A Radical Mechanism for the Vanadium-Catalyzed Deoxydehydration of Glycols

We propose a novel mechanism for the deoxydehydration (DODH) reaction of glycols catalyzed by a [Bu4N][VO2(dipic)] complex (dipic = pyridine-2,6-dicarboxylate) using triphenylphosphine as a reducing agent. Using density functional theory, we have confirmed that the preferred sequence of reaction steps involves reduction of the V(V) complex by phosphine, followed by condensation of the glycol into a [VO(dipic)(-O-CH2CH2-O-)] V(III) complex (6), which then evolves to the alkene product, with recovery of the catalyst. In contrast to the usually invoked closed-shell mechanism for the latter steps, where 6 suffers a [3+2] retrocycloaddition, we have found that the homolytic cleavage of one of the C–O bonds in 6 is preferred by 12 kcal/mol. The resulting diradical intermediate then collapses to a metallacycle that evolves to the product through an aromatic [2+2] retrocycloaddition. We use this key change in the mechanism to propose ways to design better catalysts for this transformation. The analysis of the mechanisms in both singlet and triplet potential energy surfaces, together with the location of the MECPs between them, showcases this reaction as an interesting example of two-state reactivity.Xunta de Galicia and Ministerio de Economiá y Competitividad for funding through Projects EM2014/040 and CTQ2013-48937-C2-1-P and CTQ2013-48937-C2-2-P, respectively. R.S. thanks the Junta de Castilla y León for funding through projects BU237U13 and BU076U16

Frequência e manifestações clínicas da síndrome pós-poliomielite em um centro terciário brasileiro

OBJECTIVE: To determine the frequency and clinical manifestations of patients with post-poliomyelitis syndrome (PPS) in a Brazilian division of neuromuscular disorders. METHODS: A total of 167 patients with prior history of paralytic poliomyelitis was investigated for PPS, based on international diagnostic criteria. Other variables analyzed were: gender, race, age at poliomyelitis infection, age at PPS onset, and PPS symptoms. RESULTS: One hundred and twenty-nine patients presented PPS, corresponding to 77.2% of the studied population. 62.8% were women and 37.2% were men. Mean age of patients with PPS at onset of PPS symptoms was 39.9±9.69 years. Their main clinical manifestations were: new weakness in the previously affected limbs (69%) and in the apparently not affected limbs (31%); joint pain (79.8%); fatigue (77.5%); muscle pain (76%); and cold intolerance (69.8%). CONCLUSIONS: Most patients of our sample presented PPS. In Brazil, PPS frequency and clinical features are quite similar to those of other countries.OBJETIVO: Determinar a frequência e as manifestações clínicas de pacientes com síndrome pós-poliomielite (SPP) em um setor terciário de doenças neuromusculares brasileiro. MÉTODOS: Um total de 167 pacientes com história prévia de poliomielite paralítica foi estudado para diagnóstico de SPP, de acordo com critérios diagnósticos internacionais. Além da SPP, as variáveis analisadas foram: gênero, raça, idade à época da poliomielite aguda e idade no início dos sintomas da SPP. RESULTADOS: Cento e vinte e nove pacientes apresentaram SPP, correspondendo a 77,2% da população estudada. Mulheres constituíram 62,8% dos pacientes e os homens, 37,2%. A média de idade dos pacientes com SPP à época do início dos sintomas foi de 39,9±9,69 anos. Suas principais manifestações clínicas foram: manifestações novas de fraqueza em membros previamente afetados (69%) e em membros aparentemente não afetados (31%); dores articulares (79,8%); fadiga (77,5%); dor muscular (76%) e intolerância ao frio (69,8%). CONCLUSÕES: A maioria dos pacientes da presente casuística apresentou SPP. No Brasil, a frequência e as características clínicas da SPP são similares às observadas em outros países.Federal University of São Paulo Division of Neuromuscular Disorders Department of Neurology and NeurosurgeryCentro Universitário Adventista de São Paulo Neurologic Rehabilitation Service of the PoliclínicaUNIFESP, Division of Neuromuscular Disorders Department of Neurology and NeurosurgerySciEL

Taxonomic review of Hisonotus Eigenmann & Eigenmann (Siluriformes: Loricariidae: Hypoptopomatinae) from the laguna dos Patos system, southern Brazil

The species of Hisonotus from the laguna dos Patos system are reviewed. Two species with wide distributions are redescribed: Hisonotus laevior and H. nigricauda. Six new species are described from that system: H. notopagos from the rio Camaquã drainage; H. carreiro and H. prata, endemic from the headwaters of rio Taquari drainage; H. vireo, widely distributed in the rio Jacuí basin; and H. brunneus and H. heterogaster restricted to tributaries of the rio Jacuí drainage. Hisonotus leptochilus is here considered a junior synonym of H. laevior. Hisonotus armatus, H. charrua, H. leucofrenatus, and H. taimensis are also present in the region and in total there are twelve species of Hisonotus in the laguna dos Patos system. Their distributions are discussed, species are illustrated and a taxonomic key is provided.</jats:p

Differentiating cave Aspidoras catfish from a karst area of Central Brazil, upper rio Tocantins basin (Siluriformes: Callichthyidae)

Two cave populations of Aspidoras albater catfish with reduced eyes and pigmentation were recently found near the city of Posse, São Domingos karst area, Goiás State, representing the first known case of a troglomorphic callichthyid catfish. Cave specimens are described and compared to epigean specimens of A. albater, but morphometric differences between the epigean and the cave populations are not adequate to delimit as distinct species.</jats:p

