Tensile test models for low-carbon microalloyed steels with high niobium contents

U ovom se istraživanju proučavao utjecaj parametara valjanja (2 redukcijske brzine i 3 brzine hlađenja) i kemijskih elemenata kao što su: C, Mn, Nb, Ti, Mo, Ni, Cr, Cu i B na svojstva čvrstoće niskougljičnih mikrolegiranih čelika s visokim sadržajem niobija (do 0,12 wt. % Nb). U tu je svrhu konstruiran pokusni uređaj zasnovan na inteligentnom dizajnu eksperimenata (DoE), rezultirajući s 26 odljevaka (laboratorijskih odljevaka). Kombinacijom metalografije, Electron Back-Scattered Diffraction (EBSD) i vlačnih ispitivanja proučavalo se kako obradni parametri i kemijski sastav djeluju na čvrstoću. Kada je ispitivanje rezultiralo naprezanjem, rasteznom čvrstoćom, jednoličnom deformacijom ili deformacijom zbog loma, rezultati su statistički analizirani tehnikom višestrukelinearne regresije, koja je dovela do odgovarajućih jednadžbi. Ustanovilo se da se učinak niobija na povećanje čvrstoće smanjuje kako se povećava sadržaj ugljika.In the present investigation, the effect of both: rolling parameters (2 reduction rates and 3 cooling rates) and chemical elements such as: C, Mn, Nb, Ti, Mo, Ni, Cr, Cu and B, has been studied in relation to strength properties in low-carbon microalloyed steels with high niobium contents (up to 0,12 wt. % Nb). For this purpose, an experimental set-up was designed based on an intelligent design of experiments (DoE), resulting in 26 casts (laboratory casts). A combination of metallography, Electron Back-Scattered Diffraction (EBSD) and tensile tests have been performed to study how processing parameters and chemical composition affect the strength. The results, where the proof stress, tensile strength, uniform and fracture elongations are the response variables, have been analysed statistically by means of multiple linear regression technique, leading to response equations. From the results, it was found that the effectiveness of niobium increasing the strength is reduced as carbon content increases

Increased mRNA expression of cytochrome oxidase in dorsal raphe nucleus of depressive suicide victims

Suicidal behavior is a problem with important social repercussions. Some groups of the population show a higher risk of suicide; for example, depression, alcoholism, psychosis or drug abuse frequently precedes suicidal behavior. However, the relationship between metabolic alterations in the brain and premorbid clinical symptoms of suicide remains uncertain. The serotonergic and noradrenergic systems have frequently been, implicated in suicidal behavior and the amount of serotonin in the brain and CSF of suicide victims has been found to be low compared with normal subjects. However, there are contradictory results regarding the role of noradrenergic neurons in the mediation of suicide attempts, possibly reflecting the heterogeneity of conditions that lead to a common outcome. In the present work we focus on the subgroup of suicide victims that share a common diagnosis of major depression. Based on post-mortem studies analyzing mRNA expression by in situ hybridization, serotonergic neurons from the dorsal raphe nucleus (DRN) from depressive suicide victims are seen to over-express cytochrome oxidase mRNA. However, no corresponding changes were found in the expression of tyrosine hydroxylase (TH) mRNA in the noradrenergic neurons of the Locus Coeruleus (LC). These results suggest that, despite of the low levels of serotonin described in suicide victims, the activity of DRN neurons could increase in the suicidally depressed, probably due to the over activation of serotonin re-uptake. No alteration was found in noradrenergic neurons, suggesting that they play no crucial role in the suicidal behavior of depressive patients

Challenging Methods and Results Obtained from User-Generated Content in Barcelona’s Public Open Spaces

User-generated content (UGC) provides useful resources for academics, technicians and policymakers to obtain and analyse results in order to improve lives of individuals in urban settings. User-generated content comes from people who voluntarily contribute data, information, or media that then appears in a way which can be viewed by others; usually on the Web. However, to date little is known about how complex methodologies for getting results are subject to methodology-formation errors, personal data protection, and reliability of outcomes. Different researches have been approaching to inquire big data methods for a better understanding of social groups for planners and economic needs. In this chapter, through UGC from Tweets of users located in Barcelona, we present different research experiments. Data collection is based on the use of REST API; while analysis and representation of UGC follow different ways of processing and providing a plurality of information. The first objective is to study the results at a different geographical scale, Barcelona’s Metropolitan Area and at two Public Open Spaces (POS) in Barcelona, Enric Granados Street and the area around the Fòrum de les Cultures; during similar days in two periods of time - in January of 2015 and 2017. The second objective is intended to better understand how different types of POS’ Twitter-users draw urban patterns. The Origin-Destination patterns generated illustrate new social behaviours, addressed to multifunctional uses. This chapter aims to be influential in the use of UGC analysis for planning purposes and to increase quality of life

