987 resultados para Kerr non-linearity


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Introduction: The psychobiological seven-factor model proposed by Cloninger et al. (1993) takes into account temperament and character dimensions to describe personality. Four of the dimensions are linked with biological, genetic and neuroanatomic structures, whereas the three other dimensions are related to the degree of individual, social and spiritual development. A study conducted by Wills et al. (1994) with adolescents showed that substance abuse was associated with high scores on Novelty Seeking and low scores on Harm Avoidance and Reward Dependence. The aim of the present study was, firstly, to create a short form of Cloninger's (1993) Temperament and Character Inventory (TCI) and, secondly, to study the impact of nicotine dependence as well as demographic variables on a sample of young adults. Method: We created a short form of the TCI containing 56 items (TCI-56), 8 for each scale. Responses are made on a five-point Likert type scale. A Swiss sample (n=211), of 116 women and 95 men, aged from 15 to 30 years, participated in this study. Our population was divided into a group of 81 smokers and another of 130 non-smokers, according to their scores on the Fagerstörm test for nicotine dependence (1999). Results: The structural validation consisted of two separate factor analysis with varimax rotations, one for the temperamental items, and the other, for the character ones. The first factor analysis conducted on the items of the temperament scales allowed to extract 4 factors explaining 40.7% of the variance. The correlations between factors and scales are the following: r=.71 for Novelty Seeking, r=.69 for Persistence, r=.95 for Harm Avoidance, r=.94 for Reward Dependence. The second factor analysis conducted on the items of the character scales allowed to extract 3 factors explaining 41.5% of the variance. The correlations between factors and scales are the following: r=.94 for Self-Directedness, r=.91 for Cooperativeness and r=.99 for Self-Transcendence. The internal consistencies range from α=.65 to α=.75 for the temperament scales, and from α=.71 to α=.83 for the three character scales. Concerning, the impact of the nicotine dependence, we observed that smokers have significantly higher scores for Novelty seeking, than non-smokers (p=.01). We found no difference for Harm Avoidance and Reward Dependence. Nevertheless, smokers seem to have the tendency to score higher on Transcendence (p=.06). Moreover, people having smoked more than 100 cigarettes in their life have significantly higher scores on this scale (p.04) and the correlation between Transcendence and the Fagerstörm test is significant (r=.19). We also found gender differences: the women (N=116) obtain significantly higher scores for Harm Avoidance (p<.001), for Reward Dependence (p<.001) and for Cooperation (p=.01). We further found a significant correlation between age and Self-Directedness, r=.34. We observed no interaction between gender and smoking or age and smoking on the dimensions of the TCI-56. Discussion: The TCI short form (TCI-56) seems to be a valid and useful inventory to assess personality differences. Confirming the results of others about the relation between addiction and personality, we found that smokers have significantly higher scores for Novelty seeking, than non-smokers. But we were not able to find any significant differences for Harm Avoidance and Reward Dependence. This might be due to our sample that was made of young adults. This study also shows that Transcendence could be an interesting dimension for studies on Tobacco smoking to consider. Concerning the impact of demographic variables, we observed that age and gender have specific and coherent influence on personality.

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The multiple endocrine neoplasia type 2A (MEN2A) is a monogenic disorder characterized by an autosomal dominant pattern of inheritance which is characterized by high risk of medullary thyroid carcinoma in all mutation carriers. Although this disorder is classified as a rare disease, the patients affected have a low life quality and a very expensive and continuous treatment. At present, MEN2A is diagnosed by gene sequencing after birth, thus trying to start an early treatment and by reduction of morbidity and mortality. We first evaluated the presence of MEN2A mutation (C634Y) in serum of 25 patients, previously diagnosed by sequencing in peripheral blood leucocytes, using HRM genotyping analysis. In a second step, we used a COLD-PCR approach followed by HRM genotyping analysis for non-invasive prenatal diagnosis of a pregnant woman carrying a fetus with a C634Y mutation. HRM analysis revealed differences in melting curve shapes that correlated with patients diagnosed for MEN2A by gene sequencing analysis with 100% accuracy. Moreover, the pregnant woman carrying the fetus with the C634Y mutation revealed a melting curve shape in agreement with the positive controls in the COLD-PCR study. The mutation was confirmed by sequencing of the COLD-PCR amplification product. In conclusion, we have established a HRM analysis in serum samples as a new primary diagnosis method suitable for the detection of C634Y mutations in MEN2A patients. Simultaneously, we have applied the increase of sensitivity of COLD-PCR assay approach combined with HRM analysis for the non-invasive prenatal diagnosis of C634Y fetal mutations using pregnant women serum.

