Removal of metronidazole by TiO 2 and ZnO photocatalysis: a comprehensive comparison of process optimization and transformation products

Abstract

The photodegradation of antibiotic metronidazole (MNZ) was systematically studied and compared by using aqueous suspensions of TiO₂ and ZnO catalysts under 100-W UV irradiation. The degradation conditions were optimized using the central composite design and response surface methodology. The optimal photodegradation conditions obtained were at pH 6.0 with 1.5 g L⁻¹ of TiO₂ (86.10% removal for 50 mg L⁻¹ MNZ) and at pH 9.5 with 0.5 g L⁻¹ of ZnO (60.32% removal for 30 mg L⁻¹ MNZ) after 60-min irradiation at 20 °C. The degradation efficiency in the presence of TiO₂ was higher than that of ZnO. The participation of active species such as hydroxyl radicals (OH·), holes (h⁺), and superoxide radicals (O₂⁻·) during MNZ photodegradation over TiO₂ and ZnO catalysts was also examined. Experimental results showed that MNZ oxidation was mainly driven by the presence of holes and superoxide radicals. Totally, 10 major intermediates were detected in UV/TiO₂ and UV/ZnO photocatalysis of MNZ using LC-QTof/MS system, in which 5 same intermediates were found. The remaining different intermediates led to the variations of degradation pathways of both processes. Moreover, some bigger transformation products than the parent MNZ were detected.

Proton therapy patterns of care among pediatric and adult patients with CNS tumors

Given the lack of exit radiation dose, proton therapy (PT) has been used for primary CNS tumors to minimize dose to adjacent, radiosensitive brain structures. For example, exposure of the hippocampus to even a low radiation dose has been associated with neurocognitive impairment.^1,2 While PT efficacy and toxicity for CNS tumors is being studied, data on the patterns of care for PT use is limited and based on only pediatric patients.^3–5 We used a multicenter registry to identify which CNS patients receive PT and whether differences exist between adult and pediatric CNS PT patients.

Physiological responses and metal uptake of Miscanthus under cadmium/arsenic stress

Abstract

The aim of this study is to explore the impact of cadmium (Cd) and arsenic (As) stress on physiological indexes and Cd/As uptake ability of Miscanthus, including Miscanthus sacchariflorus A0104, Miscanthus sinensis C0424 and C0640. Cd and As concentration showed significant hormesis effects on some physiological indexes, such as chlorophyll content, net photosynthetic rate, and MDA content. Compared with control group, Cd uptake can be most greatly enhanced by above fourfold with 150 mg/kg Cd treatment. As uptake of A0104 was increased by 3 ~ 33 folds with 200 mg/kg As treatment, C0424 was increased by 7–12 folds with 100 mg/kg As treatment, while C0640 was increased 1 ~ 6 folds with 250 mg/kg As treatment. The results also showed that C0640 was relatively better for the Cd remediation in the high Cd concentration (150 mg/kg) contaminated soil, while A0104 and C0424 were relatively better for the As remediation in the high As concentration (100 ~ 200 mg/kg) contaminated soil. Additionally, significantly (p < 0.05) close correlations were found among physiological indexes (except MDA content), while physiological indexes showed no significant relationship with the heavy metal contents in root, stem, and leaf.

The missclassification of obesity affects the course of migraine

Measuring the frequency of consumer hair combing and magnitude of combing forces on individual hairs in a tress and the implications for product evaluation and claims substantiation

International Journal of Cosmetic Science, Volume 0, Issue ja, -Not available-.

Melanoma subungueal: estudio descriptivo de 34 pacientes

Publication date: Available online 3 August 2018

Source: Actas Dermo-Sifiliográficas

Author(s): A. Talavera-Belmonte, M. Bonfill-Ortí, L. Martínez-Molina, R. Fornons-Servent, A. Bauer-Alonso, J.R. Ferreres-Riera, J. Marcoval

Resumen

Introducción y objetivos

El melanoma subungueal constituye un reto diagnóstico por su presentación clínica frecuentemente atípica. El objetivo del estudio fue revisar las características clínico-patológicas de los pacientes con melanoma subungueal diagnosticados en un hospital universitario de tercer nivel y analizar los factores posiblemente asociados al retraso del diagnóstico.

Material y métodos

Fueron analizados los datos de 34 pacientes diagnosticados de melanoma subungueal durante 20 años en nuestro centro.

Resultados

Del total de pacientes, 18 eran mujeres y 16 eran varones, con una edad mediana al diagnóstico de 66 años. Únicamente 5 de los pacientes presentaron melanoniquia longitudinal al ser visitados en nuestro Servicio de Dermatología. De los 34 pacientes, 19 presentaron melanoma invasivo al diagnóstico, con una mediana de índice de Breslow de 3,70 mm; 16 presentaron ulceración y 8 invasión ganglionar regional al diagnóstico. Cinco pacientes fueron diagnosticados en fase de melanoma in situ. La mediana del tiempo de evolución de las lesiones desde su aparición hasta la consulta al Centro de Asistencia Primaria fue de 15 meses, y desde la consulta al Centro de Asistencia Primaria hasta el diagnóstico en nuestro hospital fue de 5,5 meses. Las lesiones localizadas en los dedos de los pies presentaron con mayor frecuencia ulceración (p = 0,017) y una mayor probabilidad de invasión ganglionar regional al diagnóstico (p = 0,012).

Conclusiones

Los factores que en nuestro estudio se asociaron a un mayor retraso del diagnóstico del melanoma subungueal fueron la ausencia de melanoniquia como presentación clínica inicial y la localización de las lesiones en los dedos de los pies.

Abstract

Introduction and objectives

Subungual melanoma constitutes a diagnostic challenge because it often has an atypical clinical presentation. The aims of this study were to revise the clinical and pathologic characteristics of patients with subungual melanoma diagnosed at a tertiary care university hospital and analyze the factors potentially associated with a delayed diagnosis.

Material and methods

We analyzed data for 34 patients diagnosed with subungual melanoma at our hospital over a period of 20 years.

Results

The study population comprised 18 women and 16 men with a median age at diagnosis of 66 years. Only 5 of the patients had longitudinal melanonychia when examined at the dermatology department. At the time of diagnosis, 19 of the 34 patients had invasive melanoma (median Breslow thickness, 3.70 mm); 16 had ulceration and 8 had regional lymph node involvement. Five patients had subungual melanoma in situ at diagnosis. The median time from appearance of the lesions to consultation at a primary care center was 15 months; the corresponding time from primary care consultation to diagnosis at our hospital was 5.5 months. Lesions located on the toes were more likely to be ulcerated (P = .017) and to be accompanied by regional lymph node involvement at diagnosis (P = .012).

Conclusions

The factors associated with a longer diagnostic delay in patients with subungual melanoma were absence of melanonychia as a presenting feature and involvement of the toes.

Graphical abstract