Facile Preparation Method of TiO2/Activated Carbon for Photocatalytic Degradation of Methylene Blue.

The development of nanocomposite photocatalysts with high photocatalytic activity, cost-effectiveness, a simple preparation process, and scalability for practical applications is of great interest. In this study, nanocomposites of TiO2 Degussa P25 nanoparticles/activated carbon (TiO2/AC) were prepared at various mass ratios of (4:1), (3:2), (2:3), and (1:4) by a facile process involving manual mechanical pounding, ultrasonic-assisted mixing in an ethanol solution, paper filtration, and mild thermal annealing. The characterization methods included XRD, SEM-EDS, Raman, FTIR, XPS, and UV-Vis spectroscopies. The effects of TiO2/AC mass ratios on the structural, morphological, and photocatalytic properties were systematically studied in comparison with bare TiO2 and bare AC. TiO2 nanoparticles exhibited dominant anatase and minor rutile phases and a crystallite size of approximately 21 nm, while AC had XRD peaks of graphite and carbon and a crystallite size of 49 nm. The composites exhibited tight decoration of TiO2 nanoparticles on micron-/submicron AC particles, and uniform TiO2/AC composites were obtained, as evidenced by the uniform distribution of Ti, O, and C in an EDS mapping. Moreover, Raman spectra show the typical vibration modes of anatase TiO2 (e.g., E1g(1), B1g(1), Eg(3)) and carbon materials with D and G bands. The TiO2/AC with (4:1), (3:2), and (2:3) possessed higher reaction rate constants (k) in photocatalytic degradation of methylene blue (MB) than that of either TiO2 or AC. Among the investigated materials, TiO2/AC = 4:1 achieved the highest photocatalytic activity with a high k of 55.2 × 10-3 min-1 and an MB removal efficiency of 96.6% after 30 min of treatment under UV-Vis irradiation (120 mW/cm2). The enhanced photocatalytic activity for TiO2/AC is due to the synergistic effect of the high adsorption capability of AC and the high photocatalytic activity of TiO2. Furthermore, TiO2/AC promotes the separation of photoexcited electron/hole (e-/h+) pairs to reduce their recombination rate and thus enhance photocatalytic activity. The optimal TiO2/AC composite with a mass ratio of 4/1 is suggested for treating industrial or household wastewater with organic pollutants.

Limb versus life: the outcomes of osteosarcoma in Cambodia.

PURPOSE: Osteosarcoma (OS) is a serious disease affecting mainly children and young adults. In a resource poor setting the treatment options are limited and further obstacles can be found with respect to late presenting pathology, access to modern treatment modalities such as effective chemotherapy, and cultural reluctance to undergo certain treatments. Clinical outcome studies and epidemiology for this disease in developing countries are scarce. METHODS: We report on the outcomes of 30 patients treated by the CSC, a rehabilitative surgery centre in Cambodia, from 2002 to present. Enneking staging, location, and treatment protocols were evaluated. Outcome measures were months of survival, EDQ5S life quality scores and clinically relevant inquiries. Kaplan-Meier analysis estimates and the Wilcoxon chi-square test were used for statistical inferences. RESULTS: We find a grim prognosis for patients diagnosed with OS in Cambodia, 53% survive the first year after presentation and the five-year survival stands at 8%. There is a higher mean age for presentation of OS compared to Western norms, namely, 18.8 years and 21.7 years for females and males, respectively. CONCLUSIONS: Most patients opted for surgical treatment without adjuvant chemotherapy, which is not within the means of many Cambodian patients. Acceptance of amputation, earlier diagnosis, patient education, and access to standardized chemotherapy needs to be enhanced if Cambodian patients are to have a fighting chance.

A hybrid approach to telepathology in Cambodia.

We established a hybrid telepathology network at the Children's Surgical Centre (CSC) in Cambodia, based on store-and-forward communication using iPATH and videoconferencing using Skype. We retrospectively analysed all data from the CSC stored on the iPATH server and reviewed the patient notes over an 8-month period. Of 115 patients for histopathology diagnosis during the study period, 38 cases were uploaded onto iPATH for further telemedicine discussion. The median number of days it took a specialist, other than the local one, to comment on the case on iPATH was 5 days (range 0-15). In three cases (8%) there was no reply from a specialist on iPATH. During the study period, seven clinical conferences were held, with an average of 6 cases (range 4-7) discussed at each conference. All 38 cases discussed had a final agreed diagnosis and firm management plans were made. Of the 24 cases where proactive management was advised, 17 patients followed through with the recommendations. Although the combination of video consultations and store-and-forward communication has not been used much before in the developing world, it has benefited patient care and outcomes at the CSC.