The combination of gold and copper is a good way to pull down the cost of gold and ameliorate the instability of copper. Through shape control, the synergy of these two metals can be better exploited. Here, we report an aqueous phase route to the synthesis of pentacle gold–copper alloy nanocrystals with fivefold twinning, the size of which can be tuned in the range from 45 to 200 nm. The growth is found to start from a decahedral core, followed by protrusion of branches along twinning planes. Pentacle products display strong localized surface plasmon resonance peaks in the near-infrared region. Under irradiation by an 808-nm laser, 70-nm pentacle nanocrystals exhibit a notable photothermal effect to kill 4T1 murine breast tumours established on BALB/c mice. In addition, 70-nm pentacle nanocrystals show better catalytic activity than conventional citrate-coated 5-nm Au nanoparticles towards the reduction of p-nitrophenol to p-aminophenol by sodium borohydride.
Holey defective g-C N photocatalysts, which are easily prepared via a novel photoassisted heating process, are reported. The photoassisted treatment not only helps to create abundant holes, endowing g-C N with more exposed catalytic active sites and crossplane diffusion channels to shorten the diffusion distance of both reactants from the surface to bulk and charge carriers from the bulk to surface, but also introduces nitrogen vacancies in the tri-s-triazine repeating units of g-C N , inducing the narrowing of intrinsic bandgap and the formation of defect states within bandgap to extend the visible-light absorption range and suppress the radiative electron-hole recombination. As a result, the holey defective g-C N photocatalysts show much higher photocatalytic activity for H O production with optimized enhancement up to ten times higher than pristine bulk g-C N . The newly developed synthetic strategy adopted here enables the sufficient utilization of solar energy and shows rather promising for the modification of other materials for efficient energy-related applications.
BackgroundStudies have shown that inadequate access to healthcare is associated with lower levels of health and well-being in older adults. Studies have also shown significant urban-rural differences in access to healthcare in developing countries such as China. However, there is limited evidence of whether the association between access to healthcare and health outcomes differs by urban-rural residence at older ages in China.MethodsFour waves of data (2005, 2008/2009, 2011/2012, and 2014) from the largest national longitudinal survey of adults aged 65 and older in mainland China (n = 26,604) were used for analysis. The association between inadequate access to healthcare (y/n) and multiple health outcomes were examined—including instrumental activities of daily living (IADL) disability, ADL disability, cognitive impairment, and all-cause mortality. A series of multivariate models were used to obtain robust estimates and to account for various covariates associated with access to healthcare and/or health outcomes. All models were stratified by urban-rural residence.ResultsInadequate access to healthcare was significantly higher among older adults in rural areas than in urban areas (9.1% vs. 5.4%; p < 0.01). Results from multivariate models showed that inadequate access to healthcare was associated with significantly higher odds of IADL disability in older adults living in urban areas (odds ratio [OR] = 1.58–1.79) and rural areas (OR = 1.95–2.30) relative to their counterparts with adequate access to healthcare. In terms of ADL disability, we found significant increases in the odds of disability among rural older adults (OR = 1.89–3.05) but not among urban older adults. Inadequate access to healthcare was also associated with substantially higher odds of cognitive impairment in older adults from rural areas (OR = 2.37–3.19) compared with those in rural areas with adequate access to healthcare; however, no significant differences in cognitive impairment were found among older adults in urban areas. Finally, we found that inadequate access to healthcare increased overall mortality risks in older adults by 33–37% in urban areas and 28–29% in rural areas. However, the increased risk of mortality in urban areas was not significant after taking into account health behaviors and baseline health status.ConclusionsInadequate access to healthcare was significantly associated with higher rates of disability, cognitive impairment, and all-cause mortality among older adults in China. The associations between access to healthcare and health outcomes were generally stronger among older adults in rural areas than in urban areas. Our findings underscore the importance of providing adequate access to healthcare for older adults—particularly for those living in rural areas in developing countries such as China.
Abbreviations: ANXA5, annexin A5; CASP3, caspase 3, apoptosis-related cysteine peptidase; CTSB, cathepsin B; DLS, dynamic light scattering; DMEM, Dulbecco's Modified Eagle's medium; EGFP-LC3, enhanced green fluorescent protein-tagged LC3; ICP-MS, inductively coupled plasma-mass spectrometry; I-MEF, immortalized mouse embryonic fibroblast; MDC, monodansylcadaverine; MTOR, mechanistic target of rapamycin; P-MEF, primary mouse embryonic fibroblast; PI, propidium iodide; PI3K, phosphoinositide 3-kinase; PtdIns3K, phosphatidylinositol 3-kinase; PVP, polyvinylpyrrolidone; RPS6KB, ribosomal protein S6 kinase, 70 kDa; s.c., subcutaneously; SQSTM1, sequestosome 1; TEM, transmission electron microscopy; TUNEL, terminal deoxyribonucleotidyl transferase (TDT)-mediated dUTPdigoxigenin nick end labeling; UV-Vis, ultraviolet visible; XRD, X-ray diffraction.Silver nanoparticles (Ag NPs) are cytotoxic to cancer cells and possess excellent potential as an antitumor agent. A variety of nanoparticles have been shown to induce autophagy, a critical cellular degradation process, and the elevated autophagy in most of these situations promotes cell death. Whether Ag NPs can induce autophagy and how it might affect the anticancer activity of Ag NPs has not been reported. Here we show that Ag NPs induced autophagy in cancer cells by activating the PtdIns3K signaling pathway. The autophagy induced by Ag NPs was characterized by enhanced autophagosome formation, normal cargo degradation, and no disruption of lysosomal function. Consistent with these properties, the autophagy induced by Ag NPs promoted cell survival, as inhibition of autophagy by either chemical inhibitors or ATG5 siRNA enhanced Ag NPs-elicited cancer cell killing. We further demonstrated that wortmannin, a widely used inhibitor of autophagy, significantly enhanced the antitumor effect of Ag NPs in the B16 mouse melanoma cell model. Our results revealed a novel biological activity of Ag NPs in inducing cytoprotective autophagy, and inhibition of autophagy may be a useful strategy for improving the efficacy of Ag NPs in anticancer therapy.
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