66 research outputs found

    High-yield synthesis and optical properties of g-C₃N₄

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    Graphitic carbon nitride (g-C₃N₄), a metal-free semiconductor with a band gap of 2.7 eV, has received considerable attention owing to its fascinating photocatalytic performances under visible-light. g-C₃N₄ exhibits high thermal and chemical stability and non-toxicity such that it has been considered as the most promising photocatalyst for environmental improvement and energy conservation. Hence, it is of great importance to obtain high-quality g-C₃N₄ and gain a clear understanding of its optical properties. Herein, we report a high-yield synthesis of g-C₃N₄ products via heating of high vacuum-sealed melamine powder in an ampoule at temperatures between 450 and 650°C. Using transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM), electron energy loss spectroscopy (EELS), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS), the chemical composition and crystallization of the as-produced g-g-C₃N₄ are demonstrated. A systematic optical study of g-g-C₃N₄ is carried out with several approaches. The optical phonon behavior of g-C₃N₄ is revealed by infrared and Raman spectroscopy, and the emission properties of g-C₃N₄ are investigated using photoluminescence (PL) spectroscopy, while the photocatalytic properties are explored by the photodegradation experiment

    Ciprofloxacin, diclofenac, ibuprofen and 17α-ethinylestradiol differentially affect the activity of acetogens and methanogens in anaerobic communities

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    Pharmaceutical compounds end up in wastewater treatment plants but little is known on their effect towards the different microbial groups in anaerobic communities. In this work, the effect of the antibiotic Ciprooxacin (CIP), the non-steroidal anti-inammatory drugs Diclofenac (DCF) and Ibuprofen (IBP), and the hormone 17-ethinylestradiol (EE2), on the activity of acetogens and methanogens in anaerobic communities, was investigated. Microbial communities were more affected by CIP, followed by EE2, DCF and IBP, but the response of the different microbial groups was dissimilar. For concentrations of 0.01 to 0.1 mg/L, the specic methanogenic activity was not affected. Acetogenic bacteria were sensitive to CIP concentrations above 1 mg/L, while DCF and EE2 toxicity was only detected for concentrations higher than 10 mg/L, and IBP had no effect in all concentrations tested. Acetoclastic methanogens showed higher sensitivity to the presence of these micropollutants, being affect by all the tested pharmaceutical compounds although at different degrees. Hydrogenotrophic methanogens were not affected by any concentration, indicating their lower sensitivity to these compounds when compared to acetoclasts and acetogens.e Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2019 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. Ana Rita Silva holds a Grant from FCT, reference SFRH/BD/131905/2017info:eu-repo/semantics/publishedVersio

    Manufacture Techniques of Chitosan-Based Microcapsules to Enhance Functional Properties of Textiles

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    In recent years, the textile industry has been moving to novel concepts of products, which could deliver to the user, improved performances. Such smart textiles have been proven to have the potential to integrate within a commodity garment advanced feature and functional properties of different kinds. Among those functionalities, considerable interest has been played in functionalizing commodity garments in order to make them positively interact with the human body and therefore being beneficial to the user health. This kind of functionalization generally exploits biopolymers, a class of materials that possess peculiar properties such as biocompatibility and biodegradability that make them suitable for bio-functional textile production. In the context of biopolymer chitosan has been proved to be an excellent potential candidate for this kind of application given its abundant availability and its chemical properties that it positively interacts with biological tissue. Notwithstanding the high potential of chitosan-based technologies in the textile sectors, several issues limit the large-scale production of such innovative garments. In facts the morphologies of chitosan structures should be optimized in order to make them better exploit the biological activity; moreover a suitable process for the application of chitosan structures to the textile must be designed. The application process should indeed not only allow an effective and durable fixation of chitosan to textile but also comply with environmental rules concerning pollution emission and utilization of harmful substances. This chapter reviews the use of microencapsulation technique as an approach to effectively apply chitosan to the textile material while overcoming the significant limitations of finishing processes. The assembly of chitosan macromolecules into microcapsules was proved to boost the biological properties of the polymer thanks to a considerable increase in the surface area available for interactions with the living tissues. Moreover, the incorporation of different active substances into chitosan shells allows the design of multifunctional materials that effectively combine core and shell properties. Based on the kind of substances to be incorporated, several encapsulation processes have been developed. The literature evidences how the proper choices concerning encapsulation technology, chemical formulations, and process parameter allow tuning the properties and the performances of the obtained microcapsules. Furthermore, the microcapsules based finishing process have been reviewed evidencing how the microcapsules morphology can positively interact with textile substrate allowing an improvement in the durability of the treatment. The application of the chitosan shelled microcapsules was proved to be capable of imparting different functionalities to textile substrates opening possibilities for a new generation of garments with improved performances and with the potential of protecting the user from multiple harms. Lastly, a continuous interest was observed in improving the process and formulation design in order to avoid the usage of toxic substances, therefore, complying with an environmentally friendly approach

    Review of MXenes as new nanomaterials for energy storage/delivery and selected environmental applications

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    The effect of acupressure application on chemotherapy-induced nausea, vomiting, and anxiety in patients with breast cancer

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    WOS: 000355111400022PubMed: 24787745Objective: The purpose of this study was to determine the effect of acupressure applied to the pericardium 6 (P6 or neiguan) acupuncture point on chemotherapy-induced nausea, vomiting, and anxiety in patients with breast cancer. Method: The study was conducted using a quasi-experimental model with a control group. It included a total of 64 patients with stages 1-3 breast cancer who received cycle two and more advanced chemotherapy in an ambulatory chemotherapy unit. There were 32 patients in the experimental group and 32 patients in the control group. Acupressure was applied to the P6 acupuncture point of patients in the experimental group with the help of a wristband. A Patient Information Form, the Beck Anxiety Inventory, and the Index of Nausea, Vomiting and Retching were employed to collect the data. Results: It was determined that the mean nausea, vomiting, and retching scores, the total (experience, occurrence, and distress) scores, and the mean anxiety scores for patients to whom acupressure was applied at the P6 acupuncture point were statistically significantly lower compared with the scores of patients in the control group. Significance of Results: The efficacy of applying acupressure was demonstrated. We determined that applying acupressure at the P6 point is effective in decreasing chemotherapy-induced nausea, vomiting, and anxiety in patients with breast cancer. Further research with more subjects is needed.Ataturk UniversityAtaturk University [BAP-2008/240]This study was funded by the Funds for Scientific Research Projects, Ataturk University (BAP-2008/240). The authors declare that they have no conflicts of interest
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