Chirality Transfer in a Calixarene-Based Directional Pseudorotaxane Complex

Hexamethoxycalix[6]arene 3 forms a directional pseudorotaxane complex with the chiral axle (S)-(alpha-methyl-benzyl)benzylammonium 2(+). Between the two (endo-chiral)-2(+)@3 and (exo-chiral)-2(+)@3 pseudorotaxane stereoisomers, the former is preferentially formed. This result confirms the validity of the "endo-alpha-methyl-benzyl rule", previously reported by us. DFT calculations suggest that C-H horizontal ellipsis pi interactions between the methyl group of 2(+) and the calixarene aromatic rings, determine the stereoselectivity of the threading process toward the "endo-alpha-methyl-benzyl preference". An amplification of optical rotation is observed upon formation of the pseudorotaxane complex (endo-chiral)-2(+)@3 with respect to free axle 2(+). Thus, the specifical rotation of the 1:1 mixture of chiral 2(+)center dot B(ArF)(4)(-) salt and achiral 3 was augmented upon formation of the pseudorotaxane and DFT calculations were used to rationalize this result

El deporte ¿“templa el espíritu” o “evade de la realidad”? : Preguntas desde la sociología para un abordaje del deporte lo menos normativo posible

El presente trabajo procura apelar a la tradición sociológica con el afán de subrayar, una vez más, el estatuto determinante de la dimensión empírica a la hora de producir discursos académicos sobre los fenómenos sociales en general, y sobre los deportivos en particular. En efecto, puede esperarse de una sociología contemporánea del deporte una disposición a desmarcarse (por la vía de resituarlos como parte del objeto estudiado) tanto de los proyectos celebratorios como de los condenatorios del fenómeno deportivo. Por este camino, se trata de restituir verdadera prioridad al fenómeno empírico en su diversidad y su variabilidad circunstanciada, compuesto tanto por las experiencias de los sujetos involucrados, como por los marcos y los contextos en que tienen lugar. Con el propósito de presentar algunos aportes de la corriente sociológica disposicionalista al estudio del campo de los fenómenos deportivos, es que en lo que sigue voy a glosar y sistematizar algunos ejes que fueran oportunamente trabajados por Bernard Lahire (2006) en su conferencia de 2002 “Disposiciones y contextos de acción: el deporte en preguntas”, articulando su propuesta con una serie de ejemplos y recorridos bibliográficos que serán oportunamente indicados. Finalmente, voy a concluir el texto reflexionando sobre la relación entre el discurso sociológico y las representaciones normativas acerca del deporte y su relación con la sociedad.Facultad de Humanidades y Ciencias de la Educació

Country, Sex, EDSS Change and Therapy Choice Independently Predict Treatment Discontinuation in Multiple Sclerosis and Clinically Isolated Syndrome

We conducted a prospective study, MSBASIS, to assess factors leading to first treatment discontinuation in patients with a clinically isolated syndrome (CIS) and early relapsing-remitting multiple sclerosis (RRMS). The MSBASIS Study, conducted by MSBase Study Group members, enrols patients seen from CIS onset, reporting baseline demographics, cerebral magnetic resonance imaging (MRI) features and Expanded Disability Status Scale (EDSS) scores. Follow-up visits report relapses, EDSS scores, and the start and end dates of MS-specific therapies. We performed a multivariable survival analysis to determine factors within this dataset that predict first treatment discontinuation. A total of 2314 CIS patients from 44 centres were followed for a median of 2.7 years, during which time 1247 commenced immunomodulatory drug (IMD) treatment. Ninety percent initiated IMD after a diagnosis of MS was confirmed, and 10% while still in CIS status. Over 40% of these patients stopped their first IMD during the observation period. Females were more likely to cease medication than males (HR 1.36, p = 0.003). Patients treated in Australia were twice as likely to cease their first IMD than patients treated in Spain (HR 1.98, p = 0.001). Increasing EDSS was associated with higher rate of IMD cessation (HR 1.21 per EDSS unit, p<0.001), and intramuscular interferon-β-1a (HR 1.38, p = 0.028) and subcutaneous interferon-β-1a (HR 1.45, p = 0.012) had higher rates of discontinuation than glatiramer acetate, although this varied widely in different countries. Onset cerebral MRI features, age, time to treatment initiation or relapse on treatment were not associated with IMD cessation. In this multivariable survival analysis, female sex, country of residence, EDSS change and IMD choice independently predicted time to first IMD cessation

Historical changes of seasonal differences in the frequency of multiple sclerosis clinical attacks: a multicenter study

Previous papers show discordant patterns of monthly and seasonal differences in the frequency of multiple sclerosis relapses. Attacks are more often reported in spring and summer, but there are many variations, mainly as to summer peaks. This paper, an MSBase collaboration substudy, reports multiple series of relapses from 1980 to 2010, comparing ultradecennal trends of seasonal frequency of attacks in different countries. The MSBase international database was searched for relapses in series recording patient histories from 1980 up to 2010. The number of relapses by month was stratified by decade (1981-1990, 1991-2000, 2001-2010). Positive spring versus summer peaks were compared by odds ratios; different series were compared by weighted odds ratio (Peto OR). Decade comparison of the 1990s versus 2000s shows inversion of spring-summer peak (2000s = March; 1990s = July), significant in the whole group (Peto odds ratio = 1.31, CI = 1.10-1.56, p = 0.003) and in Salerno series (OR = 1.97, CI = 1.14-1.40). The global significance persisted also excluding Salerno series (Peto odds ratio = 1.25, CI = 1.04-1.50, p = 0.002). Multicentric data confirm a summer peak of relapses in the 1991-2000 decade, significantly different from the spring peak of 2001-2010. Seasonal frequency of relapses shows long-term variations, so that other factors such as viral epidemics might have more relevance than ultraviolet exposure

Discontinuing disease-modifying therapy in MS after a prolonged relapse-free period: A propensity score-matched study

Background Discontinuation of injectable diseasemodifying therapy (DMT) for multiple sclerosis (MS) after a long period of relapse freedom is frequently considered, but data on post-cessation disease course are lacking. Objectives (1) To compare time to first relapse and disability progression among 'DMT stoppers' and propensity-score matched 'DMT stayers' in the MSBase Registry; (2) To identify predictors of time to first relapse and disability progression in DMT stoppers. Methods Inclusion criteria for DMT stoppers were: age =18 years; no relapses for =5 years at DMT discontinuation; follow-up for =3 years after stopping DMT; not restarting DMT for =3 months after discontinuation. DMT stayers were required to have no relapses for =5 years at baseline, and were propensityscore matched to stoppers for age, sex, disability (Expanded Disability Status Score), disease duration and time on treatment. Relapse and disability progression events in matched stoppers and stayers were compared using a marginal Cox model. Predictors of first relapse and disability progression among DMT stoppers were investigated using a Cox proportional hazards model. Results Time to first relapse among 485 DMT stoppers and 854 stayers was similar (adjusted HR, aHR=1.07, 95% CI 0.84 to 1.37; p=0.584), while time to confirmed disability progression was significantly shorter among DMT stoppers than stayers (aHR=1.47, 95% CI 1.18 to 1.84, p=0.001). The difference in hazards of progression was due mainly to patients who had not experienced disability progression in the prebaseline treatment period. Conclusions Patients with MS who discontinued injectable DMT after a long period of relapse freedom had a similar relapse rate as propensity score-matched patients who continued on DMT, but higher hazard for disability progression