122 research outputs found

    Photocatalytic Degradation Of Phenol And 2,4-Dichlorophenol Using Rare Earth-Doped ZnO Hierarchical Micro/Nanospheres Under Fluorescent Light And Sunlight Irradiation

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    Widespread concerns continue to be raised about the impacts of exposure to chemical compounds with endocrine disrupting activities. To date, the percolation of endocrine disrupting chemical (EDC) effluent into the aquatic system remains an intricate challenge abroad the nations. Heterogeneous photocatalysis using ZnO hierarchical architectures has recently been emerged as an efficient and feasible technology for the purification of polluted water. In this study, ZnO hierarchical micro/nanospheres doped with rare earth ion (RE/ZnO, RE ion = Ce, Eu and Nd) were synthesized using a chemical precipitation method for the photocatalytic degradation of two EDCs, namely phenol and 2,4-dichlorophenol (2,4-DCP) under fluorescent light and sunlight irradiation. Kebimbangan berterusan ditambahkan terhadap kesan pendedahan kepada bahan kimia dengan aktiviti pengganggu endokrin. Setakat ini, pengasingan effluen bahan kimia pengganggu endokrin ke dalam sistem akuatik masih adalah satu cabaran yang rumit bagi banyak negara. Fotopemangkinan menggunakan hierarki ZnO baru-baru in ditampilkan sebagai teknologi yang cekap dan boleh dipraktikkan untuk rawatan air tercemar. Dalam kajian ini, hierarki ZnO berbentuk sfera mikro/nano terdop dengan ion nadir bumi (RE/ZnO, ion RE = Ce, Eu and Nd) telah disintesis dengan kaedah pemendakan kimia untuk fotodegradasi dua jenis bahan kimia pengganggu endokrin iaitu fenol dan 2,4-diklorofenol (2,4-DCP) di bawah penyinaran lampu pendarfluor dan cahaya matahari

    Photocatalytic Degradation Of Phenol In A Fluidized Bed Reactor Using TiO2 Prepared By A Hydrothermal Method Immobilized On Granular Activated Carbon

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    TiO2 immobilized on granular activated carbon (TiO2/GAC) was successfully prepared using a hydrothermal method. The prepared photocatalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and N2 physisorption. Their photocatalytic activities were evaluated through phenol degradation in a fluidized bed reactor. The characterization results revealed that the prepared photocatalysts had a single crystal phase, which was anatase

    Degrading Endocrine Disrupting Chemicals fromWastewater by TiO2 Photocatalysis: A Review

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    Widespread concerns continue to be raised about the impacts of exposure to chemical compounds with endocrine disrupting activities. To date, the percolation of endocrine disrupting chemical (EDC) effluent into the aquatic system remains an intricate challenge abroad the nations. With the innovation of advanced oxidation processes (AOPs), there has been a consistent growing interest in this research field. Hence, the aim of this paper is to focus one such method within the AOPs, namely, heterogeneous photocatalysis and how it is used on the abatement of EDCs, phthalates, bisphenol A and chlorophenols in particular, using TiO2-based catalysts. Degradation mechanisms, pathways, and intermediate products of various EDCs for TiO2 photocatalysis are described in detail. The effect of key operational parameters on TiO2 photocatalytic degradation of various EDCs is then specifically covered. Finally, the future prospects together with the challenges for the TiO2 photocatalysis on EDCs degradation are summarized and discussed

    Cr2O3 nanoparticles anchored on ZnO nanorods as active heterostructure catalysts for phenol degradation

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    With the rapid civilization and industrialization, water pollution is becoming more and more intricate. Heterogeneous photocatalysis using metal oxide loaded ZnO nanorods is a well-known environmental technology to degrade toxic organic pollutants. In this study, Cr2O3 particles anchored on the ZnO nanorods (Cr2O3/ZnO) were successfully synthesized by a hydrothermal-deposition technique. Microscopic and crystallographic analyses indicated that the synthesized samples consisted of two-phase heterostructure of Cr2O3 and ZnO. The photocatalytic results showed that the phenol degradation by Cr2O3 /ZnO heterostructures was higher than those of pure ZnO and commercial TiO2. The synergetic effect between Cr2O3 and ZnO was the pivotal reason for the improvement of photoactivity as proven by the photoluminescence and terephthalic acid–photoluminescence analyses

    The Clinical Usefulness of 18F-FDG PET/CT for the Evaluation of Lymph Node Metastasis in Periorbital Malignancies

