Mechanistic insights into transition metal-mediated bioorthogonal uncaging reactions.

Cleavage of C-O and C-N bonds mediated by transition metals is a promising bioorthogonal approach to rescue the activity of caged molecules, such as proteins and cytotoxic drugs, under biological conditions. However, the precise mechanism of such uncaging reactions remains elusive. This review provides mechanistic insights into metal-mediated bond-cleavage reactions, with the goals of understanding the main factors that influence the reaction and aiding the rational development of new caging groups/catalysts for chemical biology and drug-delivery applications.

Psychological aspects of the longest, solo, unsupported one-way polar ski expedition in Antarctica by a female adventurer.

INTRODUCTION: Antarctic expeditions present exceptional physiological and mental challenges. Research data are lacking on psychological aspects of such endeavours. The aim of our study is to provide data on changes in mood, well-being, personality traits and personal experiences during an Antarctica crossing. METHODS: This is a study of a 33-year-old female British Army officer (height 175 cm; weight 75 kg; body mass index 24.49 kg/m2; VO2max 49 mL/kg/min) who completed the longest, solo, unsupported, one-way polar ski expedition. The expedition started at Hercules Inlet and finished at Ross Ice Shelf, lasting 70 days and 16 hours covering 1484.53 km, with temperatures estimating from -12°C to -50°C and wind speeds of up to 60 miles per hour. The adventurer pulled all equipment and nutrition in a pulk (sled), weighing approximately 120 kg. Five psychometric questionnaires were completed pre post and during the expedition, including the International Personality Item Pool - Neuroticism, Extraversion and Openness-60, Brief Assessment of Mood, Positive and Negative Affective Schedule, Profile of Mood States, Wellness questionnaire, as well as an unstructured open questionnaire. RESULTS: Mood generally deteriorated, particularly positive affective mood. Scores for fatigue and muscle soreness increased, with a reduction in sleep times. Personality traits of openness, agreeableness, and conscientiousness remained stable throughout the expedition, with some reduction in extraversion and an increase in neuroticism. Personal accounts give a unique insight into the increasing demands on the mental and physical impact of the expedition. CONCLUSIONS: Meticulous preparation and planning may have led to a successful expedition, including physical preparation, prior on-field experience, and psychological preparedness and resiliance. Some of these strategies may be applicable to a range of settings, including future Antarctic expeditions, expeditions in extreme environments, or missions within a military context.

How to end up on the podium after running a 6-days-run with type 1 diabetes mellitus - A case study and literature review.

BACKGROUND: An increasing number of people living with type 1 diabetes mellitus (T1DM) are pushing their physical limits to compete at the sport's highest level. Muscle, liver, and glycogen metabolism can be normal in athletes with diabetes with good glucose management, and modifications to insulin dose and nutrition can facilitate exercise performance. CASE PRESENTATION: We report on a 66-year-old runner with insulin-dependent T1DM. He has run over 90 marathons and ultra-marathons. Thanks to an insulin pump and continuous glucose monitoring, he has completed forty-eight 24-hour runs with an average performance of 133.8 km. Over the years, the runner increased his monthly running volume significantly and decreased his glycated Hemoglobin type A1C (hba1c) levels. Meanwhile, a significant association between monthly running kilometers and hba1c levels could be shown. At the age of 66 years, he finished his sixth 6-day-run in third place overall by covering a total distance of 467.424 km. CONCLUSIONS: These findings show that it is possible to participate in ultra-endurance events while suffering from T1DM without glucose derailing. With a good understanding of the disease and its impact on an individual's body, we can curtail the preparation and execution phases of ultra-endurance events to allow athletes to compete with minimal risk.

Differences in pacing during cycling and running in ultra-triathlons - The example of 'Swissultra'.

OBJECTIVE: The knowledge of the most predictive split discipline and the pacing during a triathlon race is of utmost importance for planning an ultra-triathlon race. This study aimed at investigating the pacing during cycling and running splits in three different multi-stage ultra-triathlon race formats (i.e., Quintuple, Deca, and Double Deca Iron ultra-triathlon with 5x, 10x and 20x the daily distance of a full Ironman-distance triathlon). SUBJECTS AND METHODS: A total of 48 male ultra-triathletes competing in Quintuple (n=14), Deca (n=25), and Double Deca (n=9) Iron ultra-triathlon "swissultra" between 2016 and 2019 in Switzerland were analyzed. For each race day, we calculated the total performance (sum of all laps time), average individual performance (average of all laps time within a race day) and pacing variation (coefficient of variation of race laps time) for cycling and running. Discipline (cycling and running) and race distance (Quintuple, Deca, and Double Deca Iron ultra-triathlon) were used as independent parameters. The primary outcome variables were the time performance (daily and total) and the pacing variation. We applied two general linear models (GLM): the first model was a one-way ANOVA comparing total and daily performance by race distance, and the second model was a two-way ANOVA (race distance´ discipline) using pacing variation (average pace oscillation) as a dependent variable. RESULTS: The first GLM identified a significant race distance effect for total performance in both cycling (F = 375.6; p < 0.001; ηp2 = 0.943) and running (F = 267.8; p < 0.001; ηp2 = 0.922) with Double Deca Iron ultra-triathlon being the fastest and Quintuple Iron ultra-triathlon the slowest. The GLM for daily average performance showed no significant effect of race distance on cycling performance (F = 0.171; p = 0.843; ηp2 = 0.008), but on running performance (F = 6.408; p = 0.004; ηp2 = 0.222). The two-way GLM comparing pacing variation showed a significant effect for race distance (F = 11.81; p<0.001; ηp2 = 0.344) with Deca presenting larger pace variation than Quintuple and Double Deca Iron ultra-triathlon in both cycling and running, but not for discipline (F = 0.067; p=0.797; ηp2 = 0.001), nor for interaction (F = 1.469; p=0.241; ηp2 = 0.061). CONCLUSIONS: Athletes achieved a stable cycling performance independent of the length of the race, and the cycling split had an influence on the subsequent running split depending upon the length of the race.

