Highly ordered vertically grown zinc oxide nanorods (ZnO NRs) were synthesized on ZnO-coated SiO2/Si substrate using zinc acetylacetonate hydrate as a precursor via a simple hydrothermal method at 85 °C. We used 0.05 M of ZnO solution to facilitate the growth of ZnO NRs and the immersion time was varied from 0.5 to 4 h. The atomic force microscopy revealed the surface roughness of ZnO seed layer used to grow the ZnO NRs. The morphology of vertically grown ZnO NRs was observed by field emission scanning electron microscopy. X-ray diffraction examination and transmission electron microscopy confirmed that the structure of highly ordered ZnO NRs was crystalline with a strong (002) peak corresponded to ZnO hexagonal wurtzite structure. The growth of highly ordered ZnO NRs was favorable due to the continuous supply of Zn2+ ions and chelating agents properties obtained from the acetylacetonate-derived precursor during the synthesis. Two-point probe current-voltage measurement and UV-vis spectroscopy of the ZnO NRs indicated a resistivity and optical bandgap value of 0.44 Ω.cm and 3.35 eV, respectively. The photoluminescence spectrum showed a broad peak centered at 623 nm in the visible region corresponded to the oxygen vacancies from the ZnO NRs. This study demonstrates that acetylacetonate-derived precursors can be used for the production of ZnO NRs-based devices with a potential application in biosensors.
The purpose of this study was to evaluate the efficacy and toxicity of radiotherapy concurrently with weekly cisplatin, followed by adjuvant chemotherapy, for the treatment of N2-3 nasopharyngeal cancer (NPC) in Asian countries, especially regions of South and Southeast Asian countries where NPC is endemic. Between 2005 and 2009, 121 patients with NPC (T1-4 N2-3 M0) were registered from Vietnam, Malaysia, Indonesia, Thailand, The Philippines, China and Bangladesh. Patients were treated with 2D radiotherapy concurrently with weekly cisplatin (30 mg/m (2)), followed by adjuvant chemotherapy, consisting of cisplatin (80 mg/m(2) on Day 1) and fluorouracil (800 mg/m(2) on Days 1-5) for 3 cycles. Of the 121 patients, 56 patients (46%) required interruption of RT. The reasons for interruption of RT were acute non-hematological toxicities such as mucositis, pain and dermatitis in 35 patients, hematological toxicities in 11 patients, machine break-down in 3 patients, poor general condition in 2 patients, and others in 8 patients. Of the patients, 93% completed at least 4 cycles of weekly cisplatin during radiotherapy, and 82% completed at least 2 cycles of adjuvant chemotherapy. With a median follow-up time of 46 months for the surviving 77 patients, the 3-year locoregional control, distant metastasis-free survival and overall survival rates were 89%, 74% and 66%, respectively. No treatment-related deaths occurred. Grade 3-4 toxicities of mucositis, nausea/vomiting and leukopenia were observed in 34%, 4% and 4% of the patients, respectively. In conclusion, further improvement in survival and locoregional control is necessary, although our regimen showed acceptable toxicities.
The aim of this study was to evaluate the toxicity and efficacy of radiotherapy concurrent with weekly cisplatin for T3-4 and N0-1 nasopharyngeal cancer. Between 2005 and 2010, 70 patients with nasopharyngeal cancer (T3-4 N0-1 M0, World Health Organization Type 2-3) from Vietnam, Indonesia, Malaysia and Thailand were registered. Patients were treated with 2D radiotherapy concurrent with weekly cisplatin (30 mg/m(2)). Neither adjuvant nor induction chemotherapy was given. Ninety-three percent of the patients completed at least four cycles of weekly cisplatin during radiotherapy. The median total doses for the primary tumor and positive lymph nodes were 70 and 66 Gy, respectively. The median overall treatment time of concurrent chemoradiotherapy was 52 days. No treatment-related deaths occurred. Grade 3-4 acute toxicities of mucositis, nausea/vomiting and leukopenia were observed in 34%, 4% and 4% of patients, respectively. With a median follow-up time of 52 months for the 40 surviving patients, the 3-year local control, locoregional tumor control, distant metastasis-free survival and overall survival rates were 80%, 75%, 74% and 80%, respectively. In conclusion, the current results illustrate that our concurrent chemoradiotherapy regimen was feasible, but disease control remained insufficient. Further research is encouraged in order to improve clinical outcomes.