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1.
Water Sci Technol ; 75(5-6): 1177-1184, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28272046

RESUMEN

Biochar has been developed in recent years for the removal of contaminants such as Cr (VI) in water. The enhancement of the adsorption capacity of biochar and its recyclable use are still challenges. In this study, magnetic biochar derived from corncobs and peanut hulls was synthesized under different pyrolysis temperatures after pretreating the biomass with a low concentration of 0.5 M FeCl3 solution. The morphology, specific surface area, saturation magnetization and Fourier transform infrared spectroscopy (FT-IR) spectra were characterized for biochar. The magnetic biochar performed well in combining adsorption and separation recycle for the removal of Cr (VI) in water. The Cr (VI) adsorbance of the biochar was increased with the increase in pyrolysis temperature, and the magnetic biochar derived from corncobs showed better performance for both magnetization and removal of Cr (VI) than that from peanut hulls. The Langmuir model was used for the isothermal adsorption and the maximum Cr (VI) adsorption capacity of corncob magnetic biochar pyrolyzed at 650 °C reached 61.97 mg/g. An alkaline solution (0.1 M NaOH) favored the desorption of Cr (VI) from the magnetic biochar, and the removal of Cr (VI) still remained around 77.6% after four cycles of adsorption-desorption. The results showed that corncob derived magnetic biochar is a potentially efficient and recoverable adsorbent for remediation of heavy metals in water.


Asunto(s)
Carbón Orgánico/química , Cromo/aislamiento & purificación , Reciclaje , Contaminantes Químicos del Agua/aislamiento & purificación , Adsorción , Arachis/química , Biomasa , Soluciones , Espectrometría por Rayos X , Espectroscopía Infrarroja por Transformada de Fourier , Temperatura , Zea mays/química
2.
Chin Med Sci J ; 29(3): 180-4, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25264887

RESUMEN

OBJECTIVE: To report a case of the implantation of thyroid hyperplastic or neoplastic tissue after endoscopic thyroidectomy and discuss this complication in aspects of prevalence, pathogenesis, protection, and therapies. METHODS: A systematic search of literature from the PubMed database was conducted for identifying eligible studies on implantation of thyroid hyperplastic or neoplastic cells after endoscopic thyroid surgery. RESULTS: Overall, 5 reported cases on patients suffering from endoscopic thyroid surgery with implantation of thyroid hyperplastic or neoplastic cells were included in the systematic review. CONCLUSIONS: Unskilled surgeons, rough intraoperative surgical treatment, scarification or rupture of tumor, contamination of instruments, chimney effect, aerosolization of tumor cells may be associated with the implantation after endoscopic thyroidectomy. To minimize the risk of such complication, we should be more meticulous and strict the endoscopic surgery indications.


Asunto(s)
Endoscopía , Hiperplasia/patología , Neoplasias de la Tiroides/cirugía , Adulto , Femenino , Humanos , Neoplasias de la Tiroides/patología , Adulto Joven
3.
Front Oncol ; 11: 747532, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34631584

RESUMEN

PURPOSE: To investigate the potential clinical benefits of using stereotactic body radiation therapy (SBRT) with simultaneous integrated boost (SIB) technique for locally advanced pancreatic cancer (LAPC) among different treatment modalities and planning strategies, including photon and proton. METHOD: A total of 19 patients were retrospectively selected in this study: 13 cases with the tumor located in the head of the pancreas and 6 cases with the tumor in the body of the pancreas. SBRT-SIB plans were generated using volumetric modulated arc therapy (VMAT), two-field Intensity Modulated Proton Therapy (IMPT), and three-field IMPT. The IMPT used the robust optimization parameters of ± 3.5% range and 5-mm setup uncertainties. Root-mean-square deviation dose (RMSD) volume histograms were used to evaluate the target coverage robustness quantitatively. Dosimetric metrics based on the dose-volume histogram (DVH), homogeneity index (HI), and normal tissue complication probability (NTCP) were analyzed to evaluate the potential clinical benefits among different planning groups. RESULTS: With a similar CTV and SIB coverage, two-field IMPT provided a lower maximum dose for the stomach (median: 18.6GyE, p<0.05) and duodenum (median: 32.62GyE, p<0.05) when the target was located in the head of the pancreas compared to VMAT and three-field IMPT. The risks of gastric bleed (3.42%) and grade ≥ 3 GI toxicity (4.55%) were also decreased. However, for the target in the body of the pancreas, VMAT showed a lower maximum dose for the stomach (median 30.93GyE, p<0.05) and toxicity of gastric bleed (median: 8.67%, p<0.05) compared to two-field IMPT and three-field IMPT, while other maximum doses and NTCPs were similar. The RMSD volume histogram (RVH) analysis shows that three-field IMPT provided better robustness for targets but not for OARs. Instead, three-field IMPT increased the Dmean of organs such as the stomach, duodenum, and intestine. CONCLUSION: The results indicated that the tumor locations could play a critical role in determining clinical benefits among different treatment modalities. Two-field IMPT could be a better option for LAPC patients whose tumors are located in the head of the pancreas. It provides lower severe toxicity for the stomach and duodenum. Nevertheless, VMAT is preferred for the body with better protection for the possibility of gastric bleed.

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