Central Nervous System Vasculitis: Still More Questions than Answers

The central nervous system (CNS) may be involved by a variety of inflammatory diseases of blood vessels. These include primary angiitis of the central nervous system (PACNS), a rare disorder specifically targeting the CNS vasculature, and the systemic vasculitides which may affect the CNS among other organs and systems. Both situations are severe and convey a guarded prognosis. PACNS usually presents with headache and cognitive impairment. Focal symptoms are infrequent at disease onset but are common in more advanced stages. The diagnosis of PACNS is difficult because, although magnetic resonance imaging is almost invariably abnormal, findings are non specific. Angiography has limited sensitivity and specificity. Brain and leptomeningeal biopsy may provide a definitive diagnosis when disclosing blood vessel inflammation and are also useful to exclude other conditions presenting with similar findings. However, since lesions are segmental, a normal biopsy does not completely exclude PACNS. Secondary CNS involvement by systemic vasculitis occurs in less than one fifth of patients but may be devastating. A prompt recognition and aggressive treatment is crucial to avoid permanent damage and dysfunction. Glucocorticoids and cyclophosphamide are recommended for patients with PACNS and for patients with secondary CNS involvement by small-medium-sized systemic vasculitis. CNS involvement in large-vessel vasculitis is usually managed with high-dose glucocorticoids (giant-cell arteritis) or glucocorticoids and immunosuppressive agents (Takayasu’s disease). However, in large vessel vasculitis, where CNS symptoms are usually due to involvement of extracranial arteries (Takayasu’s disease) or proximal portions of intracranial arteries (giant-cell arteritis), revascularization procedures may also have an important role

Las alteraciones metabólicas asociadas a la obesidad están ya presentes en los primeros años de vida: estudio colaborativo español

Los objetivos de este estudio son, realizar una descrip-ción de las características demográficas, antropométricas y de las alteraciones metabólicas de niños atendidos por obe-sidad resaltando las características aquellos casos de obesidad de inicio temprano (< 10 años) y los de inicio precoz (< 5 años), y evaluar la capacidad diagnóstica de la definición de síndrome metabólico (SM) según diferentes criterios. Métodos: Es un estudio retrospectivo, caso-control, trans-versal, multicéntrico. Han participado un total de 10 Uni-dades de Endocrinología Pediátrica de diferentes hospitales españoles con un grupo de 469 niños con obesidad de inicio temprano y otro grupo de 30 niños con obesidad de inicio precoz. El grupo control estuvo constituido por 224 niños sanos menores de 10 años. Se realizó una valoración antro-pométrica y determinación analítica de parámetros del me-tabolismo de los hidratos de carbono y lipidograma. Resultados: La presencia de alteraciones metabólicas asociadas a la obesidad en la etapa infanto-juvenil en Espa-ña es notable, de forma aislada, o englobada bajo la defini-ción de SM. La prevalencia de éste aumenta sustancialmen-te cuando se considera la resistencia periférica a la acción de la insulina como criterio diagnóstico. Se demuestra cómo en niños menores de 10 años, dichas alteraciones están presen-tes en un porcentaje reseñable, y se encuentran las primeras alteraciones metabólicas ya en niños obesos < 5 años. Conclusión: En los niños españoles existen alteracio-nes metabólicas asociadas a la obesidad en la etapa in-fanto-juvenil de forma aislada o englobada bajo la de-finición de SM, y ya están presentes a edades precoces. The objectives of this study are to provide a description of the demographic, anthropometric characteristics and metabolic abnormalities in children with early-onset (< 10 years) and of very-early-onset obesity (< 5 years). We also evaluate the diagnostic ability using the definition of meta-bolic syndrome (MS) according to different criteria. Methods: It is a retrospective, case-control, cross-sec-tional, multicenter study. A total of 10 Pediatric Endo-crinology Units in different Spanish hospitals were in-volved. A group of 469 children with early-onset obesity and another group of 30 children with very early-onset obesity were studied. The control group consisted of 224 healthy children younger than 10 years. Anthropometric and analytical determination of carbohydrates metabo-lism parameters and the lipid profile were performed. Results: The presence of metabolic alterations associa-ted with obesity in children and adolescents in Spain is remarkable, either on their own, or encompassed within the definition of MS. This prevalence increases substan-tially when considering the peripheral resistance to in-sulin action as a diagnostic criterion. It also shows how children who could not be diagnosed with MS according to the definition provided by the International Diabetes Federation (IDF) due to age below 10 years, these altera-tions are already present in a remarkable percentage. In fact, metabolic abnormalities are already present in the very-early-onset obese children (<5 years). Conclusion: In Spanish children there are metabolic alterations associated with obesity in the infant-juvenile stages alone or encompassed within the definition of MS, and are already present at earlier ages

