The urgent demand of high energy density and high power density devices has triggered significant interest in high dielectric constant (high-k) flexible nanocomposites comprising dielectric polymer and high-k inorganic nanofiller. However, the large electrical mismatch between polymer and nanofiller usually leads to earlier electric failure of the nanocomposites, resulting in an undesirable decrease of electrical energy storage capability. A few studies show that the introduction of moderate-k shell onto a high-k nanofiller surface can decrease the dielectric constant mismatch, and thus, the corresponding nanocomposites can withstand high electric field. Unfortunately, the low apparent dielectric enhancement of the nanocomposites and high electrical conductivity mismatch between matrix and nanofiller still result in low energy density and low efficiency. In this study, it is demonstrated that encapsulating moderate-k nanofiller with high-k but low electrical conductivity shell is effective to significantly enhance the energy storage capability of dielectric polymer nanocomposites. Specifically, using BaTiO nanoparticles encapsulated TiO (BaTiO@TiO) core-shell nanowires as filler, the corresponding poly(vinylidene fluoride-co-hexafluoropylene) nanocomposites exhibit superior energy storage capability in comparison with the nanocomposites filled by either BaTiO or TiO nanowires. The nanocomposite film with 5 wt % BaTiO@TiO nanowires possesses an ultrahigh discharged energy density of 9.95 J cm at 500 MV m, much higher than that of commercial biaxial-oriented polypropylene (BOPP) (3.56 J cm at 600 MV m). This new strategy and corresponding results presented here provide new insights into the design of dielectric polymer nanocomposites with high electrical energy storage capability.

Telomere shortening is a hallmark of aging and is counteracted by telomerase. As in humans, the zebrafish gut is one of the organs with the fastest rate of telomere decline, triggering early tissue dysfunction during normal zebrafish aging and in prematurely aged telomerase mutants. However, whether telomere-dependent aging of an individual organ, the gut, causes systemic aging is unknown. Here we show that tissue-specific telomerase expression in the gut can prevent telomere shortening and rescues premature aging of tert−/−. Induction of telomerase rescues gut senescence and low cell proliferation, while restoring tissue integrity, inflammation and age-dependent microbiota dysbiosis. Averting gut aging causes systemic beneficial impacts, rescuing aging of distant organs such as reproductive and hematopoietic systems. Conclusively, we show that gut-specific telomerase expression extends the lifespan of tert−/− by 40%, while ameliorating natural aging. Our work demonstrates that gut-specific rescue of telomerase expression leading to telomere elongation is sufficient to systemically counteract aging in zebrafish.

Polymer nanocomposites have attracted broad attention in the area of dielectric and energy storage. However, the electrical and chemical performance mismatch between inorganic nanoparticles and polymer leads to interfacial incompatibility. In this study, phosphonic acid molecules with different functional ligands were introduced to the surface of BaTiO3 (BT) nanoparticles to tune their surface properties and tailor the host–guest interaction between BT and poly(vinylideneflyoride-co-hexafluroro propylene) (P(VDF-HFP)). The dielectric properties and electrical energy storage capability of the nanocomposites were recorded by broadband dielectric spectroscopy and electric displacement measurements, respectively. The influence of the ligand length and polarity on the dielectric properties and electrical energy storage of the nanocomposites was documented. The nanocomposite with 5 vol% 2,3,4,5,6-pentafluorobenzyl phosphonic acid (PFBPA)-modified BT had the highest energy density of 12.8 J cm−3 at 400 MV m−1, i.e., a 187% enhancement in the electrical energy storage capability over the pure P(VDF-HFP). This enhancement can be attributed to the strong electron-withdrawing effect of the pentafluorobenzyl group of PFBPA, which changed the electronic nature of the polymer–particle interface. On the other hand, PFBPA improves the compatibility of the host–guest interface in the nanocomposites and decreases the electrical mismatch of the interface. These results provide new insights into the design and preparation of high-performance dielectric nanocomposites.

Telomere shortening is a hallmark of aging and is counteracted by telomerase. The gut is one of the earliest organs to exhibit short telomeres and tissue dysfunction during normal zebrafish aging. This is recapitulated in prematurely aged telomerase mutants (tert-/-). Here, we show that gut-specific telomerase activity in tert-/- zebrafish prevents premature aging. Induction of telomerase rescues gut senescence and low cell proliferation to wild-type levels, while restoring gut tissue integrity, inflammation, and age-dependent gut microbiota dysbiosis. Remarkably, averting gut dysfunction results in a systemic beneficial impact. Gut-specific telomerase activity rescues premature aging markers in remote organs, such as the reproductive (testes) and hematopoietic (kidney marrow) systems. Functionally, it also rescues age-dependent loss of male fertility and testes atrophy. Finally, we show that gut-specific telomerase activity increases the lifespan of telomerase mutants. Our work demonstrates that delaying telomere shortening in the gut is sufficient to systemically counteract aging in zebrafish.

Background: Although midazolam is widely administered as an anxiolytic premedication, it may cause over-sedation and hypoxia in geriatric patients. Cranial electrotherapy stimulation (CES) is a nonpharmacological device with anxiolytic effect. This study compared the effects of CES and midazolam as a preoperative treatment in geriatric patients.Methods: Eighty patients, under the age of 65 to 79 years, undergoing general anesthesia were randomly assigned into midazolam premedication group (M group, n = 40) or CES pretreatment group (CES group, n = 40). The patients in the M group were intramuscularly injected with midazolam (0.07 mg/kg) 30 minutes before receiving general anesthesia. The patients in the CES group received 20 minutes of CES pretreatment on the day before and on the morning of the surgery.Results: In the preoperative holding area, the anxiety score (P = .02) and the sedation score (P < .001) were significantly lower in the CES group compared with those in the M group. The oxygen saturations at the preoperative holding area and the operating room were significantly higher in the CES group than those in the M group (P < .001).Conclusion: CES pretreatment relieved preoperative anxiety with less risk of over-sedation and respiratory depression than midazolam premedication in geriatric patients.