convulsive SE and SE in coma soon and aggressively, to prevent a dismal outcome. On the other side, it is unclear if complex-partial SE induces permanent neuronal damage, and absence SE has an excellent prognosis: it appears therefore advisable not to proceed automatically to coma induction in these cases. SE related to post-anoxic coma has generally a poor prognosis, but some selected cases seem to be amenable to a better outcome if treated. SE prognosis depends on etiology, the biological background including age and comorbidities, and, possibly, treatment; each of these points deserves to be specifically addressed. A simple prognostic score has been recently validated and, helping to orient early treatment strategies and improve SE management.
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Integrative and conjugating elements (ICE) are self-transferable DNAs widely present in bacterial genomes, which often carry a variety of auxiliary genes of potential adaptive benefit. One of the model ICE is ICEclc, an element originally found in Pseudomonas knackmussii B13 and known for its propensity to provide its host with the capacity to metabolize chlorocatechols and 2-aminophenol. In this work, we studied the mechanism and target of regulation of MfsR, a TetR-type repressor previously found to exert global control on ICEclc horizontal transfer. By using a combination of ICEclc mutant and transcriptome analysis, gene reporter fusions, and DNA binding assays, we found that MfsR is a repressor of both its own expression and that of a gene cluster putatively coding for a major facilitator superfamily efflux system on ICEclc (named mfsABC). Phylogenetic analysis suggests that mfsR was originally located immediately adjacent to the efflux pump genes but became displaced from its original cis target DNA by a gene insertion. This resulted in divergence of the original bidirectional promoters into two separated individual regulatory units. Deletion of mfsABC did not result in a strong phenotype, and despite screening a large number of compounds and conditions, we were unable to define the precise current function or target of the putative efflux pump. Our data reconstruct how the separation of an ancestor mfsR-mfsABC system led to global control of ICEclc transfer by MfsR.
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AIM: In type 1 diabetic patients (T1DM), nocturnal hypoglycaemias (NH) are a serious complication of T1DM treatment; self-monitoring of blood glucose (SMBG) is recommended to detect them. However, the majority of NH remains undetected on an occasional SMBG done during the night. An alternative strategy is the Continuous glucose monitoring (CGMS), which retrospectively shows the glycaemic profile. The aims of this retrospective study were to evaluate the true incidence of NH in T1DM, the best SMBG time to predict NH, the relationship between morning hyperglycaemia and NH (Somogyi phenomenon) and the utility of CGMS to reduce NH. METHODS: Eighty-eight T1DM who underwent a CGMS exam were included. Indications for CGMS evaluation, hypoglycaemias and correlation with morning hyperglycaemias were recorded. The efficiency of CGMS to reduce the suspected NH was evaluated after 6-9 months. RESULTS: The prevalence of NH was 67% (32% of them unsuspected). A measured hypoglycaemia at bedtime (22-24 h) had a sensitivity of 37% to detect NH (OR=2.37, P=0.001), while a single measure < or =4 mmol/l at 3-hour had a sensitivity of 43% (OR=4.60, P<0.001). NH were not associated with morning hyperglycaemias but with morning hypoglycaemias (OR=3.95, P<0.001). After 6-9 months, suspicions of NH decreased from 60 to 14% (P<0.001). CONCLUSION: NH were highly prevalent and often undetected. SMBG at bedtime, which detected hypoglycaemia had sensitivity almost equal to that of 3-hour and should be preferred because it is easier to perform. Somogyi phenomenon was not observed. CGMS is useful to reduce the risk of NH in 75% of patients.
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In order to characterize inverse agonism at alpha1B-adrenoceptors, we have compared the concentration-response relationships of several quinazoline and non-quinazoline alpha1-adrenoceptor antagonists at cloned hamster wild-type (WT) alpha1B-adrenoceptors and a constitutively active mutant (CAM) thereof upon stable expression in Rat-1 fibroblasts. Receptor activation or inhibition thereof was assessed as [3H]inositol phosphate (IP) accumulation. Quinazoline (alfuzosin, doxazosin, prazosin, terazosin) and non-quinazoline alpha1-adrenoceptor antagonists (BE 2254, SB 216,469, tamsulosin) concentration-dependently inhibited phenylephrine-stimulated IP formation at both WT and CAM with Ki values similar to those previously found in radioligand binding studies. At CAM in the absence of phenylephrine, the quinazolines produced concentration-dependent inhibition of basal IP formation; the maximum inhibition was approximately 55%, and the corresponding EC50 values were slightly smaller than the Ki values. In contrast, BE 2254 produced much less inhibition of basal IP formation, SB 216,469 was close to being a neutral antagonist, and tamsulosin even weakly stimulated IP formation. The inhibitory effects of the quinazolines and BE 2254 as well as the stimulatory effect of tamsulosin were equally blocked by SB 216,469 at CAM. At WT in the absence of phenylephrine, tamsulosin did not cause significant stimulation and none of the other compounds caused significant inhibition of basal IP formation. We conclude that alpha1-adrenoceptor antagonsits with a quinazoline structure exhibit greater efficacy as inverse agonists than those without.
