Isolation and structural characterization of stable carbamic-carbonic anhydrides: an experimental and computational study

Carbamic-carbonic anhydrides are elusive species that have been only indirectly detected under controlled conditions. This functional group is transiently formed during the reaction of secondary amines with anhydrides in the presence of nucleophilic catalysts such as 4-(dimethylamino)pyridine. In this work, the synthesis and isolation of two carbamic-carbonic anhydrides are reported, including the first-ever solid-state structure of this functional group. The remarkable stability of these chiral carbamic-carbonic anhydrides allowed their study by NMR, HRMS, FTIR-ATR, and thermal analysis techniques (DSC and TGA). A thorough analysis of the bonding situation by computational studies hints that the origin of this unusual stability relies on n -> sigma* stabilizing orbital interactions hampering the occurrence of decarboxylation

Influence of Heat Treatments on the Impact Toughness of a Ti-stabilized 12%Cr Supermartensitic Stainless Steel

The supermartensitic stainless steels (SMSS) are a relatively new class of corrosion resistant alloys developed to obtain a better combination of weldability, strength, toughness and corrosion resistance than conventional martensitic stainless steels. The final properties of SMSS are strongly influenced by quenching and tempering heat treatments. In this work, different routes of heat treatments were tested in a Ti-stabilized 12%Cr supermartensitic stainless steel with the objective to improve mechanical properties, specially the low temperature (-46ºC) toughness. Double and triple quenching were tested and compared to single quenching heat treatments. Two tempering temperatures (500ºC and 650ºC) were tested. The results obtained with instrumented Charpy impact tests showed that a triple quenching treatment was able to increase the density of fine TiC particles and improve the mechanical properties of specimens heat treated by quenching and tempering at 650ºC

AGRONOMIC AND MOLECULAR CHARACTERIZATION OF DIPLOID IMPROVED BANANA GENOTYPES

An investigation about the genetical diversity among eleven banana diploid genotypes using nine agronomical characteristics and sixteen microsatellite markers was implanted at Embrapa Cassava and Tropical Fruits. Cruz das Almas (BA), Brazil. The generalized distance of Mahalanobis indicated the presence of genetic diversity. The genotypes were grouped into tree clusters. Among the investigated characteristics, the plant height, number of bunch's, number of fruits per bunch and pseudostem exhibited high contribution towards genetic divergence. The average number of alleles per primer was 7.51, with a total of 120 alleles identified. The average similarity among the all diploid was 0.44, range from 0.29 up to 0.60. New parental combinations can be identified with base of the divergence between these diploids, contributing for development of new improved diploids preventing the narrow genetic base and creating new genetic variability for selection.31115416

Structure of a lectin from Canavalia gladiata seeds: new structural insights for old molecules

<p>Abstract</p> <p>Background</p> <p>Lectins are mainly described as simple carbohydrate-binding proteins. Previous studies have tried to identify other binding sites, which possible recognize plant hormones, secondary metabolites, and isolated amino acid residues. We report the crystal structure of a lectin isolated from <it>Canavalia gladiata </it>seeds (CGL), describing a new binding pocket, which may be related to pathogen resistance activity in ConA-like lectins; a site where a non-protein amino-acid, α-aminobutyric acid (Abu), is bound.</p> <p>Results</p> <p>The overall structure of native CGL and complexed with α-methyl-mannoside and Abu have been refined at 2.3 Å and 2.31 Å resolution, respectively. Analysis of the electron density maps of the CGL structure shows clearly the presence of Abu, which was confirmed by mass spectrometry.</p> <p>Conclusion</p> <p>The presence of Abu in a plant lectin structure strongly indicates the ability of lectins on carrying secondary metabolites. Comparison of the amino acids composing the site with other legume lectins revealed that this site is conserved, providing an evidence of the biological relevance of this site. This new action of lectins strengthens their role in defense mechanisms in plants.</p

The occurrence and dissemination of methicillin and vancomycin-resistant Staphylococcus in samples from patients and health professionals of a university hospital in Recife, State of Pernambuco, Brazil

Introduction Methicillin-resistant Staphylococcus aureus (MRSA) strains have been responsible for many nosocomial outbreaks. Within hospitals, colonized employees often act as reservoirs for the spread of this organism. This study collected clinical samples of 91 patients admitted to the intensive care unit (ICU), hemodialysis/nephrology service and surgical clinic, and biological samples from the nasal cavities of 120 professionals working in those environments, of a University Hospital in Recife, in the State of Pernambuco, Brazil. The main objective of this study was to determine the occurrence and dissemination of methicillin- and vancomycin-resistant Staphylococcus spp. Methods The isolates obtained were tested for susceptibility to oxacillin and vancomycin and detection of the mecA gene. In addition, the isolates were evaluated for the presence of clones by ribotyping-polymerase chain reaction (PCR). Results MRSA occurrence, as detected by the presence of the mecA gene, was more prevalent among nursing technicians; 48.1% (13/27) and 40.7% (11/27) of the isolates were from health professionals of the surgical clinic. In patients, the most frequent occurrence of mecA-positive isolates was among the samples from catheter tips (33.3%; 3/9), obtained mostly from the hemodialysis/nephrology service. Eight vancomycin-resistant strains were found among the MRSA isolates through vancomycin screening. Based on the amplification patterns, 17 ribotypes were identified, with some distributed between patients and professionals. Conclusions Despite the great diversity of clones, which makes it difficult to trace the source of the infection, knowledge of the molecular and phenotypic profiles of Staphylococcus samples can contribute towards guiding therapeutic approaches in the treatment and control of nosocomial infections

