A simple and straightforward method using microwave-assisted reactions is presented for the functionalization of graphene oxide with aromatic and non-aromatic amines, notedly dibenzylamine (DBA),
p
...-phenylenediamine (PPD), diisopropylamine (DPA) and piperidine (PA). The as-synthesized amine-functionalized graphene oxide materials (amine-GO) were characterized using spectroscopic techniques including XRD, FTIR,
13
C NMR, XPS, TEM for imaging and thermogravimetric analysis (TGA). The characterization confirmed the functionalization for all amines, reaching relatively high surface nitrogen atomic concentrations of up to 8.8%. The investigations of electrochemical behavior for the amine-GOs show the significant improvement in GO's electrochemical properties through amine functionalization, exhibiting long life cycle stability and reaching specific capacitance values of up to 290 F g
−1
and 260 F g
−1
for GO-PA and GO-DPA samples, respectively, confirming their potential application as alternative supporting materials in supercapacitors.
A simple and straightforward method using microwave-assisted reactions is presented for the functionalization of graphene oxide with aromatic and non-aromatic amines.
Ultrasensitive detection and spatially resolved mapping of neurotransmitters, dopamine and serotonin, are critical to facilitate understanding brain functions and investigate the information ...processing in neural networks. In this work, we demonstrated single molecule detection of dopamine and serotonin using a graphene–Au nanopyramid heterostructure platform. The quasi-periodic Au structure boosts high-density and high-homogeneity hotspots resulting in ultrahigh sensitivity with a surface enhanced Raman spectroscopic (SERS) enhancement factor ∼1010. A single layer graphene superimposed on a Au structure not only can locate SERS hot spots but also modify the surface chemistry to realize selective enhancement Raman yield. Dopamine and serotonin could be detected and distinguished from each other at 10–10 M level in 1 s data acquisition time without any pretreatment and labeling process. Moreover, the heterostructure realized nanomolar detection of neurotransmitters in the presence of simulated body fluids. These findings represent a step forward in enabling in-depth studies of neurological processes including those closely related to brain activity mapping (BAM).
Trigeminal electrical stimulation of the dorsal anterior mucosal surface of the tongue has demonstrated its efficacy in a variety of neurological disorders in which anatomical or functional ...alterations are present. The pathogenesis of such disorders is often linked to altered arousal circuits, and the benefits of tongue stimulation are attributed to the rebalancing of this system. Dental ULFTENS shows efficacy in acting on the muscular, autonomic system and control of the descending pathways that modulate pain. It is administered at the skin level in the area anterior to the tragus and not on the mucosal surface of the tongue. The use of this stimulation technique at the tongue level could have new applications and clinical results if it were able to reduce the activity of arousal circuits.
A new intraoral device allowed electrical stimulation of the dorsal anterior mucosa of the tongue in 32 healthy young women. The effects on HRV were monitored by photoplethysmographic wave (PPG) and compared with a control group. The HRV parameters studied were RMSSD, HF, LF, LF/HF, REC, DET.
The group of stimulated subjects showed a significant change in some of the HRV parameters that was maintained even in the epoch after the end of electrical stimulation. This effect can be considered as a vagal activation and a change of HRV trend. The control group of unstimulated subjects showed an opposite trend. There were no undesirable or annoying effects of stimulation.
Stimulation of the dorsal anterior (trigeminal) mucosal surface of the tongue with ULFTENS applied with an intraoral device was shown to be able to increase HRV.
The lack of diversity among faculty at universities and medical schools in the United States is a matter of growing concern. However, the factors that influence the career choices of underrepresented ...minority and female postdoctoral researchers have received relatively little attention. Here we report the results of a survey of 1284 postdocs working in the biomedical sciences in the US. Our findings highlight possible reasons why some underrepresented minority and female postdocs choose not to pursue careers in academic research, and suggest interventions that could be taken in the early stages of postdoctoral training to prevent this attrition of underrepresented groups.
