The objective of this study was to synthesize a nanocomposite, aptamer-gold nanoparticle-hybridized graphene oxide (Apt-AuNP-GO), to facilitate targeted treatment of tumor cells by near-infrared (NIR) light-activatable photothermal therapy. We also investigated whether Apt-AuNP-GO with NIR illumination modulates heat shock proteins (HSPs) expression leading to therapeutic response in human breast cancer cells. These findings can provide strategies for improving the photothermal therapy efficacy of cancer. The self-assembled Apt-AuNP-GO nanocomposite could selectively target MUC1-positive human breast cancer cells (MCF-7) due to the specific interaction between the MUC1-binding-aptamer and the MUC1 (type I transmembrane mucin glycoprotein) on cell membrane. In addition, Apt-AuNP-GO has a high light-to-heat conversion capability for photoabsorption of NIR light, and it is able to exert therapeutic effects on MCF-7 cells at an ultralow concentration without inducing adverse effects in healthy cells. The Apt-AuNP-GO nanocomposites combine the advantages of GOs, AuNPs, and Apts, possess specific targeting capability, excellent biocompatibility, and tumor cell destruction ability, suggesting great potential for application in the photothermal therapy of breast cancer. Under NIR illumination, Apt-AuNP-GO induced transient increase in HSP70 expression, which decreased thereafter. This phenomenon may cause irreversible damage to Apt-AuNP-GO-treated MCF-7 cell under NIR illumination. We also demonstrated that the combination therapy of heat and HSP70 inhibitor could synergistically generate marked tumoricidal effects against breast cancer. These results suggest that the degree and duration of HSP70 protein expression are correlated with therapeutic effects against breast cancer for Apt-AuNP-GO-assisted photothermal therapy. We believe that such a nanocomposite can be readily extended to the construction of HSP70 inhibitors-loaded Apt-AuNP-GO, which could deliver both heat and HSP70 inhibitors to tumorigenic regions for the chemo-photothermal therapy.

This study reports a two-step method to synthesize spermidine-capped fluorescent carbon quantum dots (Spd-CQDs) and their potential application as an antibacterial agent. Fluorescent carbon quantum dots (CQDs) are synthesized by pyrolysis of ammonium citrate in the solid state and then modified with spermidine by a simple heating treatment without a coupling agent. Spermidine, a naturally occurring polyamine, binds with DNA, lipids, and proteins involved in many important processes within organisms such as DNA stability, and cell growth, proliferation, and death. The antimicrobial activity of the as-synthesized Spd-CQDs (size ≈4.6 nm) has been tested against non-multidrug-resistant E. coli, S. aureus, B. subtilis, and P. aeruginosa bacteria and also multidrug-resistant bacteria, methicillin-resistant S. aureus (MRSA). The minimal inhibitory concentration value of Spd-CQDs is much lower (>25 000-fold) than that of spermidine, indicating their promising antibacterial characteristics. The mechanism of antibacterial activity is investigated, and the results indicate that Spd-CQDs cause significant damage to the bacterial membrane. In vitro cytotoxicity and hemolysis analyses reveal the high biocompatibility of Spd-CQDs. To demonstrate its practical application, in vitro MRSA-infected wound healing studies in rats have been conducted, which show faster healing, better epithelialization, and formation of collagen fibers when Spd-CQDs are used as a dressing material.

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We detected 52 seismic events associated with landslides and submarine slumps on 8 August 2009 when Typhoon Morakot hit Taiwan. These events were neither felt nor reported because their seismic energy was primarily in the long period band (20–50 s). Most of these events were located in mountain areas where the accumulated rainfall was extremely high, though some were found offshore southern Taiwan. Among all events, the fatal landslide earthquake was located at Hsiaolin Village, where 474 people were buried. Inversion modelling of the seismic waveforms generated by the Hsiaolin landslide shows that the seismic source was represented by single force, consistent with downhill sliding. Some offshore seismic events indicate that submarine slumps probably occurred along submarine canyons and steep slopes. Our study shows that broadband seismic monitoring can be used to issue early warnings for mitigating disasters generated by inland and offshore landslides.

In this work, we demonstrate that carbon dots (CDs) can be used as a dispersing agent for graphene as well as a reducing agent for KMnO4 for the synthesis of manganese oxide (MnO x )–graphene hybrid nanocomposites for supercapacitor applications. CDs obtained from the pyrolysis of ammonium citrate under dry heating possess excellent solubility in water due to their oxygen- and nitrogen-containing functional groups. In addition, the sp2-carbon-rich CDs exhibited strong interaction with graphene through π–π stacking for self-immobilizing on graphene in the preparation of water-soluble CD/graphene nanocomposites (CDGs). Interestingly, MnO x could be grown in situ on CDGs after reaction with KMnO4 in aqueous solution under a mild reaction temperature (75 °C). Under the mild reaction conditions, CDs undergo sacrificial oxidation for the formation of MnO x nanoparticles on graphene, whereas the graphene’s graphitic carbons are protected. The as-formed nanostructured MnO x on CDGs (MnO x –CDGs) was employed to fabricate flexible solid-state supercapacitor which exhibited good capacitance properties (specific capacitance ∼280 F g–1) with very high charge–discharge cyclic stability (>10 000 cycles) and good capacitance retention at 90° bending angle. Compared to other graphene-based nanocomposites, our one-pot synthesis route for MnO x –CDGs is relatively green, simple, rapid, and cost-effective and has a great potential for the synthesis of different metal oxide-decorated graphene nanocomposites for energy conversion and storage applications

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The Tatun Volcano Group lies at the northern tip of Taiwan only 15 km north of the capital Taipei. A seismic array consisting of 5 stations equipped with both broadband and short‐period sensors was installed in 2003 in order to monitor the seismic activity of the area. It recorded a variety of events including common volcano‐tectonic earthquakes and volcanoseismic signals like tornillos, short duration monochromatic events (10–15 s) and long duration spasmodic bursts (∼15 min). An analysis of the complex frequencies of the tornillo/monochromatic signals shows that Q‐values are of the order of several hundreds. Based on the model of a fluid‐filled crack, such Q‐values can result from the oscillations of a crack containing a misty or dusty gas. These observations put into doubt the long‐standing suggestion that the Tatun volcanoes are extinct and prompt for a thorough assessment of the volcanic hazard for this area.