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排序方式: 共有241条查询结果,搜索用时 15 毫秒
1.
Yi-Feng Wang Chunqiu Zhang Keni Yang Yufei Wang Shaobo Shan Yan Yan Kenneth A Dawson Chen Wang Xing-Jie Liang 《国家科学评论(英文版)》2021,8(6):17-27
Liposomes, especially cationic liposomes, are the most common and well-investigated nanocarriers for biomedical applications, such as drug and gene delivery. Like other types of nanomaterials, once liposomes are incubated in a biological milieu, their surface can be immediately cloaked by biological components to form a protein corona, which confers a new ‘biological identity’ and modulates downstream interactions with cells. However, it remains unclear how the protein corona affects the transportation mechanism after liposomes interact with cells. Here, we employed home-made aggregation-induced-emission-visualized nanoliposomes TR4@Lipo as a model to investigate transportation with or without the protein corona by optical imaging techniques. The results show that the protein corona can change the cellular transportation mechanism of TR4@Lipo from energy-independent membrane fusion to energy-dependent endocytosis. The protein corona also modulates the intracellular distribution of loaded cargoes. This knowledge furthers our understanding of bio-nano interactions and is important for the efficient use of cationic liposomes. 相似文献
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Paul S. R. Goods Brian Dawson Grant J. Landers Christopher J. Gore Kevin Croft Peter Peeling 《European Journal of Sport Science》2016,16(8):1047-1054
This investigation examined the oxidative stress (F2-Isoprostane; F2-IsoP) and inflammatory (interleukin-6; IL-6) responses to repeat-sprint training in hypoxia (RSH). Ten trained male team sport athletes performed 3(sets)*9(repetitions)*5?s cycling sprints in simulated altitude (3000?m) and sea-level conditions. Mean and peak sprint power output (MPO and PPO) were recorded, and blood samples were collected pre-exercise, and again at 8 and 60?min post-exercise. Both MPO and PPO were significantly reduced in hypoxia (compared to sea-level) in the second (MPO: 855?±?89 vs. 739?±?95?W, p?=?.006; PPO: 1024?±?114 vs. 895?±?112?W, p?=?.010) and third (MPO: 819?±?105 vs. 686?±?83?W, p?=?.008; PPO: 985?±?125 vs. 834?±?99?W, p?=?.008) sets, respectively. IL-6 was significantly increased from pre- to 1?h post-exercise in both hypoxia (0.7?±?0.2 vs. 2.4?±?1.4?pg/mL, p?=?.004) and sea-level conditions (0.7?±?0.2 vs. 1.6?±?0.3?pg/mL, p?.001), with a large effect (d?=?0.80) suggesting higher IL-6 levels of post-hypoxia. F2-IsoP was significantly lower 1?h post-exercise in both the hypoxic (p?=?.005) and sea-level (p?=?.002) conditions, with no differences between trials. While hypoxia can impact on exercise intensity and may result in greater post-exercise inflammation, it appears to have little effect on oxidative stress. These results indicate that team sport organisations with ready access to hypoxic training facilities could confidently administer RSH without significantly increasing the post-exercise inflammatory or oxidative stress response. 相似文献
4.
This study investigated the effects of a brief meditation intervention on perceived stress, mindfulness, and sleep quality for college freshmen who have aged out of foster care. Thirty-six youth who had aged out of foster care and enrolled at a large midwestern 4-year university (n?=?16 experimental group, n?=?20 control group) participated in a study in which they were assessed three times on the dependent variables. Students also participated in a focus group after the intervention ended. Four sessions of the brief mindfulness intervention resulted in significant short-term reductions in stress levels and increases in sleep quality. Finding effective personal interventions to increase chances for college success for students with histories in foster care can also offer potential insight toward the development of educational models and resources for other vulnerable college student populations. 相似文献
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OBJECTIVE: To describe a pattern of abusive head injury in a series of children older than 4 years of age. METHODS: A hospital chart review of abused children with skull fractures from 1999 to 2001 was carried out. The clinical features, social background, and subsequent outcome and management are described. RESULTS: An 11-year-old girl and a pair of brothers of ages 7 and 9 were identified. The girl was attacked with a hammer during sleep by her stepmother, who committed suicide shortly afterwards. After craniotomy and intensive care, the child survived her multiple depressed fractures, intracranial bleeding, and brain contusion. Two brothers from a second family were attacked from behind with a hammer by their biological father, who was subsequently found to have undiagnosed schizophrenia. A depressed occipital fracture, without intracranial injury, was found in each child. The elder brother also had metacarpal fractures. Both children recovered without surgical intervention. CONCLUSION: A pattern of abusive head injury was described in older children with depressed skull fractures from blunt injury. The abusing parents were seriously mentally disturbed, and the abusive acts closely resembled child homicide. 相似文献
7.