Over the past decades, self-assembled, vertically-aligned nanotubes have been generated on metallic substrates via anodization, which attracted significant scientific interest for a broad range of ...applications. These nano-tubular structures integrate highly controllable geometry at the nano-scale with fascinating chemical and biological properties. In this review, we first discussed mechanistic aspects of nanotube growth primarily on titanium (Ti) substrates by controlled anodization, a relatively inexpensive and scalable electrochemical process. We thoroughly reviewed electrochemical conditions that led to formation of self-assembled, vertically-aligned nano-tubular layers as they apply primarily to Ti substrates; we also reviewed anodization conditions that have led to formation of nanotubes on zirconium and various Ti alloys. We discussed how to adjust a set of anodization parameters to fine-tune the geometry of vertically oriented titania (TiO2) nanotubes, such as nanotube diameter, wall thickness, and length. We critically analyzed the key anodization parameters in the literature, including applied voltage, anodization duration, voltage ramp, electrolyte composition and concentration, electrolyte pH, electrolyte temperature, and electrolyte fluoride and water concentrations. Lastly, we discussed the promising properties of anodically grown TiO2 nano-tubular arrays for a wide range of biomedical applications, including directing cell bioactivity, anti-bacterial efficacy, modulating deposition of hydroxyapatite, drug delivery, biosensors, and orthopedic implants (in vivo). We highlighted ongoing in vitro and in vivo studies on the effects of nanotube geometry and aspect ratio on their hydrophilicity and interactions with biological entities at the protein, cellular and tissue level.
The US COVID‐19 crises: facts, science and solidarity Cipriano, Pamela F.; Boston‐Leary, Katie; Mcmillan, Kendra ...
International nursing review,
December 2020, 2020-Dec, 2020-12-00, 20201201, Letnik:
67, Številka:
4
Journal Article
Recenzirano
Odprti dostop
The United States leads the world in COVID‐19 cases and deaths. The government’s poorly coordinated response has lacked national mandates, failed to deploy adequate personal protective equipment, ...supplies and testing and devalued advice of science experts. COVID‐19 exposed racial disparities in health care and as protests against racial injustice erupted, nurses have responded to the call to confront racism as a public health crisis. Nurses also suffer from lack of personal protective equipment, burnout, extreme workloads, overwhelming deaths and fear of contracting COVID‐19. While facing danger, nurses have implemented practice changes and fostered new roles and teamwork to provide safer care. Advancing policy to provide personal protective equipment as well as financial and mental health support for nurses is a priority nationally and globally.
The shielding tensor in 13C nuclear magnetic resonance (NMR) offers important information about the structural aspects of carbon materials from a local point of view. Not only the symmetry of the ...carbon site but also the presence of local structural distortions can affect the values of the isotropic shielding constant, the shielding anisotropy, and the deviation from axial symmetry. In this report, the 13C shielding in a single graphene sheet was calculated using density functional theory (DFT) via the gauge-including projector augmented plane wave (GIPAW) method. After performing convergence tests involving changes of k sampling and supercell size, the calculations were extended to graphene-based systems, including graphene bilayer and stacked graphene sheets, finally leading to hexagonal graphite. The calculated results showed good agreement with experimental values obtained by 13C NMR measurements in different types of carbon materials, evidencing the power of the DFT calculations for predicting NMR parameters in graphene-based nanocarbons.
