The development of efficient catalysts for ethanol oxidation in alkaline medium requires a synthetic approach that may prevent the surfactant molecules from being adsorbed at the catalytic sites and decreasing the electrochemical performance of the final direct ethanol fuel cell. Toward this goal, the recently reported surfactant-less Bromide Anion Exchange (BAE) method, appears as a promising route to conveniently aim at preparing PtRh alloys dispersed on carbon substrates. The catalysts prepared herein by the BAE method were characterized physicochemically to obtain structural information on the PtRh/C nanomaterials, their morphology (size and shape), and their chemical and surface composition. Electrochemical behavior and properties of these electrodes were then investigated in a half-cell before the implementation of a direct ethanol fuel cell (DEFC) in a home-made anion exchange membrane Teflon cell. The analysis of the electrolytic solution in the anodic compartment by chromatography revealed that acetate was the major reaction product and the carbonate amount increased with the Rh content in the bimetallic composition. With 2.8–3.6 nm particle sizes, the Pt50Rh50/C catalyst exhibited the highest activity towards the ethanol electrooxidation.The development of efficient catalysts for ethanol oxidation in alkaline medium requires an approach that avoids surfactant molecules from being adsorbed at active sites and decreasing the electrochemical performance of the direct ethanol fuel cell.相似文献
Cd is a non-essential metal and highly toxic to plants, animals and humans, even at very low concentrations. Cd has been found in cocoa beans and in their products, as in the case of chocolate. Mn plays an important role in photosynthetic and can interact with Cd and attenuate its toxic effects on plants. The objective of this work was to evaluate the mechanisms of Mn response in the mitigation of Cd toxicity in young plants of the CCN 51 cacao genotype submitted to 0.8?mmol?Cd kg?1, 1.6?mmol Mn kg?1 or the combination of 0.4?mmol?Cd kg?1?+?0.8?mmol Mn kg?1 soil, together with the control treatment (without addition of Cd and Mn in soil), by means of analysis of changes in the profile of exclusive proteins (EP) and differentially accumulated proteins (DAP). Leaf and root proteins were extracted and quantified from the different treatments, followed by proteomic analysis. About eight DAP and 38 EP were identified in leaves, whereas in roots 43 DAP and 21 EP were identified. Some important proteins induced in the presence of Cd and repressed in the presence of Cd?+?Mn or vice versa, were ATPases, isoflavone reductase, proteasome and chaperonin. It was concluded that proteins involved in oxidoreduction and defense and stress response processes, in addition to other processes, were induced in the presence of Cd and repressed in the presence of Cd?+?Mn. This demonstrated that Mn was able to mitigate the toxic effects of Cd on young plants of the CCN 51 cocoa genotype.
The elderly population is growing rapidly. Political and socio-economic
changes led to the demographic transition in this population with the
highest number of surgeries and as well as many comorbidities.
OBJECTIVE
To evaluate the impact of cardiovascular intervention on quality of life of
elderly patients after three and six months.
METHODS
Analytical prospective cohort study with elderly between 60 and 80 years of
age, of both sexes, with a diagnosis of coronary artery disease and
underwent cardiovascular intervention during the period June 2010 to June
2011. Data were collected by individual interviews in the pre and
postoperative periods (after three and six months) by telephone. We used the
SF-36 to analyse quality of life in order to assess the physical and mental
health of the study population.
RESULTS
Of the 44 individuals evaluated, 59.1% were men, 75% in the range of 65 to 74
years, 38.6% were white and 38.6% were black, 31.8% were uneducated, 43.2%
were married and 68.2% had less than a minimum wage. Prevailed patients:
non-diabetics (68.2%), non-obese (81.8%), hypertensive (84.1%),
non-alcoholic and non-smokers (68.2% and 61.4%, respectively). A significant
increase in the average of the SF-36 scores between pre and post-surgical
periods (three and six months) for the domains: functional capacity, pain,
general health, vitality and emotional aspect.
CONCLUSION
The elderly population undergoing intervention may have cardiovascular
benefits and improvements of quality of life. Physical fitness improvement
measures can be taken to resume that capability. 相似文献
Non-androgenic growth factors are involved in the growth regulation of prostate cancer (PCa).
Objective
This is the first Brazilian study to correlate, in a population of patients operated for PCa, PSA, total testosterone, insulin-like growth factor-I (IGF-I) and insulin-like growth factor-binding protein-3 (IGFBP-3) with Gleason score and to compare with a control group with benign prostate hyperplasia (BPH).
Materials and Methods
This retrospective single-center study included 49 men with previously diagnosed PCa and 45 with previously diagnosed BPH. PSA, testosterone, IGF-I, IGFBP-3 were determined in both groups.
Results
PSA and IGFBP-3 levels were significantly higher in the PCa group as compared to the BPH group (p<0.001 and p=0.004, respectively). There was a significant difference when we compared the PSA before surgery (p<0.001) and at the inclusion in the study (p<0.001) and IGFBP3 (0.016) among patients with Gleason <7, ≥7 and BPH. In the PCa group, PSA, testosterone, IGF-I and IGFBP-3 levels were comparable between Gleason <7 and ≥7.
Conclusions
Our data suggest that in localized PCa, the quantification of PSA and, not of IGF-1, may provide independent significant information in the aggressiveness. IGFBP-3 could be a biochemical marker of disease control in PCa patients. 相似文献
After laryngectomy for treatment of laryngeal cancer, the distal esophageal contractions have low amplitude. Our hypothesis is that proximal esophageal contractions are also impaired. We studied the proximal esophageal contractions in 20 laryngectomized patients (16 men) with a mean age of 44.2 years, 12 rehabilitated patients with esophageal speech, and 12 controls (7 men, mean age of 46.5 years). We used the manometric method with continuous perfusion. All subjects were studied in the sitting position and performed five swallows of a 5-ml bolus of water alternated with five dry swallows. The contractions were measured 2 cm below the high-pressure zone of the pharyngoesophageal transition. The results showed that the amplitude and duration of contractions were different in laryngectomized patients compared with controls. The amplitude of contractions of patients (wet swallows: 37.3 ± 20.7 mmHg, mean ± SD) was lower than that of controls (81.1 ± 31.7 mmHg). The duration of contractions was also lower in laryngectomized patients (2.2 ± 0.7 s) than in controls (2.6 ± 0.6 s). We conclude that the proximal esophageal contraction amplitude and duration of laryngectomized patients are lower than controls, a fact suggesting that laryngectomy may affect the proximal esophageal contractions. 相似文献