3 research outputs found
Carbon Nanotubes with Tailored Density of Electronic States for Electrochemical Applications
The density of electronic states
(DOS) is an intrinsic electronic
property that works conclusively in the electrochemistry of carbon
materials. However, seldom has it been reported how the DOS at the
Fermi level influences the electrochemical activity. In this work,
we synthesized partially and fully unzipped carbon nanotubes by longitudinally
unzipping pristine carbon nanotubes (CNTs). We then studied the electrochemical
activity and biosensitivity of carbon materials by means of the CNTs
and their derivatives to elucidate the effect of the DOS on their
electrochemical performances. Tailoring of the DOS for the CNT derivatives
could be conveniently realized by varying the sp<sup>2</sup>/sp<sup>3</sup> ratio (i.e., graphite concentration) through manipulating
the oxidative unzipping degree. Despite the diverse electron transfer
mechanisms and influence factors of the four investigated redox probes
(IrCl<sub>6</sub><sup>2–</sup>, [FeÂ(CN)<sub>6</sub>]<sup>3–</sup>, Fe<sup>3+</sup>, and ascorbic acid), the CNT derivatives exhibited
consistent kinetic behaviors, wherein CNTs with a high DOS showed
superior electrochemical response compared with partially and fully
unzipped carbon nanotubes. For biological detection, the CNTs could
simultaneously distinguish ascorbic acid, dopamine, and uric acid,
while the three CNT derivatives could all differentiate phenethylamine
and epinephrine existed in the newborn calf serum. Moreover, the three
CNT derivatives all presented wide linear detection ranges with high
sensitivities for dopamine, phenethylamine, and epinephrine
Total dietary flavonoid intake and risk of cardiometabolic diseases: A dose-response meta-analysis of prospective cohort studies
Several epidemiological studies have suggested that flavonoid intake is associated with a decreased risk of cardiometabolic disease. However, the results remained inconsistent and there is no dose-response meta-analysis for specific outcomes. We conducted a meta-analysis to synthesize the knowledge about their associations and to explore their dose-response relationships. We comprehensively searched the PubMed, Embase, and Web of Science databases for prospective cohort studies published up to December 1, 2021. Summary relative risks (RR) and 95% confidence intervals (CI) were pooled for the association between flavonoid intake and cardiometabolic disease. Evaluations of linear or nonlinear dose-response were presented by restricted cubic splines. We identified 47 articles, including 1,346 676 participants and 127,507 cases in this meta-analysis. The summary of RR per 500 mg/d increase in flavonoid intake was 0.93 (95% CI 0.88–0.98) for cardiovascular disease, 0.89 (95% CI 0.84–0.94) for diabetes, and 0.97 (95% CI 0.94–0.99) for hypertension, respectively. We also found a linearity dose-response association between total flavonoid intake and cardiovascular disease (p nonlinearity = 0.541), and diabetes (p nonlinearity = 0.077). Our finding based on quantitative data suggested that a higher level of flavonoid intake is beneficial for the prevention of cardiometabolic diseases.</p