IntroductionA significant number of patients with COVID-19 may experience dyspnoea, anxiety, depression, pain, fatigue and physical impairment symptoms, raising the need for a multidisciplinary ...rehabilitation approach, especially for those with advanced age, obesity, comorbidities and organ failure. Traditional pulmonary rehabilitation (PR), including exercise training, psychosocial counselling and education, has been employed to improve pulmonary function, exercise capacity and quality of life in patients with COVID-19. However, the effects of inspiratory muscle training (IMT) in PR programmes remain unclear. This study aimed to determine whether the addition of a supervised IMT in a PR is more effective than PR itself in improving dyspnoea, health-related quality of life and exercise capacity in symptomatic patients with post-COVID-19.Methods and analysisThis parallel-group, assessor-blinded randomised controlled trial, powered for superiority, aimed to assess exercise capacity as the primary outcome. A total of 138 are being recruited at two PR centres in Brazil. Following baseline testing, participants will be randomised using concealed allocation, to receive either (1) standard PR with sham IMT or (2) standard PR added to IMT. Treatment effects or differences between the outcomes (at baseline, after 8 and 16 weeks, and after 6 months) of the study groups will be analysed using an ordinary two-way analysis of variance.Ethics and disseminationThis trial was approved by the Brazilian National Ethics Committee and obtained approval on 7 October 2020 (document number 4324069). The findings will be disseminated through publications in peer-reviewed journals and conference presentations.Trial registration numberNCT04595097.
Objective. To investigate the effects of an early neuromuscular electrical stimulation (NMES) protocol on muscle quality and size as well as signaling mediators of muscle growth and systemic ...inflammation in patients with traumatic brain injury (TBI). Design. Two-arm, single-blinded, parallel-group, randomized, controlled trial with a blinded assessment. Setting. Trauma intensive care unit at a university hospital. Participants. Forty consecutive patients on mechanical ventilation (MV) secondary to TBI were prospectively recruited within the first 24 hours following admission. Interventions. The intervention group (NMES; n = 20) received a daily session of NMES on the rectus femoris muscle for five consecutive days (55 min/each session). The control group (n = 20) received usual care. Main Outcome Measures. Muscle echogenicity and thickness were evaluated by ultrasonography. A daily blood sample was collected to assess circulating levels of insulin-like growth factor I (IGF-I), inflammatory cytokines, and matrix metalloproteinases (MMP). Results. Both groups were similar at baseline. A smaller change in muscle echogenicity and thickness (difference between Day 1 and Day 7) was found in the control group compared to the NMES group (29.9 ± 2.1 vs. 3.0 ± 1.2, p<0.001; −0.79 ± 0.12 vs. −0.01 ± 0.06, p<0.001, respectively). Circulating levels of IGF-I, pro-inflammatory cytokines (IFN-y), and MMP were similar between groups. Conclusion. An early NMES protocol can preserve muscle size and quality and maintain systemic levels of signaling mediators of muscle growth and inflammation in patients with TBI. This trial is registered with https://www.ensaiosclinicos.gov.br under number RBR-2db.
Background: Low-frequency electrical stimulation (LFES) is an adjuvant method for heart failure (HF) patients with restrictions to start an exercise. However, the impact on molecular changes in ...circulating is unknown. We investigated the effects of 10 weeks of home-based LFES on plasma cytokines profile, redox biomarkers, metalloproteinases (MMPs) activity, and exercise performance in HF patients. Methods: Twenty-four HF patients (52.45 ± 9.15 years) with reduced ejection fraction (HFrEF) (EF < 40%), were randomly assigned to a home-based LFES or sham protocol. Plasma cytokines profile was assessed through interleukins, interferon-gamma, and tumor necrosis factor levels. Oxidative stress was evaluated through ferric reducing antioxidant power, thiobarbituric acid-reactive substances, and inducible nitric oxide synthase. The MMPs activity were analyzed by zymography. Cardiorespiratory capacity and muscle strength were evaluated by cardiopulmonary test and isokinetic. Results: LFES was able to increase the active-MMP2 activity post compared to pre-training (0.057 to 0.163, p = 0.0001), while it decreased the active-MMP9 (0.135 to 0.093, p = 0.02). However, it did not elicit changes in cytokines, redox biomarkers, or exercise performance (p > 0.05). Conclusion: LFES protocol is a promising intervention to modulate MMPs activity in HFrEF patients, although with limited functional effects. These preliminary responses may help the muscle to adapt to future mechanical demands dynamically.
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