The Effects of Beetroot Juice on VO2max and Blood Pressure during Submaximal Exercise

International Journal of Exercise Science 12(2): 332-342, 2019. Beetroot juice (BR) has been shown to reduce blood pressure (BP) at rest and improve several performance parameters during exercise. However, the effect of BR on BP during submaximal exercise has not been investigated and its effects on VO2max are inconclusive. The purpose of this study was to investigate the effects of BR on VO2max and BP during submaximal exercise. 20 healthy, recreationally trained volunteers (age 21.8±2.35 years, weight 75.10±10.62 kg, height 177.4±6.39 cm) participated in this study, which had a double-blind placebo controlled randomized crossover design. Participants supplemented with either 237 ml servings of placebo or 70 ml BR servings (nitrate concentration of 6.4 mmol/day) for 7 days. Participants completed a ramp treadmill protocol to determine VO2max. BP was taken at 70% max heart rate calculated using the Karvonen method. There was no significant change in VO2max after BR supplementation (51.07±6.12 ml/kg/min) versus placebo (50.46±6.06 ml/kg/min), t(19)=1.41, p=0.17. There was no significant change in either systolic BP after BR supplementation (180.65±23.37 mm Hg) versus placebo (177.65±22.07 mm Hg), t(19)=0.49, p=0.63, or in diastolic BP after BR (92.90±18.89 mm Hg) versus placebo (90.75±17.73 mm Hg), t(19)=0.51, p=0.62. BR did not affect VO2max, nor did it affect BP during submaximal exercise

Cortical and Subcortical Effects of Transcutaneous Spinal Cord Stimulation in Humans with Tetraplegia.

An increasing number of studies supports the view that transcutaneous electrical stimulation of the spinal cord (TESS) promotes functional recovery in humans with spinal cord injury (SCI). However, the neural mechanisms contributing to these effects remain poorly understood. Here we examined motor-evoked potentials in arm muscles elicited by cortical and subcortical stimulation of corticospinal axons before and after 20 min of TESS (30 Hz pulses with a 5 kHz carrier frequency) and sham-TESS applied between C5 and C6 spinous processes in males and females with and without chronic incomplete cervical SCI. The amplitude of subcortical, but not cortical, motor-evoked potentials increased in proximal and distal arm muscles for 75 min after TESS, but not sham-TESS, in control subjects and SCI participants, suggesting a subcortical origin for these effects. Intracortical inhibition, elicited by paired stimuli, increased after TESS in both groups. When TESS was applied without the 5 kHz carrier frequency both subcortical and cortical motor-evoked potentials were facilitated without changing intracortical inhibition, suggesting that the 5 kHz carrier frequency contributed to the cortical inhibitory effects. Hand and arm function improved largely when TESS was used with, compared with without, the 5 kHz carrier frequency. These novel observations demonstrate that TESS influences cortical and spinal networks, having an excitatory effect at the spinal level and an inhibitory effect at the cortical level. We hypothesized that these parallel effects contribute to further the recovery of limb function following SCI.SIGNIFICANCE STATEMENT Accumulating evidence supports the view that transcutaneous electrical stimulation of the spinal cord (TESS) promotes recovery of function in humans with spinal cord injury (SCI). Here, we show that a single session of TESS over the cervical spinal cord in individuals with incomplete chronic cervical SCI influenced in parallel the excitability cortical and spinal networks, having an excitatory effect at the spinal level and an inhibitory effect at the cortical level. Importantly, these parallel physiological effects had an impact on the magnitude of improvements in voluntary motor output

A mini review focused on the proangiogenic role of silicate ions released from silicon-containing biomaterials

Angiogenesis is considered an important issue in the development of biomaterials for the successful regeneration of tissues including bone. While growth factors are commonly used with biomaterials to promote angiogenesis, some ions released from biomaterials can also contribute to angiogenic events. Many silica-based biomaterials have been widely used for the repair and regeneration of tissues, mainly hard tissues such as bone and tooth structure. They have shown excellent performance in bone formation by stimulating angiogenesis. The release of silicate and others (Co and Cu ions) has therefore been implicated to play critical roles in the angiogenesis process. In this short review, we highlight the in vitro and in vivo findings of angiogenesis (and the related bone formation) stimulated by the various types of silicon-containing biomaterials where silicate ions released might play essential roles. We discuss further the possible molecular mechanisms underlying in the ion-induced angiogenic events

Immediate Surgical Repositioning Following Intrusive Luxation: A Case Report and Review of the Literature

This report presents a case of severe intrusive luxation of mature maxillary lateral incisor in a 10-year-old boy. The intruded tooth was immediately repositioned (surgical extrusion) and splinted within 2 h following injury. Tetracycline therapy was initiated at the time of repositioning and maintained for 10 days. Pulp removal and calcium hydroxide treatment of the root canal was carried out after repositioning. Splint was removed 1 month later. Definitive root canal treatment with gutta percha was accomplished at the second month recall. Clinical and radiographic examination 28 months after the surgical extrusion revealed satisfactory apical and periodontal healing

Asymmetrical transfer effects of cognitive bias modification: Modifying attention to threat influences interpretation of emotional ambiguity, but not vice versa.