Relapses in patients with giant-cell arteritis: prevalence, characteristics and associated clinical findings in a longitudinally followed cohort of 106 patients.

Giant cell arteritis (GCA) is a relapsing disease. However, the nature, chronology, therapeutic impact, and clinical consequences of relapses have been scarcely addressed. We conducted the present study to investigate the prevalence, timing, and characteristics of relapses in patients with GCA and to analyze whether a relapsing course is associated with disease-related complications, increased glucocorticoid (GC) doses, and GC-related adverse effects. The study cohort included 106 patients, longitudinally followed by the authors for 7.8 ± 3.3 years. Relapses were defined as reappearance of disease-related symptoms requiring treatment adjustment. Relapses were classified into 4 categories: polymyalgia rheumatica (PMR), cranial symptoms (including ischemic complications), systemic disease, or symptomatic large vessel involvement. Cumulated GC dose during the first year of treatment, time required to achieve a maintenance prednisone dose <10 mg/d (T10), <5 mg/d (T5), or complete prednisone discontinuation (T0), and GC-related side effects were recorded. Sixty-eight patients (64%) experienced at least 1 relapse, and 38 (36%) experienced 2 or more. First relapse consisted of PMR in 51%, cranial symptoms in 31%, and systemic complaints in 18%. Relapses appeared predominantly, but not exclusively, within the first 2 years of treatment, and only 1 patient developed visual loss. T10, T5, and T0 were significantly longer in patients with relapses than in patients without relapse (median, 40 vs 27 wk, p  < 0.0001; 163 vs 89.5 wk, p = 0.004; and 340 vs 190 wk, p = 0.001, respectively). Cumulated prednisone dose during the first year was significantly higher in relapsing patients (6.2 ± 1.7 g vs 5.4 ± 0.78 g, p = 0.015). Osteoporosis was more common in patients with relapses compared to those without (65% vs 32%, p = 0.001). In conclusion, the results of the present study provide evidence that a relapsing course is associated with higher and prolonged GC requirements and a higher frequency of osteoporosis in GCA

Effect of glucocorticoid treatment on computed tomography angiography detected large-vessel inflammation in giant-cell arteritis. A prospective, longitudinal study.

Computed tomography angiography (CTA) detects signs of large-vessel vasculitis (LVV) in about 67.5% of patients with giant-cell arteritis (GCA) at the time of diagnosis and early aortic dilatation in 15%. The outcome of CTA-findings of LVV upon glucocorticoid treatment has not been prospectively evaluated. The aim of our study was to prospectively assess glucocorticoid-induced changes in CTA findings of LVV in patients with GCA. Forty biopsy-proven GCA patients evaluated by CTA at diagnosis were prospectively followed and scheduled a new CTA approximately after 1 year of treatment. Vessel wall thickening, diameter, and contrast enhancement of the aorta and its tributaries were evaluated. Results were compared to those obtained at the time of diagnosis. CTA was repeated to 35 patients after a median follow-up of 13.5 months (IQ25-75% 12.4-15.8). Arterial wall thickening was still present in 17 patients (68% of the patients who initially had LVV). The number of affected segments and wall thickness at various aortic segments significantly decreased and no patients developed new lesions, new aortic dilation or increase in previous dilation. Contrast enhancement disappeared in 15 (93.75%) of 16 patients in whom this finding could be assessed. Signs of LVV improve with treatment. While contrast enhancement resolves in the majority of patients, vessel wall thickening persists in two thirds. However, the number of affected aortic segments as well as aortic wall thickness significantly decreases. Longer follow-up is necessary to determine the clinical significance of persisting wall thickening and its relationship with relapses or subsequent development of aortic dilatation or large-vessel stenoses