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AIMS/HYPOTHESIS: The molecular mechanisms of obesity-related insulin resistance are incompletely understood. Macrophages accumulate in adipose tissue of obese individuals. In obesity, monocyte chemoattractant protein-1 (MCP-1), a key chemokine in the process of macrophage accumulation, is overexpressed in adipose tissue. MCP-1 is an insulin-responsive gene that continues to respond to exogenous insulin in insulin-resistant adipocytes and mice. MCP-1 decreases insulin-stimulated glucose uptake into adipocytes. The A-2518G polymorphism in the distal regulatory region of MCP-1 may regulate gene expression. The aim of this study was to investigate the impact of this gene polymorphism on insulin resistance. METHODS: We genotyped the Ludwigshafen Risk and Cardiovascular Health (LURIC) cohort ( n=3307). Insulin resistance, estimated by homeostasis model assessment, and Type 2 diabetes were diagnosed in 803 and 635 patients respectively. RESULTS: Univariate analysis revealed that plasma MCP-1 levels were significantly and positively correlated with WHR ( p=0.011), insulin resistance ( p=0.0097) and diabetes ( p<0.0001). Presence of the MCP-1 G-2518 allele was associated with decreased plasma MCP-1 ( p=0.017), a decreased prevalence of insulin resistance (odds ratio [OR]=0.82, 95% CI: 0.70-0.97, p=0.021) and a decreased prevalence of diabetes (OR=0.80, 95% CI: 0.67-0.96, p=0.014). In multivariate analysis, the G allele retained statistical significance as a negative predictor of insulin resistance (OR=0.78, 95% CI: 0.65-0.93, p=0.0060) and diabetes (OR=0.80, 95% CI: 0.66-0.96, p=0.018). CONCLUSIONS/INTERPRETATION: In a large cohort of Caucasians, the MCP-1 G-2518 gene variant was significantly and negatively correlated with plasma MCP-1 levels and the prevalence of insulin resistance and Type 2 diabetes. These results add to recent evidence supporting a role for MCP-1 in pathologies associated with hyperinsulinaemia.
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A catalogue of type specimens of Collembola, Diplura, Archaeognatha, Ephemeroptera, and Blattaria deposited in the Invertebrate Collection of the Instituto Nacional de Pesquisas da Amazônia (INPA), Manaus, Brazil, is presented and updated to June, 2007. It contains a total of 22 holotypes and 18 lots of paratypes of 22 species of Collembola; one holotype and one paratype of one species of Diplura; four holotypes and four paratypes of four species of Archaeognatha; 10 holotypes and thirteen lots of paratypes of 11 species of Ephemeroptera; and one holotype and two lots of paratypes of one species of Blattaria. Specific names are listed alphabetically within family, followed by bibliographical citation, original genus name, status of type, collection number and locality data.
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A catalogue of the type specimens of Isoptera, Mantodea, Mecoptera, Orthoptera, Plecoptera, Trichoptera, and Zoraptera deposited in the Invertebrate Collection of the Instituto Nacional de Pesquisas da Amazônia (INPA), Manaus, Brazil, is presented and updated to December, 2007. A total of eight holotypes and seven lots of paratypes of nine species of Isoptera; three holotypes and one paratype of three species of Mantodea; five holotypes and five lots of paratypes of five species of Mecoptera; eight holotypes and five lots of paratypes of eleven species of Orthoptera; three holotypes, three neotypes and two lots of paratypes of seven species of Plecoptera; six holotypes and seven lots of paratypes of ten species of Trichoptera; and two holotypes and three lots of paratypes of three species of Zoraptera, are listed. Specific names are listed alphabetically within the family, followed by bibliographic citation, original genus name, status of type, collection number, locality data and remarks when appropriate.
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Background: Medical treatment of inflammatory bowel disease (IBD) is becoming more and more complex, as several classes of immuno-modulating drugs (IMD) are often used simultaneously. Thus, the probability of adverse effects is greatly increased. Most studies reporting on adverse effects focus on single therapy, and studies providing a global survey of side effects for multiple treatments are lacking. Aim: To assess the type and frequency of adverse events in IBD patients treated with single and multiple IMD therapy. Methods: Analysis of data from the Swiss IBD Cohort Study (SIBDCS) that collects data on a large sample of IBD patients from hospitals and private practices across Switzerland. The following IMD categories were analyzed: 5-ASA, azathioprine (Aza), 6-mercaptopurine (6-MP), methotrexate (MTX), anti-TNF (infliximab, adalimumab, certolizumab-pegol), cyclosporine, tacrolimus, and steroids. The following side effects were assessed: hepatitis, pancreatitis, leucopenia, thrombopenia, nephritis, allergic reaction, pneumonitis, infections (including tuberculosis), osteoporosis, abdominal pain/diarrhea (unrelated to IBD activity), cataract, diabetes, exanthema, hirsutism, lupus-like syndrome, myalgias, depression/psychosis, tumor development. Results: A total of 1,961 patients were analyzed (977 [50%] female, mean age 42.1 ± 14.4 years): 1,119 with Crohn's disease (CD), 800 with ulcerative colitis (UC), and 42 with indeterminate colitis (IC). Three-hundred eighteen (16.2%) patients were not treated with any of the above-mentioned medications, while 650 (33.2%), 569 (29%) and 424 (21.6%) patients had one-, two-, and three- or more- IMD therapy, respectively. Of the 1,643 patients treated with IMD, 535 (32.6%) patients reported at least one side effect. We found a significant correlation between the number of drugs used by a patient and the frequency of side effects (17.4% side effects for one drug, 29% for 2 drugs, and 60.6% for three or more drugs, p < 0.001). The frequency of side effects for the different IMD classes were as follows: 5-ASA (n = 980 treated patients) 10.8%, Aza/6-MP (n = 636) 51.9% (pancreatitis in 57 = 9%, hepatitis in 17 = 2.7% of treated patients), MTX (n = 146) 42.5% (hepatitis in 4 = 2.7% of treated patients), anti-TNF (n = 255) 23.1%, cyclosporine (n = 49) 10.2%, tacrolimus (n = 5) 20%, steroids (systemic or topical, n = 1,150) 9.6%. Conclusion: IBD treatment is associated with a significant number of side effects. A direct correlation between the number of IMD used simultaneously and the frequency of side effects was observed. The results of this study indicate that treating physicians should be vigilant for the occurrence of side effects in IBD patients under single and/or multiple drug therapy.