Adsorption of Phosphonic-Acid-Functionalized Porphyrin Molecules on TiO2(110)

We studied the adsorption geometry and bonding of mono- and tetraphosphonic-acid-functionalized tetraphenylporphyrin molecules on rutile TiO2(110) surfaces. The investigation was carried out by means of X-ray photoelectron spectroscopy and near edge X-ray absorption fine structure (NEXAFS) measurements. We found that the molecules bind covalently to the surface in a mixed monodentate and bidentate mode implying deprotonation of one or two phosphonate hydroxyl groups. Our NEXAFS data suggest that molecules containing one functional phosphonic acid group are on average tilted further away from the surface than molecules with four functional groups. The highest occupied electronic state of both molecules is in the band gap at 2.1 eV below the Fermi level. Our results demonstrate that the number of functional phosphonic acid groups determine the adsorption geometry of tetraphenylporphyrins.Fil: Fernández, Cynthia Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Wechsler, Daniel. Universitat Erlangen-Nuremberg; AlemaniaFil: Rocha, Tulio C. R.. Brazilian Center for Research on Energy and Materials ; BrasilFil: Steinrück, Hans-Peter. Universitat Erlangen-Nuremberg; AlemaniaFil: Lytken, Ole. Universitat Erlangen-Nuremberg; AlemaniaFil: Williams, Federico José. Universitat Erlangen-Nuremberg; Alemania. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentin

Cryopreservation of swine ovarian tissue : effect of different cryoprotectants on the structural preservation of preantral follicle oocytes

The present study aimed to test different cryoprotectants on cryopreservation of pig ovarian tissue. Pig ovaries (n = 3) were collected at a local slaughterhouse. From each ovary, ten cortex samples were taken. One was immediately fixed (control) and another placed in short-term tissue incubation (STTI control). The other 8 samples were cryopreserved, in pairs, using 4 different cryoprotectants: dimethyl sulphoxide (Me2SO – 1.5 M), ethylene glycol (EG – 1.5 M), propanediol (PROH – 1.5 M) and glycerol (GLY – 10%), all with 0.4% sucrose. Samples were slow cooled and stored in liquid nitrogen for 7 days. After thawing and cryoprotectant removal, one sample from each treatment was immediately fixed and the other was placed in short-term tissue incubation (STTI) for 2 h and then fixed. Samples were processed for histology and transmission electron microscopy. The percentages of morphologically normal follicles (MNF) in cryopreserved tissue using Me2SO (67.0 ± 4.9), EG (81.8 ± 1.4) and PROH (55.9 ± 9.9) were significantly lower (P < 0.05) than observed in fresh control tissue (97.7 ± 1.2). When ovarian tissue was cryopreserved with GLY, no morphologically normal follicles could be found (0%). After STTI, PROH showed a significantly lower percentage of MNF when compared with all other treatments and the control. After ultrastructural analysis, follicles cryopreserved with Me2SO and EG showed some small alterations, but no signs of advanced degeneration. Overall, these were similar to follicles from the control group. In conclusion, it is possible to cryopreserve preantral follicles from pig ovarian tissue using Me2SO or EG

Human Bocavirus Infection in Children with Gastroenteritis, Brazil

Human bocavirus (HBoV) was detected in 14 (2%) of 705 fecal specimens from Brazilian children with gastroenteritis. Coinfection with rotavirus, adenovirus, or norovirus was found in 3 (21.4%) HBoV-positive specimens. None of the HBoV-positive patients had respiratory symptoms

Health Care Workers Occupational Accidents in a Brazilian Hospital

Universidade Federal de São Paulo, São Paulo, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilWeb of Scienc

Health Care Worker Immune Status and Risk Perception of Acquisition of Vaccine Preventable Diseases

Universidade Federal de São Paulo, São Paulo, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilWeb of Scienc

Molecular determinants of the SARS-CoV-2 fusion peptide activity

The COVID-19 pandemic, caused by the SARS-CoV-2 virus, emerged in late 2019 and quickly spread worldwide, resulting in over 125 million infections and 2.7 million deaths as of March 2021 accordingly to the World Health Organization. Despite the great advances achieved by the scientific community in providing crucial information about this virus, we are still far from completely understanding it. SARS-CoV-2 is an enveloped virus, meaning that it is encapsulated by a lipid membrane, which needs to be fused to the host membrane to begin the infection process. Fusion between viral and host membrane is catalyzed by the spike (S) glycoprotein. The S-protein is composed of essential elements for the infection mechanism, namely the receptor-binding domain known to bind to angiotensin-converting enzyme 2 during the viral entry pathway. Another important region, known as the fusion peptide (FP), plays an essential part in the fusion mechanism, by inserting into and disturbing the host membrane. There is still not a consensus among scientists in terms of the fusion peptide location on the S-protein sequence, with two major candidate regions having been proposed. We recently used a machine learning-based tool developed by us to identify viral FPs with accuracies over 85%. With this tool a putative FP, previously suggested in the literature, has been identified, as well as other proposals including the requirement of more than one FP. To further address this question, we are performing a systematic analysis of the SARS-CoV-2 putative FPs, using Molecular Dynamics (MD) simulations, which provide a detailed perspective of how these peptides insert and interact with the membrane. In parallel, we are characterizing these systems experimentally. Additionally we are exploring therapeutic strategies targeting these regions. Given the major role of the FP in the virus infection process, this work provides relevant insights and contributes to the fight against COVID-19.info:eu-repo/semantics/publishedVersio