Melanoma maligno da próstata primária : Malignant melanoma of the primary prostate

Introdução: Descreve-se um caso de melanoma maligno da próstata primário. Será possível compreender que a próstata é um local raro de se encontrar um melanoma maligno primário e que devido a sua infrequência, possui um prognóstico ruim e um difícil diagnóstico. Apresentação do caso: Paciente do sexo masculino, 47 anos, solteiro, negro, motorista de caminhão, compareceu a UBS com queixa de jato urinário fraco, nocturia e hematoespermia, 3 episódios, início há um ano. Discussão:&nbsp; Grande parte dos casos relatados, são de origem do epitélio de transição da uretra prostática ou de uma lesão metastática.&nbsp; Essa patologia possui um comportamento altamente agressivo e deve receber grande atenção. Devido a sua infrequência, é de difícil diagnóstico e tratamento. O tratamento indicado é a excisão, se o paciente não tiver doença sistêmica. Conclusão: o conhecimento dessa patologia e sua suspeição devem ser melhor propagados no meio científico, para que haja o diagnóstico e posterior tratamento mais precocemente possível, objetivando melhores prognósticos

SURVEY OF SANDFLY FAUNA (DIPTERA: PSYCHODIDAE) IN UBERLÂNDIA, MINAS GERAIS STATE, BRAZIL, 2003-2004

We analyzed the sandflies around houses and domestic animal shelters located in residences close to forests in localities on the banks of the Araguari River, Uberl&#226;ndia, MG, from February 2003 to November 2004. The phlebotomines were captured in the peridomiciliary area, where Shannon traps were utilized in the peridomicile and CDC traps in animal shelters. 2,783 specimens of sandflies were captured, 2,140 females (76.9%) and 643 males (23.1%), distributed between 17 species. The most abundant species was Nyssomyia neivai (88.1%), followed by Nyssomyia whitmani (3.1%). The presence of Lutzomyia longipalpis was also confirmed, it is the main vector of Leishmania (L.) infantum chagasi which causes visceral leishmaniasis. The presence of species involved in the transmission of leishmaniases in the municipality of Uberl&#226;ndia is cause for concern. The presence of L. longipalpis indicates that its urbanization may not have been aleatory and instead occurred through the destruction of wild ecotopes. More studies of their occupation in anthropic environments need to be made

Doença de Erdheim Chester com envolvimento isolado do SNC: Erdheim Chester disease with isolated CNS involvement

Introdução: A Doença de Erdheim-Chester é&nbsp; uma forma de&nbsp; histiocitose&nbsp; de&nbsp; células&nbsp; não-Langerhans&nbsp; que&nbsp; ocorre&nbsp; mais&nbsp; frequentemente&nbsp; após&nbsp; os&nbsp; 40&nbsp; anos&nbsp; de&nbsp; idade,&nbsp; com leve&nbsp; predomínio&nbsp; no&nbsp; sexo&nbsp; masculino. Apresentação do caso: Paciente, sexo masculino, branco, X anos de idade, admitido no Hospital das Clínicas de Goiânia, com sintomas de cefaléia crônica, de caráter progressivo de inicio há 3 meses, associados a sintomas neurológicos de ataxia e diplopia. Referiu febre baixa diária, não aferida, com perda de 10kg no período descrito, não associado a dieta ou mudança de hábitos de vida. Nega comorbidades ou uso de medicamentos.&nbsp; Ao exame físico, apresenta quadro de Nistagmo e Romberg positivo e alteração da úvula para direita. Paciente não apresentava outros sinais dignos de nota. Discussão: Foram selecionados para a revisão, os artigos de relato de caso ou séries de caso relacionados a manifestações clínicas da doença de Erdheim-Chester. Os principais tipos manifestações clínicas relatadas na literatura são: neurológicas, cardiovasculares, oftálmicas, endócrinas, urinárias, hematológicas, ósseas, cutâneas, respiratórias, gastrointestinais, envolvimento de múltiplos sistemas e outras. Entre esses tipos de manifestações, as mais frequentes foram neurológicas, cardiovasculares e oftálmicas, correspondendo a 48% das manifestações relatadas. Conclusão: É fundamental ter uma equipe multidisciplinar acompanhando o paciente,&nbsp; para que sejam evitadas complicações e se possa proporcionar qualidade de vida ao paciente. &nbsp