RESUMEN
Acenes, the group of polycyclic aromatic hydrocarbons (PAHs) with linearly fused benzene rings, possess distinctive electronic properties with potential applicability in material science. Hexacene was the largest acene obtained and characterized in the last century, followed by heptacene in 2006. Since then, a race for obtaining the largest acene resulted in the development of several members of this family as well as diverse innovative synthetic strategies, from solid-state chemistry to the promising on-surface chemistry. This last technique allows the obtention of large acenes, up to tridecacene, the largest acene so far. This review presents the different methodologies employed for the synthesis of acenes, highlighting the newest studies, to provide a much more thorough understanding of the essence of the electronic structure of this captivating group of organic compounds.
RESUMEN
Hypothenar hammer syndrome is a rare cause of vascular insufficiency. Generally, patients report a history of repetitive trauma to the hypothenar region of the hand. Symptoms often consist of cold intolerance, pain, paleness, and paresthesia due to digital ischemia. The severity of these symptoms will depend on the extent of ulnar artery occlusion and the presence or absence of collaterals between this artery's superficial and deep branches. It is a rare clinical entity, which on multiple occasions requires a surgical approach. We present a 63-year-old man with bilateral Raynaud's phenomenon secondary to hypothenar hammer syndrome successfully treated by vascular repair surgery. In patients with Raynaud's phenomenon, it is important to know that there are reversible causes such as hypothenar hammer syndrome.
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Introduction: The association of rheumatoid arthritis (RA) and ankylosing spondylitis (AS) in a single patient is a rarely described phenomenon. AS and RA are conditions that can have a high impact on the morbidity and mortality of patients. Methods: We described the clinical, epidemiological, analytical, and radiological characteristics of 81 patients with concomitant diagnosis of rheumatoid arthritis (RA) and ankylosing spondylitis (AS). Of these patients, seven were diagnosed at our hospital. A literature review was carried out using Medline, Embase, Scopus, and virtual hospital libraries, including the period from January 1950 to April 2020. Results: Regarding the results, 71% of the patients were men, with a mean age of 53 years (±14.83). RA was the first disease diagnosed in 52% of the cases. Approximately 53% of the patients had rheumatoid nodules, and 83% reported inflammatory lumbar pain during their evaluation. Erosions were observed on radiographs of the hands and/or feet in 85% of the cases, and almost all the patients (80/81) had sacroiliitis on imaging studies. Approximately 92% of the cases were rheumatoid factor (RF) positive and 90% HLA B-27 positive. Conclusions: The coexistence of RA and AS is highly uncommon. With the data obtained in this review, it seems that there exist erosive radiological patterns, positivity for RF, involvement of the axial skeleton, and rheumatoid nodules at a higher frequency than those patients with a single diagnosis of the two entities. More data are needed to corroborate this association.
RESUMEN
The Dutos e Terminais do Centro Sul (DTCS) is one of the largest petroleum terminals of the South America located in the São Sebastião Channel (SSC) on the southeastern Brazilian coast. The aims of this study were to compare the sediment quality near the DTCS with that of several sites in the SSC region including the Araçá (AR) domestic sewage outfall and to assess the efficiency of the DTCS wastewater treatment plant. To achieve these goals, textural, geochemical, and living benthic foraminifera results were analyzed for the DTCS, AR, and SSC regions. Sediments in the DTCS area were silty with high concentrations of total organic carbon (1.7-2.4%), total nitrogen (0.2-0.3%), total sulfur (0.4-0.6%), and total (0.12-0.18%) and inorganic phosphorous (0.07-0.11%). These values were higher than those in sediments collected in the SSC and Araçá regions. The sediments' concentrations of As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn in the SSC and AR regions were lower than their corresponding probable effect levels (PELs). However, sediments near the DTCS were enriched with As, Cu, and Ni, whose concentrations exceeded their corresponding threshold effect levels (TELs). Around the DTCS outfall diffusers, living foraminiferal densities and diversities were lower than those for the other areas studied. In the DTCS area, it was necessary to search 50 to 190 cm3 of sediment to find 100 live specimens. In the SSC and Araçá areas, a maximum of 40 cm3 of sediment was enough to locate 100 live specimens. The lower density and diversity of living foraminifera around the DTCS than around the other areas illustrates the impact of the environmental stress caused by the presence of pollutants. These results indicate that the wastewater treatment plant efficiency is low and its discharge of pollutants from petrochemical waste liquids affects the benthic fauna around the DTCS in a potentially harmful manner.