BACKGROUND AND OBJECTIVES: It is well established that attention bias and interpretation bias each have a key role in the development and continuation of anxiety. How the biases may interact with one another in anxiety is, however, poorly understood. Using cognitive bias modification techniques, the present study examined whether training a more positive interpretation bias or attention bias resulted in transfer of effects to the untrained cognitive domain. Differences in anxiety reactivity to a real-world stressor were also assessed. METHODS: Ninety-seven first year undergraduates who had self-reported anxiety were allocated to one of four groups: attention bias training (n = 24), interpretation bias training (n = 26), control task training (n = 25) and no training (n = 22). Training was computer-based and comprised eight sessions over four weeks. Baseline and follow-up measures of attention and interpretation bias, anxiety and depression were taken. RESULTS: A significant reduction in threat-related attention bias and an increase in positive interpretation bias occurred in the attention bias training group. The interpretation bias training group did not exhibit a significant change in attention bias, only interpretation bias. The effect of attention bias training on interpretation bias was significant as compared with the two control groups. There were no effects on self-report measures. LIMITATIONS: The extent to which interpretive training can modify attentional processing remains unclear. CONCLUSIONS: Findings support the idea that attentional training might have broad cognitive consequences, impacting downstream on interpretive bias. However, they do not fully support a common mechanism hypothesis, as interpretive training did not impact on attentional bias

Angiogenesis-promoted bone repair with silicate-shelled hydrogel fiber scaffolds

Promoting angiogenesis is a key strategy for stimulating the repair of damaged tissues, including bone. Among other proangiogenic factors, ions have recently been considered a potent element that can be incorporated into biomaterials and then released at therapeutic doses. Silicate-based biomaterials have been reported to induce neovascularization through vascular endothelial growth factor signaling pathway, potentiating acceleration of bone regeneration. Here, we designed a silicate-shelled hydrogel fiber scaffold with a hard/soft layered structure to investigate the possibility of silicate coating on biopolymer for enhancing biological properties. An alginate hydrogel was injected to form a fiber scaffold with shape-tunability that was then coated with a thin silicate layer with various sol-gel compositions. The silicate/alginate scaffold could release calcium and silicate ions, and in particular, silicate ion release was highly sustainable for over one week at therapeutically relevant levels. The ionic release was highly effective in stimulating the mRNA expression of angiogenic markers (VEGF, KDR, eNOS, bFGF, and HIF1-α) in endothelial cells (HUVECs). Moreover, the in vitro tubular networking of cells was significantly enhanced (1.5 times). In vivo implantation in subcutaneous tissue revealed more pronounced blood vessel formation around the silicate-shelled scaffolds than around silicate-free scaffolds. The presence of a silicate shell was also shown to accelerate acellular mineral (hydroxyapatite) formation. The cellular osteogenesis potential of the silicate/alginate scaffold was further proven by the enhanced expression of osteogenic genes (Col1a1, ALP and OCN). When implanted in a rat calvarium defect, the silicate-shelled scaffold demonstrated significantly improved bone formation (2-3 times higher in bone volume and density) with a concurrent sign of proangiogenesis. This work highlights that the surface-layering of silicate composition is an effective approach for improving the bone regeneration capacity of polymeric hydrogel scaffolds by stimulating ion-induced angiogenesis and providing bone bioactivity to the surface

Peer tutoring: its effects on subject mastery and Mathematics anxiety among elementary education teaching interns

Teachers’ subject mastery and anxiety towards mathematics affect their performance in teaching the subject. This quasi-experimental study aimed to determine the effects of peer tutoring on mathematics subject mastery and mathematics anxiety among teaching interns. Intact groups of 35 Bachelor of Elementary Education (BEEd) students participated as tutees and 32 Bachelor of Secondary Education (BSEd) students with specialization in Mathematics participated as tutors in this study. Quantitative data were analysed using inferential statistics. Results revealed that peer tutoring was effective in increasing mathematics subject mastery; however, it had not been effective in reducing mathematics anxiety. Moreover, albeit insignificantly, as the participants’ subject mastery increases, their anxiety decreases, and that mathematics anxiety is an insignificant predictor of subject mastery. The findings implicate that a peer tutoring program can be beneficial in equipping general education prospective teachers with sufficient content knowledge and confidence to teach mathematics; hence, further research on a functional peer tutoring process is recommended. Moreover, it is also suggested that future research be conducted on peer tutoring for other subject areas and prolonged period of peer tutoring sessions

An Integrative Model of Graduate Education in Biodiversity Conservation and Sustainable Production in Fragmented Landscapes

To achieve biodiversity conservation and sustainable production in anthropogenically fragmented landscapes, scientists need to be trained in a holistic fashion that emphasizes integration and interdisciplinary collaboration. Traditional graduate programs in natural resources, conservation biology and agricultural sciences usually fall short of this goal as they train scientists with research knowledge and skills in narrowly defined disciplines. Rarely, if ever, is integration across disciplines facilitated, valued, or emphasized in either coursework or research activities