Piezoelectric materials are excellent generators of clean energy, as they can harvest the ubiquitous vibrational and mechanical forces. We developed large-scale unidirectionally polarized, aligned ...diphenylalanine (FF) nanotubes and fabricated peptide-based piezoelectric energy harvesters. We first used the meniscus-driven self-assembly process to fabricate horizontally aligned FF nanotubes. The FF nanotubes exhibit piezoelectric properties as well as unidirectional polarization. In addition, the asymmetric shapes of the self-assembled FF nanotubes enable them to effectively translate external axial forces into shear deformation to generate electrical energy. The fabricated peptide-based piezoelectric energy harvesters can generate voltage, current, and power of up to 2.8 V, 37.4 nA, and 8.2 nW, respectively, with 42 N of force, and can power multiple liquid-crystal display panels. These peptide-based energy-harvesting materials will provide a compatible energy source for biomedical applications in the future.
The metabolic effects of omega-6 polyunsaturated fatty acids (PUFAs) remain contentious, and little evidence is available regarding their potential role in primary prevention of type 2 diabetes. We ...aimed to assess the associations of linoleic acid and arachidonic acid biomarkers with incident type 2 diabetes.
We did a pooled analysis of new, harmonised, individual-level analyses for the biomarkers linoleic acid and its metabolite arachidonic acid and incident type 2 diabetes. We analysed data from 20 prospective cohort studies from ten countries (Iceland, the Netherlands, the USA, Taiwan, the UK, Germany, Finland, Australia, Sweden, and France), with biomarkers sampled between 1970 and 2010. Participants included in the analyses were aged 18 years or older and had data available for linoleic acid and arachidonic acid biomarkers at baseline. We excluded participants with type 2 diabetes at baseline. The main outcome was the association between omega-6 PUFA biomarkers and incident type 2 diabetes. We assessed the relative risk of type 2 diabetes prospectively for each cohort and lipid compartment separately using a prespecified analytic plan for exposures, covariates, effect modifiers, and analysis, and the findings were then pooled using inverse-variance weighted meta-analysis.
Participants were 39 740 adults, aged (range of cohort means) 49-76 years with a BMI (range of cohort means) of 23·3-28·4 kg/m
, who did not have type 2 diabetes at baseline. During a follow-up of 366 073 person-years, we identified 4347 cases of incident type 2 diabetes. In multivariable-adjusted pooled analyses, higher proportions of linoleic acid biomarkers as percentages of total fatty acid were associated with a lower risk of type 2 diabetes overall (risk ratio RR per interquintile range 0·65, 95% CI 0·60-0·72, p<0·0001; I
=53·9%, p
=0·002). The associations between linoleic acid biomarkers and type 2 diabetes were generally similar in different lipid compartments, including phospholipids, plasma, cholesterol esters, and adipose tissue. Levels of arachidonic acid biomarker were not significantly associated with type 2 diabetes risk overall (RR per interquintile range 0·96, 95% CI 0·88-1·05; p=0·38; I
=63·0%, p
<0·0001). The associations between linoleic acid and arachidonic acid biomarkers and the risk of type 2 diabetes were not significantly modified by any prespecified potential sources of heterogeneity (ie, age, BMI, sex, race, aspirin use, omega-3 PUFA levels, or variants of the FADS gene; all p
≥0·13).
Findings suggest that linoleic acid has long-term benefits for the prevention of type 2 diabetes and that arachidonic acid is not harmful.
Funders are shown in the appendix.
Abstract Rapid eye movement (REM) sleep behavior disorder (RBD) occurring prior to age 50 is termed early-onset RBD. Early-onset RBD comprises a substantial minority of cases, and demonstrates the ...differences in demographics, comorbidities, and clinical considerations from previously described typical RBD with onset >50 years. The world literature on RBD is reviewed with specific focus on features that distinguish early-onset RBD, including more gender parity, increased proportion of idiopathic cases, increased proportion of cases associated with narcolepsy, parasomnia overlap disorder, antidepressants, and possibly autoimmune disorders, and clinical presentation.
The Coupled Aerobic-anoxic Nitrous Decomposition Operation (CANDO) is a two-stage process for nitrogen removal and resource recovery: in the first, ammonia is oxidized to nitrite in an aerobic ...bioreactor; in the second, oxidation of polyhydroxyalkanoate (PHA) drives reduction of nitrite to nitrous oxide (N2O) which is stripped for use as a biogas oxidant. Because ammonia oxidation is well-studied, tests of CANDO to date have focused on N2O production in anaerobic/anoxic sequencing batch reactors. In these reactors, nitrogen is provided as nitrite; PHA is produced from acetate or other dissolved COD, and PHA oxidation is coupled to N2O production from nitrite. In a pilot-scale study, N2O recovery was affected by COD/N ratio, total cycle time, and relative time periods for PHA synthesis and N2O production. In follow-up bench-scale studies, different reactor cycle times were used to investigate these operational parameters. Increasing COD/N ratio improved nitrite removal and increased biosolids concentration. Shortening the anaerobic phase prevented fermentation of PHA and improved its utilization. Efficient PHA synthesis and utilization in the anaerobic phase correlated with high N2O production in the anoxic phase. Shortening the anoxic phase prevented reduction of N2O to N2. By shortening both phases, total cycle time was reduced from 24 to 12 h. This optimized operation enabled increased biomass concentrations, increased N2O yields (from 71 to 87%), increased N loading rates (from 0.1 to 0.25 kg N/m3-d), and shorter hydraulic residence times (from 10 to 2 days). Long-term changes in operational performance for the different bioreactor systems tested were generally similar despite significant differences in microbial community structure. Long-term operation at short anaerobic phases selected for a glycogen-accumulating community dominated by a Defluviicoccus-related strain.
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•Nitrite removal as nitrous oxide was evaluated under field conditions.•Extended anaerobic/anoxic phases adversely affected nitrous oxide production.•Follow-on bench-scale studies resolved challenges observed at pilot-scale.•Optimized performance achieved with a 2-day hydraulic residence time.
An efficient antireflection coating (ARC) can enhance solar cell performance through increased light coupling. Here, we investigate solution-grown ZnO nanostructures as ARCs for Si solar cells and ...compare them to conventional single layer ARCs. We find that nanoscale morphology, controlled through synthetic chemistry, has a great effect on the macroscopic ARC performance. Compared with a silicon nitride (SiN) single layer ARC, ZnO nanorod arrays display a broadband reflection suppression from 400 to 1200 nm. For a tapered nanorod array with average tip diameter of 10 nm, we achieve a weighted global reflectance of 6.6%, which is superior to an optimized SiN single layer ARC. Calculations using rigorous coupled wave analysis suggest that the tapered nanorod arrays behave like modified single layer ARCs, where the tapering leads to impedance matching between Si and air through a gradual reduction of the effective refractive index away from the surface, resulting in low reflection particularly at longer wavelengths and eliminating interference fringes through roughening of the air−ZnO interface. According to the calculations, we may further improve ARC performance by tailoring the thickness of the bottom fused ZnO layer and through better control of tip tapering.
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