Temperature and barometric pressure are related to running speed and pacing of the fastest runners in the 'Berlin Marathon'.

OBJECTIVE: The influence of environmental conditions, such as temperature, barometric pressure, humidity, precipitation, sunshine and cloud cover on marathon running has been widely investigated. However, the influence of such conditions on the pacing of elite marathoners has not been considered yet. The present study aimed to investigate whether environmental conditions are related to the running speed and pacing of the fastest marathoners competing in the fastest racecourse in the world, the 'Berlin Marathon'. SUBJECTS AND METHODS: A total of 668,735 finishers (520,715 men and 148,020 women) competing between 1999 and 2019 in the 'Berlin Marathon' were analyzed by comparing elite and recreational runners. The associations between time-adjusted averages of the environmental conditions, the race times and running speeds were investigated. The runners were divided into performance groups consisting of recreational (all runners) and elite runners (the top 100, the top 10 and the top 3) which were separately analyzed for male and female participants. RESULTS: During race days, the temperature increased while humidity decreased showing a strong negative correlation between the two variables. For all runners, the average running speed through the race showed a strong negative correlation with temperature and a strong positive correlation with the level of humidity. Faster runners experienced lower temperatures and higher humidity levels than slower runners. When the performance groups were analyzed, temperature and humidity remained correlated to a similar extent for the top 100 but dropped dramatically for the top 10 and top 3, suggesting a weaker influence. In addition, barometric pressure showed a positive correlation with running speed in the top 100 and top 3 groups. CONCLUSIONS: Temperatures increased during race days while humidity decreased and both variables were negatively and significantly correlated. Faster runners experienced lower temperatures and higher humidity levels, while slower runners experienced higher temperatures and lower humidity levels which had a stronger negative impact on running speeds. Running speed was also significantly and positively correlated with barometric pressure in elite runners.

Effect of surface and porosity of biochar on water holding capacity aiming indirectly at preservation of the Amazon biome.

As part of efforts to reduce pressure on the Amazon and other biomes, one approach considered by Brazilian authorities and scientists is more intensive use of the soils of the interior of the northeast of the country, which are generally sandy, with low contents of organic matter and low water holding capacity and are frequently affected by severe droughts. In this work, biochars produced from waste biomasses were tested for the improvement of these soils. The highest BET (Brunauer-Emmett-Teller) specific surface areas were observed for all biochars. In the pH range studied, the water hyacinth plants (WH) sample showed the most negative zeta potentials, as well as the highest water holding capacity (WHC) values, while the zeta potentials of two quartzarenic neosol soils were consistent with their WHC values. The results suggested that despite the effect of porosity on water retention, the zeta potential could be associated with the presence of negative charges by which hydrated cationic counterions were absorbed and retained. The surface energy and its polar and dispersive components were associated with water retention, with sugar cane bagasse, orange peel, and water hyacinth biochars presenting higher SE values and larger polar components.

Características físicas e bucais em pacientes portadores da Síndrome do X-Frágil / Physical and oral characteristics in patients with fragile X syndrome

A Síndrome do X-Frágil é um distúrbio genético, identificado microscopicamente por uma cons- trição denominada sítio frágil no braço longo do cromossomo X; é considerada como principal causa hereditária de deficiência mental associada a diversas alterações neurológicas. O objetivo deste estudo foi verificar características físicas e bucais, presença de alterações sistêmicas e características comportamentais presentes em pacientes portadores da Síndrome do X-Frágil, além de divulgar esta síndrome aos Cirurgiões-Dentistas. Foram analisados 31 voluntários portadores da Síndrome do X- -Frágil por meio da aplicação de questionário estruturado, exame físico geral, bucodental e análise de prontuário multidisciplinar. Os dados obtidos foram tabulados e submetidos ao teste Qui-Quadrado (p

The fragile X syndrome is a genetic disorder, identified microscopically by a constriction called fragile site on the long arm of chromosome X, considered the main inherited cause of mental disability associated with severa I neurological disorders. The aim of this study were analyzed physical and oral characteristics, medical problems and behavioral characteristics in patients with fragile X syndrome, and diffuse this syndrome among dentists. Volunteers (n=31) with fragile X syndrome were submitted a structured form, physical and oral exam and the multidisciplinary form was analyzed. The data were submitted to statistical analyses (Chi-square; P<.05). Regular use of medicine was reported by 68% (P<.05), the most commonly used was the anticonvulsants (61%). The presence of biofilm (93%) and gingivitis (81%) was statistically significant when the amount of positive and negative cases were compared. Malocclusion and atresic palate were present in 93% ofthe volunteers (P<.05). Ali subjects reported the presence of family history of mental retardation. Among the facial features elongated face, ears and forehead prominent and behavioral aspects of hyperactivity and anxiety were statically significant differences. Thus, we conclude that there are large variability among the characteristics expressed by individuais with the Fragile X syndrome, frequently these individuais have elongated face, prominent ears and mental retardation associated with oral problems such as malocclusion, atresic palate and enamel hypoplasia. In addition poor oral hygiene and regular medicine is common in this patients.