Resposta imune a doenças infecciosas

The interaction between pathogens and immune system occurs in a dynamic way with sophisticate mechanisms of evasion and immune control of infection, respectively. Therefore, it is a sine qua non condition to understand the complexity of this relationship in order to developed new strategies for infection control. Although the immune system has specialized mechanisms to control infection, different conditions involved in the interaction between immune system and pathogens can or cannot determine the development of disease. Interestingly, a protective immune response against one kind of parasite may not be protective against another. So, each pathogen presents a specific way of interaction with the immune system. The development of research in this area has contributed with a better comprehension of the immune system and pathogen relationship and opened perspective in improving the treatment with the development of new drugs and/or vaccines.A interação do sistema imune com os agentes infecciosos ocorre de uma maneira dinâmica, com mecanismos de controle da infecção e de escape sofisticados. A compreensão dessa complexidade é condição sine qua non para que se estabeleça uma ação total no controle dessas infecções. Embora a resposta imune desenvolvida para controle das diferentes infecções apresente certas particularidades, em geral, apresentam também mecanismos comuns. A priori os mecanismos podem ser redundantes, no entanto existe uma gama de sutilezas entre a interação hospedeiro-parasita que define o estabelecimento ou não de doença. Por outro lado, não se pode deixar de alertar que melhores condições de saneamento básico diminuiriam a incidência de inúmeras doenças. A classificação de uma resposta imune protetora tem que ser avaliada sempre em relação ao tipo de agente agressor, pois um mecanismo protetor conta um vírus pode não ser essencial contra uma bactéria extracelular. De qualquer forma, o avanço na pesquisa com diferentes patógenos tem contribuído para uma melhor compreensão da resposta imune decorrente da interação entre o hospedeiro e parasita o que pode resultar no desenvolvimento de novas drogas e vacinas

Cladosporium tenuissimum URM 7803: a promising new β-galactosidase producer

The Cladosporium genus, defined by Link in 1816, is one of the largest and most heterogeneous Hyphomycetes genus. It comprises more than 189 species still rarely explored biotechnologically. One of the most studied microbial enzymes, -galactosidase is a glycoside hydrolase enzyme that catalyzes the hydrolysis of -galactosides into monosaccharides through the breaking of a glycosidic bond. Recently, new studies comprising new microbial sources of -galactosidase, presenting biotechnologically interesting characteristics, have been encouraged. In this context, the present study evaluated the production of -galactosidase by a new isolate of Cladosporium tenuissimum. A C. tenuissimum inoculum was prepared adding 107 spore/mL in sterile saline solution 0.85% (w/v) NaCl containing 0.01% (w/v) Tween 80 and added to fermentation medium for enzyme production. The fermentation medium, composed of (% w/v): lactose (2), peptone (0.4), yeast extract (0.4) and salts (KH2PO4 (0.2), Na2HPO4.12H2O (0.8) and MgSO4.7H2O (0.025), pH 6.5, was maintained at 28° C and 180 rpm for 13 days. One sample (50 mL erlenmeyer) was removed every 24 hours and -galactosidase activity was evaluated using ONPG (ortho-Nitrophenyl--galactoside) method. The results showed maximum -galactosidase production by C. tenuissimum URM 7803 on thirteenth day, displayed enzymatic activity of 462.13 U/mL. The C. tenuissimum URM 7803 isolate proved to be a powerful new -galactosidase producer with potential application for food processing.info:eu-repo/semantics/publishedVersio

Impacto de programa fisioterapêutico no desempenho funcional da criança com doença de Charcot-Marie-Tooth tipo 2: estudo de caso

This case study aimed at verifying the influence of a physical therapy program on the functional performance of a child with diagnosis of Charcot-Marie-Tooth) disease type 2. The 6 year-old male child presented low and upper limbs affected at both motor and sensitive levels. Before and after the program, the subject was assessed by means of the Pediatric Evaluation Disability Inventory (PEDI), designed for children between 6 months through 7.5 years old. PEDI is divided into three parts – functional skills (involving selfcare, mobility and social function), caregiver assistance, and environment modification – and only the first part was used in this study. Drawing on the difficulties detected at the first evaluation, a physical therapy program was designed, based on the neurodevelopmental concept. The program lasted two months, with two 50-minute sessions per week (a total of 15 sessions). At the post-program evaluation, self-care score raised from 20.8 to 26.7, and mobility scare, from 40 to 54,9, specially in transference and going up and downstairs skills. Thus, the therapy program was effective in improving the subject's functional performance.O estudo visou verificar a influência de um programa fisioterapêutico nodesempenho funcional de uma criança com diagnóstico de Charcot-Marie-Tooth tipo 2. O participante (sexo masculino, 6 anos) apresentava comprometimento motor e sensitivo em membros superiores e inferiores. Antes e após o programa, o participante foi avaliado pelo Pediatric Evaluation Disability Inventory (PEDI), questionário que avalia o desempenho funcional de crianças na faixa de 6 meses a 7 anos e meio. O PEDI divide-se em três partes: habilidades funcionais (envolvendoautocuidado, mobilidade e função social), assistência do cuidador e modificações do ambiente; este estudo limitou-se à parte de habilidades funcionais. A partir das dificuldades detectadas na avaliação inicial, elaborou-se um programa de intervenção fisioterapêutica com base no conceito neuroevolutivo Bobath. O programa foi aplicado por 2 meses, sendo realizadas 2 sessões semanais de 50 minutos cada, totalizando 15 sessões. Na avaliação após a aplicação do programa, aumentou o escore normativo no PEDI, nas áreas de autocuidado (de 20,8 para 26,7) e mobilidade (de 40 para 54,9), especialmente nas habilidades de transferência, subir e descer escadas. Portanto, o programa de intervenção fisioterapêutica mostrou-se eficaz, promovendo melhora no desempenho funcional da criança