Effects of rest interval during high-repetition resistance training on strength, aerobic fitness, and repeated-sprint ability 总被引:1,自引:0,他引:1
The effect of altering the rest period on adaptations to high-repetition resistance training is not well known. Eighteen active females were matched according to leg strength and repeated-sprint ability and randomly allocated to one of two groups. One group performed resistance training with 20-s rest intervals between sets, while the other group employed 80-s rest intervals between sets. Both groups performed the same total training volume and load. Each group trained 3 days a week for 5 weeks [15- to 20-repetition maximum (RM), 2 - 5 sets]. Repeated-sprint ability (5x6-s maximal cycle sprints), 3-RM leg press strength, and anthropometry were determined before and after each training programme. There was a greater improvement in repeated-sprint ability after training with 20-s rest intervals (12.5%) than after training with 80-s rest intervals (5.4%) (P = 0.030). In contrast, there were greater improvements in strength after training with 80-s rest intervals (45.9%) than after training with 20-s rest intervals (19.6%) (P = 0.010). There were no changes in anthropometry for either group following training. These results suggest that when training volume and load are matched, despite a smaller increase in strength, 5 weeks of training with short rest periods results in greater improvements in repeated-sprint ability than the same training with long rest periods. 相似文献
8.
In this paper we critically review recent developments in policies, practices and philosophies pertaining to the mediation
between science and the public within the EU and the UK, focusing in particular on the current paradigm of Public Understanding
of Science and Technology (PEST) which seeks to depart from the science information-transmission associated with previous
paradigms, and enact a deliberative democracy model. We first outline the features of the current crisis in democracy and
discuss deliberative democracy as a response to this crisis. We then map out and critically review the broad outlines of recent
policy developments in public-science mediation in the EU and UK contexts, focusing on the shift towards the deliberative-democratic
model. We conclude with some critical thoughts on the complex interrelationships between democracy, equality, science and
informal pedagogies in public-science mediations. We argue that science and democracy operate within distinct value-spheres
that are not necessarily consonant with each other. We also problematize the now common dismissal of information-transmission
of science as inimical to democratic engagement, and argue for a reassessment of the role and importance of informal science
learning for the “lay” public, provided within the framework of a deliberative democracy that is not reducible to consensus
building or the mere expression of opinions rooted in social and cultural givens. This, we argue, can be delivered by a model
of PEST that is creative and experimental, with both educational and democratic functions. 相似文献
9.
Georgina L. Kent Brian Dawson Lars R. McNaughton Gregory R. Cox Louise M. Burke Peter Peeling 《Journal of sports sciences》2019,37(3):339-346
This investigation assessed the effect of dietary nitrate (NO3?) supplementation, in the form of beetroot juice (BR), on repeat-sprint performance in normoxia and normobaric hypoxia. 12 male team-sport athletes (age 22.3 ± 2.6 y, VO2peak 53.1 ± 8.7 mL.kg?1.min?1) completed three exercise trials involving a 10 min submaximal warm-up and 4 sets of cycling repeat-sprint efforts (RSE; 9 × 4 s) at sea level (CON), or at 3000 m simulated altitude following acute supplementation (140 mL) with BR (HYPBR; 13 mmol NO3?) or NO3–depleted BR placebo (HYPPLA). Peak (PPO) and mean (MPO) power output, plus work decrement were recorded during the RSE task, while oxygen consumption (VO2) was measured during the warm-up. There were no significant differences observed between HYPBR and HYPPLA for PPO or MPO; however, work decrement was reduced in the first RSE set in HYPBR compared with HYPPLA. There was a moderate effect for VO2 to be lower following BR at the end of the 10 min warm-up (ES = 0.50 ± 0.51). Dietary NO3? may not improve repeat-sprint performance in hypoxia but may reduce VO2 during submaximal exercise. Therefore, BR supplementation may be more effective for performance improvement during predominantly aerobic exercise. 相似文献
10.
Maddison J. Jones Brian Dawson Daniel F. Gucciardi Peter R. Eastwood Joanna Miller Shona L. Halson 《Journal of sports sciences》2019,37(8):864-870
The present study aimed to investigate pre-sleep behaviours (including evening electronic device use) and sleep quantity in well-trained athletes. Seventy well-trained athletes (44 females, 26 males) aged 21 ± 4 y from a range of team and individual sports were asked to complete an online sleep diary for 7 days. The sleep diary included questions about pre-sleep behaviours (e.g. napping, caffeine intake), electronic device use in the 2 h prior to bedtime (e.g. type of device and duration of use) and sleep (e.g. time in bed, sleep onset latency). On average, athletes spent 8:20 ± 1:21 h in bed each night. Associations between age, time in bed and sleepiness suggested that younger athletes spent more time in bed (B = -0.05, p = 0.001) but felt sleepier (r = -0.32, p < 0.01) than older athletes. On average, athletes mostly used electronic devices for 0–30 min prior to sleep. The use of multiple devices in the evening was associated with more perceived difficulty in falling asleep (B = 0.22, p = 0.03), but no associations existed with other sleep variables. In summary, younger athletes may require later start times or improved sleep quality to resolve excessive sleepiness. 相似文献