Articles you may be interested inInelastic electron and Raman scattering from the collective excitations in quantum wires: Zero magnetic field AIP Advances 3, 042103 (2013); 10.1063/1.4800685 Counting statistics in an InAs nanowire quantum dot with a vertically coupled charge detector Appl. Phys. Lett. 100, 072110 (2012); 10.1063/1.3687198Linear and nonlinear conductance of ballistic quantum wires with hybrid confinementWe study the transport in a system of coupled quantum wires and show evidence for a resonant interaction that occurs whenever one of them is biased close to pinch off. Measuring the conductance of one of the wires, as the width of the other is varied, we observe a resonant peak in the conductance that is correlated to the point at which the other wire pinches off. The origin of this interaction remains undetermined at present, although its characteristics appear consistent with predictions that a correlated many-body state should form in narrow wires as their conductance vanishes.

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In this study, we investigated the induction of apoptosis by ultrasound in the presence of the novel porphyrin derivative DCPH-P-Na(I). HL-60 cells were exposed to ultrasound for up to 3 min in the presence and absence of DCPH-P-Na(I), and the induction of apoptosis was examined by analyzing cell morphology, DNA fragmentation, and caspase-3 activity. Reactive oxygen species were measured by means of ESR and spin trapping technique. Cells treated with 8 μM DCPH-P-Na(I) and ultrasound clearly showed membrane blebbing and cell shrinkage, whereas significant morphologic changes were not observed in cells exposed to either ultrasound or DCPH-P-Na(I) alone. Also, DNA ladder formation and caspase-3 activation were observed in cells treated with both ultrasound and DCPH-P-Na(I) but not in cells treated with ultrasound or DCPH-P-Na(I) alone. In addition, the combination of DCPH-P-Na(I) and the same acoustical arrangement of ultrasound substantially enhanced nitroxide generation by the cells. Sonodynamically induced apoptosis, caspase-3 activation, and nitroxide generation were significantly suppressed by histidine. These results indicate that the combination of ultrasound and DCPH-P-Na(I) induced apoptosis in HL-60 cells. The significant reduction in sonodynamically induced apoptosis, nitroxide generation, and caspase-3 activation by histidine suggests active species such as singlet oxygen are important in the sonodynamic induction of apoptosis. These experimental results support the possibility of sonodynamic treatment for cancer using the induction of apoptosis.

Cancer cells tend to have a high requirement for lipids, including fatty acids, cholesterol and triglyceride, because of their rapid proliferative rate compared to normal cells. In this study, we investigated the effects of inhibition of lipid synthesis on the proliferation and viability of human pancreatic cancer cells. Of the inhibitors of lipid synthesis that were tested, 5-(tetradecyloxy)-2-furoic acid (TOFA), which is an inhibitor of acetyl-CoA carboxylase, and the fatty acid synthase (FAS) inhibitors cerulenin and irgasan, significantly suppressed the proliferation of MiaPaCa-2 and AsPC-1 cells. Treatment of MiaPaCa-2 cells with these inhibitors significantly increased the number of apoptotic cells. In addition, TOFA increased caspase-3 activity and induced cleavage of poly (ADP-ribose) polymerase in MiaPaCa-2 cells. Moreover, addition of palmitate to MiaPaCa-2 cells treated with TOFA rescued cells from apoptotic cell death. These results suggest that TOFA induces apoptosis via depletion of fatty acids and that, among the various aspects of lipid metabolism, inhibition of fatty acid synthesis may be a notable target for the treatment of human pancreatic cancer cells.

Background/Aim: Sonodynamic cancer therapy is based on the preferential uptake and/or retention of a sonosensitizing drug (sonosensitizer) in tumor tissues and the subsequent activation of the drug by ultrasound irradiation. In the present study, we investigated the sonodynamically-induced antitumoral effect with functionalized carbon nanotubes, such as poly-ethylene glycol-modified carbon nanotubes (PEGmodified CNTs). Materials and Methods: Antitumor effects were evaluated using histological observation and assessing tumor growth following sonodynamic exposure to PEGmodified CNTs. Results: The combined treatment of 100 μM PEG-modified CNT and ultrasound induced a 2-fold cytotoxicity. Sodium azide, which quenches singlet oxygen, significantly inhibited ultrasonication induced cell damage in the presence of PEG-modified CNTs. This suggests that singlet oxygen produced by the combined use of PEG-modified CNTs and ultrasound is involved in the induction of antitumoral effects. The destruction of tumor tissue was observed with the ultrasonic treatment in combination with PEG-modified CNTs, while neither the treatment with PEG-modified CNTs alone nor ultrasound alone caused any necrosis. Conclusion: These results indicate that PEG-modified CNT functions as a sonosensitizer and is effective for sonochemical treatment of solid tumors.There is a new promising strategy for cancer treatment using the synergistic effect of ultrasound and chemicals, which can efficiently cause crushing (cavitation), as a result of repeated expansion and contraction of microbubbles by ultrasound irradiation. In this way the biological effects of some chemicals can be enhanced. Substances activated via this non-thermal action are called ultrasound sensitizers (1-5). However, compared to the thermal effects of an ultrasoundabsorbing tumor treatment, there are only few research reports on non-thermal effects, such as sonochemical effects based on cavitation (2, 6-7).We have previously reported that photochemically active compounds, such as hematoporpyrin, ATX-70, pheophorbide A, rose bengal, adriamycin FAD104, THP-adriamycin, ATX-S10, and porfimer sodium, may be sonosensitizers that can be activated by ultrasound irradiation (2-4, 6, 8-16). Porphyrins have been observed to accumulate in tumor tissues following intravenous administration (5,7,(17)(18). The administration of such compounds followed by ultrasound to treat implanted murine tumors has been shown to significantly suppress tumor growth, whereas the application of ultrasound alone only slightly inhibits growth (5,7,(19)(20)(21)(22)(23)(24)(25)(26). This suggests that combinational use of sonodynamically active porphyrins and ultrasound may have antitumoral effects. We have proposed that this potential modality be called sonodynamic therapy (2,26).Nanomedicine is a medical application of nanotechnology for the diagnosis and treatment of human illnesses, using precisely designed materials (nanoparticles) with a diameter of typically 1-100 nm (27). Nanomaterials, such as functionalized car...