30 research outputs found

    New examples of Ru(II)-tetrazolato complexes as thiocyanate-free sensitizers for dye-sensitized solar cells

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    A set of three new Ru(ii) polypyridyl complexes decorated with 5-aryl tetrazolato ligands (R-CN4)-, (D series, namely D1, D3 and D4), is presented herein. Whereas complex D1 represents the pyrazinyl tetrazolato analogue of a previously reported Ru(ii) complex (D2) with the general formula cis-[(dcbpy)2Ru(N^N)]+, in which dcbpy is 2,2′-bipyridine-4,4′-dicarboxylic acid and N^N is the chelating 2-pyridyl tetrazolato anion, the design of the unprecedented Ru(ii) species D3 and D4 relied upon a completely different architecture. More specifically, the molecular structure of thiocyanate-based species cis-[(dcbpy)2Ru(NCS)2], that is typically found in benchmark Ru(ii) dyes for dye sensitized solar cell (DSSCs), was modified with the replacement of two of the -NCS ligands in favour of the introduction of 5-aryl tetrazolato anions, such as the deprotonated form of 5-(4-bromophenyl)-1H-tetrazole, for complex D3 and 5-(4-cyanophenyl)-1H-tetrazole in the case of complex D4. To streamline the behavior of the D series of Ru(ii) complexes as photosensitizers for DSSCs, an in-depth analysis of the excited state properties of D1, D3 and D4 was performed through TDDFT calculations and TDAS (nanosecond transient difference absorption spectroscopy). The obtained results highlight a trend that was confirmed once D1, D3 and D4 were tested as photosensitizers for DSSC under different conditions. Along the series of the Ru(ii) complexes, the neutrally charged species D3 and D4 displayed the best photovoltaic performances. This journal i

    Growth of tropical tree species and absorption of copper in soil artificially contaminated

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    Abstract Reclamation of copper contaminated sites using forest species may be an efficient alternative to reduce the negative impact. The aim of this study was to quantify the growth and evaluate the quality of seedlings of native species at different doses of copper in the soil. The experimental design was completely randomized, with seven replications in a factorial arrangement (3×9), using three indigenous species of plants (Anadenanthera macrocarpa, Mimosa scabrella and Apuleia leiocarpa) and nine doses of copper in the soil (0, 60, 120, 180, 240, 300, 360, 420 and 480 mg kg–1).The experiment was carried out in a greenhouse which the seedlings were grown for 180 days. The experimental units were plastic pots of 125 cm3 filled with Oxisol. The results indicated that the levels of copper applied to the soil decreased the quality of seedlings and growth of Apuleia leiocarpato a lesser extent compared with Mimosa scabrella and Anadenanthera macrocarpa. Anadenanthera macrocarpa was the forest species that resulted in the lowest copper translocation from roots to shoots. In addition, the Apuleia leiocarpa exhibited high resistance and tolerance for copper in the soil and also, it is highlighted an ability for copper phytoremediation

    Development and validation of a patient-physician relationship index in the advanced cancer setting

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    BACKGROUND: The quality of the relationship between patient and medical staff is crucial in oncological settings. We have developed and validated a short, self-administered questionnaire to measure patients' satisfaction with their relationship with the physician: the Patient-Physician Relationship Index (PPRI). MATERIALS AND METHODS: Content validity was evaluated by a two-stage (development and judgment) process. One hundred and nine cancer patients with metastatic disease were assessed during the second cycle of chemotherapy and 59 were reassessed eight weeks later. Quality of life and anxiety and depression were also evaluated. RESULTS: The PPRI is monofactorial. Cronbach's alpha coefficient was 0.81. Sensitivity to change was shown by the correlation with changes in patients' conditions. The PPRI scores were only weakly correlated with the majority of the EORTC and HAD subscale scores. CONCLUSION: The PPRI is an easy-to-use, self-administered questionnaire, developed in a population of patients with advanced cancer. It has good internal consistency and sensitivity to change

    Biofeedback as an adjunctive treatment for post-stroke dysphagia: a pilot-randomized controlled trial

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    Background and Purpose: Post-stroke dysphagia affects almost half of the survivors and severely influences quality of life, thus becoming swallowing rehabilitation of paramount importance. However, there is little adequate evidence on which the best rehabilitative strategy can be. Surface electromyography (sEMG) allows for recording swallowing muscles’ activity and provides real time visual feedback, as a biofeedback adjunctive technique to improve treatment outcome. This study aimed to analyze the effectiveness of biofeedback rehabilitation of swallowing through sEMG compared to standard techniques, in post-stroke dysphagia. Methods: A pilot-randomized controlled trial included 17 patients diagnosed with post-stroke dysphagia. Nine underwent sEMG-biofeedback rehabilitation; seven controls were submitted to control treatment, one dropout. The primary outcome was the functional oral intake scale (FOIS), secondary outcomes was pharyngeal clearance and safe swallowing, assessed through fiberoptic endoscopic evaluation of swallowing (FEES). Results: FOIS improved in all patients, regardless of treatment. sEMG-biofeedback rehabilitation led to improvements of the pharyngeal clearance and swallowing safety. The rehabilitative effects appeared stable at 2-months follow-up. Conclusions: The application of biofeedback based on sEMG in post-stroke dysphagia patients resulted in an effective rehabilitative technique, in particular for pharyngeal clearance improvements and safe swallowing, thus reducing the risk of aspiration and malnutrition
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