Two new, remarkably colored species of the Neotropical catfish genus Cetopsorhamdia Eigenmann & Fisher, 1916 (Siluriformes, Heptapteridae) from Chapada dos Parecis, western Brazil, with an assessment of the morphological characters bearing on their phylogenetic relationships

Two new species of heptapterid catfish genus Cetopsorhamdia are described from close localities in western Brazil, at Chapada dos Parecis, an area with extremely high level of endemism. One species is from the upper Rio Madeira system, Rondônia State, and the other from the upper Rio Tapajós system, Mato Grosso State. The two species are diagnosed, among several other features, by their markedly distinctive color patterns, with the former having well-defined quadrangular marks in trunk flanks while the latter bearing irregular, vertical bars along the trunk. The monophyly of Cetopsorhamdia is discussed, with two putative synapomorphies being proposed to support the genus. Potentially informative morphological characters to resolve the internal relationships of the genus are presented and discussed. Despite the striking external differences between the two species herein described, they are found to likely form a clade

A new species of Rhamdella Eigenmann & Eigenmann, 1888 (Siluriformes: Heptapteridae) from the coastal basins of southern Brazil

Rhamdella zelimai, new species, is described from the coastal river drainages in northeastern Rio Grande do Sul and southern Santa Catarina States, Brazil. The new species is readily distinguished from its congeners by the hypertrophy of the rictal fold, mainly its lower portion, consisting of a large and fleshy lobe that bends ventrally on itself. The phylogenetic relationships of the new species are assessed and it was recovered as belonging to the clade composed of R. eriarcha (from the laguna dos Patos basin), R. longiuscula (from the rio Uruguai), and R. cainguae (from the lower rio Paraná)

Chemical, functional, and structural properties of spent coffee grounds and coffee silverskin

Spent coffee grounds (SCG) and coffee silverskin (CS) represent a great pollution hazard if discharged into the environment. Taking this fact into account, the purpose of this study was to evaluate the chemical composition, functional properties, and structural characteristics of these agro-industrial residues in order to identify the characteristics that allow their reutilization in industrial processes. According to the results, SCG and CS are both of lignocellulosic nature. Sugars polymerized to their cellulose and hemicellulose fractions correspond to 51.5 and 40.45 % w/w, respectively; however, the hemicellulose sugars and their composition significantly differ from one residue to another. SCG and CS particles differ in terms of morphology and crystallinity, but both materials have very low porosity and similar melting point. In terms of functional properties, SCG and CS present good water and oil holding capacities, emulsion activity and stability, and antioxidant potential, being therefore great candidates for use on food and pharmaceutical fields.The authors acknowledge the financial support of the Science and Technology Foundation of Portugal (FCT) through the grant SFRH/BD/80948/2011 and the Strategic Project PEst-OE/EQB/LA0023/2013. The authors also thank the Project "BioInd - Biotechnology and Bioengineering for improved Industrial and Agro-Food processes", REF. NORTE-07-0124-FEDER-000028 co-funded by the Programa Operacional Regional do Norte (ON.2-O Novo Norte), QREN, FEDER. Thanks are also given to Prof. Jose J.M. Orfao, from the Department of Chemical Engineering, Universidade do Porto (Portugal), for his assistance with the porosity analyses

Survey of Third-Party Parenting Options Associated With Fertility Preservation Available to Patients With Cancer Around the Globe

Purpose: In the accompanying article, “Analysis of Fertility Preservation Options Available to Patients With Cancer Around the Globe,” we showed that specific fertility preservation services may not be offered at various sites around the world because of cultural and legal barriers. We assessed global and regional experiences as well as the legal status of third-party reproduction and adoption to serve as a comprehensive international data set and resource for groups that wish to begin oncofertility interventions. Methods: We provide data on the legalities of third-party assisted reproductive technologies and other family-building options in the 28 oncofertility-practicing countries surveyed. Results: We found regional and country differences that will be important in the development of tailored resources for physicians and for patient brochures that are sensitive to these local restrictions and cultural norms. Conclusion: Because many patients first consult Web-based materials, the formal assessment of the availability of these options provides members of the global oncofertility community with data to which they might otherwise not have ready access to better serve their patients

The effect of luting techniques on the push-out bond strength of fiber posts

Aim: This study aimed to evaluate the effect of using a chemical co-initiator and/or an additional coat of a hydrophobic resin on the bond strength of fiber posts luted with a dual-cured resin cement. In addition, the use of the resin cement only was also evaluated. Methods: Fiber posts were luted with dual-cured resin cement (Enforce) and using one of five adhesive procedures: G1 - Prime&amp;Bond 2.1 (PB), G2 - PB + Self-cure activator (SC), G3 - PB + bonding agent of Scotchbond Multi-Purpose (SMP), G4 – PB + SC + SMP and G5 – no adhesive. The root samples were sectioned transversally into three slabs (coronal, middle and apical third) that were submitted to push-out testing. Data were submitted to split-plot ANOVA and Tukey’s test (α = 0.05). Results: When the adhesives were used, the hydrophobic resin application (G3 and G4) increased fiber post retention in comparison to G2 only in the coronal third. For the other thirds, there was no difference between the adhesive methods. G5 presented the lowest values in the coronal and middle thirds, but it was similar to all other groups in the apical third. Conclusion: post retention seemed not to benefit from the adhesive application in the apical region