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PURPOSE: The prevalence of anaplastic lymphoma kinase (ALK) gene fusion (ALK positivity) in early-stage non-small-cell lung cancer (NSCLC) varies by population examined and detection method used. The Lungscape ALK project was designed to address the prevalence and prognostic impact of ALK positivity in resected lung adenocarcinoma in a primarily European population. METHODS: Analysis of ALK status was performed by immunohistochemistry (IHC) and fluorescent in situ hybridization (FISH) in tissue sections of 1,281 patients with adenocarcinoma in the European Thoracic Oncology Platform Lungscape iBiobank. Positive patients were matched with negative patients in a 1:2 ratio, both for IHC and for FISH testing. Testing was performed in 16 participating centers, using the same protocol after passing external quality assessment. RESULTS: Positive ALK IHC staining was present in 80 patients (prevalence of 6.2%; 95% CI, 4.9% to 7.6%). Of these, 28 patients were ALK FISH positive, corresponding to a lower bound for the prevalence of FISH positivity of 2.2%. FISH specificity was 100%, and FISH sensitivity was 35.0% (95% CI, 24.7% to 46.5%), with a sensitivity value of 81.3% (95% CI, 63.6% to 92.8%) for IHC 2+/3+ patients. The hazard of death for FISH-positive patients was lower than for IHC-negative patients (P = .022). Multivariable models, adjusted for patient, tumor, and treatment characteristics, and matched cohort analysis confirmed that ALK FISH positivity is a predictor for better overall survival (OS). CONCLUSION: In this large cohort of surgically resected lung adenocarcinomas, the prevalence of ALK positivity was 6.2% using IHC and at least 2.2% using FISH. A screening strategy based on IHC or H-score could be envisaged. ALK positivity (by either IHC or FISH) was related to better OS.

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Trypanosoma cruzi infection has a large public health impact in Latin American countries. Although the transmission rates via blood transfusions and insect vectors have declined sharply in the past 20 years due to policies of the Southern Cone countries, a large number of people are still at risk for infection. Currently, no accepted experimental model or descriptions of the clinical signs that occur during the course of acute murine infection are available. The aim of this work was to use non-invasive methods to evaluate the clinical signs of Balb/c mice infected with the Y strain of T. cruzi. The infected mice displayed evident clinical changes beginning in the third week of infection. The mice were evaluated based on physical characteristics, spontaneous activity, exploratory behaviour and physiological alterations. We hope that the results presented in this report provide parameters that complement the effective monitoring of trypanocidal treatment and other interventions used to treat experimental Chagas disease.

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PURPOSE: To retrospectively assess the influence of prophylactic cranial irradiation (PCI) timing on brain relapse rates in patients treated with two different chemoradiotherapy (CRT) regimens for Stage IIIB non-small-cell lung cancer (NSCLC). METHODS AND MATERIALS: A cohort of 134 patients, with Stage IIIB NSCLC in recursive partitioning analysis Group 1, was treated with PCI (30 Gy at 2 Gy/fr) following one of two CRT regimens. Regimen 1 (n = 58) consisted of three cycles of induction chemotherapy (ICT) followed by concurrent CRT (C-CRT). Regimen 2 (n = 76) consisted of immediate C-CRT during thoracic radiotherapy. RESULTS: At a median follow-up of 27.6 months (range, 7.2-40.4), 65 patients were alive. Median, progression-free, and brain metastasis-free survival (BMFS) times for the whole study cohort were 23.4, 15.4, and 23.0 months, respectively. Median survival time and the 3-year survival rate for regimens 1 and 2 were 19.3 vs. 26.1 months (p = 0.001) and 14.4% vs. 34.4% (p < .001), respectively. Median time from the initiation of primary treatment to PCI was 123.2 (range, 97-161) and 63.4 (range, 55-74) days for regimens 1 and 2, respectively (p < 0.001). Overall, 11 (8.2%) patients developed brain metastasis (BM) during the follow-up period: 8 (13.8%) in regimen 1 and 3 (3.9%) in regimen 2 (p = 0.03). Only 3 (2.2%) patients developed BM at the site of first failure, and for 2 of them, it was also the sole site of recurrence. Median BMFS for regimens 1 and 2 were 17.4 (13.5-21.3) vs. 26.0 (22.9-29.1 months), respectively (p < 0.001). CONCLUSION: These results suggest that in Stage IIIB NSCLC patients treated with PCI, lower BM incidence and longer survival rates result from immediate C-CRT rather than ITC-first regimens. This indicates the benefit of earlier PCI use without delay because of induction protocols.

