Electronic And Structural Study Of Pt-modified Au Vicinal Surfaces: A Model System For Pt-au Catalysts.

Two single crystalline surfaces of Au vicinal to the (111) plane were modified with Pt and studied using scanning tunneling microscopy (STM) and X-ray photoemission spectroscopy (XPS) in ultra-high vacuum environment. The vicinal surfaces studied are Au(332) and Au(887) and different Pt coverage (θPt) were deposited on each surface. From STM images we determine that Pt deposits on both surfaces as nanoislands with heights ranging from 1 ML to 3 ML depending on θPt. On both surfaces the early growth of Pt ad-islands occurs at the lower part of the step edge, with Pt ad-atoms being incorporated into the steps in some cases. XPS results indicate that partial alloying of Pt occurs at the interface at room temperature and at all coverage, as suggested by the negative chemical shift of Pt 4f core line, indicating an upward shift of the d-band center of the alloyed Pt. Also, the existence of a segregated Pt phase especially at higher coverage is detected by XPS. Sample annealing indicates that the temperature rise promotes a further incorporation of Pt atoms into the Au substrate as supported by STM and XPS results. Additionally, the catalytic activity of different PtAu systems reported in the literature for some electrochemical reactions is discussed considering our findings.

Clinical trials in Brazilian journals of ophthalmology: where we are

PURPOSE: To compare clinical trials published in Brazilian journals of ophthalmology and in foreign journals of ophthalmology with respect to the number of citations and the quality of reporting [by applying the Consolidated Standards for Reporting Trials (CONSORT) statement writing standards]. METHODS: The sample of this systematic review comprised the two Brazilian journals of ophthalmology indexed at Science Citation Index Expanded and six of the foreign journals of ophthalmology with highest Impact Factor® according ISI. All clinical trials (CTs) published from January 2009 to December 2010 at the Brazilians journals and a 1:1 randomized sample of the foreign journals were included. The primary outcome was the number of citations through the end of 2011. Subgroup analysis included language. The secondary outcome included likelihood of citation (cited at least once versus no citation), and presence or absence of CONSORT statement indicators. RESULTS: The citation counts were statistically significantly higher (P<0.001) in the Foreign Group (10.50) compared with the Brazilian Group (0.45). The likelihood citation was statistically significantly higher (P<0.001) in the Foreign Group (20/20 - 100%) compared with the Brazilian Group (8/20 - 40%). The subgroup analysis of the language influence in Brazilian articles showed that the citation counts were statistically significantly higher in the papers published in English (P<0.04). Of 37 possible CONSORT items, the mean for the Foreign Group was 20.55 and for the Brazilian Group was 13.65 (P<0.003). CONCLUSION: The number of citations and the quality of reporting of clinical trials in Brazilian journals of ophthalmology still are low when compared with the foreign journals of ophthalmology with highest Impact Factor®.

Influence of English language in the number of citations of articles published in Brazilian journals of Ophthalmology

PURPOSE: To determine the association between language and number of citations of ophthalmology articles published in Brazilian journals. METHODS: This study was a systematic review. Original articles were identified by review of documents published at the two Brazilian ophthalmology journals indexed at Science Citation Index Expanded - SCIE [Arquivos Brasileiros de Oftalmologia (ABO) and Revista Brasileira de Oftalmologia (RBO)]. All document types (articles and reviews) listed at SCIE in English (English Group) or in Portuguese (Portuguese Group) from January 1, 2008 to December 31, 2009 were included, except: editorial materials; corrections; letters; and biographical items. The primary outcome was the number of citations through the end of second year after publication date. Subgroup analysis included likelihood of citation (cited at least once versus no citation), journal, and year of publication. RESULTS: The search at the web of science revealed 382 articles [107 (28%) in the English Group and 275 (72%) in the Portuguese Group]. Of those, 297 (77.7%) were published at the ABO and 85 (23.3%) at the RBO. The citation counts were statistically significantly higher (P<0.001) in the English Group (1.51 - SD 1.98 - range 0 to 11) compared with the Portuguese Group (0.57 - SD 1.06 - range 0 to 7). The likelihood citation was statistically significant higher (P<0.001) in the English Group (70/107 - 65.4%) compared with the Portuguese Group (89/275 - 32.7%). There were more articles published in English at the ABO (98/297 - 32.9%) than at the RBO (9/85 - 10.6%) [P<0.001]. There were no significant difference (P=0.967) at the proportion of articles published in English at the years 2008 (48/172 - 27.9%) and 2009 (59/210 - 28.1%). CONCLUSION: The number of citations of articles published in Portuguese at Brazilian ophthalmology journals is lower than the published in English. The results of this study suggest that the editorial boards should strongly encourage the authors to adopt English as the main language in their future articles.