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Grignard and organocuprate reagents catalyze ring opening reactions of 3, 4-disubstituted N-BOC-beta-lactams to yield alpha,gamma-disubstituted beta-amino ketones. NMR analysis of the crude mixtures helps estimate the proportion of products generated in the reaction. Nature of Grignard reagents influences the reaction. The disubstituted ketones help synthesize alpha-amino acids and polyhydroxylated nitrogen-containing products.

Studies reveal that asymmetric 1, 4-addition of higher order silylcuprates to Oppolzer's N-enoylsultams is as diastereofacially selective as carbocupration of beta-silyl-substituted N-enoylsultams. Silylcupration efficiently yields enantiomerically pure beta-silyl carboxylic acid. H NMR spectroscopy yields the diastereomeric ratio for the addition reactions after flash chromatography of the initial reaction mixture.

A stereocontrolled synthetic route to racemic thienamycin precursors and beta-(hydroxymethyl)aspartic acid derivatives involves the formation of cis- and trans-3- 1'-(dimethylphenylsilyl)ethyl -4-alkoxycarbonyl beta-lactams. The beta-lactams result from the condensation of glyoxylic ester imines with acid chlorides (which leads to the cis-form) or with organocopper enolates (which leads to the trans-form), using the dimethylphenylsilyl group as a masked hydroxy function.

Background: Myostatin has been proposed as a candidate biomarker for frailty and sarcopenia. However, the relationship of myostatin with these conditions remains inconclusive.Objective: To determine the association of serum myostatin concentration with body composition, physical fitness, physical activity level, and frailty in long-term nursing home residents. We also aimed to ascertain the effect of an exercise program on myostatin levels.Methods: We obtained study data on 112 participants from long-term nursing homes. Participants were randomly assigned to a control or an intervention group and performed a 6-month multicomponent exercise program. Serum myostatin levels were analyzed by ELISA. Assessments also included body composition (anthropometry and bioelectrical impedance), physical fitness (Senior Fitness Test), physical activity level (accelerometry), and frailty (Fried frailty criteria, Clinical Frailty Scale, and Tilburg frailty indicator).Results: The concentration of myostatin at baseline was positively correlated with: a leaner body composition (p < 0.05), and a higher number of steps per day and light and moderate-vigorous physical activity in women (p < 0.005); greater upper and lower limb strength, endurance, and poorer flexibility (p < 0.05) in men; and better performance (less time) in the 8-ft timed up-and-go test in both women (p < 0.01) and men (p < 0.005). We observed higher concentrations of serum myostatin in non-frail than in frail participants (p < 0.05). Additionally, we found that the implemented physical exercise intervention, which was effective to improve physical fitness, increased myostatin concentration in men (p < 0.05) but not in women. The improvements in physical condition were related with increases in serum myostatin only in men (p < 0.05-0.01).Conclusions: Higher serum levels of myostatin were found to be associated with better physical fitness. The improvements in physical fitness after the intervention were positively related to increases in myostatin concentrations in men. These results seem to rule out the idea that high serum myostatin levels are indicative of frailty in long-term nursing home residents. However, although the direction of association was opposite to that expected for the function of myostatin, the use of this protein as a biomarker for physical fitness, rather than frailty, merits further study. [ABSTRACT FROM AUTHOR]

Background: The purpose of the Aging-ONDUAL-TASK study is to determine if a supervised dual-task program carried out in long-term nursing homes is able to attenuate frailty in a greater extent than the same multicomponent exercise program alone.Methods: This multicenter randomized controlled trial will include 188 participants who will be randomly allocated to either a multicomponent exercise program or to the same multicomponent program with simultaneous cognitive training (dual-task training). Inclusion criteria are as follows: ≥ 70 years, ≥ 50 on the Barthel Index, ≥ 20 on the Mini Examen Cognoscitivo (MEC-35) who are able to stand up and walk independently for 10 m. Subjects in the multicomponent group will attend a twice-a-week multicomponent exercise program of 1-h duration per session, consisting of strength and balance exercises. Participants in the dual-task group will perform the same multicomponent exercise program with concurrent individually tailored cognitive tasks. Study assessments will be conducted at baseline and at 3 months. The primary outcome measure will be gait speed under dual-task conditions and secondary outcomes will include physical fitness measurements, gait spatiotemporal parameters, cognition and emotional assessments, several frailty scales and objectively measured physical activity.Discussion: The present research will add valuable information to the knowledge around the effects of the dual-task program in long-term nursing home residents, taking altogether physical, cognitive and emotional variables linked to frailty.Trial Registration: Australian and New Zealand Clinical Trials Registry (ANZCTR) with the identifier: ACTRN12618000536268 . Registration date: 11/04/2018. [ABSTRACT FROM AUTHOR]

Exoskeleton-assisted gait rehabilitation is a promising complement to traditional motion rehabilitation programs for afflictions such as stroke or spinal cord injury. However, some challenges persist that hinder the translation of this approach to the clinical practice. One of these aspects is the objective assessment of patients' progress from information collected during exoskeleton-assisted therapy sessions with minimal hardware setup. In order to carry out an objective assessment with the data collected during the sessions, in this work: (1) we implement and compute a set of metrics (Harmonic Ratio, Joint Trajectory Correlation, and Intralimb Coordination) from data provided by the exoskeleton and two inertial motion units (IMUs) while subjects walked during their rehabilitation sessions, (2) we evaluate the capacity of the metrics to discriminate between the different patients' physical conditions, and (3) assess the correspondence of the patient evaluations using the mentioned metrics and traditional clinical scores. Our results show that Intralimb Coordination has the greatest capacity to discriminate between different physical states of the patients and presents the best correlation with their clinical assessment.Clinical relevance- This work could guide clinicians and researchers to formulate a more objective assessment of progress of patients who have experienced a spinal cord in- jury using data collected during exoskeleton-assisted therapy sessions.