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    PURPOSE: Surgical treatment of malignancies in the oral cavity and subsequent radiotherapy often result in an oral condition unfavorable for prosthodontic rehabilitation. This study assessed the quality of life related to oral function in edentulous head and neck cancer patients following oncology treatment of malignancies in the lower region of the oral cavity. MATERIALS AND METHODS: Patients treated between 1990 and 2000 with surgery and radiotherapy for a squamous cell carcinoma in the oral cavity who were edentulous in the mandible and had been treated with a conventional, non-implant-retained denture received an invitation for a clinical check-up (clinical assessment, questionnaires regarding oral function and quality of life). RESULTS: Sixty-seven of the 84 patients who fulfilled the inclusion criteria were willing to participate in the study. The mean irradiation dosage that these patients had received in the oral region was 61.8 +/- 5.4 Gy. Half of the patients (n=33) were not very satisfied with their prostheses; they wore their mandibular prostheses at most a few hours per day. It was concluded from the clinical assessment that two thirds of the patients (n 4) could benefit from an implant-retained mandibular denture. Analyses of the questionnaires revealed no significant associations between functional assessments, quality of life, and parameters such as size of the primary tumor, location of the primary tumor, and different treatment regimes. Despite cancer treatment, the patients reported a rather good general quality of life. CONCLUSIONS: Sequelae resulting from radiotherapy probably dominate oral function and quality of life after oncology treatment. In two thirds of the patients, improvement of oral function and related quality of life would be expected with the use of an implant-retained mandibular denture

    Combined 18F-FDG PET/CT Imaging for the Initial Evaluation of Glottic Cancer

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    ObjectivesThe primary aim of this study was to determine whether 18F-FDG-PET/CT (PET/CT) scans provide additional diagnostic information in addition to the direct laryngoscopic examination (L/E) and contrast-enhanced CT (CT) in patients with glottic cancer during the initial evaluation.MethodsFifty-five consecutive patients with glottic cancer of the larynx that had L/E, CT and PET/CT were enrolled. The diagnostic value of each modality was compared for their accuracy in predicting the extent of the primary tumors on sub-site based analysis and the final tumor staging. The reference standards were either the surgical pathology findings or clinical/radiological follow-up outcome. Changes in patient care based on PET/CT results were compared with the treatment decisions based on L/E with CT.ResultsFor primary tumor sub-site based analysis, the sensitivity was significantly higher for L/E (92.8%) than for PET/CT (79.4%, P=0.028). The comparisons between L/E vs. CT and CT vs. PET/CT did not reach statistical significance. As an initial tumor-staging method the L/E had a diagnostic accuracy of 76.4%, compared to 61.8% for CT and 41.8% for PET/CT. The L/E and CT were better than the PET/CT (P=0.0009 and 0.049) for the initial TNM staging. PET/CT scanning changed the clinical decision-making based on the L/E with CT results in 12.7% of cases, of whom 5.5% had no additional PET/CT related benefit.ConclusionThe results of this study showed that PET/CT imaging added no clinical information benefit compared to the L/E and CT for the initial evaluation of patients with glottic cancer

    Sentinel Lymph Node Radiolocalization with 99mTc Filtered Tin Colloid in Clinically Node-Negative Squamous Cell Carcinomas of the Oral Cavity

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    The objective of this study was to evaluate the feasibility of sentinel lymph node biopsy by using a radiotracer lymphatic mapping technique in patients with squamous cell carcinoma of the oral cavity, and the diagnostic value of this technique. We studied twenty patients with previously untreated squamous cell carcinomas of the oral cavity and N0 necks. After the peritumoral injection of 99mTc filtered tin colloid preop-eratively, lymphoscintigraphy and intraoperative mapping using a gamma detector were performed to localize sentinel nodes. An open biopsy of the sentinel node was followed by complete neck dissection. We identified the sentinel nodes in 19 of 20 patients (95.0%) by lymphoscintigraphy and in all (100%) by intraoperative gamma detector. In all cases, the status of the sentinel node accurately predicted the pathologic status of the neck with the false negative rate being 0%. The negative predictive value for the absence of cervical metastases was 100%. In conclusion, our radio-localization technique of sentinel nodes using 99mTc filtered tin colloid in N0 squamous cell carcinomas of the oral cavity is technically feasible and appears to accurately predict the presence of the occult metastatic disease

    The Significance of Gastric Juice Analysis for a Positive Challenge by a Standard Oral Challenge Test in Typical Cow's Milk Protein-Induced Enterocolitis

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    This study was performed to investigate the significance of gastric juice analysis (GJA) as a diagnostic criterion of a positive challenge in a standard oral cow's milk challenge (OCC) to confirm typical cow's milk protein-induced enterocolitis (CMPIE). Data from 16 CMPIE patients (aged 14 to 44 days) were analyzed. A standard OCC was openly executed using 0.15 g/kg of protein. Three symptoms (vomiting, lethargy, and bloody or pus-like stool), and four laboratory findings (GJA [3 hr], changes in peripheral blood absolute neutrophil count [ANC] [6 hr], C-reactive protein [6 hr], and stool smear test for occult blood or leukocytes) were observed after OCC. Before OCC, baseline studies were conducted; a stool smear test, blood sampling, and GJA. Positive OCC results were; vomiting (87.5%) (observed 1-3 hr after OCC), lethargy (62.5%) (1-3 hr), bloody or pus-like stool (43.8%) (6-10 hr), abnormal GJA (93.8%), an ANC rise >3,500 cells/µL (93.8%), and an abnormal stool smear test (75.0%). A single GJA test after a standard OCC is a sensitive diagnostic criterion of a positive challenge, and may provide an early confirmatory diagnosis of CMPIE. An investigation of positive OCC outcomes helps to find out a diagnostic algorithm of criteria of a positive challenge in CMPIE
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