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The spleen plays a crucial role in the development of immunity to malaria, but the role of pattern recognition receptors (PRRs) in splenic effector cells during malaria infection is poorly understood. In the present study, we analysed the expression of selected PRRs in splenic effector cells from BALB/c mice infected with the lethal and non-lethal Plasmodium yoelii strains 17XL and 17X, respectively, and the non-lethal Plasmodium chabaudi chabaudi AS strain. The results of these experiments showed fewer significant changes in the expression of PRRs in AS-infected mice than in 17X and 17XL-infected mice. Mannose receptor C type 2 (MRC2) expression increased with parasitemia, whereas Toll-like receptors and sialoadhesin (Sn) decreased in mice infected with P. chabaudi AS. In contrast, MRC type 1 (MRC1), MRC2 and EGF-like module containing mucin-like hormone receptor-like sequence 1 (F4/80) expression decreased with parasitemia in mice infected with 17X, whereas MRC1 an MRC2 increased and F4/80 decreased in mice infected with 17XL. Furthermore, macrophage receptor with collagenous structure and CD68 declined rapidly after initial parasitemia. SIGNR1 and Sn expression demonstrated minor variations in the spleens of mice infected with either strain. Notably, macrophage scavenger receptor (Msr1) and dendritic cell-associated C-type lectin 2 expression increased at both the transcript and protein levels in 17XL-infected mice with 50% parasitemia. Furthermore, the increased lethality of 17X infection in Msr1 -/- mice demonstrated a protective role for Msr1. Our results suggest a dual role for these receptors in parasite clearance and protection in 17X infection and lethality in 17XL infection.

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Black flies, a non-target species of the insecticides used in fruit production, represent a severe medical and veterinary problem. Large increases in the level of resistance to the pyrethroids fenvalerate (more than 355-fold) and deltamethrin (162-fold) and a small increase in resistance to the organophosphate azinphos methyl (2-fold) were observed between 1996-2008 in black fly larvae under insecticide pressure. Eventually, no change or a slight variation in insecticide resistance was followed by a subsequent increase in resistance. The evolution of pesticide resistance in a field population is a complex and stepwise process that is influenced by several factors, the most significant of which is the insecticide selection pressure, such as the dose and frequency of application. The variation in insecticide susceptibility within a black fly population in the productive area may be related to changes in fruit-pest control. The frequency of individuals with esterase activities higher than the maximum value determined in the susceptible population increased consistently over the sampling period. However, the insecticide resistance was not attributed to glutathione S-transferase activity. In conclusion, esterase activity in black flies from the productive area is one mechanism underlying the high levels of resistance to pyrethroids, which have been recently used infrequently. These enzymes may be reselected by currently used pesticides and enhance the resistance to these insecticides.

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Triatoma infestans (Klug) is the main vector of Chagas disease, which is a public health concern in most Latin American countries. The prevention of Chagas disease is based on the chemical control of the vector using pyrethroid insecticides. In the last decade, different levels of deltamethrin resistance have been detected in certain areas of Argentina and Bolivia. Because of this, alternative non-pyrethroid insecticides from different chemical groups were evaluated against two T. infestans populations, NFS and El Malá, with the objective of finding new insecticides to control resistant insect populations. Toxicity to different insecticides was evaluated in a deltamethrin-susceptible and a deltamethrin-resistant population. Topical application of the insecticides fenitrothion and imidacloprid to first nymphs had lethal effects on both populations, producing 50% lethal dose (LD50) values that ranged from 5.2-28 ng/insect. However, amitraz, flubendiamide, ivermectin, indoxacarb and spinosad showed no insecticidal activity in first instars at the applied doses (LD50 > 200 ng/insect). Fenitrothion and imidacloprid were effective against both deltamethrin-susceptible and deltamethrin-resistant populations of T. infestans. Therefore, they may be considered alternative non-pyrethroid insecticides for the control of Chagas disease.